Surgical treatment of ValvularHeart Diseases

Dr. R S DhaliwalMBBS,MS,DNB(Surg),MCh,DNB(CTVSurg),

FACSFCCP,FAMS,FNCCP,FICA,FICASProf of CTV Surgery UCMS

Former Prof & HOD CTV Surgery, PGIMER, Chandigarh,India

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Introduction

• Valvular heart disese is the commonest type of heart disease in India and most of Afro –Asian countries

• Rheumatic heart disease is the commonest cause of valvular heart disease

• Mitral valve is the most common valve involved followed by Aortic and Tricuspid valve, rarely pulmonary valve

Surgical anatomy

• Heart valves function to maintain pressure gradient between heart chambers and ensure unidirectional flow of blood

• Atrioventricular valve – Situated between atria and ventricle , Mitral valve between LA and LV, it is bicuspid, Tricuspid valve lies between RA and RV and has three cusps

• Semilunar valves – have three cusps, lies between venticle and great vessel, Aortic valve between LV and aorta and Pulmonary valve between PA and RV

Normal heart valves

NYHA functional classification of LVF

• Stage 1 –Pt is asymptomatic and has no physical limitations

• Stage II – Pt has mild symptoms when doing activities of daily living (ADL’s)

• Class III- Pt has difficulty doing simple ADL’s

• Class IV- Pt is mostly in bed or wheel chair and becomes breathless while doing any simple activity

Mitral valve disease

• Causes of mitral valve disease • Stenosis -

a.Rheumatic heart disease b. Calcification of valve or MV appratusc. Congenital (rare)

• Regurgitation

a. Rheumatic heart disease b. MVP – M V prolapsec. LV dilatation or hypertrophy d Post MI regurgitation e. Bacterial endocarditis

Mitral regurgitation• Any pathology affecting the mitral valve appratus will

lead to mitral regurgitation . It can be Acute (due to ischemic papillary muscle rupture or infective endocarditis) or Chronic(due to rheumatic fever or myxomatous degeneration )

• In acute MR the LV ejects blood back into a small poorly compliant LA causing sudden rise in LA pressure followed by rise in PV pressure (more than

oncotic pressure) leading to acute pulmonary oedema

• In chronic MR process is slow allowing LA and LV hypertrophy and dilatation, LA is able to strech and take regurgitant blood without increase in pressure and protecting the pulmonary circulation.Later on LA pressure rises causing rise in pulm venous pressure

INVESTIGATIONS

• ECG- P mitrale due to enlargement of LA ( P wave absent when there is AF), RAD and RVH in mitral stenosis, LVH in MR

• Chest X-ray- Small aorta and large PA,Large LA Prominent ULV, RVH in MS , LVH in MR

• Echo with Doppler and TEE- It will tell about valve pathology , stenosis or regurgitation, degree of calcification and regurgitation, LV function and EF, Clot in LA ,

• Cardiac catheterisation- Is done if there is no correlation between symptoms of pt and echo findings .Also done in older pts to rule out CAD

Echo in Mitral valve disease

Treatment of mitral valve disease

• Medical management- 1.Heart rate control –Digoxin, beta blockers, amiodrone, -Diuretic for pulm congestion -Anticoagulants for AF in older pts

• Indications for Surgery-1.Severe symptoms NYHA class III or IV 2.On Echo MVA < 1cm , mod or severe MR3. H/O of embolism, large clot in LA present

• Mitral valve operations-Mitral valvotomy – closed - open (on CPB )PMBV –Percutaneous mitral ballon valvotomyMitral valve repair or mitral valve replacement

Surgical options for heart valve diseases

• Opening the Stenosed (narrow) valve by closed or open heart techniques –Mital,aortic or pulmonary valvotomy

• Repair of valves by open heart techniques –Mitral and tricuspid valve repair are common and quite successful , Aortic valve repair is uncomm-on and results are not as good as mitral

