ANATOMICAL SIGNIFICANCE OF RIGHT CONUS ARTERY IN SOUTH INDIAN POPULATION

Thesis submitted in Partial Fulfillment for the Award of

Degree of Doctor of Philosophy

in Medical Anatomy

BY

T.UDAYASANKARI

UNDER THE GUIDANCE OF

PROF. DR.M.L JAIN, M.S

VINAYAKA MISSIONS UNIVERSITY (Vinayaka Missions Research Foundation Deemed University)

SALEM, TAMIL NADU- INDIA PIN CODE – 636 308 NOVEMBER- 2016

TABLE OF CONTENTS

S.NO

TITLE

PAGE No

1 Declaration

i

2 Certificate By The Guide

ii

3 Acknowledgement

iii

4 List of Figure

vii

5 List of graph viii

6 List Of Tables

ix

7 List of Symbols and Abbreviations

x

8 Abstract xii

9 Introduction

1

10 Review of Literature

8

S.NO

TITLE

PAGE No

11 Need for the study

69

12 Objectives

70

13 Methodology

71

14 Results and discussion 87

15 Conclusion 138

16

Bibliography

139

17 Annexure I - Ethical committee clearance certificate 167

18 Annexure II - Informed consent form and patient

information sheet 168

19 Annexure III - List of publications 170

i

DECLARATION

I, T.Udaya Sankari, declare that the thesis entitled ANATOMICAL

SIGNIFICANCE OF RIGHT CONUS ARTERY IN SOUTH INDIAN

POPULATION submitted by me for the degree of Doctor of

Philosophy in Medical anatomy is the record of research work carried

out by me during the period from January 2011 to November -2016

under the guidance of Dr. M.l.Jain , M.S, Former Professor and HOD

VMMCH, and has not formed the basis for the award of any degree,

diploma, associate-ship, fellowship, titles in this or any other

university or other similar institutions of higher learning.

Place: Signature of candidate

Date: (Mrs.T.UDAYA SANKARI)

ii

VINAYAKA MISSIONS UNIVERSITY

CERTIFICATE BY THE GUIDE

I, Dr. M.L.Jain, certify that the thesis entitled ANATOMICAL

SIGNIFICANCE OF RIGHT CONUS ARTERY IN SOUTH INDIAN

POPULATION submitted for the degree of Doctor of Philosophy in

Medical anatomy by Mrs T. Udaya Sankari, is the record of research

work carried out by her during the period from January 2011 to

November -2016 under my guidance and supervision and that this

work has not formed the basis for the award of any degree, diploma,

associate-ship, fellowship, titles in this or any other university or other

similar institutions of higher learning.

Place: Signature of the Supervisor

Date:

(Dr .M .l. Jain)

Former Prof.&HOD of anatomy

VMMC &H karaikal.

iii

ACKNOWLEDGEMENT

First and foremost, my heartfelt gratitude to GOD, who has helped

me in various forms, to be an instrument in the completion of this

research works.

My sincere gratitude goes to our honorable Founder, Late

Dr.A.Shanmugasundaram, for allowing me to do this PhD research

work under our esteemed Vinayaka Missions University, Salem.

I express my sincere obligations to THE HONORABLE CHAIRMAN,

Dr. A.S. Ganesan, the Vice President Mr.Chandrasekar,

Dr. R. Annabelle,M.D., Dean, Vinayaka Mission’s Medical College,

Karaikal, for their constant encouragement and help.

I sincerely thank Dr.C.L. Prabavathi, the controller of examinations,

Vinayaka missions University for her kind support and permission.

I greatly express my thankfulness to the Former Dean Prof. Dr.K

Jayabal, the Present Dean Prof.Dr.P.S.Manoharan VMKV medical

college, Salem for providing with all necessary support to carry out

this PhD research work.

iv

I am deeply indebted to my esteemed teacher and revered guide,

Prof. Dr.M.L.Jain, M.S., Former Professor and Head, Department of

Anatomy, VMMC&H, Karaikal, for his masterly guidance, inspiration

and personal supervision, which made possible this work to present

shape.

I would like to thank Dr. K.Shanthini arulselvi, M.D., Professor

H.O.D, Department of anatomy for her encouraging comments on this

work.

I express my sincere obligations to Dr. Rajendran, PhD, Former

Dean (Research), Vinayaka Missions University, for the strict

guidance and motivation given by him and his enormous patience

with which he answered my repeated phone calls about the research

work.

I also thank Dr Dr. K. Srinivasan, M.S., former Dean, Vinayaka

Mission’s Medical College and Hospital, Karaikal for helping me to

start my PhD research work.

I am very much thankful Dr. Srinivasan M.D., cardiology,

Meenakshi Hospital, Tanjavur and Dr. Ragupthy M.D., cardiologist

v

ESI hospital Chennai for their great help and guidance in the clinical

orientation for the assessment of my study subjects.

My sincere gratitude is also due for my Former Prof. Dr. Sharatha

kathirasen and Prof. Dr.Saraswathi for their valuable suggestions

and guidance, as a supporting backbone in all aspects right from the

beginning of the work until successful completion.

I offer my heartfelt thanks to Dr.Abdul Majeed, Mr.kalaivannan,

Dr.Indu ,Dr.lakshmipraba, Dr.Radha, Dr. Jasmine Department of

anatomy, Vinayaka missions Medical College and Hospital, karaikal,

for their constant support, valuable suggestions and help throughout

my research work.

I am grateful to the statistician, Mr. Felix, Annamalai University, for

his useful guidance in the statistical work done for this research work.

I feel special pleasure to thank Mr.Packirisamy and Mr.Raju

dissection hall attender, Mr.manoj kumar, Record Clerk,

Mr.Jaikumar office attender, Mr.Srinivasan artist, Mr.kamaraj Lab

attender, and Mrs. Sujatha and Mrs .Megala ward aid, who always

stood by my side in need during this thesis work in my department.

vi

My humble gratitude to my Parents, Mr.T.Tamilarasan And Mrs

T.Santha , my Gurus and my husband, Dr. Vengadasubbu for their

blessings and guidance throughout my study.

I express my sincere thanks to my dear daughters V.Sruthika and

V.Harshitha for their sacrifice and support. Lastly, I am also very

much thankful to all my study subjects for their co-operation to pursue

my research work.

PLACE:

DATE:

(T.UDAYASANKARI)

vii

LIST OF FIGURES

S.No FIGURE TITLE PAGE

NO

1 Development of Coronary Vessels. 15

2 Final Stages of Coronary Artery Development. 16

3 Dissection Instruments 71

4 Manual Goniometer 72

5 Angulations of R.con.a with respect to aorta 72

6 Angulations of R.con.a with respect to RCA 74

7 Digital vernier caliper. 75

8

Diameter of right conus artery in coronary angiogram.

83

9 Single Ostium in right anterior aortic sinus. 88

10 Double Ostium in right anterior aortic sinus. 88

11 Multiple Ostium In right anterior aortic sinus 89

12 STJ- SINU TUBULAR JUNCTION 94

13 R.CON. A from RCA 101

14

Common Ostial Origin From Aorta (R. CON.A & RCA)

102

15 Separate Aortic Origin Of R.CON. A. 102

16 Angulations Of R.CON.A with respect to aorta 111

17 Angulations OF R.CON.A with Respect to RCA 112

18 R. CON.A. With 3 Short Branches 129

19 R.CON.A. Short & Long Terminal Branches 130

20 R.CON.A. With Only One Long Branch 130

viii

LIST OF GRAPH

S.No Graph Title Page No

1 Number Of Ostia In Right Aortic Sinus 89

2 Percentages Of Ostia In Right Aortic Sinus 90

3 Level Of Ostia 95

4 Percentages of Level Of Ostia 96

5 Comparison of Three Patterns Of Origin In Cadaveric And In Angiogram Study 103

6 Percentage Comparison of Pattern Of Origin In Angiogram And Cadaver 104

7 Angles between Right conus artery and RCA 112

8 Angles between right conus artery and aorta 113

9 Common Origin Angulations 113

10 Mean Angulations of Right Conus Artery 114

11 comparison of external diameter of right conus artery having common origin in cadaver and in angiograms 120

12 Comparison of external Diameter of right Conus artery from right Coronary artery in Cadaver and in Angiograms 121

13 Outer Diameter Of Right Conus Artery From Aortic Origin In Cadaver 122

14 Comparison Of Mean Diameter of Right Conus Artery in Cadaver And Angiograms 122

15 Long And Short Branches of Right Conus Artery 131

16 Comparison of long branches of conus artery seen in cadaveric and angiogram study 131

17 Comparison of Only Short Branches In Cadaveric and Angiographic study 132

18 Percentage Of Long and Short Branches in cadaver and Angiograms 132

ix

LIST OF TABLES

S.No TABLE TITLE PAGE No

1 Heart samples collection. 85

2 Number of ostia seen in 150 hearts. 87

3 Level of ostia with regard to sinu tubular junction seen in 150 hearts.

94

4 Pattern of origin. 100

5 Prevalance of aortic origin of right conus artery (TCA) in various populations.

109

6 Angulation of right conus artery with respect to its origin

110

7 Statistical analysis and result for angulations of right conus artery with respect to aortic origin and origin from right coronary artery

115

8 Statistical analysis and result for comparison of angulations of right conus artery when arising from right coronary artery and common origin

116

9 Outer diameter of right conus artery with respect to its origin in cadaveric hearts

119

10 Outer diameter of right conus artery with respect to its origin in coronary angiograms

123

11 Statistical analysis of comparison for outer diameter of right conus artery arising from right coronary artery in cadaver and in coronary angiograms:

124

12 Branches of right conus artery in cadaver and in coronary angiograms

128

13 Statistics comparing the diameter of right conus artery when long branch is present or absent.

136

x

ABBREVIATIONS

Apo Apoptotic cells

CTCA Computerized Tomographic Coronary Angiography

ECG electrocardiogram

En Endothelium

EPIC Epicardium

FGF Fibroblast growth factor

ICA isolated conus artery

IVSD Interventricular septal defect

LAD Left Anterior Descending artery

LCA Left coronary artery

LMCA Left main coronary artery

MCP monocyte chemoattractant protein

MDCT Multi detected Computed Tomography

PTR Peri truncal ring

PTV Peritruncal capillary plexus

QCAP quantitative coronary analysis plus

R.Con.A Right conus artery

RCA Right coronary artery

xi

SPSS Statistical package for social sciences

STJ Sinu tubular junction

TCA Third coronary artery

TGF Transforming growth factor

TM Tunica media

TNF tumor necrosis factor

VGEF Vascular endothelial growth factor

VSMC Vascular smooth muscle coat

xii

ABSTRACT

Introduction: Understanding the anatomy and its variations of

coronary arteries forms the base for coronary artery disease

diagnosis and planning of surgeries.

Objectives: To find the number and level of ostia in anterior aortic

sinus with regard to sinu –tubular junction in cadaveric hearts, the

pattern of origin of right conus artery in cadaveric hearts and coronary

angiograms, the relation between the angulations of right conus

artery with respect to aortic origin and origin from right coronary

artery, the relation between angulations of right conus artery when

arising from right coronary artery and having a common origin, the

relation between outer diameter of right conus artery in cadaveric

hearts and coronary angiograms, the relation between the diameter

of right conus artery with and without the presence of long branches

in both cadaveric hearts and angiograms.

METHODOLOGY

TOOLS: Manual goniometer, Digital Vernier caliper, Dissection

forceps (pointed, tooth, blunt), Scalpel, Scissors, Gp (gutta percha)

sticks, Hand lens, Quantitative coronary analysis plus software and

xiii

SPSS software. METHODS TO BE USED: Dissection method,

Coronary angiogram. SAMPLING METHOD USED: Sampling

method used in the study is PURPOSIVE SAMPLING. 150

embalmed cadaveric hearts received from various south Indian

states, which were preserved in various collages of Tamilnadu and

Pondicherry was used in this study. 150 coronary angiograms of

patients from various south Indian states who came for treatment to

Meenakshi Mission Hospital Thanjavur and Madurai were collected

during the period of 2011 to 2016 and used in the study.

STATISTICS USED: Statistical significance was determined with help

of Student unpaired t-test, Percentage calculation and Pearson’s

correlation coefficient.

RESULTS: Out of 150 cadaveric heart single ostia is seen in 80.67%

two ostia seen in 18% and three or more ostia seen in 1.33% of heart

samples. In our study, out of 150 cadaveric hearts in 143 the ostia is

seen underneath the STJ. In 4 hearts the ostia is seen along with STJ

and in 3 hearts the ostia is seen over the STJ. In our study on

cadaveric hearts, out of 150 hearts in 108 hearts the right coronary

vessels offered ascend to the right conus supply route. Common

starting point of right conus artery with right coronary supply route

xiv

was found in 12 hearts. Aortic root of right conus artery was found in

30 hearts. 106 hearts demonstrated right conus artery branching from

RCA in 150 traditional angiograms.15 hearts displayed common

ostium . So rest of 29 heart angiograms may have had their conus

artery branched from aorta as right conus supply route was not seen.

The P value of less than 0.0001 was obtained on comparing the

angulations of right conus artery having aortic origin with that of the

conus artery having origin from right coronary artery. Also a P value

of 0.8838 was obtained while comparing the angulations of right

conus artery arising from aorta with that of the right conus artery from

coronary artery. Conus artery diameter obtained from cadaveric

hearts and angiograms were compared and the resulted p value is

less than 0.0001 which is considered to be extremely statistically

significant. The number of long branches and short branches are

studied with regard to the diameter of right conus artery. Pearson’s

correlation coefficient was 0.1716 which is positive.

CONCLUSION: The presence of single, double and triple ostia at

different levels (at, below, above) with respect to sinu-tubular junction

were studied and its presence has been interpreted embryologically.

In most of the cases right coronary artery gave rise to right conus

xv

artery. Acute angulations were seen in both cases when right conus

artery has a common origin or arose from right coronary artery. The

mean diameter of right conus artery obtained from cadaveric study

and from angiograms proved to be different from one another. The

diameter of right conus artery is more when having a long branch.

KEY WORDS: Right conus artery, Third coronary artery, Right

coronary artery, Coronary ostia, anterior aortic sinus, Sinu tubular

junction.

1

1. INTRODUCTION

Heart disease is becoming a major cause of death in India. Earlier

heart disease is seen in old age people. Today due to life style

changes, diet, lack of physical activities and stress have caused

younger generation to suffer from heart diseases. In India there are

30 million heart patients and 2 lakh surgeries are performed every

year. One fifth of the heart disease is coronary heart disease which is

caused by partial or complete obstruction of coronary arteries. This

obstruction is caused by deposition of cholesterol in the walls of

arteries known as plaque thus reducing the blood flow to the heart

(Udayasankari T.et al 2016).

To compensate the reduction in blood flow collateral arteries

play an important role. The conus artery plays a major role as a

collateral artery. Starting from the right anterior aortic sinus the right

coronary artery passes through the posterior coronary sulcus which

end as posterior inter ventricular branch or sometimes it may

anastamose with the left circumflex artery. Many parts of the heart

were supplied by branches of right coronary artery which includes

2

right atrium right ventricle and atrioventricular septum. The right

conus artery sometimes arises directly from anterior aortic sinus.

Then it is named as third coronary artery (aortic origin of right conus

artery). It is otherwise called conus arteriosus, preinfundibular artey,

right vieussens conduit, arteria accessoria or fat supply route

(Rebecca et al 2012). The conus supply route goes through the sub

epicardial fat tissue of pneumonic conus and front mass of right

ventricle. The right conus supply route as a rule structures an

anastomosis with the comparing branch of left conus course or

branches of left anterior descending artery.This anastomosis between

left and right conus artery is known as the Vieussen’s arterial ring

which functions as an important collateral pathway supplying conus

part of the pulmonary trunk. The right conus artery supplies the

conus part of pulmonary infundibulum, anterior wall of right ventricle

and sometimes supplies the interventricular wall.

The right conus artery sometimes gets occluded by

atherosclerosis. When this happens, a selective angiogram should be

done on right conus artery especially when conus artery arises as a

separate origin. So awareness of right conus artery, its origin,

angulations, diameter and distribution plays a significant role in

3

evaluation of coronary insufficiency which helps in proper planning of

myocardium revascularization surgery.

Variation in arterial supply of heart leads to coronary

insufficiency. Hence it is necessary to study the variations of conus

coronary artery.

The life system of coronary conduits frames the base for finish

comprehension of the coronary illness. A cadaveric study in an

unsuspected population gives the premise to comprehension the

varieties in the coronary courses (Kalpana et al 2003). This study

helps the cardiologist during routine diagnostic work and in planning

of surgeries.

Ventricular arrhythmias were mostly caused by the changes in

the Right Ventricular Out flow Tract. Dysfunction of the TCA (aortic

origin of right conus artery) have a significant role in RVOT

arrhythmogenesis. This is because the TCA has been proposed to

form a ‘back-up’ source of collateral circulation, important during

pathological occlusion of the main coronary arteries (RCA or LCA), a

possibility that has been supported by various studies. Position of

coronary ostia gains importance because of coronary catheterization.

