Our Experience with St.Jude Prosthetic Mitral Valve Replacement in 179 Consecutive Patients

Gopal, M (2007) Our Experience with St.Jude Prosthetic Mitral Valve Replacement in 179 Consecutive Patients. Masters thesis, Madras Medical College, Chennai.

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Abstract

INTRODUCTION: Rheumatic heart disease plays a major debilitating role in Indian population causing high morbidity and mortality, affecting the population in their productive phase of life. It impairs the quality of life and leads to psycho-social and economic burden to their family and the society. With the clinical introduction of cardiac valvular prosthesis in 1960, valve replacement has saved a number of lives affected by hemodynamically significant valvular disease. However, prosthetic valve replacement is not with out danger and it became evident that "valve replacement is simply exchanging one disease for another". In spite of tremendous strides toward perfecting materials and design, the ideal valve remains elusive. Thromboembolism continues to be a major cause of morbidity and mortality in patients who have undergone mechanical valve replacement. Recent surgical trend in treating Rheumatic mitral valve disease is to Repair the valve. If Repair is not feasible, then valve replacement is still undertaken knowing the complications unique to prosthetic valve replacement in the interest of saving the life. AIMS AND OBJECTIVES: 1) To study the complications associated with Mechanical Mitral valve replacement. 2) To Study the influence of AF on outcome following Mitral valve replacement. MATERIALS AND METHODS: This prospective study was conducted between June 2005 to December 2006 on 179 consecutive patients undergoing valve replacement with St. Jude prosthetic Mitral valve. Valve lesion other than tricuspid valve was not included in this study. Similarly ischaemic mitral regurgitation was not included. Previous open heart surgery patients were not included in this study. St.Jude bileaflet low profile prosthetic valve Masters series MJ 501 with standard polyester cuff was used in all patients. Male patients 40 years and above and female patients 45 years and above without risk factor for ischemic heart disease and those patients who are at high risk for ischemic heart disease were subjected to coronary angiogram pre operatively. Operative technique:- Surgery was conducted with a midline sternotomy incision, standard cardiopulmonary bypass with Aortic , bicaval cannulation, core was cooled to 28*C. Heart was arrested with hyperkalemic blood cardioplegia, with topical ice slush being used to cool myocardial temperature .Left atrium was opened parallel to the interatrial groove in those patients who have isolated mitral pathology .In ASD, Tricuspid regurgitation, LA myxoma patients Right atrium was also opened . Surgery was conducted after inspecting the mitral valve for suitability for chordal preservation . St.Jude prosthetic mitral valve MJ501 masters series was used in all patients and suturing was done with 2 0 Ethibond sutures with plegets using a horizontal interrupted mattress technique. Continuous suture technique for those annulus not severly diseased or calcified was employed too .The valve was placed in intra annular position. Patients were ventilated electively and ionotropes used depending up on the hemodynamic needs. On first post operative day heparin was given along with oral anticoagulant (Acenocoumarol) and continued until the target INR of 2.5 to 3.0 reached, then heparin stopped. Anticoagulant dose was regulated by surgeons during hospitalization and during subsequent follow up in the outpatient department. Patients came for regular follow up every 15 days for drug collection and for clinical assessment. In those patients who were symptomatic or clinical suspicion of deterioration were present subjected to detailed evaluation. 75% of the patients were still in follow up. SUMMARY : Between June 2005 and December 2006 , 179 St Jude mechanical mitral valves were implanted. Age ranged from 8 to 59years, mean age 29.31+/-10.75 with median of 27 years. Majority being female 109(60.9%) with Rheumatic heart disease 173(96.6%) being the commonest etiology with Mitral stenosis 84(46.9%) as the major lesion . overall mortality was 19(10.8%) and in hospital mortality was 14(7.8%) and about 75% of the patients were still in regular follow up. LA clot 21(56.8%) being the major co -morbid condition followed by ASD 5(13.5%) and TR & CAD 3(8.1%) constituted each. One patient had LA Myxoma 1(2.7%); Mitral restenosis 20(11.2%). NYHA class preoperatively 3 and 4 combined173(96.6%). Most patients were in NSR109(60.9%) and AF (39.1%) with majority having LVEF fifty and above 170(95%). Isolated MVR 144(80.4%) being the commonest procedure , CABG & Devega annuloplasty being 3 (1.7%) each. Classical procedure MVR 96(53.6%) and chordal preservation in 83(46.4%)only. Post operatively out of 80 Pre. op normal EF patients only49(61.3%) had normal EF in the classical group. And in the chordal preservation group out of 81 pre op. normal EF patients 78(96.3%) had normal EF postoperatively . Most of valve replacement patients had definitive symptomatic improvement in NYHA class, majority were in NYHA 1 and 2 combined 136(76%). Majority of the patient were in Sinus Rhythm 110(61.5%) , AF 67(37.4%). There was no structural valve failure, no paravalvular leak or valve related hemolysis. There were 6 (3.4%) valve thrombosis; prosthetic valve endocarditis 2(1.1%); anticoagulant related hemorrhage 4(2.2%); thromboembolism 2(1.1%); myocardial failure 8(4.5%); LV rupture 2(1.1%). High NYHA Class , AF, associated CAD, Redo mitral surgery were significant risk factors for inhospital mortality and the presence of AF was a significant risk factor for increased mortality and morbidity on follow up. CONCLUSION: Mitral valve replacement cannot normalize the life expectancy. Valve replacement has its own limitations. Population coming for mitral valve replacement are under privileged, and they lack financial backup to manage the post valve replacement sequelae. Valve replacement is not the end of the disease but a new beginning of a chronic disease lying dormant , ready to blow off at any time, given a chance. The best way to address this issue is to stress the importance of mass education, school health education, strict implementation of secondary prophylaxis and an early clinical trial for vaccines for rheumatic fever. In failed cases earlier intervention should be done and not to wait until the heart fails, or AF sets in. Timely intervention when the valve is suitable for conservative procedures and to promote valve sparing surgery as much as possible, there by avoiding the prosthetic valve. In the established cases conservative surgery in the form of chordal preservation should be done with antiarrythymic surgery whenever possible. A diligent search should be made to find a valve substitute that lacks the problems, presently available prosthesis have.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Experience ; St.Jude Prosthetic Mitral Valve Replacement ; 179 Consecutive Patients.
Subjects: MEDICAL > Cardio Vascular and Thoracic Surgery
Depositing User: Kambaraman B
Date Deposited: 10 Nov 2017 16:58
Last Modified: 10 Nov 2017 16:58
URI: http://repository-tnmgrmu.ac.in/id/eprint/3871

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