HANCOCK-II PORCINE BIOPROSTHESIS - EXCELLENT DURABILITY AT INTERMEDIATE-TERM FOLLOW-UP

Objectives. This study aimed to assess the clinical performance and du rability of a new generation of porcine valve, the Hancock II bioprost hesis, at intermediate-term follow-up. Background. Standard porcine bi oprostheses undergo progressive structural deterioration, mainly due t o cusp and commissural calcification, affecting durability and requiri ng reoperation. The Hancock II bioprosthesis, which is currently under going clinical investigation, is made from a porcine aortic valve trea ted with a calcium-retarding agent (sodium dodecyl sulfate [T6]), whic h should delay onset of calcification and increase durability. Methods . From May 1983 to December 1992, we used the Hancock II bioprosthesis in aortic (59 patients), mitral (101 patients) and mitral-aortic (25 patients) valve replacement procedures. Postoperative follow-up ranged from 0.1 to 8.7 years (mean [+/-SD] 4.5 +/- 2.6 years) and was 100% c omplete. Freedom from major postoperative events was calculated at 7 y ears for patients with aortic valve replacement and at 8 years for tho se with mitral and mitral-aortic valve replacement. Results. The actua rial survival rate was 48 +/- 10%, 76 +/- 3% and 63 +/- 6%; freedom fr om valve-related mortality was 91 +/- 4%, 94 +/- 2% and 89 +/- 6%; fre edom from thromboembolism was 80 +/- 11%, 90 +/- 2% and 79 +/- 7%; and freedom from reoperation was 100%, 97 +/- 1% and 89 +/- 6% after aort ic, mitral and mitral-aortic valve replacement, respectively, No struc tural valve deterioration occurred. Conclusions. At intermediate-term follow-up the Hancock II bioprosthesis showed excellent durability in all positions. However, the effectiveness of anticalcification treatme nt must be assessed with longer follow-up studies.