The zero pressure fixed medtronic intact porcine valve: an 8.5 year review

The Medtronic Intact valve is the only porcine valve which is fixed in glutaraldehyde at zero pressure. This preserves near normal extensibility of the leaflet collagen, enabling full leaflet opening without kinking, which in turn should improve durability compared with low and high pressure fixed valves. From 1983 to 1991, 265 patients had 276 Intact valves inserted (125 aortic, 129 mitral, 22 tricuspid). The mean age was 53 years (10-81), with 24% below 40 years. The 100% follow up represents 911 patient years and averaged 50 months (3-106) in survivors. The actuarial survival was 54% +/- 9% at eight years, compared with a matched general population of 82%. The mean NYHA class was 3.2 preoperatively and 1.2 at follow up. At eight years, freedom from infective endocarditis was 97% +/- 1%, from thromboembolism 89% +/- 3%, and from non-structural dysfunction 96% +/- 2%. Reoperation was required in three patients for infective endocarditis, in six for non-structural dysfunction and in seven for structural valve deterioration (SVD). Freedom from SVD in the aortic position (mean age 59 years) was 100%, in the tricuspid position (mean age 48 years) 80% +/- 7%. In the mitral position, freedom from SVD was 86% +/- 10% in patients aged 60 years or more (n = 39, two events), 96% +/- 4% in those aged 40-59 years (n = 23, one event in a patient with renal failure), 67% +/- 16% in those aged 20-39 years (n = 31, three events in two following pregnancy) and 38% +/- 28% in those under 20 years (n = 9, two events).(ABSTRACT TRUNCATED AT 250 WORDS)