mitral valve diseases & management

Mitral valve diseases & management

Dr. Md. Rezwanul HoqueMBBS,MS,FCPS, FRCSG, FRCSEd

Associate ProfessorDepartment of Cardiac SurgeryBSMMU, Dhaka, Bangladesh

ANATOMY OF MITRAL VALVEThe mitral valve is composed of leaflets (valve tissue), mitral annulus, chordae tendineae, papillary muscles, and the left ventricle. The chordae tendineae and papillary muscles form the subvalvular apparatus. Commissures are identified using two anatomical landmarks: the axis of corresponding papillary muscles and the commissural Chordae. The anterior leaflet (aortic leaflet) has a semicircular shape and is attached to two fifths whereas the posterior leaflet (mural leaflet) has a quadrangular shape and is attached to three fifths of the annular circumference.The mitral valve is separated into eight segments . Anterolateral and posteromedial commissures are two segments. Two indentations on the posterior leaflet divide this structure into three anatomically individualized scallops (P1,P2,P3) The anterior leaflet has three corresponding segment( A1,A2,A3). The mitral annulus is attached to the fibrous trigones. The right fibrous trigone is a dense junctional area between the mitral, tricuspid, and noncoronary cusps of the aortic annuli and the membranous septum. The left fibrous trigone is situated at the junction of both left fibrous borders of the aortic and the mitral valve. Marginal chordae (primary chordae) are inserted on the free margin of the leaflets and function to limit leaflet prolapse. Intermediate chordae (secondary chordae) are inserted on the ventricular surface of the leaflets and relieve the valvular tissue of excess tension. Basal chordae (tertiary chordae) are limited to the posterior leaflet. They are attached to the leaflet base and connect it to the mitral annulus and the surrounding myocardial tissue.

Sellke: Sabiston & Spencer Surgery of the Chest, 7th ed., Copyright © 2005 Saunders, An Imprint of Elsevier-chapter-74

Anatomy of mitral valve

Anatomy- cont.

Cause of mitral valvular diseaseCause: MS: Rheumatic fever (Lutembacher syndrome: MS with ASD); congenital very uncommon, seen in infancy, D/D-LA myxoma

MR: Rheumatic fever, infectious endocarditis, mitral valve prolapse, calcification of mitral annulus, collagen vascular disease (SLE, scleroderma), Marfan syndrome, Ehlers-Danlos syndrome, amyloidosis, sarcoidosis, LA myxoma, trauma, ischemia, congenital abnormalities

Mitral prolapse: Most frequently occurs as a primary condition; also seen in collagen-vascular disease, Marfan syndrome, von Willebrand's disease, myotonic dystrophy

Sutherland, John A. Little Black Book of Cardiology, 2nd Ed,2007, Jones and Bartlett Publishers > Table of Contents > Chapter 8 - Valvular Heart Disease

MS- other causesMS secondary to rheumatic fever in almost 99.8% of casesCongenital- Supravalvular/valvular/sub valvularSevere degenerative calcificationLA myxomaCarcinoid syndromeFabray’s diseaseHurler’s syndromeWhipple’s diseaseInfective endocarditis


William Herring. Valvularlesionsweb.pdf.2002

EpidemiologyEpidemiology: Rheumatic: 2/3 of patients are women; 25% of patients with rheumatic fever develop pure MS; another 40% have MS and MR

(Eur Hrt J 1991;12 suppl B:77)

In a community-based sample, the prevalence of mitral valve prolapse (MVP) was 2.4% . (Nejm 1999;341:1).

Women with MVP outnumber men 2:1.