4

This procedure is useful for both diagnostic and therapeutic

purposes.

The irrigation of the heart depends upon the right and left

coronary arteries. These arteries are filled, during the diastolic phase

of heart beat. Any malformation or stenosis of coronary arteries will

result in reduction in blood flow to myocardium. A complete

knowledge about variations of right coronary artery and its branches

is very essential, to identify the areas which are prone to occlusion,

haemodynamic changes, cardiac injuries for their implications on

surgeries.

Harvey acknowledged it sooner than whatever other anatomist,

that "Structure is a genuine manual for capacity; no physiological

hypothesis can be valid, unless it gives a total and last clarification of

all purposes of structure." "A private information of the life structures

of coronary supply routes, the "Crown" of the heart, is a plainly

obvious pre-essential for an entire comprehension of the coronary

corridor illness or for more clever arranging of surgery"(Kalpana

2013). In Medical history there is a great progress made in the field of

congenital and acquired cardio vascular diseases. Collateral

circulation preserves the ventricular function, when there is a total

5

occlusion of artery. The first branch of righty coronary artery has the

capability of angiogenisis and arteriogenesis. The occluded left

anterior descending artery was most probably filled by the right conus

artery thus preventing cardiac insufficiency.

The degree of coronary atherosclerosis can be predicted by the

knowledge of coronary anatomy. A few postmortem studies were

done to discover the measurements of coronary arteries (Ehrlider et

al 1931, Hutcins 1977). Not very many studies portray the ordinary

size of the solid coronary conduit by utilizing quantitative coronary

arteriography as a part of live patients. (Mcalpin et al 1973, Vieweg et

al 1976, Ratib and Mankovich 1988). Stenosis of coronary arteries

was expressed in approximate percentages than a correct value

which may lead to errors in actual stenosis in diffuse diseased artery

angiography. Thus the knowledge of dimension of healthy coronary

artery is essential to find the correct stenosis value (Brown 1977,

Vicram 2005). Cadaveric study and animal study reported the amount

of myocardium supplied by the coronary vessels is related to the size

of proximal vessel.

1.1 Coronary Anastamosis:

6

Anastamosis of left and right coronary arteries are seen

abundantly during the foetal life, which is reduced during the end of

first year of life. There are interarterial coronary connections between

the different branches of same coronary artery (homocoronary

collateral circulation) or different coronary artery (heterocoronary

collateral circulation) (Cohen1985). The function of this collateral

which makes the blood supply of ventricular wall remains the same

when there is fluctuation in the pressure of the right and left coronary

arteries

Collaterals are more effective during the chronic heart disease,

hypoxia. A sudden block of large branch of coronary artery usually

leads to myocardial infarction. The frequent sites of collateral

formation are at the apex of heart, anterior aspect of right ventricle,

the posterior aspect of left ventricle, crux, interatrial and

interventricular groove(Snell, 2004, Standring 2005).

Coronary arteries normally found in pairs, may vary in origin,

distribution and size. These arteries have several branches

responsible for irrigating the whole surface and interior of heart tissue

(standring 2005).

7

The dissection knowledge of heart shows so many variations exist

regarding morphology of the conus artery. This study provides a

complete comprehensive picture of artery in large number of

specimens.

8

2. REVIEW OF LITERATURE

2.1) Overview of Development of Heart:

Around the third week of age, as the embryo grows and

increases its size the nutrients obtained by simple diffusion becomes

insufficient. This nutritional imbalance leads to development of

circulatory system to compensate the increased metabolic demand

(David Bernanke 2002). Heart is mesodermal in origin and develops

from the primitive heart tube, which forms from the mesenchyme in

the cardiogenic area of embryo. The splanchnic mesoderm

surrounding the primitive heart tube forms myocardium and

epicardium (Vishram singh 2013).

The first system to start functioning in the embryo is

cardiovascular system and first organ to start its function is heart. The

heart starts functioning at the end of third week of intra uterine life

around 22nd day. The blood circulation begins during the fourth week

of intra uterine life. Hence, it becomes important means to reach out

growing demand of nutrition.

2.1.1) Formation of Pericardium: The endothelial heart tube forms

the endocardium of the heart. The myoepicardial mantle which is a

9

derivative of splanchnic mesoderm forms myocardium and

epicardium.

2.1.2) Early Concept in Development of Coronary Vessels:

The early concept in development of coronary vessels

describes that, in early stages coronary circulation does not exist.

The blood flowing through the lumen of simple heart tube nourishes

the endocardium and myocardium. As the heart increases in size its

nutritional demand also increases which is compensated by separate

vasculature. The coronary arteries, the coronary vein and capillary

bed develop to supply the myocardium (Bernanke 2002).

According to the early studies the coronary artery is a single

cord of endothelial cells growing from the developing aortic wall. This

solid cord of endothelial cells undergo process of canalization to form

opening from the aorta down onto the heart in the direction of

ventricles (Grant and Regnier 1926, Bennet 1936, Gold Smith and

Butler 1937, Hirakow 1983)

Another concept was suggested that the tubular branches from

the aorta at the level of sinuses were thought to grow by a process of

angiogenesis. These branches would begin as aortic outgrowth of the

10

endothelium that would extend and take on smooth muscle cell as

outer layer to become proximal roots of coronary arteries. This

concept is also seen in other species like pig (Bennet 1936), Rat

(Dbaly1968), chick (Rychter 1971), Human (Vernall 1962 and

Hutchins 1988).

2.1.3) Current Concept of Coronary Vessels Development:

Bogers (1989) and his coworkers concluded that coronary

arteries did not grow out of the aorta, but grow into the aorta from the

peritruncal ring of coronary arterial vasculature. This throws new light

on normal and abnormal development of proximal coronary arteries

and coronary orifices. He had studied 15 quail embryos by using a

monoclonal anti-endothelium antibody, which enabled a detailed

study of the development of endothelium-lined vasculature.

The observation, that the approximation of the small vessels to

the developing aorta always preceded the formation of coronary

artery orifices in the aortic sinus led to the new concept of coronary

development.

Waldo 1990 failed to observe the onset of aortic endothelial

evagination and concluded that arteries arise from a ring of capillaries

11

that can be found around the bulbous cordis portion of the developing

heart. This “controlled invation of aorta” leads to the vessels growing

and attaching to the aorta at the aortic sinuses.

Now the more generally accepted concept that arteries do not

develop as a budding and branching process but arteries begin as a

part of complex capillary network that develops from mesenchyme in

subepicardial area and then penetrate into the developing aorta

(Waldo1990)

After the heart tube folding completes it will have only two

layers – endocardium and myocardium. Then the epicardial cells from

the proepicardial organ covers the bare myocardium. The

proepicardial organ forms from intra embroyonic coelom as an

outgrowth. The hearts rhythmic contraction results in the the transfer

of epicardial cells onto the myocardium. The epicardium continues to

spread over the surface of myocardium towards the atria and sinus

venous in one direction, the proximal outflow tract (bulbous cordis) in

the other direction (Vranckens Peters et al 1995).

As the epicardium grows a layer of extracellular matrix is

formed between epicardium and myocardium. This matrix is rich in

12

mesenchymal cells derived from the epicardial layer by epithelial –

mesenchymal transformation. These mesenchymal cell turns into

smooth muscle cells and adventitial fibroblast of coronary arteries.

The mesenchyme of proepicardial organ produce endothelial

precursor cells which migrates to the subendothelial space.

In an alternative study made in experimentally modified

conditions demonstrated a compensatory growth of mesothelial cells

from the pharyngeal arches progressively investing in the outflow

tract and conotruncal region (Gitten Burger -de-Brute et al 2000)

As the epicardial layer formation completes the mesenchymal

cells in the subepicardial region increases. Histochemical

examination of this region showed the presence of capillary like

structures and blood island inclusions (Hiruma and Hirrako 1989).

Vasulogenesis followed by angiogenesis results in coronary artery

development of embryo.

2.1.4) Vasculogenesis:

Vasculogenesis is defined as the de novo formation of blood

vessels at a specific site from aggregates of endothelial precursor

cells (angioblasts) that form from mesenchyme. A group of

13

mesenchymal cells forms a clump by segregating from neighboring

cells. The precursor of vessel endothelium begins to differentiate

within this group forming spherical aggregates of cells which can line

up as strings or cords. This cord opens to form tubes. Haematopoisis

occurs midst of the angioblasts (Poole and Coffin 1989)

2.1.5) Angiogenesis:

Angiogenesis is defined as the elongation of small vessels and

formation of branches by proliferation of existing endothelial cells and

remodeling. The migratory remodeling process leads to elongation of

newly formed small vessels. This can be formed in three basic ways,

By sprouting from an established vessel.

By endothelial cells growing and dividing mother channel.

By intussusceptions, where the vessels is infiltrated by matrix

followed by vessel growth (M.H Tayaebje et al 2004)

This process of forming capillary sized vessels first takes place

along the atrioventricular sulcus and dorsal interventricular sulcus

and then surrounds the bulbous cordis region approaching the

truncus arteriosus. This pretruncal ring of capillaries joins the ventral

14

aspect with sprouts directed toward the aorta and pulmonary trunk.

But the capillary plexus joins only with the aorta. The thicker

subepicardial space at the apex of the heart receives its vessels

from interventricular sulci and provides a greater capacity for growth

of the developing coronary vessels. The coronary vessel from the

pretruncal ring selectively extends into the aorta and forms multiple

connections. Upon connecting to aorta a patent connection between

the penetrating vessel and aorta should be made. This is achieved

by apoptosis which is induced from the apoptotic cells present in the

invading vessels and not in the aortic endothelium. Even after

connection the remodeling continues with expansion of artery and

enlargement of orifice (David H Bernake 2002) (Fig 1 and Fig 2).

15

Fig 1: Development of Coronary Vessels. (Source :David H. Bernanke and

Matthew Velkey J. Development of the Coronary Blood Supply: Changing Concepts and Current Ideas. The Anatomical record (new anatomy). 2002; 269:198–208)

Coronary artery attachment to the aorta involves invasion of blind-

ended extensions of vessels from the peritruncal capillary plexus

(PTV) into the tunica media (TM) of the developing aorta superior to

the leaflets (VL) of the forming aortic tricuspid valve. Apoptotic cells

(Apo) can be found in association with the invading vessels but not

within the aortic endothelium (En). B: As the blind end of the invading

vessel contacts the aortic endothelium, a patent coronary orifice

forms by means of apoptosis. C: Even after connection to the aorta,

remodeling continues, involving both apoptosis to accommodate

expansion of the artery and enlargement of the orifice and

recruitment of a vascular smooth muscle coat (VSMC) from the

surrounding mesenchyme and aortic wall.

Source: David H Bernanke and J Mathew Valkey. The Anatomical

Record (New Anat) 2002.

16

Fig 2) Final Stages of Coronary Artery Development. (source: David

H. Bernanke and Matthew Velkey J. Improvement of the Coronary

Blood Supply: Changing Concepts and Current Ideas. The

Anatomical record (new life systems). 2002; 269:198–208)

A: At the last phases of coronary supply route arrangement, various

vessels (Cap) frame from mesenchyme by vasculogenesis inside the

lattice underneath the epicardium (Epic). B: The vessels expand a

peritruncal ring (PTR) around the aorta and aspiratory trunk,

developing by angiogenesis, and building up overwhelming channels

of vessels with bigger sizes. The different bigger vessels approach

and connect to the aorta in inclination to the pneumonic trunk, in a

procedure including apoptosis to frame holes at the level of the

coronary sinuses. C: The peritruncal narrow plexus is pared around

further apoptotic occasions to the prevalent right (RCA) and left (LCA)

coronary conduits connected to the aorta at the relating coronary

sinuses.

Source: David H Bernanke and J Mathew Valkey. The Anatomical

Record (New Anat) 2002.

17

Multiple factors govern this process, including vascular endothelial

growth factor (VEGF) and fibroblast growth factor (FGF-1) stimulating

vasculogenesis and angiogenesis, the angiopoietins and their

tyrosine kinase receptors modulating interactions between endothelial

cells and the mural components. Transforming growth factor (TGF β)

released by apoptotic cells modulates VEGF and FGF-1 and controls

the further apoptotic changes (David Bernake 2002).

2.1.6 Arteriogenesis:

Arteriogenesis is defined as the growth of pre existent collateral

arterioles into functional arteries. Both coronary and peripheral

circulation has pre existent arterioles. This mechanism was first

proposed by Oxford University in 1669 (Niels Van Royen et al 2001).

The heart is in great need of vital heat and nourishment, so when

deficiency of this need occurs it is guarded by such anastamosis

(Lower R 1932). He not only precisely observed the pre existing

collaterals but also observed their function as the alternative pathway

for blood flow in case of insufficiency.

The collateral connections between coronary arteries were

abundantly present in human, irrespective of presence of coronary

18

disease (Fulton 1965). In 1971 studies showed that for first time the

pre existing collateral arterioles develop into large collateral arteries

through the proliferation of endothelial and smooth muscle (Schaper

1971).

The factor governing this arteriogenesis is mechanically

induced sheer stress. When stenosis occurs in main arteries the

blood flow is distributed through pre existing arterioles which

experience a high sheer stress. This causes activation of endothelium

with increase in expression of MCP-1 and the receptors involved in

monocyte tethering, rolling and migration are activated. The MCP-1

induces the attraction of more monocytes to the site and TNF-α

provides the inflammatory environment in which collaterals develop.

2.2. Number and level of ostia:

Renaissance 1513 was the first to describe about the sinus of

valsalva from the description and diagrams of Leonardo Da Vinci.

Aortic sinus or sinus of valsalva which is three bulges of aortic wall

named after the Italian anatomist Anatonia Valsalva (1970). The

aortic sinus is more prominent than the pulmonary sinus (Susan

Standring 2006). There are three Aortic sinuses namely right, left

19

which host the origin of coronary arteries and non coronary sinus.

The most commonly affected sinus is right and non coronary sinus

due to aneurismal dilatation which is a rare condition (Hudson 1965,

Burchell 1951, Edwards 1957). Aortic sinus is limited proximally by

valve leaflet and distally by sinutubular junction. The Walls of aortic

sinus is thinner than the native aorta.

2.2.1) Sinu Tubular Junction:

The upper limit of the aortic valve beyond the level of free

border of cusp forms the circumferential sinu tubular ridge (Susan

Standring 2006). The sinu tubular junction separates the aortic root

and ascending aorta (Sievers HH 2012). Dilatation of sinu tubular

junction is the cause of central aortic insufficiency. The replacement

of ascending aorta with a short tubular graft can restore valve

competence (Efstratios 2013).

The variation and distribution of the coronary arteries in 119 hearts of

individuals from 4th month of intra-uterine life to 40 years old who died

of non-cardiovascular causes were studied. All individuals included in

his study were natives of the Mosul area of Northern Iraq. The

coronary arteries were examined by injection-corrosion and unaided

20

dissection. Practically 90% of the eccentricities viewed were in the

right coronary course in that 9 hearts (8% of total example) had

ectopic ostia in the right coronary sinus for the right coronary and

conus supply route. The event of a different conus course gives off an

impression of being irregular as opposed to equivocal, as generally

reported in the writing. One example had isolate ostium for the left

circumflex and LAD from the left coronary artery. The examples of

coronary supply route conveyance were named left (14%) and right

(46%) pre-ponderant, and adjusted (40%) (kurjia et al 1996). Since

variations of the origin of coronary artery and their aortic ostia varies

with age, sex and ontogeny, it requires further study in non-caucasian

patients to improve the care of these patients.

Miyazaki et al. (1988) expressed that the third coronary supply

route (right conus course) emerged from the aorta and structures

anastomoses in the fetal stage. They explored 622 ordinary human

hearts and decided the starting point of the third coronary supply

route. The root of the third coronary corridor hole was grouped into

3 sorts: 10, 9 and8 o'clock positions. The pathologic hearts had a

higher occurrence of different holes for third coronary supply route

21

than ordinary hearts, which contribute for coronary circulation

after birth.

Sahini D 1989 concentrated on beginning and size of coronary

conduits in northwest Indians. The frequency of beginning of right

coronary over the supra valvular edge was 3.4% in males and 1.7%

in females.

Turner, Navarathnam 1996 studied the coronary arterial ostia in 38

adult cadavers. Out of this 37 had three cusps and one had bicuspid.

6 specimens had accessory ostia near the right coronary artery

ostium. Majority of the ostia situated below the supra valvular ridge.

In single specimen the aortic valve which was bicuspid, the ostia lie

above the anterior cusp.

The location of coronary artery orifices in 23 normal autopsied adult

hearts was studied. The right coronary vessel emerged from inside

the anterior aortic sinus in 18 samples, over the intersection in 3 and

at the level of intersection 2 samples. A supplement ostium was

found in the anterior aortic sinus in 17 samples and third ostia in this

sinus were found in 5 hearts (Muriago 1997). Accessory coronary

arteries are found mostly in right anterior aortic sinus.

