Bovine valved venous xenograft in pulmonary position: medium term evaluation of risk factors for dysfunction and failure after 156 implants.

AIM: This study evaluated risk factors for dysfunction and failure of the bovine Contegra valved conduit for right ventricle outflow tract reconstruction. METHODS: A total of 156 bovine jugular vein conduits were reviewed. Early and late mortality were evaluated. Seriate echocardiography was performed through the follow-up (mean 58±43.2 months, range 12 to 108 months), and risk factors and adverse events evaluation were analyzed by multivariate logistic regression. RESULTS: Hospital mortality was 7% (11/156). The only independent predictor of early mortality were cardiopulmonary bypass time >120 minutes and age <1 year. Postoperative mean RV to PA gradient was 10.4±9.1 mm Hg, increased to 18.7±14.5 mm Hg during the follow-up. A late gradient >30 mm Hg was assessed in 22 patients (15.1%),while 12 patients developed conduit valve regurgitation greater than 2+ without evidence of aneurismal formation. All patients with right ventricular (RV) to left ventricular (LV) pressure ratio >0.6 had conduit valve regurgitation. Acquired distal conduit stenosis was observed only in 1 patient. Thirteen patient underwent conduit replacement, diameter ≤14 mm was the only independent risk factor for reoperation. All explanted conduits were free from calcification and valve leaflets were intact and pliable. The Contegra graft itself was never cause of adverse event. CONCLUSION: The Contegra conduit provided excellent results and freedom from calcification in a medium-term follow-up. Younger age at operation was associated with higher need of replacements for conduit patient mismatch due to patient growth.

Double valve Implantation. Long-term evaluation of 8 different bioprostheses.

From January 1976 through December 1987, 194 patients with a mean age of 43.3 +/- 13.7 years (range, 11 to 74 years) underwent double (mitral and aortic) replacement of native valves with 8 types of bioprostheses: Carpentier-Edwards, 127 valves; Hancock, 76 valves; Liotta-Bioimplant, 57 valves; Ionescu-Shiley, 53 valves; Vascor, 27 valves; Carpentier-Edwards Pericardial, 22 valves; Angell-Shiley, 20 valves; and Implamedic, 6 valves. Concomitant cardiac procedures were performed in 25 patients (12.8%). There were 18 operative deaths (9.27%). Our retrospective analysis was restricted to 352 bioprostheses implanted in the 176 patients who survived surgery and were considered at risk for valve tissue failure. The overall cumulative duration of follow-up was 1,174.1 patient-years (range, 1 to 13 years). The durations of follow-up for specific valves were: Carpentier-Edwards, 920.2 valve-years; Hancock, 383.8 valve-years; Liotta-Bioimplant, 310.2 valve-years; Ionescu-Shiley, 357.7 valve-years; Vascor, 131.2 valve-years; Carpentier-Edwards Pericardial, 52.0 valve-years; Angell-Shiley, 167.0 valve-years; and Implamedic, 31.0 valve-years. Thirty patients had thromboembolic accidents, for a linearized incidence of 2.5% per patient-year. At 13 years, the actuarial freedom from thromboembolic accidents was 85.8% +/- 10.7%. Nine patients had endocarditis, for a linearized incidence of 0.7% per patient-year. At 13 years, the actuarial freedom from endocarditis was 92.0% +/- 1.5%. Twenty-four patients had valve tissue failure, for a cumulative linearized incidence of 1.87% per valve-year. The cumulative actuarial probability of freedom from valve tissue failure was 78.6% +/- 3.7% at 10 years and 51.2% +/- 10.7% at 13 years. The 24 patients with valve tissue failure all underwent reoperation: 20 of these had double valve replacement, 3 had aortic valve replacement alone, and 1 had mitral valve replacement alone. The mean interval between initial valve implantation and reoperation was 66.9 +/- 28.8 months. At reoperation, the hospital mortality was 15.1% (5 patients). This study showed that the long-term results of valve implantation are not significantly influenced by either prosthesis design or material. Moreover, the incidence of degenerative change was similar in the aortic and mitral positions.

Bioprostheses at twelve years.

From January 1976 through December 1986, seven different types of bioprostheses have been implanted in our center. The following bioprostheses (total 1,414) were implanted in 1,098 patients: Carpentier-Edwards 567, Hancock 302, Liotta 268, Ionescu-Shiley 127, Angell-Shiley 72, Vascor 68, Implamedic 10. Follow-up ranged from 1 to 12 years, cumulative duration of follow-up was 6,747 patient-years and 8,637 valve-years, being 95.4% complete. Cumulative actuarial probability of being free from tissue valve failure (TVF) was 85.1% +/- 2.0% at 10 years, and 61.6% +/- 9.6% at 12 years. Actuarial probability of being free from TVF was 71.2% +/- 10.8% at 12 years for Carpentier-Edwards, 51% +/- 21.7% at 12 years for Hancock, 73.4% +/- 14.1% at 11 years for Angell-Shiley, 53% +/- 27.4% at 9 years for Liotta, 68% +/- 14.8% at 11 years for Ionescu-Shiley, 53.2% +/- 22.2% at 7 years for Vascor, 72.2% +/- 21.5% at 5 years for Implamedic bioprostheses. In this comparison of seven different bioprostheses, there is a large group of valves behaving in a very similar way. Only a few prostheses showed a constant and early negative trend.

[Routine clinical use of a new disposable bubble oxygenator: a comparative study (author's transl)]. / Impiego clinico rutinario di un nuovo ossigenatore a bolle monouso. Una valutazione comparativa.

The new bubble Oxybel oxygenator (Bellco Laboratories) has been used for routine clinical perfusions in this Institution. A comparison has been made between two groups of 51 patients each, one group perfused with on Oxybel oxygenator (OXY) and the other with the Harvey H 1000 oxygenator (H-H). Among these patients a wide range of acquired and congenital cardiac lesions have been encountered. Both series were comparable for patients' age, sex distribution, body weight, procedures performed, perfusion time and preoperative values of hematocrit, serum creatinine, platelet count, plasma hemoglobin. The gas/blood flow ratio was 2.09 +/- 0.07 (+/- SE) for the H-H oxygenator and 1.38 +/- 0.06 for the OXY series (P < 0.001). Serum-creatinine 24-hrs postoperative values (mg/100 ml) were 1.58 +/- 0.17 for the H-H and 1.30 +/- 0.06 for the OXY series (NS); 48-hrs postoperative values were 1.28 +/- 0.11 for the H-H and 1.20 +/- 0.11 for the OXY (NS). The 60 minutes postoperative platelet count was 127.9 +/- 7 X 10(3) for the H-H and 120.9 +/- 6 X 10(3) for the OXY series (NS). Fourtyeight-hrs postoperative platelet count was 153.0 +/- 5 X 10(3) for the H-H and 151.8 +/- 6 X 10(3) for the OXY series (NS). Postoperative plasma hemoglobin values (mg/100 ml) were 91.55 +/- 7.18 for H-H and 117 +/- 17.8 for the OXY series (NS). Total postoperative bleeding was 1037.9 +/- 94 ml in the H-H and 1056.7 +/- 98.9 ml in the OXY series (NS). The more favorable gas/blood flow ratio observed with the Oxybel oxygenator did not affect clinical and haematologic results. These were comparable in both series.