Handling Extensive Mitral Annular Calcification via a Minimally Invasive Right Mini-Thoracotomy Approach

Mitral annular calcification is a chronic and degenerative process of the fibrous base of the mitral valve. Surgical management of mitral valve dysfunction with severe annular calcification remains technically demanding and, to date, the preferred approach is still a standard full sternotomy. We aimed to analyze and report our experience with mitral valve surgery addressing annular calcification via the minimally invasive approach through a right mini-thoracotomy. Data of patients with mitral valve disease and underlying annular calcification undergoing minimally invasive surgery from 2018 to 2022 were prospectively collected and retrospectively analyzed. The severity of mitral annular calcification was categorized with an angio-computerized tomography scan analysis as mild, moderate or severe according to calcium thickness, calcium distribution, and trigone and leaflet involvement using the Mitral Annular Calcification Computerized Tomography-score. During the study period, 27 patients with mitral valve disease and associated mitral annular calcification were enrolled. The most common etiology was advanced Barlow’s disease, which was encountered in 18 cases (67%). Mitral valve replacement was performed in 21 patients (78%). No intraoperative death, atrioventricular disruption, or circumflex coronary artery injury occurred. Conversion to sternotomy was necessary in a single case. Residual moderate periprosthetic leak requiring early reoperation and permanent heart block mandating permanent pacemaker implantation were reported in one and in three patients, respectively. No cases of stroke were reported. Two patients died, accounting for a 7.4% perioperative mortality. At a median follow-up of 9 months, one patient had residual moderate mitral regurgitation, whereas two patients required short-term reoperation and prosthetic valve (re)replacement. Minimally invasive mitral valve surgery via right mini-thoracotomy should be considered an and effective approach to be indicated also in patients with mild-to-severe mitral annular calcification. Routine angio-computerized tomography scan during work-up is a mandatory step to stratify the anatomical extension and severity of the mitral annular calcification.