22

Piegger J 2001 et al studied about the extremely high origin of right

coronary artery from the ascending aorta. They explained that in

some cases the ostium was few mm just above the supra valvular

ridge which has less complication. But in their case the coronary

ostium was seen 38 mm above the supra valvular region.

Kalpana (2003) studied the normal patterns of coronary arteries with

reference to the predominance and variations. She found that 90% of

the ostia for right coronary and 80% of the ostia for left coronary

arteries were below the sinu-tubular junction (STJ). The ostium for

the third coronary artery was present in 24%. She also said that there

was right dominance in 89% and left dominance in 11% of the

specimens studied.

Jennecy Sales CavalCanti 2003 et al studied the morphometric and

topographic study of coronary ostia. They observed the level of

ostium with respect to the aortic leaflets. Over 60% of cases were

below the sinu tubular junction and around 28% of cases above the

sinu tubular junction and only 12% at the level of sinu tubular

junction.

23

Von Leudinghausen (2003) contemplated the morphology of the

coronary vasculature in 200 cadaveric examples and 30 erosion

casts. The subjects were haphazardly chosen and concentrated on

as for different eccentricities of coronary arteries and their branches.

Ivan Stankovic et al. (2004) revealed that in each one of the

illustrations, the ostium of the TCA was to the other side and superior

to the ostium of the RCA. "The additional third coronary artery framed

the Vieussen's vein ring in half of the cases with the TCA, while the

conus branch of the right coronary supply course molded the

anastomosis with the conus branch of left coronary channel at a

higher incidence (63%of the cases). Ivan Stankovic et al (2004).

Murli Manju et al did a morphometric study on 50 adult human

formalin settled hearts. they found accessory coronary ostia in 6% of

the cases. Right coronary ostium was found underneath sinu-tubular

convergence in 82% of the cases, at the STJ in 16% of the cases or

above the sinu tubular crossing point in 2% of the cases.

Galit Aviram et al. (2006) studied coronary ostia using computerized

tomographic coronary angiography (CTCA). He used CTCA of 25

patients to study the axial and sagittal 2D and volumetric 3D

24

reconstructions of the aorto-coronary junction. All patients exhibited a

funnel–shaped aortic-coronary junction in at least one plane, and

none of them had an entirely straight tube shape. The mean coronary

orificial funnel depth and ostial cross-sectional diameters were

measured. This measurement is necessary in designing stents for

aortic- ostial coronary lesions in order to achieve optimal results and

reduce restenosis.

Duran et al. (2007) studied about accessory coronary artery ostia in

man and non-human mammals. He reported that the incidence of

accessory ostia in normal and anomalous coronary artery patterns

were quite similar. He suggested that, the morphogenetic deviations

producing the coronary artery anomalies do not alter the connections

of the septal and conus arteries to the aorta.

Markou et al. (2007) found a correlation between anomalous high

origin of the right coronary artery and myocardial ischemia. High take-

off of the RCA ostium or inter arterial course should be considered a

risk factor for myocardial ischemia under certain conditions. He

suggested that surgical repair of the coronary anomaly may be

considered as the best way to prevent a future fatal cardiac

myocardial ischemia.

25

Pejovic (2008) explained the level of ostia with respect to sinu

tubular junction in right coronary sinus of valsalva was at the level in

71% of cases, above in 19% of cases, below in 10% of cases.

Joseph Knig et al. (2009) studied the coronary ostia location in one

hundred and fifty patients by CT coronary angiogram and seventy five

cadavers using open measurement techniques. The location of the

right and left coronary arteries in connection to the aortic annulus and

the stature of the sinus of Valsalva were measured. His study

provided significant differences between in vivo and ex vivo

measurements. The observed large variations in the origin of

coronary ostia emphasize the importance during treatment.

Pinar Kosar et al. (2009) studied the anatomic variation of coronary

artery with computed tomography coronary angiography (CTCA) in

700 patients. 76%of the patients had right dominance and

91%exhibited left dominance and 14.8% of patients had co

dominance. Separate ostium for right conus artery was seen in 22%

and 0.2 % of patients had tow ostia giving rise to two separate conus

arteries.

26

Jamshid Shirani et al. (2009) reported that one or more infundibular

(conus) arteries arose from separate ostia in the aorta and also

reported as many as five separate ostia for right conus artery.

Louis et al. (2010) found the ostium for right coronary artery (RCA)

just below the sinu-tubular junction of the right (anterior) sinus of

Valsalva. He also reported that the oblique origin, intramural (within

the wall of the aorta) course, or positioning between the great

arteries, puts the coronary arteries at risk for compression and limits

the reservoir capacity of the the epicardial coronary system which in

turn cause coronary ischaemia.

Subhash et al. (2010) performed a cadaveric study on the location of

the ostia below the sinutubular ridge (89%) and also studied the

various shapes of the ostia; vertical, circumferential and slit- like

ostia.

Maha Al Mohaissen 2010 studied the anomalous origin of the entire

coronary system by three separate ostia within the right coronary

sinus, which is a rarely observed coronary anomaly. So in his case

the patient complains of chest pain. He underwent diagnostic

coronary angiography which uncovered the blocked right coronary

27

conduit; however no specific canulation was accomplished. At that

point CCTA uncovered three coronary supply routes emerging from

discrete ostia in right coronary sinus. The blocked right coronary

supply route and septal branch were about watched. The left anterior

descending artery (LAD), which ran foremost to the pneumonic

conduit, had direct stenosis (50-75%).Then there was moderate to

severe stenosis (75-99%) in left circumflex artery. The patient was

referred to surgical opinion.

Dattatry D Dombe et al 2012 studied the clinically relevant

morphometric analysis in 64 human adult cadaveric hearts for left

coronary artery. The level of left coronary artery ostium below supra

valvular ridge in 51 cases (79.7%) cases, at sinu valvular ridge in 11

cases (17.2%) and above sinu valvular ridge in 2 cases (3.1%).

Parimala Sirkonda, S Sreelatha 2012 considered the estimations

and area of presence of coronary ostia. They examined the presence

of coronary ostia, and its relation to inter commissural line in 100

human hearts. The outcome demonstrated that the usual number of

coronary ostia ie 1 in anterior aortic sinus and 1 in left posterior aortic

sinus. Third coronary supply route was seen in 19% of the studied

hearts. One heart demonstrated two ostia in left posterior aortic sinus,

28

one for LAD and one for left circumflex artery. Right coronary ostium

was found underneath inter commissural line in 62% and left

coronary ostium was beneath inter commissural line in 44 % of

samples.

Daliber kaur et al (2012) contemplated a morphometric study of

coronary ostia in south Indians .They investigated the 77 adult human

formalin fixed cadaveric heart sample. Area of presence and position

of every coronary ostium was accounted for. Right coronary artery

was emerging from the anterior aortic sinus in all heart examples.

Tiny coronary ostia were seen in anterior aortic sinus in 12 secimens.

64 of ostia situated underneath the sinu tubular junction, 11 hearts

had their ostia at the STJ and 2 over the STJ.

Vijayakumar Shankar Shindae et al (2012) examined the variations

in which the coronary ostia presents itself using 60 north Karnataka

resident heart examples. Only in 3.33% of hearts three coronary ostia

were seen. In 8.33% of cases coronary ostia were found over the

STJ.

Ranjani Singh et al (2013) reported a variant conus vessel emerging

independently from the anterior coronary sinus is especially at peril

29

amid ventriculostomy or different heart surgeries. In her case the

anomalous conus artery originates from the abnormally located

ostium in aorta supplies the conus, continues up to the left margin of

left ventricle crossing aorta, infundibulum. Usually these regions are

supplied by left coronary artery.

Prajapathi, Suthar K et al 2013 contemplated the diversity of

coronary ostium 100 heart samples. The location of presence of right

coronary ostium was concentrated and identified with the STJ and

found that 91 hearts the ostia was found to be beneath the STJ and 9

hearts exhibited the ostia to be over the STJ. Similarly left coronary

ostia was related to the STJ to find 94 hearts ostia below and 6

hearts ostia above the STJ.

Sanchita Roy et al 2014 did a morphometric study in eastern region

of India using adult hearts. They studied the left coronary ostium in

detail relating it to the STJ to find 64 hearts ostium above, 33 hearts

ostium below and 31 hearts ostium at the level of STJ.

Nagaraj Malla Shetty 2014 did a broad study to discover 30 hearts

to discover 2 ostia in 27 hearts and 3 ostia in the rest of the 3 hearts.

He additionally expressed when two ostia is available it is more often

30

than not for the privilege and left coronary supply route. At the point

when 3 ostia is available then conus begins from it

Shubhangi Ramesh Mutyal et al 2014 studied the anatomical

variation in origin of coronary arteries in 60 cadaveric hearts. Out of

these 53 hearts (88.33%) showed 1 ostial opening in right aortic

sinus. 2 Ostia were seen in 6 (10%) heart specimens and 3 Ostia

were seen in 1(1.67%) heart specimen. He also studied the site of

origin of coronary arteries at three levels. Right coronary ostium was

seen at the sinus in 46 (76.67%) heart specimens, at sinu aortic area

in 9 (15%) heart specimen and at aortic area in 5 (8.33%) heart

specimen.

Manisha Randhir Dhobale 2015 et al focused on the third coronary

vasculature in human cadaveric hearts. Single common ostium

shared for right coronary supply and third coronary conduit was found

in 2% hearts. The presence of two ostia shared between right

coronary artery and one for third coronary supply course were seen in

26% hearts. Two ostia shared by three arteries ie one for right

coronary supply course and the other one shared by 2 third coronary

artery (conus branch) was found in 0.67% of heart samples. 2% of

hearts demonstrated three ostia, one for right coronary course and

31

two separate ostia for third coronary supply course were found. Four

ostia, one for RCA two for TCA and the remaining one for vasa

vasorum was found in 1.33% of heart samples.

Quazi Waheed Ulla 2015 studied to find the variation in the number

and location of coronary Ostia in Pakistani population. He studied in

30 heart specimen. 29 out of 30 hearts had single ostium in both

sinuses. Just 1 heart had supplement ostium in right aortic sinus, that

ostium offered starting point to right conus supply route. He likewise

reported that the right coronary ostium to be found at the level of sinu

tubular intersection in 8 cases, above sinu tubular intersection in 3

cases, underneath sinu tubular intersection in 19 cases.

D’Souza 2015 et al studied the variation of origin of coronary artery

and their importance in 51 formalin fixed adult heart specimen. He

studied 96 ostia out of which 64.5% were located below inter

commissural line, 11.4% above it and 18.7% at its level.

In a study conducted on 38 cadaveric hearts by dissection method 1

coronary ostia is seen in 2 specimens. 3 coronary ostia were seen in

2 specimens. Coronary ostia were seen below the sinu tubular

32

junction in 34 hearts. And also 4 hearts exhibited their coronary ostia

above the STJ (Poornima B et al. 2015)

Anatomic variability in coronary ostia was studied using 80 hearts.

Tricuspid valve was seen in 78 of the hearts while the other 2 had

bicuspid aortic valve. In 1 heart right coronary artery arose from the

left posterior aortic sinus. 63 hearts had 1 right coronary ostium while

14 had 2 right coronary ostia. 2 hearts had 3 ostia and 1 heart had 4

right coronary ostia (Hima Bindhu Nalluri 2016).

2.3) Pattern Of Origin:

Schlesinger (1949) was the first person who reported the conus

artery as supplying the conus arteriosus (right ventricular

infundibulum or out flow tract) and recognized that it arose as an

independent vessel from the anterior aortic sinus in which it was

considered to be the third coronary artery.

David c Levin, Carl et al (1981) were the first to study the frequency

and clinical significance of failure to visualize the conus artery during

coronary arteriography. He determined this anatomic variation

through coronary angiograms performed in 508 adult patients with

suspected coronary heart disease. Among 508 cases, the conus

33

artery was adequately visualized in 404 (80.5%). Inadequate

visualization occurred in 22 cases (4.3%) and non visualization

occurred in 77 cases (15.2%). In 19.5% of cases the conus artery

could not be properly evaluated.

Edwards (1981) reported that the conus coronary artery arose

independently from the aorta, in approximately 45 percent of hearts.

In his study, 305 necropsy specimens were examined to determine

the origin of the conus artery and its variations in patterns of origin.

Three examples were perceived:

Design I- The right conus branch emerged autonomously from the

aorta.

Design II- The right conus course and the right coronary supply

route emerged from a typical ostium.

Design III- The conus artery took inception from the right coronary

arteries (Edwards 1981).

The relative incidence of the three patterns varied with age.

Pattern I was recognized in 14 to 24 per cent of specimens. The study

was done in necropsy specimen under the age of 2 years, whereas in

34

older, it occurred in 41 to 63 per cent. These data suggest that aortic

origin of the conus arterial ostium may appear in some individuals

between 2 and 4 years of age, and they support the concept that,

some coronary arterial patterns are not fully established at the time of

birth.

Gupta et al (1987) reported a case on supernumerary right coronary

artery. They reported that the third coronary artery, the conus artery

also called adipose artery, occurs in 33-50% of people and supplies

the conus arteriosus and superior portion of sternocostal surface of

right ventricle.

Sahini D (1989) in her study identified TCA in 38.4% male and 27.8%

female hearts in northwest Indian residents.

As indicated by Ivan Stankovic et al. (2004) the right conus artery

presents itself in two ways. Emerging as first branch from the RCA or

emerging straightforwardly from aorta as TCA. The conus supply

route emerging from aorta was found in eight out of twenty three

hearts.

Valentina Nikolic, Gordana Teofilovski et al (2004) was the first to

concentrate third coronary supply route in monkey heart. The reason

35

for the study is to quantify the outer distance across of right coronary

artery and the third coronary conduit, level of opening in aortic sinus

and to gauge the angulations between aortic root and beginning a

portion of right coronary supply route, angulations amongst aorta and

third coronary corridor. 55 monkey hearts started from east Africa is

considered by stereo infinitesimal analyzation. In 54 out of 55 non

human primates (98.2%) the heart was provided by two coronary

courses. In 1 out of 55 hearts (1.8%), a third coronary course was

available. 48 out of 58 hearts (82.3%) right coronary artery diameter

was arranged 0.2 to 1.2 mm over the free edge of aortic root.

Susan standring (2006) reported that the right conus artery arose

separately from the anterior aortic sinus in 36% of the individuals and

named it as “the arteria conii arteriosi” or “the right conus artery”.

Sarah B Clauss (2006) studied the pattern of origin of septal conal

artery in 25 hetrozygous c x 43 α1 K O mouse. She explained that

branching pattern and origin of septal branch in 25 mice. 5 hearts

exhibits septal conal branch. Out of these 5 hearts 2 hearts had

septal conal artery arising from both left coronary and right coronary

artery, 3 hearts arising solely from the left coronary artery.

36

Olabu et al (2007) studied 148 cadaveric hearts by gross dissection

and micro dissection with hand lens for the prevalence and

topographical anatomy of conus artery emerging directly from aorta

(TCA). 52 hearts showed its presence. The TCA began either from

two openings (2 cases), or single ostia separate from that of the right

coronary conduit (RCA) (26 cases) or from a typical opening with the

RCA (24 cases). He stated that the distribution of this artery may be

important in understanding the extent and progression of acute

myocardial infarction.

David M Fiss MD (2007) depicted the typical coronary life systems

and anatomic variety. He clarifies about the conus conduit is also

called infundibular supply route, fat conduit, third coronary corridor,

course of vieussens. It runs semi circularly along from right coronary

supply route or the epicardial front surface of right ventricle at the

level of pneumonic valve. This structures the Anastamotic Bridge and

assumes a vital part as security pathway to left front plummeting

course. He likewise expressed that the conus branch emerges as the

immediate branch of aorta was around 23% to 51%.

Almira lujinovic (2008) took 25 adult human hearts from bosanian

population .out of 25 hearts 8 hearts had conal artery. In this 1 heart

37

(4%) had four coronary arteries. In 2 heart (8%) the third coronary

artery anastamosed with anterior interventricular branch and formed

vieussens arterial ring.

Cademartiri et al (2008) examined the commonness of anatomical

difference and coronary inconsistencies with 64 cut CT coronary

angiography in 543 patients of dutch populace. Variations of conus

corridor as from proximal right coronary course was seen in 64.1% of

populace and from regular ostium was seen in 22.3% and from aorta

was seen in 11.6% of patients.

Luis Ernesto Ballesteros (2011) proposed the morphometrical

investigation of right coronary course in 221 cadaveric hearts of

Colombian population. His outcomes demonstrated that conus

arteriosus emerges from the right coronary artery in 164 (74.2%) and

aorta in 57 hearts (25.8%). He additionally expressed that third

coronary conduit was available in 50(27.6%) guys and seven (17.5)

female without critical distinction (p=0.22).

Rebecca A.B Burton, Jurgen E. Schneider et al (2012) considered

the minute attractive reverberation of hearts uncovering high

commonness of third coronary course in human and rabbit hearts.

38

The study was done to recognize third coronary conduit its

predominance and qualities in human and rabbit hearts. 11 New

Zealand white rabbits heart and 7 human cadaveric hearts were

altered, gadolinium treated, agar installed for imaging based

recreation. Third coronary supply route was found in every one of the

11 rabbit hearts and 6 out of 7 human hearts. The external breadth of

third coronary supply route had a normal of 1.26 mm in human hearts

and 0.27 mm in rabbit hearts.

Tekbas (2012) studied the determination of variation and relationship

of third coronary artery with 64 slice computed tomography in 370

patients. He identified 71 conus artery arising from right coronary

artery (28.06%). 92 conus artery arose from the aorta (36.6%) and 90

conus artery originated from aorta and right coronary artery having a

common origin.

Jyothi Kulkarni (2013) contemplated the variation life systems of

coronary artery. She studied in 60 formalin settled cadaveric hearts.

She reported the conus artery emerging from right coronary supply

route in 92% of cases. In 8% of cases the conus conduit had

autonomous beginning.

39

Ritu Mehta (2013) concentrated on the recurrence and clinical

implications of the conus vasculature as TCA in 64 slice CT

angiograph. She expressed that out of 111 angiograms the right

conus conduit branched from the RCA in 69.3% cases. The right

conus artery originates from the same ostium in 15 individuals

(13.5%) and from separate ostium (aortic origin) were seen in 18

cases (16.2%). She recommends the selective angiography for conus

artery as the third coronary artery was screened in 29.7% of CAT

scan coronary angiography.

Kandaregulu jothirmayi et al (2013) studied the morphological and

morphometrical parameters of coronary arteries in 50 dead aborted

fetuses of 13 to 36 weeks of gestational age of both sexes. They

found the right conus supply was seen emerging independently from

the anterior aortic sinus as TCA in one specimen of 25 week

gestational age in males.

The right coronary supply route in pigs was concentrated on with a

plan to decide the anatomic articulation of right coronary course in

158 pig hearts. The conus course emerges from right coronary supply

route in 100 examples 63.3% and from aorta 8 examples 5.1 %(

Gomez et al 2013).

40

Marios loukas, swetal patel et al (2014) concentrated on the clinical

life systems of conal conduit and recognized the conal branches in

300 adult human cadaveric hearts and also with 300 coronary

angiograms. Conal starting point was arranged into 5 designs in

which conal artery emerged as branch of right coronary course was

sort A which was seen in 193 hearts (32.1%). In sort B conal course

rose up out of the typical coronary ostium with right coronary supply

96 hearts (16%).In 242 hearts (40.3%) typeC conal channel took

cause from the benefit aortic sinus as a self-governing course.In sort

D 48 hearts (8%),multiple conal branches were accessible and rose

up out of specific branches 32 hearts (66.6% ),from general ostium

with right coronary supply course in 8 hearts (16.6%) or from aortic

sinus 8 hearts(16.6%).In sort E 22 hearts 3.6 % , the conal supply

course rose as a branch of right ventricular branch in 17 hearts

(2.8%) or exceptional unimportant conductor in 5 hearts (0.8%)

(Marios loukas,swetal patel et al 2014).They watched the morphology

and geology of conal corridor shifted fundamentally with the level of

coronary lumen stenosis and level of hypertrophied ventricular

divider.

41

Agneszka Mlynarska, Rafal Mlynarski (2014) studied 79 patients

aged 56±12.9 years. They utilized non invasive coronary angiography

to dissect the conus course to be seen in 64 (81%) patients. They

demonstrated that 53% of patients the conus supply route began

from the main section of right coronary artery. The second most

frequent variant is the conus artery arising directly from aorta was

seen in 30 (37.9%) patients. The rarest variant of right conus artery

having common trunk for both vessels was seen in 14% of heart.

Charanjeet Kaur et al 2014 contemplated the anatomic fanning

example of right coronary supply route in 25 heart example. In 21

examples single conus artery was seen. Out of this 15 examples right

conus branch was emerging from right coronary artery and in 6

example conus supply route emerging straightforwardly from aortic

sinus. In 3 example 2 conus supply route were seen Out of which one

example had both conus course emerging from the aortic sinus. In 2

examples one conus artery emerging from anterior aortic sinus and

another conus course emerges from right coronary artery.

E I Syed (2015) 30 saved heart in Middle Easterner population and

distinguished that conus branch was found to emerge at the

separation of 0.5 to 2.4 cm with the mean of 1.5 ± 0.6 cm from the

42

earliest starting point of right conus course. In 3.3% the privilege

conus course was found to emerge out from the anterior aortic sinus.

Yadukul (2015) did an autopsy study of third coronary artery. They

studied in 550 dissected human cadaveric hearts. They reported that

the third coronary artery (conal artery) present in male was 109 out of

293 (37.2%) hearts and in females it is found to be 75 out of 257

(29.18%) hearts. According to the position of third coronary artery,

83.15% was in 10 o clock position n=153, 13.04% was in 9 O clock

position n=24, 2.71% was in 8 O clock position n= 5 and 1.08% was

in 7 O clock position n=2. 145 (78.8%) had an independent course

without obvious anastamosis and rest 39 (29.2%) anastamosed with

the right coronary artery.

2.4) Angulation:

The literature regarding angulation of right conus artery is very few in

numbers. No literature had explained clearly about the angulation of

right conus artery.

Kohler 1981 studied the angulation between the coronary arteries

and aorta which averaged 45º on the left coronary artery and with

right coronary artery was 102º.

43

Reig Vilallonga 2003 concentrated on anatomical variety of coronary

arteries the most regular variety.She stated the angle of origin of

coronary arteries with regard to aorta is the most frequent variation.

The coronary arteries branch off from the aorta wall at a variety of

angle 90 º perpendicular origin, <90º (Tangential origin) and practical

0º (intussusception).

Valentina Nicolic et al 2004 concentrated on the angulation of third

coronary artery in 55 monkey hearts (30 cercopithecus aethiops and

25 maccaca facicularis). The angulation of third coronary course

concerning aorta was 90º.

Ivan Stankovic 2004 studied the morphometric characteristics of

conal coronary artery in 23 adult human cadaveric hearts. He found

the angle between the third coronary conduit and aorta, Right

coronary artery supply route and Right Conus course were

73.4°±35.2°and 82.3°±39.8° separately.

Jose R Lopez Minguez et al 2006 concentrated on the elements of

the sinus of valsalva and the proximal part of the coronary arteries.

The pertinence to retrograde aorto coronary dismemberment was

utilized to study 16 postmortum hearts. He quantified the angulation

44

of coronary supply routes with aorta. The point between the aorta and

beginning a portion of right coronary supply route is mostluy in right

angles to aortic sinus framing an mean angle of 71.5º±8.5º .

Pejkovic 2008 in his research reported the mean angulations

between beginning segment of right coronary course and longitudinal

turn of rising aorta ranges from 15º-150º. In 20% right coronary

course was s shaped which ranges from 40º-90º.

2.5) External Diameter of Right Conus Artery:

Kohler 1981 explained about the ostial diameter which is averaged

on right coronary ostia is 3.83mm and with left coronary artery ostia is

4.83mm.

“The diameter of conus artery was small with average of 0.5-2 mm

and arise as a separate vessel from right coronary sinus, anterior to

within a few millimeters of the mouth of the right coronary artery”

(Gupta et al 1987). In their case they had seen the separate origin of

conus branch and recommended selective catheterization and

arteriography.

Grover m hutchins et al 1988 studied the vessel caliber and branch

angle of human coronary artery branch points in 738 autopsy human

45

heart .He stated the cube of the diameter of the parent coronary

artery equals the sum of the cubes of its branch vessel diameter .they

concluded that there was no relationship seen between coronary

artery branch vessel diameter and branch angle.

Sahini D 1989 studied origin and size of coronary arteries in

northwest Indians. She found that the mean diameter of right

coronary artery at its origin was 3.2 ± 0.5 mm in males and 3.2 ±

0.6mm in females.

Valentina Nicolic et al 2004 was the first to think about the outside

measurement of right conus supply route in 55 monkey hearts (30

cercopithecus aethiops and 25 maccaca facicularis). She reported

the predominance of third coronary supply route in monkey heart

furthermore reported the outside distance across of third coronary

corridor at its source was 0.3mm.

Cheemlapati Saikrishna et al 2006 studied the normal coronary

artery dimensions in Indians. They attempted the data base normal

dimensions of coronary segments during life by using 94 patients who

underwent quantitative coronary angiography who had no coronary

disease. The mean distance across of proximal right coronary supply

46

route is 2.75 mm in males and in females is 2.55 mm with a p value

of 0.11. The mid of right coronary artery 2.47± 0.66mm in males and

2.31 ± 0.13 mm in females and p value obtained was 0.28(

Cheemlapati Saikrishna et al 2006). In general male had large

coronary artery than female artery. This difference is however was

not statistically significant in right coronary artery. There is no

correlation between the diameter of coronary artery and body surface

area either in males or females.

Fazliogullari Z et al 2010 found that the external measurement of

right coronary conduit was 3.32 ± 0.79 mm.

Rebecca A B Burton et al 2012 considered magnetic resonance

imaging uncovers high commonness of third coronary corridor in

human and rabbit heart. The mean width of left coronary course was

observed to be 1.1 mm and 4.02 mm in rabbit and human heart

separately. The mean breadth of right coronary artery is 0.72 mm and

2.54 mm in rabbit and human heart individually. The mean

measurement of third coronary supply route (right conus conduit) was

observed to be 0.27 mm and 1.26 mm in rabbit and human heart

separately. The third coronary supply route breadth is significantly

littler than the right coronary course, both in rabbit and human

47

Dattatry D Dombe et al 2012 considered the clinically applicable

morphometric examination in 64 human grown-up cadaveric hearts

for left coronary artery. The mean distance across of left anterior

descending artery is 3.19 ± 0.55 mm and the mean measurement of

left circumflex artery was 2.94 ± 0.70mm.

A Avirmed et al 2012 examined the microcirculation of hearts in

infants. They studied in 40 infant hearts which were visualized post

mortem by injection of coronary arteries with X ray opaque dye for the

imaging study. Also, black ink cast and silver impregnation

specimens were studied. Their outcome expresses that the distance

across of the collateral branches of the right coronary course ranged

from 113.3±23.1 µm to 736 ± 92.5 µm.

Darmendra et al 2013 contemplated the clinically noteworthy

anatomical variety of left coronary supply route in 93 human

cadaveric hearts. They recognized the birthplace, length, number of

terminal division of left coronary vasculature and the range

appropriation of left primary coronary artery was noticed .The mean

external width of left coronary supply was 4.64 ± 1.03mm.

48

Gomez 2013 concentrated on right coronary vasculature in 158 pig

hearts and found the mean measurement of right coronary course

was 3.85mm.

Nagaraj malla Shetty 2014 reported the outside measurement of

right and left coronary artery in 30 heart examples. External

measurement of right coronary course is 4.1mm and external breadth

measurement of left coronary supply route is 4.3mm.

Sukhendu Dutta 2014 concentrated on the rate and dispersion of

odd coronary supply route investigation of necropsy cases. He

expressed the breadth of right coronary was observed to be 4 mm,

which emerges as the immediate branch from the aortic sinus. The

breadth of left coronary corridor was 3mm at the proximal part, soon

after root from aortic sinus.

Imad Ghanem Shukri et al 2014 et al did an angiographic study of

the normal coronary artery in patients attending ulaimani centre for

heart disease. He analysed the study in 88 patients who underwent

quantitative coronary angiography. They reported the diameter of

coronary arteries were larger in males than females. The mean

distance across of right coronary supply route measured at the

49

beginning for both male and female was 3.1 mm. in males the mean

breadth of proximal RCA was 3.26 mm and in females the proximal

distance across of right coronary vessel averaged to 3.02 mm.

2.6) Branches of Right Conus Artery:

Luis Ernesto Ballesteros (2011) contemplated the morphometrical

analysis of right coronary artery in 221 cadaveric hearts of Colombian

population. The right conus artery that irrigate the conus arteriosus,

anterior wall also supplies the superior and middle ventricular surface

in 87% while 13% reached the inferior ventricular segment.

Gomez 2013 compared human human coronary vasculature with that

of pig in 158 pig hearts. Conus supply route was seen in 63.3% of the

heart out of which 41% of hearts the studied conus artery was found

to wind up at the cone. Conus course closes at the upper third of the

anterior wall of right ventricle in 19%, at the mid third in 37% and at

the lower in 3% of cases. 5.1% of conus supply route which emerges

from right aortic sinus supplied the cone, upper and mid sections of

right ventricle.

Manisha randhir dhobale et al (2015) examined the third coronary

artery in grown-up human cadaveric hearts. They took 150 cadaveric

50

hearts and watched the source, course and degree, dispersion,

distance across of third coronary vasulature and finding the

myocardial bridge. They clarified about degree and dispersion of third

coronary vasulature. The conduit that finishes over the privilege

ventricular outpouring tract (infundibulum) provided the conus

arteriosus in around 24 hearts (16%). Hearts in which the third

coronary artery stretch out up to the center of the right ventricle

disperses the infundibulum with piece of anterior wall of right ventricle

was around 16 hearts (10.66%). Third coronary course bigger than

the right coronary artery augmenting up to the mediocre outskirt of

the heart supplies the infundibulum with anterior wall of right ventricle

and ventricular septum was found in 6 hearts (4%). Third coronary

artery bigger than the right coronary conduit and consummation by

anastamosis with ventricular branch of left coronary course at the

peak of the heart supplies infundibulum with the anterior wall of right

ventricle, interventricular septum and a portion of left ventricle close

zenith was found in 2 hearts (Manisha randhir dhobale 2015).She

stated the third coronary artery is present frequently, hence role of

third coronary artery should always be considered during diagnostic

and therapeutic interventions.

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2.7) Clinical significance of right conus artery:

Ralph w Alexander et al 1956 studied the oddities of the coronary

arteries and their clinical importance in 54 cases was found among

18,950 examinations they made. They Separated 39 cases with

irregularities of coronary ostia. Absence of right coronary ostium was

seen in 4 patients who had cardiac symptoms like palpitations,

angina pectoris and cardiac failure. During autopsy of these 4

patients showed significant cardio vascular findings such as

myocardial infarction, rheumatic mitral and aortic disease with

bacterial vegetations. Common ostium in the right sinus of valsalva

had been seen in 2 cases with cardiac symptoms like cyanosis,

hypertension and angina pectoris. Significant cardio vascular findings

found in these 2 cases were interventricular septal defect (IVSD),

right ventricular hypertrophy, patent foramen ovale and ductus

arteriosis. 1 patient had separate ostium was seen in right sinus of

valsalva with cardiovascular disease like right ventricular hypertrophy.

3 ostia of right coronary artery in normal sinus of valsalva was seen in

2 patients who died because of ruptured apendicial abscess and

cardiovascular finding during autopsy revealed the old posterolateral

infarct. Two ostia of right coronary artery were seen in 6 patients with

52

cardiac symptoms like hypertension, dyspnoea, chest pain and

cyanosis. Cardiovascular findings showed left ventricular

hypertrophy, pericardial effusion and bicuspid aortic valve. Ostia of

right coronary artery seen above the sinus of valsalva or

commissures were seen in 5 patients who had rheumatic aortic,

rheumatic mitral and tricuspid disease with bacterial vegitations, left

ventricular hypertrophy, right ventricular hypertrophy and fibrous

pericarditis as cardiovascular findings.

Abdul Rathor (1973) reported a case of survival through conus

artery collateralization in severe coronary heart diseases. He reported

a case of 64 year old woman with unremitting angina pectoris.

Selective coronary arteriography and left ventriculography were

performed. The right coronary supply route was completely blocked

promptly distal to the take off of the conus artery and sinu nodal

course. The conus corridor provided extensive security branches to

the right marginal vessel, LAD and its diagonal branch. All the

collateral major arteries were perfused mainly by the large dilated

conus branch of right coronary artery. ventriculography reveals

adequate contraction without regional dyskinesis and left ventricular

end diastolic pressure.

53

Takumi Sumimoto et al. (1992) analyzed coronary arteriogram in 66

patients with hypertrophic cardiomyopathy (HCM). Four out of these

patients showed a large conus artery supplying the interventricular

septum. He suggested that in some patients with hypertrophic

cardiomyopathy, the right conus artery plays a compensatory

mechanism in hypertrophied myocardium.

Steven Feld, MD Menashi Epsten 1995 concentrated on LAD which

could not be imaged using routine diagnostic technique, uncovered a

specific conus supply route catheterization. Specific right coronary

supply route catheterization of a 67 year old man indicated mid right

coronary flow impediment and there was no indication of collateral to

LAD. The conus artery was not seen during the selective injection in

right coronary artery. Fortunately resting left ventriculography showed

a normal anterior wall motion. Cannulation with contrast material of

separate ostium in right aortic sinus revealed a large conus artery

which forms an extensive collateral circulation and complete exposing

LAD with the blood filling proximal to the site of left anterior

descending artery impediment.

