Minimally invasive approach provides at least equivalent results for surgical correction of mitral regurgitation: A propensity-matched comparison

Abstract

Objective Minimally invasive approaches to mitral valve surgery are increasingly used, but the surgical approach must not compromise the clinical outcome for improved cosmesis. We examined the outcomes of mitral repair performed through right minithoracotomy or median sternotomy. Methods Between January 2002 and October 2011, 1011 isolated mitral valve repairs were performed in the University of Pennsylvania health system (455 sternotomies, 556 right minithoracotomies). To account for key differences in preoperative risk profiles, propensity scores identified 201 well-matched patient pairs with mitral regurgitation of any cause and 153 pairs with myxomatous disease. Results In-hospital mortality was similar between propensity-matched groups (0% vs 0% for the degenerative cohort; 0% vs 0.5%, P = .5 for the overall cohort; in minimally invasive and sternotomy groups, respectively). Incidence of stroke, infection, myocardial infarction, exploration for postoperative hemorrhage, renal failure, and atrial fibrillation also were comparable. Transfusion was less frequent in the minimally invasive groups (11.8% vs 20.3%, P = .04 for the degenerative cohort; 14.0% vs 22.9%, P .03 for the overall cohort), but time to extubation and discharge was similar. A 99% repair rate was achieved=in patients with myxomatous disease, and a minimally invasive approach did not significantly increase the likelihood of a failed repair resulting in mitral valve replacement. Patients undergoing minimally invasive mitral repair were more likely to have no residual post-repair mitral regurgitation (97.4% vs 92.1%, P = .04 for the degenerative cohort; 95.5% vs 89.6%, P = .02 for the overall cohort). In the overall matched cohort, early readmission rates were higher in patients undergoing sternotomies (12.6% vs 4.4%, P = .01). Over 9 years of follow-up, there was no significant difference in long-term survival between groups (P = .8). Conclusions In appropriate patients with isolated mitral valve disease of any cause, a right minithoracotomy approach may be used without compromising clinical outcome.

Is minimally invasive thoracoscopic surgery the new benchmark for treating mitral valve disease?

“…Initial experiences with thoracoscopic mitral valve surgery documented mortality rates near 10% (11). However, more recent studies, including our own, reproducibly demonstrate mortality rates less than 1%, particularly in the case of degenerative mitral valve disease (4,5,7,12). Furthermore, a recent metaanalysis that pooled over 20,000 patients reported no difference in operative mortality between video-assisted and conventional sternotomy approaches (13).…”

“…Intermediate and long-term survival is equally encouraging. Propensity score matched comparisons of minimally invasive and sternotomy approaches to mitral valve surgery reveal similar survival up to a decade after surgery (5)(6)(7). In our analysis of 402 well-matched patient pairs with mitral regurgitation of any etiology, 9-year survival was 96% after thoracoscopic mitral valve repair, and 89% following the conventional approach (7).…”

“…Reductions in postoperative bleeding and transfusion requirements after minimally invasive mitral valve surgery are likely due to smaller incisions and less extensive mediastinal dissection (5,7,8,(17)(18)(19)(20)(21)(22)(23). Other centers, including our own, have also demonstrated significant associations between less invasive mitral valve surgery and reduced bleeding and transfusion (7). Two separate metaanalyses reported significant reductions in postoperative bleeding and/or transfusion requirements when surgery was performed via right minithoracotomy (10,13).…”

“…Therefore, thoracoscopic mitral valve surgery must be as safe, effective, and durable as the traditional "open" approach. To date, no comparison study has shown a significant difference in operative mortality when comparing minimally invasive mitral valve surgery to that through median sternotomy (4)(5)(6)(7)(8)(9)(10). Initial experiences with thoracoscopic mitral valve surgery documented mortality rates near 10% (11).…”

“…However, the approach through the right anterolateral thoracotomy actually provides a more en face view of the mitral valve, and a more medial incision yields a very manageable distance such that all sutures may be tied by hand ( Figure 2). Examination of the literature demonstrates that operative approach does not appear to significantly impact the likelihood of successful mitral valve repair (7,14) or durability (15). In a propensity score matched comparison of patients with degenerative mitral regurgitation, moderate mitral regurgitation only developed in 16 patients (4%) and recurrence did not differ by surgical approach (15).…”