Minimally Invasive Surgery: Standard of Care for Mitral Valve Endocarditis

Abstract

Background. Minimally invasive surgery via right mini-thoracotomy has become the standard of care for the treatment of mitral valve disease worldwide, particularly at high-volume centers. In recent years, the spectrum of indications has progressively shifted and extended to fragile and higher-risk patients, also addressing more complex mitral valve disease and ultimately including patients with native or prosthetic infective endocarditis. The rationale for the adoption of the minimally invasive approach is to minimize surgical trauma, promote an earlier postoperative recovery, and reduce the incidence of surgical wound infection and other nosocomial infections. The aim of this retrospective observational study is to evaluate the effectiveness and the early and late outcome in patients undergoing minimally invasive surgery for mitral valve infective endocarditis. Methods. Prospectively collected data regarding minimally invasive surgery in patients with mitral valve infective endocarditis were entered into a dedicated database for the period between January 2007 and December 2022 and retrospectively analyzed. All comers during the study period underwent a preoperative evaluation based on their clinical history and anatomy for the allocation to the most appropriate surgical strategy. The selection of the mini-thoracotomy approach was primarily driven by a thorough transthoracic and especially transesophageal echocardiographic evaluation, coupled with total body and vascular imaging. Results. During the study period, 92 patients underwent right mini-thoracotomy to treat native (80/92, 87%) or prosthetic (12/92, 13%) mitral valve endocarditis at our institution, representing 5% of the patients undergoing minimally invasive mitral surgery. Twenty-six (28%) patients had undergone previous cardiac operations, whereas 18 (20%) presented preoperatively with complications related to endocarditis, most commonly systemic embolization. Sixty-nine and twenty-three patients, respectively, underwent early surgery (75%) or were operated on after the completion of the targeted antibiotic treatment (25%). A conservative procedure was feasible in 16/80 (20%) patients with native valve endocarditis. Conversion to standard sternotomy was necessary in a single case (1.1%). No cases of intraoperative iatrogenic aortic dissection were reported. Four patients died perioperatively, accounting for a thirty-day mortality of 4.4%. The causes of death were refractory heart or multiorgan failure and/or septic shock. A new onset stroke was observed postoperatively in one case (1.1%). Overall actuarial survival rate at 1 and 5 years after operation was 90.8% and 80.4%, whereas freedom from mitral valve reoperation at 1 and 5 years was 96.3% and 93.2%, respectively. Conclusions. This present study shows good early and long-term results in higher-risk patients undergoing minimally invasive surgery for mitral valve infective endocarditis. Total body, vascular, and echocardiographic screening represent the key points to select the optimal approach and allow for the extension of indications for minimally invasive surgery to sicker patients, including active endocarditis and sepsis.

Keywords: cardiac reoperation; infective endocarditis; mini-thoracotomy; minimally invasive cardiac surgery; mitral valve; prosthetic valve endocarditis; systemic embolization.

Figure 1

Exposure of the mitral valve via a right mini-thoracotomy and endoscopic view. (a) Example of large vegetation on scallop A2 with leaflet perforation. (b) Extensive resection of the anterior leaflet around the infected tissue. (c) Mitral valve repair with patch on the anterior leaflet and ring annuloplasty.

Figure 2

(a) Kaplan–Meier curve of survival probability. (b) Freedom from MV reoperation according to diagnosis.