R A Karensky et al (1995) studied the antegrade filling of an

occluded right coronary artery via collaterals from a separate conus

54

artery, a previously undescribed collateral artery. They reported a

case with ostial right coronary artery occlusion. In selective coronary

artery injection reveals excellent collaterals which pass directly to the

proximal RCA. In initial time this was mistaken for diffuse disease of

ostium and proximal portion of the right coronary artery.

Antonello Musiani et al (1995) reported an instance of left principle

coronary supply route atresia with related coronary atherosclerosis.

For this situation whole left coronary framework supposedly was

provided by a bifurcated conus artery originating from the right

coronary vasculature that was free of ailment. Thus blood flowing

from the right coronary artery was flowing in a retro-grade direction in

the proximal LAD to fill the circumflex artery, and in an ante-grade

direction in the distal LAD. The medical literature describes about

dozen cases of LMCA atresia which is a rare anomaly. Left main

coronary artery atresia must be differentiated from single right

coronary artery: in a single-artery system the blood flow is always

ante grade and centrifugal, from the aorta towards the periphery

through vessels whose size is diminishing, whereas in LMCA atresia

the blood flow is partly centripetal and retrograde, toward the proximal

end of a left-sided artery and from the right coronary artery to the

55

collateral branch which is smaller than the right coronary artery and

then to the left-sided artery which is a larger vessel when compared

to the collaterals.

The left coronary course blood stream may originate from the

right coronary conduit to the LAD through collateral vessels that

incorporate the conus vasculature and ventricular anastomoses and

to the circumflex supply route by means of back ventricular vessels.

Some patients with isolated LMCA atresia may have no symptoms,

but it appears that angina eventually develops in all of them, even in

the absence of coronary atherosclerosis; such symptoms can be due

to the length and tortuousness, inadequate caliber, systolic kinking, or

compression of the collateral arteries.

Tuvia Ben-Gal et al. (1997) analyzed the coronary angiograms of 28

patients. They identified two types of conus branches, small not

reaching the interventricular septum [IVS] and large conus branch

reaching the IVS. “The presence of double circulation to the right

paraseptal area (by the right conus branch of the right coronary artery

and by septal branches of the left anterior desending artery) protects

it from ischaemic damage, thus preventing the occurrence of the right

56

ventricular “steal” phenomenon and diminishing the left ventricular

ischaemic burden” (Tuvia Ben-Gal et al. 1997).

Lynn Beach 2001 studied the anomalous origin of four coronary

ostia from the right sinus of valsalva in patients with hypertrophic

cardio myopathy. A 49 year old man underwent cervical spinal fusion.

1 week after surgery with history of chest pain he suddenly collapsed.

In autopsy, the heart had moderate left ventricular hypertrophy with

mild asymmetry. Four separate ostia apparently arose from the right

aortic sinus. One ostia for LAD, one ostia form which left circumflex

artery arise, another ostia giving rise to right coronary course which is

a long conus branch and fourth ostial vessel seems to supply ramus

intermedius.

Ayalp et al 2002 examined the recurrence in the atypical starting

point of the right coronary course with angiography in Turkish

individuals. He investigated 5253 grown-up patients experienced

coronary angiogram for finding anomalous source of right coronary

supply route. Out of 5253 patients, 5 (0.09%) had irregular inception

of right coronary course which emerged from the left sinus of

57

valsalva. Out of 5 patients 2 patients (0.03%) the ostium of right

coronary vessel lies higher to the sinus of valsalva.

Mladen et al. (2004) revealed a giant coronary pseudo aneurysm

arising from Vieussen’s arterial ring formed by the anastomoses of

right and left conus artery. Mladen envisaged the importance of

Vieussen’s arterial ring which sometimes gives rise to giant coronary

pseudo aneurysm. The rupture of this vessel may go in for cardiac

tamponade.

Masakazu Yamagishi et al. (2005) inspected 639 patients who

experienced coronary angiography as a part of diagnosis for coronary

disease. Total LAD impediment was seen in 150 of these patients. In

this 45 patients had the isolated conus artery (ICA) as a collateral

supply. Among these, 30 demonstrated the ICA anastomosing with

LAD to complete blood supply. In nine of these patients, ordinary left

and right coronary angiography did not uncover some other critical

daughter vessels, and the distal LAD was perfused predominantly by

the ICA. Neither ventricular fibrillation nor localized necrosis of

myocardium happened amid these methodology. These outcomes

show that the visualizing ICA is clinically imperative.

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Eichhofer et al 2005 in his case reported the unexpected profound

transient anterior ST elevation after occlusion of the conus branch of

the right coronary artery during angiography.

Tanigawa J et al 2007 concluded that the selective injection of the

conal branch should always be attempted if no collateral filling is

visualized due to a chronically impeded left anterior descending

artery.

Markou et al 2007 in his case concluded high take-off of the RCA

ostium or inter arterial course should be considered a risk factor for

myocardial ischemia under certain conditions. He suggested that

surgical repair of the coronary anomaly may be considered as the

best way to prevent a future fatal cardiac myocardial ischemia.

Olabu et al (2007) stated that the distribution of this artery may be

important in understanding the extent and progression of acute

myocardial infarction.

Wynn et al (2008) focused on the usefulness of the right conus

course as a guarantee to a blocked LAD utilizing stress

echocardiography. They demonstrated that a collateral vessel takes

the burden to irrigate the nutrition deficit myocardium due to

59

obstruction, thus preventing focal myocardial death. They showed a

guarantee of stream of blood in an obstructed LAD passing from

joined collateral of right conus artery. They reported that this case to

be accounted for, that the right conus artery can give practically vital

blood supply to an impeded LAD.

Zhong-qun Z et al 2008 studied acute anterior wall myocardial

infarction entailing ST- segment elevation in lead V3R, V1 or aVR,

electro cardiographic and angiographic correlations. He explained

about the long conus and short conus branch in 142 patients with first

anterior wall acute myocardial infarction. Before starting reperfusion

treatment he assessed and corresponded with the left anterior

descending artery impediment site in connection to the septal

perforator, the nature of the conal branch of right coronary supply as

dictated by coronary angiography. The study pointed 60 patients with

blockage in LAD. Out of these 60 patients 20 patients had large conal

branch. ST↑ aVR, ST↑ V3R of at least 1.5 mm and ST↑V1 of at least 2

mm were also associated with the presence of small conal branch not

reaching the interventricular septum during anterior wall acute

myocardial infarction.

60

Robert H Anderson et al. (2009) studied the coronary arterial

anatomy in truncus arteriosus communis. He concluded that, in

around two third of cases the coronary vasculature exhibited

transposition of the great vessels. In those cases, a prominent branch

of the right coronary vessel crossing the right ventricle giving the

circulatory connection for anterobasal surface of both ventricles and

the upper part of the interventricular septum. These courses are at

risk in surgical techniques, for example, a privilege ventriculotomy.

Hareesh S Gouda et al. (2009) from their study concluded the

presence of third coronary artery (TCA) showed topographical

contrasts. This helps in identifying an individual if ante mortem record

and angiograph are accessible.

Owen et al (2009) studied the rupture of aneurysms of vieussen’s

arterial ring presenting an acute cardiac tamponade .In their case the

computed tomography aortography revealed the 3.5cm aneurysm of

vieussen’s arterial ring. The surgical removal of aneurysm restored

the normal blood supply of right and left coronary artery.

Louis et al. (2010) reported that the oblique origin, intramural (within

the wall of the aorta) course, or positioning between the great

61

arteries, puts the coronary arteries at risk for compression and limits

the reservoir capacity of the epicardial coronary system which in turn

cause coronary ischaemia.

Anu V Ranade et al 2010 reported a case of independent origin of

entire coronary system along with the right conus artery within the

right sinus of valsalva associated with intra myocardial tunneling. The

right sinus of valsalva through separate ostium gave rise to the left

coronary artery, a large intermediate branch, a circumflex branch and

the right conus artery.

Stojan Babic et al 2010 studied the clinical significance of collateral

blood vessels. They reported a case with chest discomfort and sense

of shortness of breath. Coronary angiography revealed 100% of

occlusion of right coronary artery with adequate patency of left

coronary artery. Coronarygraphy also showed the presence of well

developed collateral blood vessels and he was treated with statins

only. They described about the coronary collateral circulation in

presence of obstructive coronary disease.

Gajbe et al. (2010) studied the anomalous origin of multiple coronary

ostia in 30 hearts and its clinical significance. In his study he

62

suggested that, individuals with multiple ostia should be follow ups to

rule out angina, myocardial infarction, left ventricular dysfunction, etc.

He stated that when multiple ostia are observed in the anterior aortic

sinus, the most common variation is an accessory orifice for the right

conus artery.

Subhash et al (2010) Stated that the varying shape of osia may

create confusion in interpreting the images and pose a difficulty

during procedures like angiography, angioplasty and coronary artery

bypass grafting.

Jose A De Agustin 2010 contemplated the guarantee course from

the conus coronary supply route to the anterior descending coronary

artery utilising computed tomography. He reported that three patients

with serious left coronary vessel obstruction and restored flow

through conus supply route that joined a proximal or medial fragment

of LAD. In every one of the three cases the left ventricular circulation

is always restored by the dominant conus artery.

Masaru yamaki et al 2010 reported the case on possible contribution

of ischemia of conus branch to induction or augumentation of

brugada type electrocardic changes in patients with coronary artery

63

disease. Here they described about the interaction between ischemia

caused by conus branch lesion and brugada type electrographic

changes with two cases with coronary artery diseases .They suggest

that brugada syndrome and vasospastic angina might share similar

modification factors such as autonomic modulation, responsiveness

to beta blockers and possibly ST segment agumentation by ischemia

and vagal influences. Some differences were also seen in response

to ca channel blockers.

Ogano m et al 2011 reported the proarrythmic ecg deterioration

caused by myocardial ischemia of the conus branch artery in patients

with brugada ecg pattern. The ECG pattern of brugada reveals the

ST segment elevation in right precordial ecg leads, which provokes

the sudden death. In their case they experienced the patient with

saddle back brugada type ECG which exhibited the ECG conversion

followed by ventricular fibrillation episodes when there is myocardial

ischemia exclusively seen in the conus branch of right coronary

artery.

Felipe Hernandez Hernandez et al 2011 reported a case on

recurrent ventricular fibrillation and ST segment elevation in the right

precordial lead due to acute occlusion of conus branch .he studied

64

the case of 79 year old man with high blood pressure and chronic

liver disease due to hepatitis c virus . The patient was reoffered to

surgery for mitral valve regurgitation with the prolapse of p2 and p3

through the breakage of chordae tendinae .The left ventricle &

coronary arteries were normal .Emergency coronary angiography

were seen and it reveals the total occlusion of the right conus artery

which is the first branch of right coronary artery .This acute occlusion

was due to suture done to fix the cable of cardiac pace maker.

Balloon angioplasty was performed and good angiographic results

were seen .This acute occlusion due to vasospasm, atherosclerotic

disease or accidental injury during surgery in the region of pulmonary

infundibulum can give rise to myocardial ischemia in infundibular

region and in right ventricular wall. This is manifested by ST elevation

in right precodial leads and ventricular fibrillation .the risk of

arrhythmia generated by the mechanism was also seen in brugada

syndrome.

Harit Desai et al 2012 reported a case of 65 year old male who has

systolic heart failure, peripheral arterial disease, hypertension,

dyslipedemia and active tobacco use with Canadian iii angina

symptoms. On physical examination there was significant heart

65

failure with jugular venous distention and lower extremity odema.

Laboratory analysis results negative cardiac biomarkers and

diagnostic testing results that was non contributory with an

unchanged baseline electrocardiogram. Coronary and graft

angiography revealed a large conus artery via a separate ostium from

the right coronary artery supplying a rich network of collaterals to the

distal right posterior descending, distal obtuse marginal and mid to

distal left anterior descending.

Masanari Umemura et al 2012 reported a case on acute myocardial

infarction with isolated conus branch. In this case report with no

history of coronary disease the patient developed the occlusion of

conus artery. This led to acute myocardial infarction and treated with

guide wire, instead of balloon stent catheter.

Velicaglar 2013 studied the anomaly of the conus artery arising from

the right coronary artery. The author reported a case of 63 year old

man who undergone aorta coronary artery bypass surgery and

followed up by medical treatment of 7 years. He had complained of

exercise induced chest pain. Selective angiogram was performed due

to angina pectoris. It revealed a conus artery arising from the right

sinus of valsalva and communicating on the posterior pericardium

66

with the collaterals which has synchronized to each cardiac cycle.

Since synchronized movement with heart beat of an opacified

pericardium on left lateral position reveals the anomalous conus

artery communicating with posterior pericardium.

Mohammed bamoshmoosh et al 2014 studied the vieussen’s

arterial ring visualized by MDCT (multi detector computed

tomography) which was a rare case .In the two cases they observed

the vieussen’s arterial ring using multi detected computed

tomography. So they are suggesting that multi detected computed

tomography coronary angiogram was more useful than traditional

invasive coronary angiography.

Toshiki Kuno et al 2015 reported the electrocardiogram changes of

conus branch occlusion during the right coronary artery angioplasty

.He reported a case of conus branch occlusion during angioplasty

with ST elevation in V1-3 like brugada syndrome ECG. Similar

changes are seen in the ECG pattern with brugada syndrome and

conus artery occlusion. So this is considered as the substrate for

brugada syndrome. This type of ECG changes may cause the lethal

arrhythmias.

67

Maria Grazia Modena et al 2016 did a contextual analysis of patient

who experienced myocardial necrosis with impediment of three prime

coronary vessels. He described the situation as when Mother Nature

takes mind more than doctors. Study was done on 48 years of age

man who had intense myocardial localized necrosis because of

double blood vessel stent thrombosis taken place after drug eluting

stent placement. Previously in November 2005 coronary

catheterization of the patient found to have a block in the middle right

coronary artery, marginal artery and full blockage of the left anterior

descending artery which was treated with angioplasty and

implantation of two stents. Two years later patient had cardiogenic

shock with total atrio ventricular block and ST segment elevation in

both inferior and lateral electrographic leads. Coronary angiography

revealed drug eluting stent thrombus of right coronary artery in middle

part, proximal first obtuse marginal artery and total occlusion left

anterior descending artery. Specific catheterization of a dilated right

conus supply route demonstrated broad collateral course to the distal

LAD and feeble stream to the marginal vessel. From the study it is

obvious that whatever point the circulation drops in LAD or RCA due

68

to block it gets to be compulsory to image the conus conduit

sufficiently before taking restorative choices.

In Many literatures the origin and distribution of main branches of

coronary arteries were studied while smaller branches such as conus

artery are neglected. The present study focuses on right conus artery

in detail with its embryological interpretation, its clinical significance,

its origin, number and level of ostia, angulation, external diameter and

branches in south Indian population. The study also compares the

external diameter of right conus artery obtained in cadaveric and

coronary angiograms and also compares the diameter of conus artery

with branching pattern.

69

3. NEED FOR THE STUDY

One of the main vessels providing the collateral circulation is the

right conus artery. In literature the right coronary artery was studied in

depth and the importance of right conus artery is less identified and

ignored. Studies regarding the number and level of ostia in right

anterior aortic sinus were done mostly in other population and very

less data was available in south Indian population. Origin of right

conus artery was not extensively and very less data are available in

our country. The angulations of right conus artery was less studied in

literature. The external diameter of right conus artery was studied in

other species while human studies are very rare. The branches of

right conus artery was least studied and very less data available in

literature. Studies elaborating the anatomical significance of right

conus artery have not been done in our country. Therefore, this study

will analyze the right conus artery in depth and will help in better

understanding of coronary circulation and its implications in coronary

insufficiency.

70

4. OBJECTIVES

1. To find the number and level of ostia in anterior aortic sinus with

regard to sinu –tubular junction in cadaveric hearts.

2. To find the pattern of origin of right conus artery in cadaveric

hearts and coronary angiograms

3. To find the relation between the angulations of right conus artery

with respect to aortic origin and origin from right coronary artery.

4. To find the relation between angulations of right conus artery

when arising from right coronary artery and having a common

origin.

5. To find the relation between outer diameter of right conus artery

(near its proximal part) in cadaveric hearts and coronary

angiograms.

6. To find the relation between the diameter of right conus artery,

with and without the presence of long branches in both

cadaveric hearts and angiograms.

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5. METHODOLOGY

5.1) TOOLS:

Figure 3: Dissection Instruments

Manual goniometer

Digital Vernier caliper

Dissection forceps (pointed, tooth, blunt)

Scalpel , BP Handle (Blunt, Blade)

Scissors

Gp (gutta percha) sticks

Hand lens

Quantitative coronary analysis plus software.

SPSS

72

5.1.1) Manual goniometer:

A goniometer is an angle measuring device. Goniometer is

derived from two Greek words, gonia meaning angle, and metron

meaning measurement. It measures angles

or gives an accurate support to an object to be moved at a particular

angle. It is widely used in industries and various fields of science.

Figure 4: Manual Goniometer

73

A traditional therapeutic goniometer is universally accepted to

measure angle with accuracy and is used in the present study. It

consists of two arms, one is fixed and ot with a other arm with a

protractor can be moved (Fig 4). Angulations of right conus artery

was measured with respect to aorta and right coronary Artery using

manual goniometer.

i) Angulations with respect to Aorta.

