Wound HealingSuture & Needles

John P. Hunt

LSU New Orleans

Department of Surgery

Objectives• Understand basic science of

wound healing

• Relate this to clinical wound care

• Learn different types of suture & there applications

• Understand the different types of needles available and there uses

The cells that are central to wound healing are:

A) Fibroblasts

B) Macrophages

C) Polymorphic Neutrophils

D) T-cells

E) B-cells

American Board of Surgery In-training Exam - 2012

Ans – B

PMN’s arrive at the site of injury in 24-48 hours, but are gone with another 24 to 48 hours. There primary function involves phagocytosis and release of superoxides. Macrophages peak in the wound at approximately three days post-injury. They have numerous tasks which include phagocytosis, oxidative species production, wound debridement, elaboration of growth factors to stimulate fibroblast production of extracellular matrix materials and production of enzymes to destroy injured cellular matrix components (collagenase and elastase), and elaboration of growth factors to stimulate angiogenesis. Fibroblasts occur in the lag phase of wound healing and typically arrive 3-5 days post-injury and are responsible for collagen formation. T-cells peak at the 5th day and do receive antigen from macrophages. B-cells have little to do with wound healing and may even exhibit an inhibitory effect.

Phases of Wound Healing

Phases of Wound Healing

Phases of Wound Healing

Phases of Wound Healing

Phases of Wound Healing

The most common collagen found in skin and bone is:

A) Type I

B) Type II

C) Type III

D) Type IV

E) Type VI

Ans – A

The most common collagen found in adults is type I comprising 80% of all collagen found in skin and bone. The majority of the remaining 20% is type III. There are higher concentrations of type III collagen in children and early wound healing. Type II collagen is found predominantly in articular surfaces. Type IV collagen is found in basal lamina.

Phases of Wound Healing

• Wound strength is directly proportional to Type I collagen content

• Maximum strength is 80% of original and does not occur for 1-2 years

Layers of Bowel• Mucosa-

epithelial cells lamina propria muscularis mucosa

• Submucosa- Collagen• Muscularis propria- smooth

muscle • Serosa- mesothelium

connective tissue

Intestinal Anastomoses

• Strength-Submucosa • Collagenase Versus

Collagen Deposition• Weakest at 3-7 days

Wound Healing Times

Days

Wound Healing Impediments• Tension

• Blood supply

• Infection

• Hypovolemia/Shock

• Immunodeficiency

• Blood Transfusion

• Malnutrition

• Medication

Suture & Needles

Identifying suture/needles

Suture TypesAbsorbable versus Non-absorbable

Monofilament versus Braided

Synthetic versus Natural

Suture Strength

#5 = 5

#4 = 4

#3 = 3

#2 = 2

#1 = 1

0 = 0

2-0 = 00

3-0 = 000

4-0 = 0000

5-0 = 00000

6-0 = 000000

Etc.

Suture Strength

6-0 5-0 4-0 3-0 2-0 0 #1 #2

Suture Strength

Suture Strength

• Vicryl– 75% of strength at

2 weeks– 50% of strength at

3 weeks

Suture Strength

Anatomy of a Needle

The PointTapered needles

Cutting needles

Blunt needles

Combination

Needle Types

Reading the Packaging

Non-Absorbable SutureNatural Synthetic

Monofilament Braided Monofilament Braided

Steel SilkNylon

Prolene

Ethibond

Mersilene

Sternal closure

Ortho

Abdomen

UbiquitousNot skin/SubQ

VascularSkin

Adbomen

HerniaAbdomen

Absorbable SutureNatural Synthetic

Monofilament Braided Monofilament Braided

Chromic

Gut X PDS

Monocryl

Vicryl

Dexon

Liver

GU

SubQ

X Hepato-biliaryGUSkin

GISkin/SubQ

GUAbdomen