Minimally invasive versus open mitral valve surgery: a consensus statement of the international society of minimally invasive coronary surgery (ISMICS) 2010.

OBJECTIVE: : The purpose of this consensus conference was to deliberate the evidence regarding whether minimally invasive mitral valve surgery via thoracotomy improves clinical and resource outcomes compared with conventional open mitral valve surgery via median sternotomy in adults who require surgical intervention for mitral valve disease.

METHODS: : Before the consensus conference, the consensus panel reviewed the best available evidence up to March 2010, whereby systematic reviews, randomized trials, and nonrandomized trials were considered in descending order of validity and importance. The accompanying meta-analysis article in this issue of the Journal provides the systematic review of the evidence. Based on this systematic review, evidence-based statements were created for prespecified clinical questions, and consensus processes were used to derive recommendations. The American Heart Association/American College of Cardiology system was used to label the level of evidence and class of each recommendation.

RESULTS AND CONCLUSIONS: : Considering the underlying level of evidence, and notwithstanding the limitations of the evidence base (retrospective studies with important differences in baseline patient characteristics, which may produce bias in results of the evidence syntheses), the consensus panel provided the following evidence-based statements and overall recommendation:In patients with mitral valve disease, minimally invasive surgery may be an alternative to conventional mitral valve surgery (Class IIb), given that there was comparable short-term and long-term mortality (level B), comparable in-hospital morbidity (renal, pulmonary, cardiac complications, pain perception, and readmissions) (level B), reduced sternal complications, transfusions, postoperative atrial fibrillation, duration of ventilation, and intensive care unit and hospital length of stay (level B). However, this should be considered against the increased risk of stroke (2.1% vs 1.2%) (level B), aortic dissection (0.2% vs 0%) (level B), phrenic nerve palsy (3% vs 0%) (level B), groin infections/complications (2% vs 0%) (level B), and, prolonged cross-clamp time, cardiopulmonary bypass time, and procedure time (level B). The available evidence consists almost entirely of observational studies and must not be considered definitive until future adequately controlled randomized trials further address the risk of stroke, aortic complications, phrenic nerve complications, pain, long-term survival, need for reintervention, quality of life, and cost-effectiveness.