Central axis of goniometer was placed at the junction of Aorta and

origin of right conus artery. Fixed arm of goniometer was placed

along the axis of ascending aorta and the movable arm was placed

along the axis of right conus artery and the angle was measured (Fig

5).

FIG. 5: ANGULATION OF R.CON.A WITH RESPECT TO AORTA

74

ii) Angulations With Respect to Right Coronary Artery:

Goniometer was put at the meeting point of right coronary and right

conus vessel. Goniometer was set in a manner that immovable arm is

along the right coronary vessel and the versatile arm along the right

conus artery and the degree of angulation formed was measured.

(Fig 6).

Figure 6: ANGULATION OF R.CON.A WITH RESPECT TO RCA

75

5.1.2) Digital Vernier Caliper:

The vernier caliper was invented by the French scientist Pierre

Vernier. It is used to measure length and diameter with accuracy to

hundredth of a millimeter. The caliper comprises of two graduated

scales, a primary scale which resembles a ruler and a moment scale

of the vernier, which slides parallel to the ruler scale. The Vernier

scale consists of quadrants with the primary scale in half degrees.

This scale was thirty one and one half degrees in length and divided

into three equal parts. Each part was one half a degrees plus one

minute. Our study uses a digital vernier caliper which has an

electronic display that displays the diameter measurement in

millimeters or inches (Fig 7).

Figure 7: Digital vernier caliper

76

5.2) METHODS TO BE USED: Dissection method, Coronary

angiogram.

5.2.1) Dissection Method:-

i. Embalming procedure:

Embalming is done to preserve the dead bodies so that it can be

used for further human anatomical studies. In modern day embalming

is usually done with formalin dissolved in water. Many additional

agents such as germicide, preservatives were added. The study was

performed on already embalmed dissected cadaver.

ii. Removing Heart specimen from cadaver:-

Superficial muscles of chest wall were removed and bony cage

was exposed. A bone saw was used to cut across the sternum at the

level of the sternal angle and the sixth costo-sternal junction. Ribs

from 2nd to 5th are cut along the mid axillary line on each side. Now

the sternum and the rib portions were removed in one piece to

expose the thoracic cavity. The pleura were separated and

pericardium was exposed.

77

A longitudinal cut was made in the Pericardium at level of

diaphragm. An incision was made on every side at the base and at

the level of the diaphragm to seperate the pericardium. The heart lies

freely within the pericardium. Three fingers are placed beneath the

heart and are pushed upward into the oblique pericardial sinus. The

Great vessels such as aorta, pulmonary trunk, the superior vena cava

and inferior vena cava were cut. Then the heart is lifted so that the

right and left pulmonary vein can be seen and cut. Heart is then

removed and the coronary vasculature is dissected. Microdissection

was done to trace the main arteries. The outer diameter of right

conus artery was studied at the proximal part with the help of 0.01

mm sensitive digital vernier caliper. The aorta was longitudinally

opened at the level of the right posterior aortic sinus. The common

opening and separate ostium were displayed clearly by inserting GP

sticks. Manual goniometer is used to study angulations.

The coronary angiograms of patients, who had undergone this

procedure for various reasons, were utilized in this study.

78

5.2.2) CORONARY ANGIOGRAPHY:-

A coronary catheterization is the commonly used and

a minimally invasive procedure which is done to access the coronary

circulation of the heart using a catheter. It is performed for both

diagnostic and interventional (treatment) purposes.

Occlusion, stenosis, restenosis, thrombosis or aneurysmal

enlargement of the coronary artery lumens, heart chamber size, heart

muscle contraction performance, and some aspects of heart

valve function can be studied using coronary angiography.

Intermittent angina occurs when the flow of the oxygenated

blood reduces due to luminal narrowing of the artery. Heart attack

happens when advanced luminal occlusion occurs. The luminal

changes can be measured using coronary angiography.

Coronary catheterization was done under local anaesthesia

such as lidocaine and minimal sedation. The patient is usually awake

as they can report immediately of any discomfort. Medical monitors

are less reliable than the feel of the patient thereby facilitating rapid

correction in procedure.

79

Major vascular complications can occur in less than 1% of

patients undergoing catheterization. These include myocardial

infarction, stroke, serious ventricular arrhythmia and death.

i. Equipment:

Coronary catheterization is done in cath lab. The patient is

made to lie flat on the radiolucent table. There is x ray source and

imaging camera opposite to each other near the patient chest. It

moves freely using a motorized control. The images are taken in

multiple angles by the imaging camera as they rotate with the x ray

source. Advanced machines has two sets of x ray source and

imaging camera which allows two sets of image to be taken at a

given time.

Blood pressure is recorded during the whole procedure. The

imaging camera takes the x ray motion picture shadow grams of the

blood inside the coronary arteries. A small 2 mm (6 french) diameter

tube like device called catheter was inserted into the main arteries of

the body to reach coronary vasculature. The catheter is selected in

such a way that its diameter is always smaller than the diameter of

the artery in which it is inserted so that it does not block the blood

80

flow. Intra arterial blood pressure is measured always during the

procedure to make sure that the catheter does not block the arterial

blood flow.

The catheter is radio opaque so that it can be clearly seen at all

times during the procedure. The catheter allows the blood compatible

radio opaque dye to be selectively injected and mixed with the blood

flowing within the artery. 3 to 8 cc of the radio contrast agent is

injected into the artery for cardiac image which makes the blood flow

visible for 3 to 5 seconds within which it is captured by the imaging

camera. After this time the dye is washed away by the blood flow

rapidly. This imaging allows the visualization of blood flow within the

arteries or heart chambers depending on where it is injected.

The physician relies on the knowledge of the internal anatomy

to guide the catheter through the artery. Sometimes when doubt arise

a low dose of X ray and fluoroscopy was used to correct the path of

the catheter. These are not recorded by the imaging camera. When

catheter reaches the coronary arteries and ready for dye injection a

high dose of X ray termed as “cine” is activated to create better

picture quality typically at 30 frames per second. The contrast

injection and cine application are timed so as to minimize the total

81

amount of radio contrast dye injected and also to reduce the amount

of X ray used. To maximize safety the dosage of radio contrast agent

and X ray exposure time is always recorded.

ii. Pre-procedure precautions:

As drug allergy if any can lead to anaphylactic response, amid

the technique the patient is enqired and ruled out.

Fatty foods are stopped from two days before.

iii. Precautions During the procedure:

Patient is allowed to consume only water before procedure

Blood urea and creatinine levels were assessed beforehand.

An hour preceding the angiography the patient was adviced to

take β-blockers to decrease the heart rate.

ECG and pulse rate were checked constantly.

β-blockers are administered to maintain a heart rate of 55-60

beats/min during the procedure.

iv) Methods of Coronary catheterization:-

Coronary catheterization is done only by cardiologist in two ways

A. Radial artery catheterization

B. Femoral artery catheterization

82

A) Radial artery catheterization:-

Radial artery catheterization was done using 3 way top

manifold kits. The length of the guide is 280 cms and its diameter is

0.8mm or 0.32 inch. A 200 cm pressure monitor line is used. A gelco

20 gauge needle is used for artery puncture and insertion. A TIG

catheter of 100 cm length and 1.7 mm diameter is inserted into the

radial artery through the initial puncture using 20 gauge needle. The

catheter travels from radial artery to brachial artery and then through

axillary artery reaches the subclavian artery. From subclavian artery it

reaches arch of aorta and then through ascending aorta it reaches

the right anterior aortic sinus. Different catheters were used for left

and right coronary arteries.

B) Femoral artery catheterization:-

In femoral artery catheterization 18 gauge needle is used for

puncture. A catheter of 2 mm (6 French) diameter and 110 cm long is

used. When catheter is inserted into the femoral artery it reaches

common iliac artery through iliac artery. Then the common iliac artery

leads the catheter to the abdominal aorta and descending thoracic

aorta which leads to arch of aorta. From there the catheter reaches

the anterior aortic sinus through ascending aorta.

83

v) Dye:-

For right coronary artery the dye is injected in anterior aortic

sinus near the coronary ostial opening. The dye used was a non ionic

dye. It is a mixture of iodixanol and iohexol commonly called as

visipaque 320.

vi) Diameter Measurement in Coronary angiogram:-

The images taken by the imaging camera is recorded by a

computer. It is then analysed using quantitative coronary analysis

plus (QCAP) software for measuring diameter and branches of right

conus artery (Fig 8). The conus artery was best viewed in left anterior

oblique view with 35º angulation.

Figure 8: Diameter of right conus artery in coronary angiogram

84

5.3) SAMPLING METHOD USED:

Sampling method used in the study is PURPOSIVE

SAMPLING. The cadavers received from various south Indian states,

which were preserved in various collages of Tamilnadu and

Pondicherry was used in this study. 150 embalmed cadaveric hearts

from VMMC&H karaikal, Arupadaiveedu Medical College

Pudhucherry, Kribanandha Vaariyar Medical College Salem,

Annapoorna Medical College Salem were studied. 150 coronary

angiograms of patients from various south Indian states who came for

treatment to Meenakshi Mission Hospital Thanjavur and Madurai

were collected during the period of 2011 to 2016 and used in the

study.

5.3.1) CADAVERIC STUDY

INCLUSION CRITERIA:

Heart specimens in which conus artery is clearly seen.

EXCLUSION CRITERIA:

Pathologic heart

Putrefied heart

Hearts in which conus artery is not clearly seen.

85

5.3.2) ANGIOGRAPHIC STUDY:

INCLUSION CRITERIA:

Patient aged 35 to 70 years of both sexes.

EXCLUSION CRITERIA:-

Patient aged less than 35 and greater than 70years of age

Patients presented with

Atrial fibrillation (permanent or persistent)

Frequent cardiac extrasystoles

Hyperthyreosis (allergy to non-ionic contrast agents)

Implanted pacemaker.

TABLE: 1 HEART SAMPLES COLLECTION.

COLLEGE NAME TOTAL NO. OF

HEARTS SEEN

NO.

SELECTED REJECTED

VMMC&H KARAIKAL 71 60 11

KVMC&H SALEM 73 68 5

ARUPADAIVEEDU MEDICAL COLLEGE

AND HOSPITAL

18 14 4

ANNAPOORANI MEDICAL COLLEGE

AND HOSPITAL

11 8 3

86

5.4) STATISTICS USED: Statistical significance was determined with

help of Student unpaired t-test, Percentage calculation and Pearson’s

correlation coefficient.

87

6. RESULTS AND DISCUSSION

6.1) Number and Level of Ostia:

TABLE NO .2:- NUMBER OF OSTIA SEEN IN 150 HEARTS

Number of ostia Number of hearts Percentage

Single Ostia 121 80.67

Two Ostia 27 18

Three or more Ostia 2 1.33

Number and level of ostia can be visualized only in cadaveric

study. Out of 150 cadaveric heart single ostia is seen in 80.67% of

heart samples (n=121)(Fig 9). Two ostia seen in 18% of heart

samples (n=27) (Fig 10) and three or more ostia seen in 1.33% of

heart samples (n=2) (table no 2) (Fig 11).

At the point when single ostium is found in anterior aortic sinus it

offers ascend to right coronary supply route as it were. At the point

when two ostia are available, right coronary artery emerge from one

ostium and the other ostium offers ascend to right conus supply route

Or anomalous left coronary artery. Whenever at least three ostia

were seen vaso vasorum or peculiar left coronary supply route

emerge along with the right coronary artery and right conus artery.

88

Fig. 9: Single Ostium in right anterior aortic sinus

Fig10: Double Ostium in right anterior aortic sinus

89

Fig 11: Multiple Ostium In right anterior aortic sinus

GRAPH No: 1 NUMBER OF OSTIA IN RIGHT AORTIC SINUS

The bar diagram shows the number of ostia in anterior aortic sinus (X-Axis) against the number of hearts having single, double and three or more ostia (Y-Axis). The hearts having single ostium is greater in number than the hearts having double or triple ostia.

0

20

40

60

80

100

120

140

single ostium double ostia three or more ostia

NUMBER OF OSTIA

single ostium

double ostia

three or more ostia

90

GRAPH No: 2 PERCENTAGES OF OSTIA IN RIGHT AORTIC SINUS

The pie diagram shows the percentages of hearts having single, double and three or more ostia.

Out of 150 cadaveric hearts studied single ostium is seen in 121 of

heart samples (80.67%). Two ostia were seen in 27 of the heart

samples (18%) and three or more ostia were seen in 2 of the heart

samples (1.33%).

Similar study of ostia has been carried out previously by Murlimanju

(2006), Duran et al (2007), Gajbe et al (2010) Vijayakumar Shankar

Shindae (2012), Poornima B et al (2015), Hima Bindhu Nalluri (2016),

Manisha Randhir Dhobale (2015) and many others.

81%

18%

1%

PERCENTAGE OF NUMBER OF OSTIA

single ostium double ostia three or more ostia

91

The knowledge of two opening in 18% individuals may be useful in

performing coronary arteriography. Individuals having triple opening

may go in for cardiac problems. Out of three branches coming from

ascending aorta, the right coronary artery is thin and slender, other

two branches (vasa vasorum of pulmonary trunk and right conus

artery) are short. Hence all the three branches coming from ostia

were small. The above finding suggests that the irrigation for the right

side of the cardiac musculature may be poor. This knowledge of

number of opening present in anterior aortic sinus may be utilized,

while performing coronary arteriography and angiography.

In previous study on number of ostia a single right coronary ostium

was seen in 63 hearts (78.75%), two right coronary ostia were found

in 14 hearts (17.5%). Three right coronary ostia were found in 2

hearts (2.5%) and four were found in 1 heart (1.25%) (Hima Bindhu

Nalluri 2016). Our present study goes hand in hand with this study.

In a previous study, thirty eight formalin fixed adult human cadaveric

hearts were studied by dissection method. In one specimen (2.63%)

two aortic sinuses were seen. In two specimen (5.26%) solitary

coronary ostia was seen. In two specimens (5.26%) three coronary

ostia were seen (Poornima B et al 2015). In a study of 30 heart

92

specimens 29 out of 30 hearts had single ostium in both sinuses.

Merely 1 heart showed additional ostium in right aortic sinus and that

ostium offered beginning to right conus supply route (Quazi Waheed

Ulla et.al 2015). In a study to assess the number of ostia present in

right anterior aortic sinus, single ostium shared for RCA and TCA

was found in 2% of hearts. Two ostia shared, one for right coronary

course and one for TCA were seen in 26% of hearts. Two ostia, one

for right coronary supply route and the other giving rise to two TCA

were found in 0.67% hearts. Three ostia, one for right coronary artery

and two separate ostia for third coronary artery were seen in 3 (2%)

hearts. Four ostia, one for right coronary artery two for third coronary

artery and one for vasa vasorum of pulmonary trunk was seen in two

(1.33%) hearts. Our study differs from this study (Manisha Randhir

Dhobale 2015).

The presence of multiple ostium is suggestive of conus artery must

have been arising directly from the aorta, right coronary artery, SA

nodal artery, vasovasorum of pulmonary trunk and anomalous origin

of left coronary artery. Individuals with multiple ostia in right anterior

aortic sinus should be suggested for regular watch out for any related

93

symptoms of angina, myocardial infarction and left ventricular

dysfunction Gajbe et al (2010).

The study regarding development of coronary arteries

suggested that the coronary artery do not grow out of aorta, but they

grow into aorta from the peritruncal ring of coronary vasculature. This

view throws a new light on normal and abnormal development of

proximal coronary arteries (Boger et al.1989).

The coronary artery develops outside to inside i.e., the multiple

vessels arising from the peritruncal ring of capillaries. This process

involves apoptotic changes by the molecular mechanism involving,

vasculo endothelial growth factor (VEGF) and fibroblast growth factor

(FGF-I).These factors stimulate the vasculogenesis and angiogenesis

(David Bernake 2002).

In our study the multiple openings found in anterior aortic sinus

would have been due to the folding of the heart. as a result of folding

peritruncal vessels opens at the cono truncal circle either specifically

into the recently appeared aorta making multiple ostia or optionally

joins the neighbouring blood vessels encompassing the

atrioventricular hover bringing about theright conus supply route

94

emerging from right coronary artery(Ivan Stankovic 2004 ). The

information of ontogeny of the right conus conduit requires in depth

studies in the future.

Table No.3:- LEVEL OF OSTIA WITH REGARD TO SINU

TUBULAR JUNCTION SEEN IN 150 HEARTS

Level of ostia Number of hearts Percentage

Below STJ 143 95.33

At STJ 4 2.67

Above STJ 3 2

STJ- SINU TUBULAR JUNCTION

Fig 12: STJ- SINU TUBULAR JUNCTION

150 cadaveric hearts analysed in our study resulted with 143 of

hearts showing the ostia is below the STJ. In 4 hearts the ostia

95

opened at sinu tubular junction and in 3 hearts the ostia was

exhibited above STJ (table no: 3) (Fig 12).