• Valve replacement- When valve is badly deformed and damaged or calcified it is replaced by Prosthetic valve which may be Mechanical or Biological valves (stented, stentless or homograft)

Comparing options for heart valve surgery Advantages Disadvantages

Valve repair Preservation of structure Improved hemodynamicsAvoid long term anticoagulation

Technically difficult Varible failure rate

Valve replacement

Mechanical valves Readily available , Life long durability, Can be used in any age group, Extensive experience and follow up

Needs life long anticoagulation, Susceptibility to infection

Biological valves

Stented Readily avilable, Short period of anticoagulents

Limited life span

Stentless Readily available, Good hemodynamics,Short period of anticoagulents

Difficult to implant Limited life span

Homograft No anticoagulation , Good hemodynamics,

Technically difficult, Not readily available

Prosthetic valves

Types of prosthetic valves

• Mechanical valves- can be used in any age group to replace any valve, are very durable

• A. Ball and Cage valve- first generaion valves . A spherical occuluder ( barium coated silastic ball) is retained within a metal cage Starr Edwards valve belonged to this class

• B.Tilting disc valve- The best known examples are Bjork –Shiley model ( now withdrawn) and TTK valve (Indian).It has single disc which is restrained by struts

• C.Bileaflet valve- It has two cusps (disc occuluders) in a sewing ring .St Jude medical valve is the best example The major disadvantage of mechanical valve is thromboembolism , life long systemic anticoagulation is done which subjects the patient to medication, tests and constant threat of hemorrhagic complications ( intracerebral, epistaxis and GIT bleeding)

Mechanical valves-Starr Edwards valve

Ball Cage valve

Pt with S E valve 40 yrs after operation

Prosthetic valves (Mechanical) Sree Chitra TTK valve (Pride of India)

Tilting Disc valve

Prosthetic valves (Mechanical)

Bileaflet valves

Types of prosthetic valves• Biological valves- Does not require anticoagulation

a.Autograft –Pt’s own valve Pulmonary valve of pt is removed and put in aortic position and replacing pulmonary valve with aortic homograft ( Ross procedure ).It has excellent hemodynamics and long term results It is technically demanding operation b. Homograft or allogaft –removed from cadavers, antibiotic sterlised,cryo preserved.Good hemodynam ics, no anticoagulent Technically difficult to insert, in short supply and uncertain life span C.Heterograft or xenograft- from animal tissue like glutaraldehyde treated porcine (pig) valves) mounted on stents.Stentmounted Bovine pericardial valves is another type of heterograft valve. Stented valves have a life span of 10-15 yrs Stentless valves are expected to have less late calcific degeneration but technically more difficult to insert. Homo and Heterografts are indicated in pts over 60 yrs age or where anticoagulants are contraindicated ( bleeding diathesis, uncontroled hypertension , GIT ulcers etc)

Prosthetic valves -Bioprosthesis

Porcine valve

Bovine pericardial valve

AorticHomograft

Mialtral valve operations

• Median sternotomy is the common incision, left or right thoracotmymay be used and mitral valve can be approached through LA or through RA across IAS and through LA append

• Closed mitral valvotomy- It was the first operation for releif of mitral stenosis.Heart is approached by left thoracotomy, finger is put in left atrium and mital valve is felt, a Tubb’s dilator is passed from LV apex across mitral valve and valve is opened with dilator, mortality < 1%

• Percutaneous mitral ballon valvotomy PMBV- It is a catheter based approach, a special ballon tipped catheter is passed through femoral vein to RA and into LA across IAS and across MV and ballonis inflated and valve is opened

• Open mitral valvotomy- It is done on CPB and was started in pts of mitral stenosis with presence of clot in the left atrium. Mital valve is opened under vision ,fused chordae and papillary muscles are seperated and decalcification is done.

