Can we use minimally invasive mitral valve surgery as a safe alternative to sternotomy in high-risk patients?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether minimally invasive mitral valve surgery (MIMVS) should be considered as an alternative to conventional sternotomy (ST) in high-risk patients. Eighty-six papers were found by a systematic search, of which seven were comparing MIMVS with ST in high-risk patients and addressing the clinical question. Five were retrospective observational and two were propensity-matched studies. One paper included patients with infective endocarditis, one with preoperative renal failure, two papers the elderly, three papers compared redo surgery. Author, journal, date, patient group, country of publication, relevant outcomes, results and study weaknesses were tabulated. In total, these seven studies included 1254 high-risk patients (n = 523 MIMVS, 731 ST) undergoing mitral valve surgery, either repair or replacement. End-points of interest were mortality, intraoperative and postoperative outcomes and survival. With regard to MIMVS group, in-hospital mortality was lower in three studies and with no statistically significant differences in the other four; cardiopulmonary bypass (CPB) times were similar in one study, but were longer in three other studies. MIMVS led to reduced postoperative complications in six studies (one did not report complications); among studies that included late mortality, one reported better survival in the MIMVS group whereas the other two did not report differences. We conclude that, although MIMVS may be associated with longer CPB and cross-clamp times, it is at least as safe as ST in terms of both mortality and morbidity, in these high-risk groups.