Mitral Valve Replacement via Minithoracotomy Versus Conventional Median Sternotomy in Rheumatic Mitral Valve Disease: A Multicenter Retrospective Study

Background and objectives This study aimed to compare surgical outcomes, early postoperative complications, and midterm recovery in patients with severe rheumatic mitral insufficiency undergoing either minimally invasive cardiac surgery (MICS) or mitral valve replacement via conventional median sternotomy (CMS). While CMS remains the standard approach, MICS has emerged as a less invasive option with potential benefits. However, comparative data in resource-limited settings remain scarce. Methods This multicenter retrospective study included 55 adults with severe rheumatic mitral Insufficiency (RMI) who underwent elective mechanical mitral valve replacement between 2020 and 2024 in Morocco. Patients were divided into two groups: 27 received minimally invasive surgery (MICS) via minithoracotomy, and 28 underwent conventional sternotomy (CMS). The primary endpoint was 30-day all-cause mortality. Secondary outcomes included operative times, postoperative complications, intensive care unit (ICU)/hospital stay duration, 12-month functional recovery, valve performance, and event-free survival based on Kaplan-Meier analysis. Results Fifty-five patients underwent mechanical mitral valve replacement: 27 via minimally invasive cardiac surgery (MICS) and 28 via conventional median sternotomy (CMS). The 30-day mortality was similar between groups (3.7% vs 3.6%; p = .99). Compared with CMS, MICS was associated with significantly shorter cardiopulmonary bypass (68.3 vs 87.5 minutes; p < .001) and aortic cross-clamp times (54.7 vs 77.1 minutes; p < .001), reduced postoperative pneumonia (0% vs 10.7%; p = .03), and fewer arrhythmias (7.4% vs 39.3%; p = .04). Hospital stay was shorter in the MICS group (6.2 vs 7.3 days; p = .04), with similar ICU duration. At 12 months, both groups showed preserved left ventricular ejection fraction (60.1% vs 58.2%; p = .22) and comparable event-free survival (>90%), without significant differences in valve-related complications. Conclusions In this multicenter retrospective study, minimally invasive cardiac surgery (MICS) for severe rheumatic mitral insufficiency was associated with fewer early complications, shorter operative and recovery times, and equivalent 12-month outcomes compared with conventional median sternotomy. These findings support MICS as a safe and effective alternative in appropriately selected patients when performed in experienced surgical centers.