• Mitral valve repair – Carpentier developed a functional classification for valve reconstruction for mitral regurgitation based on structure of cusps, chordae tendinae and papillary muscles

Mitral valve replacement

• MVR is done in – 1. Calcific MS 2. Severe MR 3.Thickened distorted leaflets and subvalvularappratus , valve not suitable for repair 4.Significant MR after repair

• Surgical technique -Heart is exposed through midsternotomy , pt put on CP bypass, mitral valve is approached through left atrium, it is excised and a prosthe tic valve is sutured with synthetic stiches above the annulus Left atrium is closed and pt is weaned of CPB

Complications of Prosthetic valves

• Structural valve failure

• Paravalvular leak

• Thrombosis and thromboembolism

• Prosthetic valve endocarditis

• Postoperative management –

• Antithrombotic therapy

• Antibiotic prophylaxis

Mitral valve reconstruction• Prosthetic ring annuloplasty – For annular dilatation and to

restore annular shape • Quadrangular resection of posterior leaflet – For MR due

to chordal rupture or elongation • Sliding plasty with quadrangular resection - Used to

eliminate systolic anterior motion of anterior leaflet • Chordal shortening or Chordal transposition – For anterior

leaflet prolapse due to chordae elongation or chordalrupture

• Edge to edge repair (Alfieri stich) – Stiching free edge of prolapsed leaflet to corresponding free edge of opposite leaflet Results of repair for regurgitant lesions are better than stenotic lesions and repair is possible more with degenerative lesions than rheumatic lesions or endocarditis.Mortality is 1-3% and reoperation rate is 1-7% at 5yrs.There is no need of prolonged anticoagulation

Mitral stenosis• The commonest cause of MS is rheumatic fever

causing carditis .The leaflet and subvalvularappratus becomes thickenedand distorted leading to narrowing of mitral valve orifice

• Normal mitral valve area is 4-6cmsm2.Symptom starts when it is < 1cm. L A pressure rises and pulmonary congestion occcurs ,pulm venous and arterial hypertension.Left atrial hypertrophy occurs which leads to atrial fibrillation.Pulm hype rtension causes RVH and CHF

Mitral stenosis• Clinical features- Asymptomatic for long time

--Fatigue -Dyspnoea -Cough -Hemoptysis–AF irregular pulse -palpitations -Oedema feet -Loud S 1 , O S ,MDM with PSA, - CrepitationsRaised JVP - Liver enlarged

• Investigations-1. ECG – P mitrale (LAH) if no AF ,RVH 2.X- ray Chest- Large LA,PA , RVH, Prominent PA and ULPV , normal LV

• Echo with Color doppler- will tell size of valve, any clot, presence of calcium and MR

• Cardiac Cath.- Indicated in older pts for CAD, degree of PAH and when there is discrepency between symptoms and echo findings

Treatment of Mitral stenosis

• Medical management – 1.Contol of heart rate - Digoxin Amiodrone

Diuretics for CHFAnticoagulents in old pts with AF

• Closed mitral valvotomy

• Open mitral valvotomy ( on CP Bypass)

• Catheter based PMBV

• Mitral valve replacement

Closed mitral valvotomy

Logan Tubb’s dilator

Aortic valve disease

• Causes of aortic valve disease -Aortic Stenosis -* Congenital bicuspid valve

* Rheumatic heart disease * Acquired calcification with age

Aortic Regurgitation-* RHD * Infective endocarditis* Congenital * Inflamatory – SLE , * Aortic root dilatation-Marfan synderome Aortic

dissection * Systemic diseases- Syphilis Ulcerarive

colitis

Aortic stenosis• There is pressure gradient across aortic valve in AS

unlike aortic sclerosis where there is no gradient. Congenital bicuspid valve is seen in 1% of population

• Normal adultaortic valve orifice area is 3-4cms Degree of aortic stenosis can be Mild (area > 1.5cms) ,Moderate (area 1-1.5cms) and Severe (area <1 cm)In severe AS with normal cardiac output a pressure gradient over 50mm occurs. LV decompensation occurs ,LVED rises and LVF starts