6.2) LEVEL OF OSTIA

The Graph is plotted with level of Ostia along X-Axis with Y-Axis

showing the number of hearts having it. There is a greater incidence

of ostia to be seen seen below the STJ.

NUMBER OF HEARTS0

20

40

60

80

100

120

140

160

BelowSTJAt STJ

Above STJ

Graph 3 :LEVEL OF OSTIA

BelowSTJ

At STJ

Above STJ

96

The pie diagram shows the number of hearts having their ostia

above, below or at the sinu tubular junction in percentage.

Since the right conus artery did not generally emerge from the right

coronary conduit, the investigation of level of ostium increases

significance for angiographic contrast infusion. In the event that the

right conus conduit emerges specifically from the aorta it is named as

third coronary artery (Schlesinger MJ 1949). The level of ostium was

viewed in accordance to STJ.

In our study which used 150 cadaveric hearts 143 hearts (95.33%)

the ostia is seen underneath the STJ. In 4 hearts (2.67%) the ostia is

95%

3% 2%

Graph No 4: PERCENTAGES OF LEVEL OF OSTIA

Below STJ At STJ Above STJ

97

seen at the level of STJ and in 3 hearts (2%) the ostia is seen over

the STJ (Graph No 3&4).

Similar study has been previously reported by Sahini D 1989 ,

kalpana et al (2001), Jennecy Sales Cavalcanti(2003), Murli manju et

al (2006), Markou et al (2007), Pejovic(2008), Subhash et al (2010),

Daliber Kaur (2012), Prajapathi (2013), Quazi Waheed ulla(2015),

D’ Souza(2015) and many others.

In a study of normal patterns of coronary arteries with reference to

the predominance and variations, it is concluded that the ostia for

right coronary vessel in 90% of individuals was underneath the STJ.

When it comes to left coronary arteries it was found to be 80%

(Kalpana2001). In a study done to find the diversities in level of

ostium 91 heart specimens’ ostium was found underneath the sinu

tubular junction (91%). In 9 specimens the ostium was found above

the STJ (9%). This above study goes hand in hand with our present

study (Prajapathi, Suthar K 2013). Sahini D 1989 found the level of

ostium to be above the supra valvular ridge was 3.4% in males and

1.7% in females. Daliber kaur et al 2012 in their study found 83% of

the heart examples had Ostia situated beneath the STJ, 14% at STJ

98

and 3% atop STJ (Daliber kaur et al 2012). The result goes hand in

hand with our study.

Alternative study by Murli manju et al 2006 claimed the ostium to be

present at the STJ in 16% and was atop the STJ in 2% of the cases

and in 82% of cases the ostium was beneath the STJ (Murli manju et

al 2006). Our study is similar with Murli manju et al 2009 as far as

ostia seen over the STJ (2%). The difference found in below and at

the levels with reference to Murli manju et al. 2006, could have been

due to geographical differences as described by Gouda Hareesh et

al (2009).

Jennecy Sales CavalCanti et al.2003 found 60% of cases the

ostium were below the sinu tubular junction and around 28% of cases

above the sinu tubular junction and only 12% at the level of sinu

tubular junction which differs with the present study. In a study on the

variation of origin of coronary artery to find the level of ostia to be

seen below inter commissural line in 64.5%, 11.4% above it and

18.7% at its level which differs from our study (D’Souza et al 2015).

Work done on the level of ostia with respect to sinu tubular junction in

99

right coronary sinus of valsalva was at the level in 71% of cases,

above in 19% of cases, below in 10% of cases (Pejovic 2008).

The right coronary ostium was situated at the level of sinu tubular

junction in 8 cases (27%), above sinu tubular junction in 3 cases

(10%), below sinu tubular junction in 19 cases (63%) (Quazi Waheed

Ulla et al. 2015), which differs from our study which can be due to

geographical variation as the study was done in Pakistani population.

When the coronary artery ostia lies within the Aortic sinus permits

maximal coronary diastolic filling. In contrary when the ostium lies

above the sinu tubular junction decreases the coronary perfusion

(Pinar Kosar 2009). In those cases low clamping of aorta poses a

high risk

Correlation between anomalous high origin of the right coronary

artery (RCA) and myocardial ischemia was studied. High take-off of

the RCA ostium or inter arterial course should be considered a risk

factor for myocardial ischemia under certain conditions. It is

suggested that surgical repair of the coronary anomaly may be

considered as the best way to prevent a future fatal cardiac

myocardial ischemia (Markou et al 2007). They also reported that

100

the oblique origin, intramural (within the wall of the aorta) course, or

positioning between the great arteries, puts the coronary arteries at

risk for compression and limits the reservoir capacity of the epicardial

coronary system which in turn may cause coronary ischemia.

6.2) Pattern of Origin:

TABLE NO .4 PATTERN OF ORIGIN

Methods From

coronary

percent

age

Common

origin

percent

age

aortic percent

age

cadaveric 108 72 12 8 30 20

Coronary

angiogram

106 70.67 15 10 29 19.33

In our cadaveric study of 150 hearts in 72% (n=108) of the hearts, the

right conus artery emerged from the right coronary vessel (Fig 13). In

8% (n=12) hearts indicated common source for right conus supply

and right coronary vessel (Fig 14). In this study 20% (n=30) hearts

right conus supply emerged from aorta (Fig 15).

101

In our investigation of 150 coronary angiogram, in 70.67% (n=106)

hearts the right conus vessel emerged from right coronary artery. In

10% (n=15) hearts right conus artery and right coronary artery found

to emerge fom the same ostium. So staying 19.33% (n= 29) hearts

may have had their conus artery arising from their aorta (Table 4).

FIG 13: R.CON. A FROM RCA

102

Fig 14: COMMON OSTIAL ORIGIN FROM AORTA (R. CON.A & RCA)

Fig 15: SEPARATE AORTIC ORIGIN OF R.CON. A.

103

GRAPH NO 5: COMPARISON OF THREE PATTERNS OF ORIGIN

IN CADAVERIC AND IN ANGIOGRAM STUDY

The graph no 5 compares the various pattern of origin of conus

artery as seen in cadaveric heart samples and angiograms. The

number of hearts showing a particular pattern of origin is nearly

similar in both cadaveric and in coronary angiograms.

0

20

40

60

80

100

120

From Coronaryartery common origin

aortic origin

PATTERN OF ORIGIN

CADAVERIC

ANGIOGRAM

104

The graph no 6 compares the percentages of hearts (X-axis) with the

pattern of origin of right conus artery (Y-Axis) both in angiogram and

cadaver

Similar study has been previously reported by Schlesinger (1949),

David C Levin (1981), Edward (1981), Ivan Stankovic (2004),

Valentina Nikolic (2004), Susan Strandring (2006), Oluba et al

(2007), Almira Lujinovic (2008), Luis Ernesto Ballesteros (2011),

Rebecca (2012), Agneszka Mlynarska (2014), E I Syed (2015),

Yadukul (2015) and many others.

0 20 40 60 80

From Coronary Artery

Common origin

Aortic origin

GRAPH NO 6: PERCENTAGE COMPARISON OF PATTERN OF ORIGIN IN ANGIOGRAM AND CADAVER

Percentage in Angiogram

Percentage in cadaver

105

The relative incidence of the three patterns varied with age. Aortic

origin was seen in 14 to 24 per cent of specimens, common origin

was seen in 3 to 26 percent and origin from right coronary artery was

found to be 24 to 78 percent (Edwards (1981). In another study conus

branch arises as the direct branch of aorta ie aortic origin was around

23% to 51% (David M Fiss MD 2007). In an investigation of heart

samples conus artery emerging from right coronary corridor was

found in 71.43% and in 28.57% sample conus supply route emerged

straightforwardly from aortic sinus (Charanjeet Kaur 2014). In an

angiogram study the right conus course begins from the right

coronary conduit in 77 (69.3%) cases. The right conus artery

originated from the same ostium in 15 individuals (13.5%) and from

separate ostium (aortic origin) was seen in 18 cases (16.2%) (Ritu

Mehta 2013). In other study the third coronary artery i.e. the aortic

origin of conus artery was present in male was 109 out of 293

(37.2%) hearts and in females it is found to be 75 out of 257 (29.18%)

hearts with an average of 33.2% (Yadukul 2015). In a study of

northwest Indians aortic origin of the conus artery in averaged to

33.1% in both male and female hearts (Sahini D 1989). The results

obtained in these studies were similar to our present study.

106

In other study the conus artery emerging from the right coronary

coduit in 164 (74.2%) heart specimens and emerging from aorta in 57

hearts (25.8%). He found third coronary artery to be present in

50(27.6%) males and seven (17.5%) female without significant

difference (p=0.22) (Luis Ernesto Ballesteros 2011). The present

study goes hand in hand with his study but the present study did not

study the different sexes.

In a study done on 23 cadaveric heart samples to with an aim to find

the starting point of conus artery. conus artery found as a direct

branch from aorta in eight hearts (Ivan Stankovic et al 2004). In

other study the right conus artery was found to be starting from aorta

in 36% (Susan standring 2006). Olabu et al 2007 found the aortic

origin of right conus supply route was seen in 35.1% heart samples.

In contrasts the arabic residents had their conus artery branching

from aorta in only about 3.3% (E I Syed 2015). In a study on

angiograms it is found that 53% of patients the conus artery

originated from the right coronary artery. The second most frequent

variant is the conus artery arising directly from aorta was seen in 30

(37.9%) patients. The rarest variant of right conus artery having

common trunk for both vessels was seen in 14% of heart (Agneszka

107

Mlynarska, Rafal Mlynarski 2014). In a study on heart specimens and

found conus artery arising from right coronary artery was seen in

64.1% of population and from common ostium was seen in 22.3%

and from aorta was seen in 11.6% (Cademetric 2008). In a study on

cadaveric heart samples it is found that, “the conus artery arising

from right coronary artery in 92% of cases. In 8% of cases the conus

artery had independent origin” (Jyothi Kulkarni 2013). In another

study on heart samples, “71 heart samples had conus artery arising

from right coronary artery (28.06%). 92 conus artery arose from the

aorta (36.6%) and 90 conus artery originated from aorta and right

coronary artery having a common origin” (Tekbas2013).

In a study on monkey hearts it is reported 48 out of 58 hearts

(82.3%) had aortic origin (Valentina Nikolic, et al 2004). In a study

conducted in pigs found that the conus artery arose from right

coronary artery in 100 specimens 63.3% and from aorta in 8

specimens 5.1% (Gomez et al 2013). Both these studies differ from

our study as the study was conducted in different species.

In a study conducted on human and rabbit hearts high prevalence of

third coronary artery is seen in all 11 rabbit hearts and 6 out of 7

human hearts(Rebecca A.B Burton, et al (2012) in contrast to our

108

study which has only 20 percentages which may be due to

geographical variations.

Almira lujinovic et al 2008 contemplated 25 cadaveric hearts.

Dissection revealed conal artery in 8 heart specimens. In this 1

heart(4%) had four coronary conduits .In 2 heart(8%) the third

coronary artery joined with anterior interventricular branch to

construct vieussens arterial ring.

In a different study conal artery emerged as branch from right

coronary vasculature which was given a name type A was seen in

193 hearts (32.1%).Also some exhibited type B i.e. conal artery

shared a common ostium with right coronary vasculature in 96 hearts.

242 hearts were classified as type C in which the conal artery took

inception from the right aortic sinus as an autonomous artery. They

concluded the morphology and topography of conal vasculature

changed essentially with the level of coronary lumen attrition and

level of hypertrophied ventricular wall (Marios loukas et al 2014). This

study differed from the present study.

In a study on foetus the aortic origin of right conus artery was seen in

one specimen (2%) of 25 week gestational age in males

109

(Kandaregulu jothirmayi et al 2013). This study differs from our study

which may because of postnatal development of third coronary artery

(Boger et al.1989).

Table No.5:- PREVALANCE OF AORTIC ORIGIN OF

RIGHTCONUS ARTERY (TCA) IN VARIOUS POPULATIONS.

Author Year Population Incidence

Kurjia et al 1986 Iraqui 8%

Miyazaki & Kato 1988 Japanese 36.8%

Ludinghausen & Ohmachi 2001 Germans 7.1%

Ivan & Milica 2004 Bulgarians 34.8%

Susan Standring 2006 United kingdom 34%

Almira Lujinovic 2008 Bosnian 32%

Luis Ernestro 2011 Columbian 25.8%

E I Syed 2015 Arab 3.3%

Present study 2016 Indians 20%

TCA- THIRD CORONARY ARTERY

110

6.3) ANGULATIONS

TABLE NO: 6 - ANGULATION OF RIGHT CONUS ARTERY WITH

RESPECT TO ITS ORIGIN

ORIGIN Number of

hearts percentage Mean angulations

R con.A from RCA 108 72 38.4º

Rcon.Afrom Aorta 30 20 125.6º

Common origin 12 8 37.8º

The angulations of right conus artery at its origin is measured and it

ranged from minimum 15° to maximum 150°.

Thirty (20%) hearts which had aortic origin the angle between

right conus artery and ascending aorta is measured (Fig 16). The

angulations ranged from minimum of 90° and max of 150°. The mean

angulations were 125.6º (Table 6).

108 (72%) hearts in which right conus artery arising from right

coronary artery, the angle between right conus artery and right

coronary artery was measured (Fig No 17). The angulations ranged

111

from15° to 90° and the mean angulations was found to be 38.4º

(Table 6).

All the 12 (8%) hearts which had common origin the angle

between right conus artery and right coronary artery showed acute

angulations. Angle varied with minimum of 25° to maximum of

50°with mean angulations of 37.8º (Table 6).

FIG. 16: ANGULATION OF R.CON.A WITH RESPECT TO AORTA

112

Fig.17: ANGULATION OF R.CON.A WITH RESPECT TO RCA

The graph No 7 shows the heart samples (X-Axis) plotted against the angle between right conus artery and right coronary artery (Y-Axis).

0

10

20

30

40

50

60

70

80

90

100

1 5 9

13

17

21

25

29

33

37

41

45

49

53

57

61

65

69

73

77

81

85

89

93

97

10

1

10

5

Graph No 7: Angles between Right conus artery and RCA

Angles between Right conus artery and RCA

113

The graph no 8 shows the heart samples (X-Axis) plotted against the angle between right conus artery and aorta (Y-Axis).

The graph no 9 shows the heart samples (X-Axis) plotted against the

angle between right conus artery and right coronary artery having a

common origin (Y-Axis).

0

20

40

60

80

100

120

140

160

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30

Graph No 8: Angles between right conus artery and aorta

Angles Between Right conus artery and Aorta

0

10

20

30

40

50

60

1 2 3 4 5 6 7 8 9 10 11 12

Graph No 9 Common Origin Angulations

Common Origin Angulations

114

GRAPH 10: MEAN ANGULATIONS OF RIGHT CONUS ARTERY

WITH RESPECT TO ITS ORIGIN

The graph no 10 shows the angles between right conus artery and

right coronary artery, common origin and angle between right conus

artery and aorta or (X-Axis) plotted against their mean angles (Y-

Axis).

0

20

40

60

80

100

120

140

Right conus artery and RCA Common Origin Right conus artery and Aorta

Graph No 10: Mean Angulations Of Right Conus Artery

Right conus artery and RCA Common Origin Right conus artery and Aorta

115

Table no 7: Statistical analysis and result for Angulations of

Right Conus Artery with respect to Aortic origin and origin from

Right Coronary Artery

Statistical variants With respect to

aorta

With respect to

right coronary

artery

P value (by

applying

unpaired

t test)

Mean 125.67º 38.4º <0.0001

(Highly

significant)

Standard deviation

(SD)

17.14 14.07

Standard error of

mean (SEM)

±3.18 ±1.28

Number 30 120

The angulations measurements were studied by student unpaired

t-test to show the significance (Table no- 7). The P value obtained for

angulations of right conus artery with respect to its origin (aortic and

116

right coronary artery origin) was less than 0.0001 which was

extremely statistically significant. This shows that there is a significant

difference in the angulations of right conus artery depending on

whether it is arising from aorta (obtuse) or right coronary artery

(acute).

6.4) Comparison between angulations of right conus artery when

arising from right coronary artery and having a common origin.

Table no 8: Statistical analysis and result for comparison of

Angulations of Right conus Artery when arising from Right

coronary artery and having a Common origin.

Statistical variants Common

origin

With respect to

right coronary

artery

P value (by applying

unpaired t test)

Mean 37.83º 38.4º 0.8838

(Insignificant) Standard deviation

(SD)

7.41 14.65

Standard error of

mean (SEM)

±2.14 ±1.41

Number 12 108

117

The angulations measurement were studied by student unpaired

t-test to show the significance (Table no- 8).The P value obtained for

angulations of right conus artery when having a common origin and

when arising as a branch from right coronary artery was found to be

0.8838 which was statistically insignificant . From the p value it is

inferred that there is hardly any difference in the angulations of right

conus artery depending on whether it is branching from RCA or

sharing a common ostium with RCA (both acute).

