Effectiveness of Preservation of the Mitral Valvular Apparatus During Mitral Valve Replacement Surgery for Rheumatic Severe Mitral Regurgitation

Abstract Background: Conventional mitral valve replacement (MVR) even with preservation of the posterior mitral leaflet is associated with higher incidence of postoperative low cardiac output syndrome due to myocardial failure. Preserva-tion of the mitral valvular apparatus ensuring sparing chordae tendinae and thus maintaining annular-papillary muscle con-tinuity is the best adorable technique to guarantee better postoperative results. There is proved existing evidence that it reduces postoperative mortality and morbidity in addition to better preservation of the left ventricular (LV) function. But plenty of surgeons hesitate to practice this technique for fears of complexity and prolonged time of the surgical maneu-ver, inability to implant adequate large mitral prosthesis and possible consequences of the residual native anterior mitral valve leaflet causing prosthesis dysfunction, systolic anterior motion (SAM) and left ventricular outflow tract obstruction (LVOTO). Aim of Study: This study primarily aims at assessment of the effectiveness of preservation of the mitral valvular appa-ratus technique during the surgery of MVR for rheumatic severe mitral regurgitation (MR) on restoration of LV function by tracing the changes in the postoperative LV performance over one year follow-up. Secondary outcomes include estima-tion of mortality, major cardiac problems, functional status and quality of life at one-year postoperatively. Patients and Methods: This retrospective observational non-randomized study included 79 patients who presented with rheumatic severe MR and had undergone MVR by preservation of the mitral valvular apparatus technique. Postoperative mortality, morbidity outcomes, overall hospital complications, left ventricular ejection fraction (LVEF%), left ventricular end-diastolic diameter (LVEDD), left ventricu-lar end-systolic diameter (LVESD), tricuspid annular plane systolic excursion (TAPSE), pulmonary artery pressure (PAP), New Yok Heart Association (NYHA) classification and the overall one-year survival were evaluated. Results: Mean age was 30.11±3.98 years. The incidence of postoperative low cardiac output syndrome was 6.32%. The overall hospital complication rate was 25.31%. No intra-operative deaths occurred, and no mortality happened during the follow-up period (overall one-year survival rate was 100%). The cumulative duration of the study was 4.167 years. Statistically significant improvement in NYHA class (p<0.001), LVEF% (p<0.001), LVEDD (p=0.0412) and LVESD (p=0.05) was observed. Although there was improvement in PAP and TAPSE, the results were statistically insignificant. Conclusion: Preservation of the mitral valvular apparatus proved to have many pros other than conservation of the LV function. It preserves LV size and geometry, decreases intra-operative mortality, reduces the rate of the lethal postoperative low cardiac output syndrome, improves survival rate, doesn't hinder implantation of adequate large mitral prosthesis, doesn't necessarily causeLVOTO, doesn't represent complex tech-niquewith a limited time expenditure and it may enhance right ventricular function. We recommend applying a technique of preservation of the mitral valvular apparatus in patients with rheumatic severe MR undergoing MVR.