Effect of MS on heartLA hypertrophy- dilatation- AF- mural thrombusLV – normal, comparatively smallerPA pressure high leading to ↑PVRPR, RV dilatation from pressure overloadTR due to RV dilatationRA dilates due to volume overloadRVF


Effect of MS on lungs

PAH- Pulmonary vascular change-↑PVRChronic oedema of interstitial tissue and alveoli leading to fibrosisPulmonary hemosiderin deposit- calcificationRupture of pulmonary capillaries - haemoptysis


Severity of MS

Pathophysiology of mitral valve disease

MS: Normal mitral orifice is 5-6 cm2; orifice is reduced in MS due to fusion of commissures and thickening of cusps and/or chordae. A gradient develops when valve area is reduced to 2 cm2. LA pressure ≥ 25 mm Hg when valves ≤ 1 cm2 (critical MS).MR: Disorders of mitral leaflets, chordae, or papillary muscles produce a leak. Impedance to LV emptying in systole is reduced and EF remains normal or increased until LV pump failure develops.Mitral prolapse: Myxomatous proliferation of mitral leaflets and chordae cause billowing of mitral leaflets.


Presentation of MV diseaseExertional dyspnoea; orthopnoea; palpitations. Symptoms are usually less in chronic MR than in MS but are acute and severe in acute MR. 15% of patients with MS have angina-like chest pain.The frequencies of chest pain and dyspnoea are similar among subjects with and without prolapse.MS: Prominent jugular A wave; RV heave (if RV enlarged); increased S1 and P2; opening snap; diastolic rumble at apex; longer murmur = more severe MSMR: S1 normal or decreased; S2 widely split; P2 increased in pulmonary HT; S3 gallop; late/holosystolic murmur radiating to axilla that varies little with cycle length or inspirationMitral prolapse: Mid-systolic click, late systolic murmur that decreases with squatting, increases with administration of amyl nitrite and Valsalva manoeuvre (strain)Haemoptysis is more common in MS than in MR.MS: Symptoms manifest 15-20 year after an episode of rheumatic fever and progress over 3-4 year.


InvestigationECG: LAE, coarse AF, incomplete RBBB in MS. Only 15% with MR show LAE.Echocardiogram: MS: To confirm dx; determine mean gradient, mitral valve area, PA pressure, and RV dimensions; evaluate valve; identify other valve lesions.Echocardiographic mitral morphology score: Leaflet rigidity, leaflet thickening, valvular calcification, and subvalvular disease are each graded from 1+ to 4+. MR: Initial assessment of MR and LV function and to identify cause; subsequently for periodic measure of LV function and dimensions in asymptomatic patients, for changing symptoms, and after valve repair/replacementIn asymptomatic patients, echo quantification of MR (regurgitant volume, effective regurgitant orifice) predicts clinical outcome .Mitral prolapse: In all patients, to demonstrate systolic billowing of leaflets and to assess severity of MR; repeat study for changing symptoms and/or to follow degree of prolapse and MR and chamber dimensions; for suspected infectious endocarditis


Investigation- cont.TEE: Mitral valve disease with inadequate transthoracic echocardiogram or suspected LA thrombus or endocarditis; also used intraoperativelyChest X-ray: MS: Enlargement of LA, RV, or RA, pulmonary arteries; pulmonary oedemaMR: Enlargement of LV or LA; CHFCardiac catheterization: MS: Indicated to assess MR severity in candidates for balloon valvotomy if clinical and echocardiographic data are discordant; to measure PA, LA, and LV diastolic pressures if clinical and echo/Doppler data are discordant with the severity of MS by 2-D and Doppler echocardiography; or to gauge hemodynamic response of PA and LA pressures during exercise if clinical symptoms and resting hemodynamics are discordantMR: For patients with angina, prior MI, or suspected ischemia; for patients with CAD risk factors who are scheduled for mitral valve surgery; or for patients with inconclusive/discrepant noninvasive studies


Mitral stenosis

ACC/AHA 2006 Guidelines for the Management of PatientsWith Valvular Heart Disease: Executive Summary

Balloon valvuloplasty

Indicated for patients with class II-IV symptoms and valve area ≤ 1.5 cm2 or valve area > 1.5 cm2 and pulmonary HT (PA systolic pressure 50 mm Hg at rest or 60 mm Hg with exercise) and mild or no MR, no LA thrombus, and reasonable valve morphology, or for asymptomatic patients with the same characteristics and pulmonary HT, AF, or pregnancy .