• Clinical features- Asymptomatic -DyspnoeaAngina - Syncope -Associated CAD in 50% pts - Low volume pulse - Aortic component of S 2 absent - ESM preceded by click in aortic area radiating to carotids vessels

Aortic stenosis

• Investigations – 1. ECG - LVH with strain pattern (ST depression with inverted t waves in chest lead 2. Chest X-ray – Prominent aorta, LVH with lung congestion occurs with LVF 3.Echocardiography – Will tell about size of the valve ,calcification , LV function and AR Other valves are assesed

4. Card.Cath. – It is done when there is associated CAD and when there is discrepency between symptoms and echo findings of pt

Types of Aortic stenosis

Anatomical level Causes

Subvalvular stenosis Congenital memberaneI H S SLong standing A S

Valvular Senile degenerationDegeneration in bicuspid valve Rheumatic disease

Supravalvular stenosis Congenital – William’s synderomePart of aortic arch synderome

Aortic stenosis

• Natural history – 80-90% untreated symptom -atic pts of AS die within 10 yrs

• Indications for Surgery -- A peak systolic gradient > 50 mm is indication for surgery - Aortic valve area < 0.75 cms2- AS with–CAD, LV dysfunction,arrhythmiassilent ischemia

Aortic regurgitation

• Causes of AR-1. Valve leaflet disease-Congenital bicuspid valve Rheumatic heart disease Infective endocarditisary2. Aortic wall pathology -Inflamatory - SLE, Rheumatoid arthritis

Ankylosing spondylitis Systemic disease – Tertiary syphilis Degenerative – Marfan synderome, aortic root dissection, senile aortopathy causngaortic root/ annular dilatation

Aortic regurgitation• Pathophysiology-

In Acute aortic regurgitation leak causes volume overload on LV causing rise in LVED which leads to premature closure of mitral valve and rise in LA pressure. This results in sudden hemodynamic unstability, hypotension and acute pulmonary oedema In Chronic AR this process is slow and gradual leading to compensatory LV dilatation to accommodate regurgitant volume LVH occurs to maintain cardiac output.Systolicand diastolic function of LV is abnormal and sudden deterioration of patient can occur

Aortic regurgitation

• Clinical features- Chronic AR remains asymp tomaticuntill LV begins to fail and symptoms start -Dyspnoea on exertion -Angina -Water hammer (collapsing) pulse - Wide pulse pressure - Thrusting apex beat – High pitched EDM along left sternal border - Low frequency late diastolic murmur at apex

• Investigations – 1.ECG- LVH with strain pattern 2. Chest X-ray- cardiomaegaly, large asc aorta 3.Echocardiography- Tells about aortic root size and LV dimensions,degree of AR and about mital valve 3. Card.Cath.- Coronary angiography is done in older pts to rule out CAD

Aortic regurgitation

• Medical managent- Vasodilators Antianginal drugs

• Indications for Surgery --Class III or IV symptoms

-Echo criteria- LVED >70mm LVES > 50mm E S dimensions > 50mm E D dimensions> 70 mm

-Aortic valve disease with CAD • Aortic valve surgery – 1.Aortic valvotomy –

In congenital aortic stenosis in children 2 PCBV – Has role in aortic stenosis in children and old pts ( unfit for surgery) 3. Aortic valve replacement- a. Severe AR

b.Calcific AS c. AS,AR

Aortic valve replacement

• Surgical technique- 1. Aortic valvotomy – is done on CP Bypass for congenital bicuspid valve in children

• Aortic valve replacement – MidsternotomyHeart is exposed and pt put on CP BypassAorta cross clamped and opened ,direct intra

coronary cardioplegia is given , diseased aortic valve is excised and replaced with a prosthetic valve using synthetic sutures, aorta closed and pt weaned of CPB

• Results – operative mortality 5%5 yrs survival 75-85%

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