Fifteen-year experience with minimally invasive approach for reoperations involving the mitral valve.

OBJECTIVE: Reoperative sternotomy to address mitral valve pathology carries substantial risk, especially with patent bypass grafts or an aortic valve prosthesis. We previously reported our early experience with minimally invasive right thoracotomy and peripheral cannulation as an alternative strategy, and we recently reviewed our cumulative 15-year hospital outcomes with this approach.
METHODS: Between June 1996 and April 2010, we performed right minithoracotomy for reoperations involving the mitral valve on 167 patients, 85 (51%) of these since 2006. Seventy-one percent had undergone previous coronary artery bypass grafting and 38% a previous valve procedure. Fibrillatory arrest was used in 77% and aortic clamping and root cardioplegia in 23%. Nineteen procedures were performed with robotic assistance.
RESULTS: Mitral repair frequency increased during each 5-year interval of our experience (1996-2000, 43%; 2001-2005, 53%; 2006-2010, 72%; P = .019), including 80% of native mitral valves without stenosis. Concomitant procedure frequency, most commonly atrial fibrillation ablation, also increased during each 5-year interval (0%, 21%, 48%; P < .0001). Thirty-day mortality was 3.0% (5/167), 0% since 2005. There were no conversions to sternotomy or aortic dissections. Stroke, in 2.4% (4/167), was statistically unrelated to fibrillatory arrest. Increased New York Heart Association functional class (odds ratio, 5.6; 95% confidence interval 1.1-27.8; P = .037) was the only independent predictor of mortality in multivariable analysis.
CONCLUSIONS: Our updated experience confirmed the effectiveness of minimally invasive right thoracotomy to treat mitral pathology while avoiding reoperative sternotomy risk. We found fibrillatory and cardioplegic arrest methods to be safe myocardial preservation strategies with this approach.