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Background: The pericardial bovine prosthesis Pericarbon should offer some advantages in comparison with the former generations, because its development is focused on solving previous problems and resulted in the variation of the pericardial fixation method, of valve structure and of stent coating. This hypothesis was evaluated through a retrospective follow-up., Methods: Between 1985 and 1989, 78 Pericarbon prostheses O 29 were implanted in mitral position by the same surgeon. All patients received warfarin for the first three months to maintain an International Normalized Ratio between 2.5 and 3.5; after which they received antiaggregant therapy indefinitely. With an average follow-up period of 7.34 years for a total of 573 patient-years, we evaluated perioperative and late mortality, late morbidity (thromboembolic and haemorrhagic events, reoperations, primary tissue failures, endocarditic events) and patient clinical conditions., Results: Perioperative mortality was 1.28% (1/78), late mortality was 11.6% (9/77) with 5 valve-related deaths. 5-year survival was 93% and 10-year survival 97%. Fifteen patients required reoperation for prosthetic replacement, fourteen for primary tissue failure. There were ten minor thromboembolic events, one major event, one haemorrhage and one prosthetic endocarditis (the last two with patient exitus). After 10 years (75% of patients were in New York Heart Association class I-II., Conclusions: Besides the known better haemodynamic performance, Pericarbon bioprosthesis seems to present a survival and redofreedom curve comparable to the best porcine prosthesis, with less incidence of endocarditis, thromboembolic events and prosthesis leakage.

Background: Stent deformation seems to be effective in the long term performances of bioprostheses., Methods: The Inward Banding Angle (IBA) of three different models of bioprostheses explanted during the period 1991-1992 at our Division of Cardiac Surgery in 45 different patients (26 males; 9 females; mean age 59.71 +/- 10.74, range 26-75) has been measured. Explanted valves were as follow: Hancock, (H = 13); Carpentier-Edwards (C = 14) e Xenomedica (X = 18). Primary tissue failure was the most common cause of re-operation (n = 30; 66.7%) but also endocarditis (n = 6; 13.3%) and paraprothetic leak (n = 10; 22.2%). A semi-quantitative score (0-4) was used to assess calcifications (1.51 +/- 1.56); tears (0.41 +/- 0.98); vegetation's (0.51 +/- 0.99) and fibrosis (2.7 +/- 1.27). The mean follow-up was 7.77 +/- 3.79 years (range 1.5 +/- 16 years). The mean IBA evaluated after explantation was 3.34 +/- 2.29 degrees., Results: Statistical analysis showed a significance in term of IBA in the Hancock group vs Carpentier (P < 0.02); a less duration in the Xenomedica group vs H and C (p < 0.001) and an increased susceptibility to vegetation's and fibrosis in the Xvs C (p < 0.01) and H (p < 0.05) respectively. A suggestive correlation between IBA and time and between IBA and diameter was found but no statistical significance was observed., Conclusions: In conclusions, it is suggested that all materials tends to deform during time and a possible explanation of stent deformation can be the different material used in the stent fabrication. Moreover, mechanical stress and compression around the ring can be another mechanism of creep.

Optimal mitral valve repair or replacement requires an excellent exposure. We used a transeptal approach since 1975 at our Institution to obtain adequate exposure of mitral valve in 135 patients (48 males, 87 females, mean age 47.4 +/- 11.8, range 12-68). A mechanical valve (Bjork = 120; Sorin = 15) was implanted in mitral position. Associated procedures were performed in the 66% of the patients and most of them were tricuspid repair. About half of the patients were at the second or third cardiac operation after a previous closed heart mitral commissurotomy 15.15 +/- 5.6 years before. Exposure was excellent in the 95% of the cases. Hospital mortality was 12.6% and significantly major in patients at redo operation. Three patients with a concomitant aortic valve replacement required a definitive pace-marker implantation. A complete follow-up was possible in all patients who survived at operation. Actuarial survival rate at 10 years in 83% and at 20 years is 70%. Freedom from all events valve related at 10 years is 86% and at 20 years is 74%. None of the patients at echocardiographic follow-up revealed complications related to the transeptal approach to the mitral valve. In conclusion we suggest the use of transeptal approach to the mitral valve in case of redo-operations, concomitant tricuspid repair, small left atrium and in case of mitral valve repair because of the good exposure and the less inherent complications.

From March 1990 to July 1991, 110 patients (44 males, 66 females; mean age 54.44 +/- 8.8 years) underwent hearth valve replacement with a CarboMedics bileaflet prosthesis (CarboMedics Inc, Texas, USA). Preoperative pathophysiologic conditions were: aortic stenosis in 32 patients, aortic regurgitation in 22 patients; mitral stenosis in 27 patients and mitral regurgitation in 14 patients. Mitroaortic disease was present in 14 patients but 1 had triple valve disease. NYHA class was III or IV in 91 patients (83%). Operative mortality rate was 0.91% (1 patients). Actuarial survival rate is 95% at 58 months. Actuarial freedom from thromboembolic events in 95% at 58 months. Actuarial freedom from hemorrhage is 100%. Endocarditis befell in 2 patients; actuarial freedom from this complication at 58 months is 95%. Actuarial freedom from reoperation in 99%. We conclude that the low incidence of valve related events and the low mortality supports the use of the bileaflet valve CarboMedics.

Since 1990 the "Heart Transplant Program" has been instituted in the Piemonte Region. Until now the program had regular development according to the number of transplantations and the high quality of clinical results. Sixty heart transplantations has been performed with a 36 month survival close to 80%. Our data demonstrate that after heart transplantation prognosis of end-stage cardiac disease is highly improved either for life expectancy and for quality of life. Our program includes several aspects of scientific research from physiology to clinic, from biochemistry to immunology, from infectivology to pathology, from intensive care to surgery. Several very positive multi disciplinary investigations have been activated.

This paper describes a procedure of cellular dissociation which allows the isolation of single cells from the human heart while preserving their integrity and physiological function necessary for electrophysiological studies in vitro. During open heart surgery, biopsies were obtained from the right atrium of the beating heart in 16 patients immediately before starting the extracorporeal circulation. The tissue was immediately placed in a cardioplegic solution at 4 degrees, and subsequently in a free-calcium solution at 20 degrees from 20' to 30'. It was then exposed to the proteolytic action of Collagenase type I and Protease type VII (Sigma Chemical Co., St Louis, USA) at 35 degrees for a maximum of 5 hours. The cells were finally transferred into a Tyrode solution at room temperature. With this method we obtained up to 70% of intact human myocytes, 40% of which calcium-tolerant. The subsequent electrophysiological studies performed showed that the cells maintained their morphological and physiological properties.