Circ 2004;109:1572

Anticoagulation in MS

Atrial fibrillationLA thrombusH/O thromboembolismSevere MS, LA>55 mm

Indication for surgerySurgery is indicated in symptomatic patients (NYHA class III or IV) with moderate to severe mitral stenosis (MVA <1.5 cm2, gradient> 10 mm Hg) who are not appropriate for, or who have failed balloon valvulotomy.There is also a subset of asymptomatic patients with severe mitral stenosis and severe pulmonary hypertension with no favourable morphology for percutaneous balloon valvulotomy. Mitral valve surgery is recommended in this subgroup of patients in order to prevent right ventricular failure.

In patients with mild asymptomatic mitral stenosis (valve area >1.5 cm2 and mean gradient <5 mm hg), no further evaluation is required after the initial workup. These patients usually remain stable for years and should be treated medically with a close follow up.


Indication for surgery in MS

Symptomatic and gradient> 10mm HgCHF- NYHA-2,3Associated moderate to severe MRUnavailable or unsuccessful PBMVLA thrombusAsymptomatic with severe PAH

Mitral regurgitationA, posterior prolapse due to chordae tendineae rupture. B, anterior prolapse due to elongation, thinning and rupture of chordae tendineae. C, anterior and posterior prolapse secondary to elongation of the chordae tendineae and myxomatous degeneration of several segments; note the pathologic clefts in the posterior leaflet. D, Barlow's disease with myxomatous degeneration of both leaflets.

Carpentier’s functional classification

Type I, normal leaflet motion; Type II, increased leaflet motion (leaflet prolapse); Type IIIa restricted leaflet motion during diastole and systole; Type IIIb restricted leaflet motion predominantly during systole.

FED BD

AnnulusNormal or near normal valve size (annulus <32

mm)Severely dilated annulus

LeafletsThin transparent w/o excess

tissueThick w/ excess tissue

Single segment involvement

Multi segmental involvement

Involved segment is thick and distended

ChordsElongated in the affected

segment, w/ or w/o rupture

Thickened, calcified, elongated, restricted w/ or

w/o rupture

Billowing characteristicsNo billowing of the adjacent

segmentsMulti segmental billowing

Surgical Criteria for the Classification of Degenerative Mitral Valve Disease

Surgical indication in severe MR

• Symptomatic severe MR• Asymptomatic severe MR with LVEF<60%, LVESD>40 mm• Pulmonary HTN• New onset atrial fibrillation• congenital abnormality of valve apparatus

Surgical approach to mitral valveMedian sternotomy- complete, upper or lower hemisternotomyRight anterolateral thoracotomyMinimally invasive MV surgery- direct vision, video assisted, video directed robot assisted, robotic telemanipulation


Standard left atrial approach/ Sondergaad’s groove

Pezzella AT et al. Texas heart journa, 10(2), 1983

Transseptal approach

Biatrial transseptal approach

Vertical biatrial, transverse transseptal approach

Pezzella AT et al. Texas heart journa, 10(2), 1983

Superior left atrial approach

Right thoracotomy approach

MV repair- valve analysisThe entire mitral valve apparatus must be carefully examined to confirm the mechanism of mitral regurgitation, to assess the feasibility of repair, and to plan the exact operative technique. The endocardium of the left atrium is examined for jet lesions, which indicate opposite leaflet prolapse. The mitral annulus is examined to assess the severity of annular dilatation, which can be asymmetrical. The valvular apparatus is examined with a nerve hook to assess tissue pliability and to identify leaflet prolapse or restriction according to segmental valve analysis. The anterior paracommissural scallop of the posterior leaflet (P1) is often intact and rarely prolapsing in patients with degenerative disease. The P1 segment constitutes the reference point. Applying traction to the free edge of other valvular segments and comparing them with P1 determines the extent of leaflet prolapse or restriction


