No Clamp, No Problem: Ventricular Fibrillation-Induced Minimally Invasive Mitral Valve Surgery in High-Risk Patients

All articles of this category (opens in new window) Background: The demand for mitral valve surgery in patients with prior sternotomy or severe ascending aorta calcification is rising. Minimally invasive mitral valve surgery (MIMVS) performed under ventricular fibrillation with avoidance of aortic cross-clamping (ACC) may reduce perioperative complications in a high-risk population. Here, we present a retrospective analysis of outcomes of patients undergoing this technique. Methods: Between October 2009 and January 2025, 46 patients underwent MIM vs. without ACC for mitral valve regurgitation, stenosis, or both. The surgical approach consists of a right anterolateral mini-thoracotomy, femoral or subclavian cardiopulmonary bypass (CPB) with moderate hypothermia, and ventricular fibrillation during left-atrial opening. Procedural and perioperative patient data, as well as 30-day mortality, were analyzed in order to evaluate the safety and feasibility of the approach. Mean EuroSCORE II was 5.8 ± 5.7%. Results: Mean age was 63 ± 14.5 years, 59.1% were female, and 63% were in NYHA class III or IV. Ten patients (21.7%) had severe ascending aorta calcifications without prior cardiac surgery, and 36 (78.3%) were previously operated, including 13 (28.3%) after mitral valve surgery. MIM vs. was performed as a redo procedure in 31 patients (67.4%), re-redo in 4 (8.7%), and re-re-redo in 1 (2.2%). Mitral valve replacement was performed in 35 patients (76.1%), repair in 11 (23.9%), and tricuspid valve repair in 11 (30.6%). Mean operating-time, CPB-time, and hypothermia were 266.6 ± 82.6 minutes, 186.1 ± 76.5 minutes, and 27.9 ± 2.2°C, respectively. Perioperative stroke occurred in 2.2%, re-operation for bleeding in 10.9% and low cardiac output syndrome (LCOS) requiring mechanical circulatory support (MCS) in 8.7%. Seven patients (15.2%) developed pneumonia (five requiring prolonged ventilation ≥ 3 days), four (8.7%) a new-onset of atrial fibrillation, and 3 (6.5%) a new-onset of dialysis. No surgical site infections were observed. Mean ICU stay was 3.5 ± 3.4 days and hospital stay 15.9 ± 8. Thirty-day and in-hospital mortality were both 8.7%. Two patients passed away due to multiple organ failure (MOF) while on biventricular MCS, one suddenly due to suspected inner abdominal bleeding and one to LCOS and uncontrolled bleeding under MCS. Conclusion: Ventricular fibrillation induced MIM vs. without ACC represents a safe and efficient surgical technique in patients with prior sternotomy or hostile aorta. Complications such as stroke, bleeding, and dialysis remain relatively low despite the high-risk patient’s profile. Further multicenter investigation is necessary to strengthen the evidence of this technique. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany