Twelve-year follow up with the Sorin Pericarbon bioprosthesis in the mitral position.

BACKGROUND AND AIMS OF THE STUDY: The aim of this study was to evaluate the long-term follow up of the Pericarbon pericardial bioprosthesis implanted in the mitral position. METHODS: Between January 1985 and January 1991, 78 patients (26 males, 52 females; mean age 56.9 +/- 7.8 years) underwent isolated mitral valve replacement with a Pericarbon valve. All bioprostheses were size 29 mm and implanted by the same surgeon. RESULTS: Total follow up was 663.2 pt-years and it was 97% complete. Early mortality was 1.3% (1/78); two minor cerebral embolisms were observed as early complications. At 12 years the overall survival rate was 85.0 +/- and valve-related survival 93.1 +/- 3.0%; freedom from embolic events was 83.0 +/- 4.5% and from endocarditis 98.7 +/- 1.3%. Freedom from primary tissue failure was 56.8 +/- 6.6%; it was 86.3 +/- 7.5% in patients aged > 60 years and 36.8 +/- 8.2% in younger patients. There were 27 reoperations, 26 for primary tissue failure, one for endocarditis. Comparison between basal and follow up echocardiographic studies showed a significant stenotic deterioration of the bioprosthesis and a negligible incidence of regurgitation. Morphological findings of explanted bioprostheses were characterized by stenotic and diffuse microcalcification, but no tissue tear was observed. CONCLUSIONS: These results confirm that the Pericarbon bioprosthesis is structurally safe and free from the fatigue problems which afflicted the first and second generation of pericardial valves. As with other tissue valves, the rate of calcification is age-dependent, suggesting preferential use of the Pericarbon prosthesis in elderly people.

[Mitral valve bioprosthesis from bovine pericardium. Color Doppler echographic study and long-term follow up]. / Bioprotesi valvolari mitraliche di pericardio bovino. Studio ecocardiografico e color Doppler e follow-up a lungo termine.

Pericardial heart valve bioprostheses have been utilized for 20 years. In spite of encouraging initial results, long-term follow-up showed a higher incidence of structural failures and primary tissue failures than porcine bioprostheses. Pericarbon represents the newest generation of bovine pericardial bioprostheses. Aim of this study is the long-term evaluation with echocardiographic and color Doppler technique of an innovative bioprostheses, in particular, its morfological and functional characteristics. From 1985 to 1989, 78 consecutive patients (21 males, 57 females, mean age 56.5 +/- 8.16 years) underwent mitral valve replacement with Pericarbon 29, by the same operator, who preserved the mitral posterior leaflet. One month after operation, 21 of these patients underwent echo-color Doppler evaluation, in normalized hemodynamic conditions (normality ranges). In 1995, at the end of the followup, 30 of the remaining 54 patients underwent new echo-color Doppler evaluation and these data were compared with normality ranges values. Leaflets' thickness increased from 0.98 +/- 0.09 to 2.87 +/- 0.73 mm (anterior leaflet; p < 0.0001) and from 1.02 +/- 0.08 to 2.71 +/- 0.45 mm (posterior leaflet; p < 0.0001) 43.3% of anterior leaflet and 53.3% of posterior leaflet showed fibrocalcic lesions. Mean transvalvular gradient increased from 3.4 +/- 0.2 to 6.6 +/- 3.4 mmHg (p < 0.0001); also functional area decreased (p < 0.0001). We have found no paraprosthetic regurgitation and a very low number of central prosthetic regurgitation. Left ventricular function, evaluated by ejection fraction and regional kinesis, remained substantially preserved.

[Aortic dissection after aortic valve replacement: clinical and anatomic features]. / Dissecazione aortica dopo sostituzione valvolare aortica: caratteristiche cliniche e anatomiche.

BACKGROUND: Cardiac surgery has become a possible cause of ascending aortic dissection, particularly in patients who have undergone aortic valve replacement. METHODS: From January 1979 to December 1989, 134 patients with angiographic evidence of aortic dissection, were studied in the Haemodinamic Laboratory of the University of Turin. Twelve of these patients (7 men and 5 women), mean age 51.6 years, had been previously operated for aortic valve replacement. We evaluated incidence, clinical and anatomic features of ascending aortic dissection in this group. RESULTS: A dilated ascending aorta with a mean diameter of 4.92 cm. was noted in all these patients. The interval between valve replacement and diagnosis of aortic dissection was 57 months (range 1 day to 9 years). Reoperation was performed in 11 patients. Four intraoperative deaths occurred and 2 other patients died in the early post-operative period. Survival rate at 12 months was 50%. Our incidence of ascending aortic dissection after aortic valve replacement was 0.66% (10 patients out of 1499 operated for aortic valve replacement) and it is in agreement with reports from other Authors in literature. CONCLUSIONS: Replacement of the ascending aorta must be considered if an important dilatation of aortic root is found at time of aortic valve surgery. New efforts must be undertaken to identify patients at high risk for this complication because an elevated mortality rate is observed in reoperation for aortic dissection.

[Single cell preparation of the human heart. Technic of dissociation and isolation of myocytes]. / Preparato unicellulare di cuore umano. Tecnica di dissociazione ed isolamento del miocita.

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.

[Pseudomonas aeruginosa infection of the sternum and costal cartilages in cardiosurgery. Therapeutic experience using aztreonam]. / Infezioni da Pseudomonas aeruginosa dello sterno e delle cartilagini costali in cardiochirurgia. Esperienza terapeutica con Aztreonam.

Clinical effectiveness of Aztreonam was studied. This new monobactam antimicrobial agent was tasted in the treatment of post-operative infectious complications of cardiac surgical sternal wounds. Ten patients (4 men and 6 women, age range 20 to 68 years) were entered into the study. All had a Pseudomonas aeruginosa infection of sternum or sternum and ribs and all underwent an extensive regional surgery of the infection wound and received a topical and/or IV treatment with Aztreonam. In all cases we obtained a satisfactory result, with complete eradication of the infection. Both local and systemic tolerance to the drug were excellent and no side-effect was registered. Therefore Aztreonam can be considered an active and safe antibiotic for the treatment of sternal and/or costal postsurgical infections by Pseudomonas aeruginosa.