Totally endoscopic mitral valve replacement: reasons for non-feasibility of repair and 5-year outcomes

Abstract

Totally endoscopic mitral valve (MV) surgery is an established therapy for mitral regurgitation (MR) with high repair rates at experienced centers. In certain scenarios, however, repair is not feasible, necessitating chordal-sparing MV replacement. This study investigates the reasons for totally endoscopic MV replacement and reports 5-year outcomes. Between 2012 and 2022, 1,037 consecutive patients underwent totally endoscopic MV surgery. Of those, 75 patients (7.2%) underwent chordal-sparing MV replacement. Preoperative characteristics, periprocedural data, and mid-term outcomes were retrospectively analyzed and compared to a 1:1 propensity score-matched repair group. After matching, baseline characteristics were balanced. Indications for MV replacement included sclerotic leaflets (28.0%), endocarditis (26.7%), MV stenosis (17.3%), failed repair attempt (17.3%), rheumatic disease (12.0%), and residual MR after transcatheter edge-to-edge repair (7%). Cross-clamp and bypass times were similar. Re-thoracotomy occurred in 14.7% vs. 6.7%, while permanent pacemaker implantation occurred solely after replacement (16.0%). Low cardiac output rates were comparable (6.7% vs. 5.5%). Transvalvular gradients at discharge were higher after replacement ( p  < 0.001). No paravalvular leakage was observed. In-hospital mortality was 4% vs. 0%. Five-year survival was 86.7% vs. 94.7%, and reintervention rates were similar (4.0% vs. 6.7%). Totally endoscopic MV surgery at a high-volume center is infrequently associated with MV replacement. The main reasons included sclerotic leaflet pathology, MV stenosis, and endocarditis. Despite a higher comorbidity burden and residual baseline imbalance after matching, early and mid-term outcomes were acceptable. Totally endoscopic chordal-sparing MV replacement represents a safe and clinically effective treatment option for selected patients.