Long-term clinical results with the Ionescu-Shiley pericardial xenograft.

From 1977 to 1987, 829 Ionescu-Shiley pericardial valves (Shiley, Inc., Irvine, Calif.) were implanted in 766 patients at the University of Ottawa Heart Institute. There were 476 patients who had aortic valve replacement, 234 who had mitral valve replacement, and 44 who had double valve replacement. The standard-profile design was used in 508 patients and the low-profile design in 321 patients. Follow-up was obtained for 97% of patients, with calculation of event-free probabilities. At 10 years the overall probability of freedom from structural failure was 48% +/- 7% after aortic valve replacement, 44% +/- 15% after mitral valve replacement, and 79% +/- 11% after double valve replacement. Although at 5 years the probability of failure was statistically lower with the low-profile design, this favorability was lost by 6 years. Freedom from structural failure was only 47% +/- 7% for the standard-profile valve at 10 years. Thus the probability of freedom from reoperation was only 46% +/- 7% after aortic valve replacement, 39% +/- 6% after mitral valve replacement, and 65% +/- 20% after double valve replacement at 10 years. Thromboembolism occurred in 69 patients, for a predicted freedom from this complication at 10 years of 79% +/- 3% after aortic, 73% +/- 7% after mitral, and 96% +/- 4% after double valve replacement. There were 31 cases of endocarditis. The 10-year predicted freedom from endocarditis, therefore, was 86% +/- 3% after aortic, 98% +/- 1% after mitral, and 97% +/- 1% after double valve replacement. A total of 221 operative and late deaths were recorded in this series. Prosthetic valve failure accounted for 27% of late deaths. The 10-year survival rates were estimated to be 56% +/- 5% (aortic valve replacement), 54% +/- 6% (mitral valve replacement), and 51% +/- 8% (double valve replacement). We concluded that the Ionescu-Shiley pericardial xenograft provides less than optimal clinical performance and its use has been discontinued.

Omental pedicle grafting in the treatment of poststernotomy mediastinitis.

Mediastinitis after median sternotomy may be life-threatening. It should be managed by providing adequate mediastinal drainage, removing all foreign material (including infected and dead tissues) and obliterating any dead space. Obliterating dead space may be difficult using the usual method of creating a vacuum with large-bore tubes. Alternative methods consist of muscle or omental transpositions. The authors describe the cases of two men who had mediastinitis, 1 week and 3 months respectively, after coronary artery bypass grafting. In both cases, the mediastinitis was treated successfully by omental pedicle grafting. From their experience, the authors recommend omental grafting as a method of obliterating a large mediastinal dead space when the sternal edges can be approximated but the space cannot be closed by conventional methods.

Mitral valve replacement with Hancock porcine bioprostheses: up to 7-year follow-up.

From February 1976 to May 1981 at the University of Ottawa Heart Institute, 137 mitral valves were replaced with the Hancock porcine bioprosthesis. This study concerns 111 patients (55 men, 56 women) who had single-valve replacement. The average age of the patients was 53.0 years. The predominant lesion in the 102 patients who were receiving their first substitute valve was stenosis in 46% and regurgitation in 42%. Preoperatively, 82% were New York Heart Association (NYHA) class III or IV. Additional procedures were performed in 44 patients (39.6%). The 26 patients who had multiple valves replaced were considered only for durability studies. Hospital mortality was 8.9% for isolated replacement and 22% for replacement associated with aortocoronary bypass grafting. At the time of discharge, 50% of patients were in atrial fibrillation, 14% were taking warfarin and 82% antiplatelet agents. Follow-up was available for a total of 374 patient-years (average of 5.4 years per patient). The mean symptomatic improvement was 1.6 NYHA classes per patient. Actuarial analysis indicated a survival rate of 70% at 8 years. Of the 18 late deaths, 4 (22%) were valve-related. The rates of endocarditis and thromboembolism were 1.1% and 5.8% patient-year respectively. In the 137 prostheses at risk, intrinsic failure occurred at the rate of 4.7% patient-year for a cumulative rate of 35% at 8 years. The authors conclude that the Hancock porcine bioprosthesis provides good relief of symptoms in the mitral position with an acceptable rate of thromboembolism even without anticoagulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Ionescu-Shiley pericardial xenografts: follow-up of up to 6 years.

The results of valve replacement with the Ionescu-Shiley pericardial xenograft compare favorably with results obtained with other bioprostheses. From March, 1977, to July, 1983, 497 Ionescu-Shiley pericardial valves were implanted in 463 patients at the University of Ottawa Heart Institute. There were 292 patients who had aortic valve replacement (AVR), 140 with mitral valve replacement (MVR), 28 with double valve replacement, and 3 with triple valve replacement. The survivors were followed regularly. Actuarial analysis of late results indicates an expected survival of 71% at 6 years for patients who underwent AVR and 72% at 3 years for patients who had MVR. The only valve-related deaths were due to endocarditis, which occurred at a rate of 3.9% per patient-year for aortic valves and 0.6% per patient-year for mitral valves. Despite a low usage of formal anticoagulation, embolic complications occurred at a rate of 1.4% per patient-year for aortic valves and 4.0% per patient-year for mitral valves. Five valves were removed for intrinsic failure after 36 to 72 months of follow-up. New York Heart Association Functional Class improved an average of 1.28 classes per patient.