Minimally-invasive versus conventional aortic valve replacement - perioperative course and mid-term results

Objective: We performed a case-control-study to compare perioperative and m id-term results of minimally invasive with conventional aortic valve replac ement. Methods: Between 8/96 and 7/97, 113 patients underwent isolated aort ic valve replacement (minimally invasive: 29, conventional: 84) in our Depa rtment. Diagnosis, ejection fraction, pressure gradient/regurgitation fract ion, age, gender and body-mass-index were used as matching criteria for the case-control-study. For qualitative data correspondence was requested, for quantitative data deviations up to 10% were accepted. With these criteria 25 patients of the minimally invasive group were matched to 25 patients of conventional group. All patients were reexplored 1 year after aortic valve replacement. Statistical analysis was done by the Fisher's exact test for q ualitative data and the Mann-Whitney test for quantitative data. Results: W e implanted 15 (20) bioprosthesis' and 10 (five) mechanical prosthesis' in the minimally invasive, respectively, conventional group. There were no sta tistically significant differences between both groups with respect to the perioperative course, only duration of surgery (mean 201.6 vs. 143.9 min, P < 0.01) and extracorporeal circulation (mean 116.1 vs. 71.3 min, P < 0.01) as well as aortic-cross-clamp-time (mean 77.9 vs. 46.9 min, P < 0.01) were significantly longer in the minimally invasive group. Postoperative compli cations occurred in one patient of the minimally invasive group (dissection of the right coronary artery) and four patients of the conventional group (third degree AV block, pneumothorax, grand mal convulsion, cardiopulmonary resuscitation). Two patients, one of each group, died during follow-up for unknown reasons. Follow-up revealed no significant differences with respec t to clinical and echocardiographic data, but the shorter skin incision was cosmetically more accepted by patients of the minimally invasive group. Mi nor paravalvular leaks occurred in four patients of the minimally invasive and three patients of the conventional group as diagnosed by transthoracic echocardiography. Conclusions: Both surgical techniques may be performed wi th comparable perioperative and mid-term results, but the better cosmetic r esult in the minimally invasive group is paid by a longer duration of surge ry. (C) 1999 Elsevier Science B.V. All rights reserved.