MV repair-procedures

Remodelling ring annuloplastyPosterior leaflet quadrangular resection/ triangular resectionSliding leaflet repair/ leaflet perforation repairChordal transferChordal transpositionArtificial chordoplastyPapillary muscle sliding plasty/shorteningAnnular decalcification & reconstruction


Dr. Farzan Filsoufi, Dr. Alain Carpentier, and Dr. David Adams at work on their upcoming textbook "Carpentier's Valve Reconstruction".

The Alfieri techniqueThe surgical “edge-to-edge” technique was first described in early 1990`s (Alfieri)Over 1,500 pts reported in the literature

Safe, effective, durableNo occurrence of mitral stenosis

Facilitates proper leaflet coaptationDegenerative - anchor flail / prolapsing leaflets Functional - Coapt tethered leaflets to reduce time and force required to close valve

Creates tissue bridge

59Investigational Device only in the US; Not available for sale in the US

Catheter-Based Mitral Valve Repair

MitraClip® System

© Continuing Medical Implementation ®

MV Repair vs. Replacement

Lower operative mortalityBetter late outcomeCurativeAvoids anticoagulation unless atrial fibrillationOpen Afib ablation

© Continuing Medical Implementation ® …...bridging the care gap

MV Repair vs. Replacement (2)

Valve replacement:Mortality 2-7%Anti-coagulationDecreased LVEF

Tissue prosthetic valve degenerationMechanical prosthetic valve dysfunction/ thrombosis

Valve repairMortality 2-3%No anticoagulation (unless Afib)Preservation of LVEF

Valve repair always preferableFeasible in 70-90% of patients

© Continuing Medical Implementation ® …...bridging the care gap

Mitral Valve Replacement Other Issues

Mechanical valve – thromboembolism, bleed from anticoagulationBioprosthetic valve– limited durability (degeneration)Chordal/subvalvular apparatus preservation

EF preop/postop 60% to 36% VS 63% to 61% in a comparative study

Minimally invasive MV repair- since 1990

According to their increased difficulty, minimally invasive approaches are divided into four categories: limited incision with direct vision (level 1), video-assisted (level 2), video-directed and robot-assisted (level 3), and robotic telemanipulation (level 4).

There are three main approaches to minimally invasive mitral valve repair:Totally Endoscopic Mitral Valve RepairMini-Sternotomy Mitral Valve RepairMini-Thoracotomy Mitral Valve Repair All approaches require putting on a heart-lung machine (cardiopulmonary bypass), but they also all cause less trauma than open heart surgery.

Potential advantages of totally endoscopic mitral valve repair:Shorter hospital stayLess pain and scarring Reduced risk of infectionLess blood loss and need for blood transfusionsFaster recoveryQuicker return to normal activities

MV repair through transseptal approach

1. RIGHT ATRIOTOMY 2. INCISION IN THE INTERATRIAL SEPTUM

1. STAY SUTURE IN IAS 2. INSPECTION OF MV

1. SIZING TO SELECT APPROPRIATE ANNULOPLASTY RING SIZE 2. ANNULAR STITCHES

1. ANNULOPLASTY RING APPLIED 2. SUTURES PASSED THROUGH RING

1. RING APPLIED 2. IAS CLOSED

RA TOMY CLOSED

Algorithm for interpreting abnormally high transprosthetic pressure gradients after aortic or mitral valve replacement.

Pib

aro

t P

, D

um

esn

il J

G H

eart

201

2;98

:69-

78

Body surface area; DVI, Doppler velocity index EOA, effective orifice area; FU, follow-up; PPM, prosthesis–patient mismatch.

[email protected]+8801711560305

mailto:[email protected]

mitral valve diseases & management

Documents