Midterm outcomes of minimally invasive mitral valve surgery in a heterogeneous valve pathology cohort: respect or resect?

Background: Minimally invasive mitral valve surgery (MIV) through a right lateral thoracotomy has become the standard of care at specialized centers and might soon will be the only acceptable surgical treatment option in the future era of interventional procedures. The aim of our study was to analyze the outcomes of our MIV-specialized, single-center, mixed valve pathology cohort with regard to morbidity, mortality and midterm outcomes comparing two different repair techniques (respect versus resect). Methods: Baseline and operative variables, postoperative outcomes and follow-up information about survival, valve competence and freedom from reoperation were retrospectively collected and analyzed. The repair cohort was divided into three groups (resection, neo-chordae and both) and compared for outcomes. Results: Between July 22(nd) 2013 and May 31st 2022 a total of 278 consecutive patients underwent MIV. Out of those, we identified 165 eligible patients for the three repair groups: 82 patients (29.5%) had "resection", 66 "neo-chordae" (23.7%) and 17 "both" (6.1%). All preoperative variables were comparable between the groups. The predominant valve pathology of the entire cohort was degenerative disease with 20.5% Barlow's, 20.5% bi-leaflet and 32.4% double segment pathology. Bypass time was 164 +/- 47, cross-clamp time 106 +/- 36 minutes. All valves planned for repair (85.6%) were successfully repaired except for 13 resulting in a repair rate of 94.5%. Only 1 patient (0.4%) had to be converted to clamshell and 2 (0.7%) needed rethoracotomy for bleeding. Mean intensive care unit (ICU) stay was 1.8 days and hospital stay 10.6 +/- 1.3 days. In-hospital mortality was 1.1% and the incidence of stroke (1.8%). All in-hospital outcomes were comparable between the groups. Follow up was complete in 86.2% (n=237) for a mean of 3.7 +/- 0.8, up to 9 years. Five-year survival was 92.6% (P=0.5) and freedom from re-intervention 96.5% (P=0.1). All but 10 patients had mitral regurgitation less than grade 2 (95.8%, P=0.2) and all but two had less than New York Heart Association (NYHA) II (99.2%, P=0.1). Conclusions: Despite a heterogeneous cohort with mixed valve pathologies, there is a high reconstruction rate, low short- and midterm morbidity, mortality and need for re-intervention with comparable outcomes of the resect and respect technique in a specialized MIV center.