Intermediate-Term Results of 505 Consecutive Minithoracotomy Mitral Valve Procedures

BACKGROUND: : Patient demand for less invasive surgery and interest in avoiding sternotomy has led to the increased use of the minithoracotomy for mitral valve surgery. Although the feasibility of this approach has been established, few data are available regarding intermediate-term results. METHODS: : A total of 505 consecutive minithoracotomy mitral valve procedures performed between 1996 and 2004 were analyzed. Procedures were mitral replacement (191/505, 38%) and repair (314/505, 62%). Concomitant cardiac procedures were performed in 78 cases (13%) (maze 36, tricuspid 29, atrial septal defect/patent foramen ovale 13) and reoperation in 92 cases (18%). Arterial cannulation was ascending aorta in 403 cases (80%), femoral in 101 cases (20%), and axillary in 1 case (<1%). An endoluminal aortic clamp was used in 406 cases (80%), an external clamp was used in 19 cases (4%), and 80 procedures (16%) were performed with ventricular fibrillation. Robotic assistance was used in 12 cases (2%). RESULTS: : Mean patient age was 58.7 years (range 18-90 years). Median follow-up was 3.1 years. Operative mortality was 4 of 505 cases (<1%). Major complications included stroke in 7 cases (1%) and reoperation for bleeding in 18 cases (4%); there were no cases of mediastinitis. Late complications included chronic aortic dissection in 1 case (<1%) and mitral reoperation in 13 cases (3%) (subacute bacterial endocarditis 6, failed repair 2, other 5). Five-year survival was (83% ± 2%) and freedom from mitral reoperation was (96% ± 1%). Follow-up echocardiograms were available in 246 of 314 cases (78%) mitral repairs and mean mitral regurgitation grade was 1 ± 1. Mitral regurgitation was grade 3-4+ in 14 of 246 cases (6%) (subacute bacterial endocarditis 4, low ejection fraction 5, other 5). Five-year freedom from 3-4+ mitral regurgitation was 89% ± 3%. CONCLUSIONS: : Mitral valve surgery via minithoracotomy can be performed safely with a low perioperative complication rate. A durable technical result and excellent long-term survival can be expected.