AORTIC-VALVE REPLACEMENT - IS THE STENTLESS XENOGRAFT AN ALTERNATIVE TO THE HOMOGRAFT - EARLY RESULTS OF A RANDOMIZED STUDY

From November 1992 to October 1993 we randomized 101 patients over 60 years of age undergoing elective aortic valve replacement, with or wit hout concomitant coronary artery bypass grafting, to receive either a cryopreserved aortic or pulmonary homograft (n = 38) or a stentless po rcine aortic valve xenograft (Edwards Prima 2500) (n 63). The majority of all valves (92%) were inserted freehand in the subcoronary positio n, Six homografts (16%) were implanted as a free-root replacement and two xenografts (3%) were used as a mini root. There were four in-hospi tal deaths (4%), three in the homograft group and one in the xenograft group (homograft, 7.9% versus xenograft, 1.6%; p = not significant). Forty-one patients were followed at 3- to 6-month intervals for 9 +/- 2 months (3 to 14 months) and valve pathology was assessed routinely b y means of color now Doppler echocardiography. Two patients in the hom ograft group developed new aortic insufficiency grade II; all others r emained with trivial or no valve incompetence. The mean gradient remai ned unchanged to immediate postoperative measurements (homograft, 5 +/ - 1 mm Hg versus xenograft, 11 +/- 4 mm Hg; p < 0.001). Despite a slig htly higher transvalvular gradient, xenografts achieved excellent init ial results when compared to homografts. Ease of implantation and free dom from thromboembolism indicate that xenografts can be an acceptable alternative to homografts, particularly in older patients with small aortic annuli. Long-term studies assessing the durability of the xenog raft are necessary for final evaluation.