Minimally invasive and conventional aortic valve replacement: a propensity score analysis.

Background: The study aimed to compare the short-term results of aortic valve replacement through minimally invasive and sternotomy approaches.

Methods: This is a retrospective, observational, cohort study of prospectively collected data on 709 patients undergoing isolated primary aortic valve replacement between 2004 and 2011. Of these, 338 were performed through either right anterior minithoracotomy or upper ministernotomy. With propensity score matching, 182 patients (minimally invasive group) were compared with 182 patients in conventional sternotomy (control group).

Results: After propensity matching, the 2 groups were comparable in terms of preoperative characteristics. Cardiopulmonary bypass time (117.5 vs 104.1 min, p<0.0001) and aortic cross-clamping time (83.8 vs 71.3 min, p<0.0001) were longer in the minimally invasive group, with no difference in length of stay (median 6 vs 5 days, p=0.43), but shorter assisted ventilation time (median 8 vs 7 hours, p=0.022). Overall in-hospital mortality was identical between the groups (1.64 vs 1.64%, p=1.0). No difference in the incidence of major and minor postoperative complications and related morbidity was observed. Minimally invasive aortic valve replacement was associated with a lower incidence of new onset postoperative atrial fibrillation (21% vs 31%, p=0.04). Reduction of the complication rate was observed. Median transfusion pack per patient was higher in the control group (2 vs 1 units, p=0.04).

Conclusions: Our experience shows that mini-access isolated aortic valve surgery is a reproducible, safe, and effective procedure and reduces assisted ventilation duration, the need for blood product transfusion, and incidence of post-surgery atrial fibrillation.