Similar studies were done by Valentina Nicolic et al 2004, Ivan

Stankovic 2004 on right conus artery angulations.

In a study done in monkey hearts the angulations of third coronary

artery with aorta was found to have a mean angle of 90º (Valentina

Nicolic et al 2004) which differs from our study. This difference may

be due to difference in the species.

In an investigation of morphometric qualities of conal coronary

vessels the angle between the TCA and aorta measured a mean of

73.4°with a standard deviation of 35.2° and the angle between RCA

and Right Conus artery caliberated a mean angle of 82.3° with a

standard deviation of39.8° (Ivan Stankovic 2004)

118

Kohler1981, Reig Vilallonga 2003, Jose R Lopez Minguez et al 2006,

Pejovic 2008, examined the angle in which the RCA branched. Not

very many documented literatures are accessible with respect to the

angulations of right conus artery. In another study the mean

angulation between starting part of right coronary course and

longitudinal axis of aorta had a range of 15º-150º. S shaped right

coronary artery was formed in 20% of individuals and their

angulations had a range of 40º-90º (Pejkovic 2008). In a study on

cadaveric heart samples the angulations between the coronary

arteries and aorta with right coronary artery was 102º(Kohler et al

1981).The coronary arteries branch off from the aorta wall at a variety

of angle 90º perpendicular origin, <90º (Tangential origin) and

practical 0º (intussusception) (Reig Vilallonga et al 2003).

119

6.5) Diameter of right conus artery:

6.5.1) Outer diameter of right conus artery in 150 cadaveric hearts:

Table 9: Outer diameter of right conus artery with respect to its

origin in cadaveric hearts

Pattern of origin Outer diameter

mean value(mm)

Range

From right coronary

artery

1.64 ± 0.40 1mm to 2.8mm

From common ostium 1.74 ± 0.43 1.2mm to 2.4mm

From aortic 1.70 ± 0.36 1mmto 2.6mm

In cadaveric study outer diameter of right conus artery ranged with

minimum of 1mm to maximum of 2.8mm (Table no 9). The outer

diameter of right conus artery is interpreted with its pattern of origin.

At the point when the right conus corridor emerged from right

coronary course its width across ran from 1mm to 2.8 mm with a

120

mean of 1.64mm. When a single ostium shared among the RCA and

right conus arterythen the outer width of right conus artery stretched

out in a range of 1.2mm to 2.4mm with a mean of 1.74mm. Exactly

when third conus supply course arise as a division out of aorta then

the width crosswise ranged from 1mm to 2.6mm with a mean of

1.7mm.

The graph no 11 compares the cadaveric and angiogram study

plotting number of hearts against the external diameter of right conus

artery having common origin in millimeter.

0

0.5

1

1.5

2

2.5

3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Graph No 11.comparison of external diameter of right conus artery having common origin in cadaver and in

angiograms

cadaveric angiogram

121

GRAPH No 12: COMPARISON OF EXTERNAL DIAMETER OF

RIGHT CONUS ARTERY ARISING FROM RIGHT CORONARY

ARTREY BOTH IN CADAVER AND IN ANGIOGRAMS.

The graph12 compares the cadaveric and angiogram study plotting

number of hearts against the external diameter of right conus artery

arising from right coronary artery in millimeter.

0

0.5

1

1.5

2

2.5

3

1 5 9

13

17

21

25

29

33

37

41

45

49

53

57

61

65

69

73

77

81

85

89

93

97

10

1

10

5

Graph No 12.Comparison of external Diameter of right Conus artery from right Coronary artery in Cadaver and in

Angiograms

Cadaver Angiogram

122

The graph no 13 shows the number of cadaveric hearts plotted against the external diameter of right conus artery emerging from aorta in the scale of millimeter.

The graph displays the external diameter of right conus artery when arising from right coronary artery, common origin and aortic origin (X-Axis) plotted against their mean diameter (Y-Axis).

0

0.5

1

1.5

2

2.5

3

1 2 3 4 5 6 7 8 9 101112131415161718192021222324252627282930

Graph No 13: Outer Diameter Of Right Conus Artery From Aortic Origin In Cadaver

Cadaver

0

0.5

1

1.5

2

From Right CoronaryArtery

Common Origin Aortic Origin

Graph No 14: Comparison Of Mean Diameter of Right Conus Artery in Cadaver And Angiograms

Cadaver

Angiogram

123

6.5.2) Outer diameter of right conus artery in 150 coronary

angiograms:

Table 10: Outer diameter of right conus artery with respect to its

origin in coronary angiograms

Pattern of origin Outer diameter mean value

value(mm)

Range

From right coronary

artery

1.85 ± 0.21 1.17mm to

2.72mm

From common origin 1.84 ± 0.25 1.39mm to

2.48mm

In angiographic study outer diameter of right conus artery were

measured in 121 hearts which ranged with minimum of 1.17 mm to

maximum of 2.72 mm with a mean diameter of 1.85 mm (Table 10).

The remaining 29 hearts which could not be traced had aortic origin.

The conus artery when arising from right coronary artery the diameter

ranged from 1.7mm to 2.72mm with a mean of 1.85mm

124

When conus artery arose from common ostium along with right

coronary artery ie having a common origin the diameter of right conus

artery ranged from 1.39mm to 2.48mm with an average or 1.84 mm

(Table 10).

Table 11: Statistical analysis of comparison for outer diameter of

right conus artery arising from right coronary artery in cadaver

and in coronary angiograms:

Statistical variants Cadaveric Angiogram

P value (by

applying

unpaired t

test)

Mean 1.64 1.85 <0.0001

(Highly

significant)

Standard deviation

(SD)

0.40 0.21

Standard error of

mean (SEM)

±0.04 ±0.02

Number 108 106

125

In present study Students unpaired t test is used to compare outer

diameter of right conus artery arising from right coronary artery in

cadaver and in angiograms. The resulted p value is less than 0.0001

which is considered to be extremely statistically significant (Table 11).

This shows that there is a difference in the diameter of right conus

artery between cadaveric hearts and angiograms.

Similar studies on conus artery was conducted by Valentina

Nicolic, Rebecca A B Burton et al, Gupta et al and the results are

nearly similar to the present study.

Many other studies on right coronary artery were done with less

importance to right conus artery like the studies conducted by Grover

m hutchins et al1976, Kohler et al 1981, Sahini D 1989, Cheemlapati

Saikrishna 2006, Fazliogullari Z Karabulut et al 2010, A Avirmed et al

2012, Gomez 2013, Imad Ghanem Shukri et al 2014, and Nagaraj

malla Shetty et 2014.

In a study done on 55 monkeys it was reported that the external

diameter of third coronary artery at its origin was 0.3mm (Valentina

Nicolic et al 2004) which differs with our study which may be due to

species variation.

126

A study done on rabbit and human hearts finished up by resulting

mean width of third coronary course (right conus artery) was

observed to be 0.27 mm and 1.26 mm in rabbit and human

correspondingly which demonstrated the measurement of right conus

artery was significantly lesser than the right coronary artery, both in

rabbit and human (Rebecca A B Burton et al 2012).This study goes in

hand with our study.

In the study conducted using selective catheterization and

arteriography found the outer diameter of the conus artery was small

with average of 0.5-2 mm. The conus artery arose as a separate

vessel from right coronary sinus, nearer to the right coronary artery

(Gupta et al 1987). The present study showed similar results to this

study.

Kohler et al 1981 found the ostial diameter with a mean on right

coronary ostia is 3.83mm. Nagaraj malla Shetty 2014 reported the

external diameter of right coronary artery is 4.1mm and outer

diameter of left coronary artery is 4.3mm.

Fazliogullari Z Karabulut et al 2010 in their study established the

external distance across of right coronary conduit was 3.32 ± 0.79

127

mm. The mean width across of right coronary supply route in pig's

heart was found to be 3.85mm (Gomez et al 2013).

Sahini D 1989 concentrated on the mean width of right coronary

supply route at its begining and observed it to be 3.2 ± 0.5 mm in

males and 3.2 ± 0.6mm in females. Another study found the diameter

of right coronary was 4 mm, which arises as the direct branch from

the aortic sinus. It also stated the diameter of left coronary artery and

it had a mean of 3mm at the proximal part (Sukhendu Dutta 2014).

Imad Ghanem Shukri et al 2014 in their study found the width of

coronary vasculature were bigger in males than females. In guys the

mean width of proximal RCA was 3.26 mm while females showed an

average of 3.02 mm.

Avirmed et al 2012 contemplated the right coronary course utilizing

dark ink cast and silver impregnation specimens to discover the width

of the collateral branches of the right coronary supply route extended

from 113.3±23.1 µm to 736 ± 92.5 µm.

Grover m hutchins et al 1976 in his study concluded that there was

no relationship seen between coronary artery branch vessel diameter

and branch angle.

128

Cheemlapati Saikrishna et al 2006 in his research found the mean

external width of right coronary artery having a mean of 2.75mm with

a standard deviation of 0.65mm in males and in females had a mean

of 2.55mm with a standard deviation of 0.5mm. The calculated p

value was found to be 0.11. the mid of right coronary artery 2.47±

0.66mm in males and 2.31 ± 0.13 mm in females and p value

obtained was 0.28.he also found that male had large coronary artery

than female artery. This difference is however was not statistically

significant in right coronary artery.

6.6. Branches of right conus artery:

Table no 12: Branches of right conus artery in cadaver and in

coronary angiograms.

Methods Long branch and short

branch Only short branch

Cadaveric study 27 123

Coronary

angiogram 20 130

129

In the present study out of 150 hearts only 27 (18%) hearts had

long branches and 123 (82%) hearts had only short branches (Fig 18,

19 & 20). In the angiographic study 20 hearts (13.33%) showed long

branches (Table 12).

PICTURE SHOWING RIGHT CONUS ARTERY HAVING THREE

SHORT BRANCHES.

FIG 18: R. CON.A. WITH 3 SHORT BRANCHES

130

FIG.19: R.CON.A. SHORT & LONG TERMINAL BRANCHES

FIG 20: R.CON.A. WITH ONLY ONE LONG BRANCH.

131

The Graph no 15 compares the number of hearts (X Axis) with long and short branches in coronary angiogram and cadaveric study (Y Axis).

The graph no 16 compares the hearts with long branches in cadaveric and angiographic study (X axis) with the number of hearts (Y axis)

0 20 40 60 80 100 120 140

Cadaveric study

Coronary Angiogram

Graph 15 :Long And Short Branches of Right Conus Artery

Only Short branch Long Branch

0

5

10

15

20

25

30

Long Branch

Graph No 16: Comparison of long branches of conus artery seen in cadaveric and angiogram

study

Cadaveric study

Angiogram

132

The graph no 17 compares the hearts with only short branches in cadaveric and angiographic study (X axis) with the number of hearts (Y axis)

The graph no 18 compares the percentage of long and short branches in both cadaveric and in angiographic study.

0

10

20

30

40

50

60

70

80

90

Long Branch

Short branch

Graph No 18: percentage Of Long and Short Branches in cadaver and Angiograms

Cadaveric study

Angigrphic study

118

120

122

124

126

128

130

132

Only Short Branches

Graph No 17: Comparison of Only Short Branches In Cadaveric and Angiographic

study

Cadaveric Study

Angiographic Study

133

Similar study has been done by Antonello Musiani et al. (1995),

Wynn et al (2008), Luis Ernesto Ballesteros (2011), Gomez et al

2013, Manisha randhir dhobale et al 2015.

The branches of conus artery was studied in pigs by Gomez et al

2013. Gomez et al found conus artery only in 63% of hearts. Conus

artery was found to be extending to the cone in 41% of hearts. In

19% of hearts conus artery extended to the right ventricle till upper

third, mid third was found in 37% of hearts and lower third was 3%.

In Colombian population the right conus artery that irrigate the conus

arteriosus, anterior wall also supplies the in 87% had short branch

supplying superior and middle ventricular surface while 13% had

long branch reaching the inferior ventricular segment Luis Ernesto

Ballesteros et al(2011). According to the study conducted by

Takumi Sumimoto et al (1992) suggested when reduced coronary

blood flow due to hypertrophied myocardium occurs, the long

branches from the right conus artery running parallel to left anterior

descending branch (LAD) upto the apex of the heart may

compensate for the blood supply. In his study those long branches

were seen in 20% of the heart.

134

The present study focuses on long and short branches seen in

cadaver and coronary angiogram. A branch of conus artery running

till the cone of the heart is termed short branch and the branch which

runs along the anterior ventricular wall and reaching the inferior

border or nearing apex is termed as long branches. In the formalin

fixed hearts micro dissection was done to trace the branches of right

conus artery till the end of the artery. 27 of the hearts specimen had

atleast one long branches nearing the inferior border of the heart. All

other 123 heart specimens showed to have only short branches that

were found to run towards the cone of the heart. As 82% of the heart

specimens had only short branches it is evident that short branches

are more frequently found than the long branches. These 18% of the

heart specimens which had a long branch is a boon.

The angiogram study of 150 hearts showed predominant presence of

only short branches similar to the cadaveric study. 130 angiograms

showed only the presence of short branches and the remaining 20

angiograms had at least one Long Branch.

Usually ECG taken during acute myocardial infarction shows an

elevation of ST segment over lead V1. If this elevation is absent in an

ECG which was taken during myocardial infarction then it may

135

suggest presence of other artery mainly conal branch supplying

interventricular septum restoring blood flow. So the presence of long

conal artery was considered as a boon to the patients (Tuvia Ben Gal

et al1997).

The conus branch of the right coronary artery usually supplies the

outflow tract of right ventricle. Occlusion of this conus artery occurs

mostly due to iatrogenic causes during diagnostic procedures and

heart surgeries. When conus artery is occluded the ECG shows

Brugada syndrome like changes i.e. elevation of ST segment through

lead V1 to V3. Brugada syndrome is known to cause lethal ventricular

tachycardia. So whenever Brugada syndrome like changes seen in

ECG the conus artery occlusion should also is considered. In a case

report which showed ECG changes of ST segment elevation was

successfully treated only by restoring the conus artery blood flow by a

guide wire (Masanari Umemura et al 2012).

For a case of myocardial localized necrosis which occured because

of impediment of LAD, a long branch of conal course joined with the

LAD forming a life saving necklace to reestablish flow of the LAD

(Faith Cam).

136

The number of long branches and short branches are studied with

regard to the diameter of right conus artery. The right conus artery

having at least 1 Long Branch had a mean diameter of 1.87mm. If

Long Branch is absent and only short branches are seen then the

mean diameter of right conus artery was 1.83mm.

Table no 13: Statistics comparing the diameter of right conus

artery when a long branch is present or absent.

Mean diameter of right conus artery (mm) Pearson’s correlation

coefficient long branch present Only short branch

1.87 1.83 0.1716

Pearson’s correlation coefficient was 0.1716 which is positive

and it shows that the diameter of right conus artery is more when

having Long Branch than having a short branch.

From the investigated literature works of right conus artery there are

no reports correlating the branch length with the measurement of

right conus supply route. The present study correlates the width of

the conus supply to its length. The length of the conus artery falls

under 2 category i.e. long or short branch. The result showed that the

conus artery running near to the apex is greater in diameter than the

137

conus artery which ends near the cone of the pulmonary trunk. The

Long Branch with larger diameter supplies large area of anterior wall

of ventricle than the short branch having a smaller diameter.

138

7. CONCLUSION

1. Number and level of ostia: The presence of single, double and

triple ostia at different levels (at, below, above) with respect to sinu-

tubular junction were studied and its presence has been interpreted

embryologically.

2. Pattern of origin: The study demonstrated that right conus artery

emerging from RCA is more prevalent than right conus artery having

its origin from aorta or sharing a common ostium.

3. The study revealed that the angulations of right conus artery varies

relying upon whether it is emerging from aorta or RCA.

4. The study showed that the angulations of right conus artery is

about identical in both when emerging from RCA or sharing a

common ostium.

5. The diameter of right conus artery in the cadaveric study differs

with the diameter found in angiographic study.

6. The diameter of right conus artery is more when having a long

branch.

139

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168

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LIST OF PUBLICATIONS

1. The Anatomy of Right conus artery and it clinical significance.

Recent Research in science and technology 2011, 3 (10):30-39. (First

author).

2. Arteria coni arteriosi-pattern of origin with clinical and

embryological interpretation in south Indian population. Scrutiny

international research journal of health and medical

science.2014,1(1):47-54.(First author).

3. The Angulations Of Right Conus Artery And Its Anatomical

Importance. Journal of evidence based medicine and health care

2016,3(38):1906-1909.(First author)

4. Evaluating the effectiveness of ‘Three dimensional videos on the

comprehension of anatomy’ among new students of medicine (first

year mbbs students). Journal of evidence based medicine and health

care 2016, 3(33):1581. (Second author)

5. A study on morphometry of articular cartilage of talocrural joint.

Journal of evidence based medicine and health care 2016,

3(33):1594. (Second author)

171

6. A study of variation in termination of short saphenous vein. Journal

of evidence based medicine and health care 2016, 3(40):2010. (Third

author).