Mitral Valve Replacement with Chordal Preservation: A Retrospective Analysis of outcome in Comparison with Classical Mitral Valve Replacement

Girish, N (2006) Mitral Valve Replacement with Chordal Preservation: A Retrospective Analysis of outcome in Comparison with Classical Mitral Valve Replacement. Masters thesis, Madras Medical College, Chennai.

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Abstract

INTRODUCTION: It is well known that traditional mitral valve replacement when compared to mitral valve repair carries a higher morbidity and mortality. This has been attributed to the preservation of the mitral subvalvular apparatus in repair techniques, but not all valves can be repaired, especially those of rheumatic etiology. Mitral valve replacement has been the procedure of choice usually adopted in these conditions, but the results have not been comparable. By preserving the annular ventricular continuity in mitral valve repair good LV function both early and late post operative period has been achieved. A surgery in which annulo-papillary continuity is preserved during replacement has shown better early and late results than traditional MVR techniques. As the awareness of the deleterious effects of the loss of annulo -ventricular continuity has increased chordal preservation during mitral valve replacement has gained in popularity. AIMS AND OBJECTIVES: The aim in this study was to study in retrospect the possible out come benefits of chordal sparing surgery when mitral valve replacement is done for rheumatic mitral regurgitation in terms of left ventricular function by assessing parameters of left ventricular systolic and diastolic function. The parameters assessed were hemodynamic stability in the immediate peri and post operative period, left ventricular ejection fraction preoperative and postoperative, left ventricular end systolic and diastolic dimensions pre and postoperative . PATIENTS AND METHOD: 343 Patients underwent mitral valve replacement between July2003 and August 2005. Of these 105 patients underwent mitral valve replacement surgery for chronic dominant mitral valve regurgitation. In 55 of these procedures the classical mitral valve replacement technique was followed. In 50 patients chordal sparing technique was followed, in 10 patients both AML and PML and in 40 the posterior chordal apparatus was alone preserved In both groups of patients preoperative NYHA class, LV end systolic, end diastolic dimensions and preoperative ejection fraction were noted. Surgery was conducted with a standard mid sternotomy incision, bicaval and aortic cannulation, core was cooled to 28*C,. Heart was arrested with hyperkalemic blood cardioplegia, with topical ice slush being used to cool myocardial temperature further. Left atrium was opened parallel to the interatrial groove. Surgery was conducted after inspecting the valve and suitability for chordal preservation assessed. In majority a Starr Edwards caged ball prosthesis model 6120 was used. the other valve used being St. Jude mechanical bileaflet prosthetic valve . Suturing was done with continuous 2-0 ethibond suture in the classical MVR patients or after plicating the posterior leaflet with the valve fixation suture in the PML area and dividing and reattaching the anterior leaflet chordae in the complete preservation group. Patients were electively ventilated post operatively with inotropic supports being dictated by the hemodynamics of the patient. The patients out come after surgery where the subvalvar apparatus was preserved either completely or partially were compared against the group in whom the classical technique was followed. The variables assessed were post operative needs for and dosage of multiple inotropic supports, duration of ventilator support. Post operative LV function was assessed with a pre discharge echo cardiography. The parameters noted were the LV end systolic and end diastolic dimensions post operative LV ejection fraction, reduction in NYHA class. SUMMARY: Three hundred and forty three cases of mitral valve replacements were carried out between July 2003 to Aug 2005. Of these 105 patients had dominant mitral valve regurgitation. Most of the patients operated were in NYHA class II. The second peak was in class III most of these patients affected were in the second decade with males outnumbering females. Tricuspid regurgitation was found to be the most common associated pathology in this group needing an associated tricuspid deVegas annulolplasty. Significant coronary artery disease requiring CABG was noted in two patients one male and one female both under going classical MVR because of calcific valve in one and evidence of healed endocarditis in one. Ejection fraction preoperatively was normal in majority of patients with both classical MVR and chordal sparring MVR. Left ventricular end systolic dimension greater than 50mm was noted in 4 of the classical MVR and of 2 in the chordal sparring group. 35 patients had preoperative atrial fibrillation. Of the 50 patients with chordal sparring MVR10 had total preservation of the subvalvar apparatus. in the total chordal sparing mitral valve replacement group the need for prolonged postoperative ventilator support and higher inotropic supports was not seen. In the classical MVR group19 patients required prolonged ventilation support of greater than 24 hours. There were 11 deaths in this series, 5 in the chordal sparing and 6 in the classical group. Of note there were no deaths in the total chordal sparing group. Postoperative echo showed a significant improvement in the ejection fraction and decrease in end systolic dimension in the total chordal sparing mvr group. There was no left ventricular out flow tract obstruction in the total chordal sparing MVR group. CONCLUSION: Of the 50 chordal sparing MVR group either in the complete or partial form better hemodynamics were noted both in the immediate and early post operative period. Chordal sparing MVR has been established to protect the left ventricular systolic and diastolic function in the late postoperative period. A well designed prospective trial with a larger group of patients and a longer follow up period is needed to evaluate further this technique.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Mitral Valve Replacement ; Chordal Preservation ; Retrospective Analysis ; Classical Mitral Valve Replacement
Subjects: MEDICAL > Cardio Vascular and Thoracic Surgery
Depositing User: Kambaraman B
Date Deposited: 10 Nov 2017 16:51
Last Modified: 10 Nov 2017 16:51
URI: http://repository-tnmgrmu.ac.in/id/eprint/3867

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