Mitral valve surgery chordal preservation

MITRAL VALVE SURGERY

CHORDAL PRESERVATION

Dr.JYOTINDRA SINGH

MBBS,MS,M.Ch( Cardiac surgery)

PLANINTRODUCTION

ANATOMY & PHYSIOLOGY

HISTORICAL ASPECT

EFFECTS OF CHORDAL PRESERVATION

PHYSIOLOGICAL ALTERATION

TECHNIQUES OF CHORDAL PRESRVATION

RESULTS

TAKE HOME MESSAGE

INTRODUCTION

Aim of mitral valve surgery - to provide a competent,

non-obstructed valve without compromising the left

ventricular (LV) function.

Above aims are met with valve repair .

When repair is not feasible- preservation of LV

function is an important concern.

Awareness of the deleterious effects of the loss of

annulo-ventricular continuity has increased, chordal

preservation has gained popularity

INTRODUCTION

Despite the clear advantages of complete chordal preservation ,many surgeons still

retain only the posterior leaflet because of greater

technical complexity,

longer operating time,

fear of potential interference with mechanical leaflet motion,

need to undersize the mitral prosthesis

possibility of LVOTO.

However, with application of the correct surgical technique tailored to suit the

individual patient, preservation of the entire subvalvular structures is feasible in all

patients with an adequate sized prosthesis.

INTRODUCTION

The left ventricle has been dissected so as to remove its posterior wall, and is viewed from

behind in anatomically appropriate orientation.

Anderson R H , Kanani M MMCTS

2007;2007:mmcts.2006.002147

© 2007 European Association for Cardio-thoracic Surgery

2

ANNULO VENTRICULAR CONTINUITYIn 1922, Wiggers and Katz and later Rushmer et al proposed the concept.

left ventricular geometry and function are a result of a dynamic interaction between the mitral annulus and the LV wall.

The attachments between the mitral annulus and the LV wall

moderate the LV distension during diastole and wall tension during systole.

When the papillary muscles contract during the isometric phase of the cardiac cycle,the closed MV is drawn into the LV cavity thus reducingthe longitudinal axis of the LV and increasing its short axis.

Diastolic recoil.

Annulo ventricular continuity

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ANATOMY

Figure 42-5. Conventional mitral valve replacement with

complete excision of the leaflets and the entire subvalvular

apparatus, as used in the past and in cases of advanced

rheumatic disease. The mitral prosthesis is implanted using

a series of horizontal mattress sutures

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Effects of chordal transection

Hansen demonstrated that transection of chordae to the anterior mitral leaflet (AML) reduced the LV function to a greater degree as compared to the transection of chordae to the posterior mitral leaflet .

improved LV systolic performance by reduction of the LV afterload.

Chordal transection also appeared to shorten the long axis of the LV with an increase in the minor axis and dilatation of the chamber.

Transection of the chordae produced dyskinetic areas at the insertion

of severed papillary muscles

Sarris and colleagues - neo-chordal reconstruction at re-operation

Chordae and papillary muscle

Physiological changes

Chronic MR- LV function gradually declines.

Regurgitant stroke volume added to forward stroke

volume- increase EF in early phase.

Progressive LV dilatation- increase Afterload.

After MVR with chordal transection- EF determined by

contractility,preload ,afterload.

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Historical aspect

In 1964, Lillehei introduced the concept of chordal preservation during MVR to reduce the problem of post-operative low cardiac output syndrome.

David in 1981 reintroduced the concept- LV function deteriorated if the chordae were transected .

Only those patients in whom the chordae had been spared could increase the LV ejection fraction (EF) and stroke volume index.

Also in the chordal preservationgroup, there was better long-term systolic function and LV performance both at rest and during exercise.

Modified Simpson’s Method

EDV – ESV

LVEF = --------------- X 100

EDV

Colour Doppler Indicators of Mitral

Regurgitation Severity

Mild Moderate Severe

Colour Doppler

Jet area (cm2) <4 >10

Ratio of jet area to

left atrial area (%)

<20 >40

Vena contracta

width (cm)

<0.3 >0.7

PISA radius (cm) a <0.4 >1.0

Indicators of Mitral Regurgitation

Severity

Mild Moderate Severe

Multimodality

Regurgitant

volume (mL/beat)

<30 30-59 >60

Regurgitant

fraction (%)

<30 30-49 >50

Effective

regurgitant orifice

area (cm2)

<0.20 0.20-0.39 >0.40

PML Preservation-Lillehei[Preservation of the posterior mitral valve leaflet

and effect on follow-up results after additional

mitral valve implantation]..

Abstract

As early as 1964, Lillehei et al. published the technique of preservation of the

posterior mitral leaflet (PML) and chordae tendineae in combination with mitral

prosthesis implantation (MPI). In a limited randomized number of 95 patients with

MPI the influence of preservation of PML on hemodynamics and physical capacity at

least 46 months after surgery without (group A) and with preservation of PML (group

B) was investigated. Statistically significant differences in favor of group B were

found for cardiac index, pulmonary artery pressure after stress,

end-diastolic volume index (EDVI), physical capacity and

survival rate after a complication-free course. Basing on these results

at rest and after exertion (30 W), patients with preservation of PML and MPI are long-

term in a better clinical condition.

DAVID’S TECHNIQUE

DAVID’S TECHNIQUE(reduction in tumor blush

2

Feikes et all






Feikes et all

2

Khonsari I technique






2

Khonsari I & II technique

ROSE & OZ Technique

ROSE & OZ Technique

2

MIKI ET ALL






2

Nara technique






CROSSED PAPILLOPLEXY

(A) Schematic of mitral valve.

© 2003 Elsevier B.V.

detach the strip of anterior leaflet only

from the anterolateral commissure and

preserve the posteromedial commissure

attachment.

This technique does not require any

sutures other than those used for valve

attachment and causes no annular

deformation or leaflet restriction.

Furthermore, because the strip is left

attached at the annulus of posteromedial

commissure, it is easy to begin

attachment of the strip to the annulus.

This modification is simple and effective

in preventing complications associated

with the technique of chordal-sparing

mitral valve replacement.

Intraoperative photograph.

Sasaki H , Ihashi K Eur J Cardiothorac Surg 2003;24:650-

652

© 2003 Elsevier B.V.

Oblique transposition of AML

SINTEK et all

Journals

Postoperative assessment of chordal preservation and changes

in cardiac geometry following mitral valve replacement

Which one to choose

Safeguards-Ideal methodThe factors to be considered are the

simplicity and reproducibility of the technique

prevention of post-operative LVOTO due to systolic

anterior motion of the remaining AML

risk of interference with the prosthetic valve function.

The technique used should allow for implantation of

an adequate size prosthesis to prevent post-operative

patient-prosthesis mismatch..

TAKE HOME MESSAGEComplete chordal preservation advantages.

It preserves LV geometry and function,

reduces the operative mortality,

improves early and long-term survival

reduces the risk of ventricular rupture.

With appropriate surgical technique even large size prosthetic valves can be

implanted and the risk of prosthetic valve dysfunction and LV outflow tract

obstruction can be eliminated.

There is emerging evidence which suggests that RV function may improve

significantly after LV chordal preservation.

Health & Medicine

Mitral valve surgery chordal preservation