Heterologous mitral valve transplant: the first 50 patients clinical analysis.

From March 1992 to August 1993, 50 patients underwent mitral valve replacement with the new heterologous stentless mitral bioprosthesis in our institution. The development of this heart valve substitute, its technique of implantation and the results observed in the first group of 50 patients have had us to review the initial experience. The surgical protocol included an accurate mitral valve complex analysis, adequate valve size selection, attachment of the papillary muscle to the new chordal origin and approximation of the stentless mitral to the patient's annulus. There was one hospital death (2%), not related to the valve or to the technique and four reoperations: two due to endocarditis, one because of a perivalvular leak and one due to a mismatched stentless valve. The late mortality (4%) was not valve-related. The follow-up has shown excellent valve performance with improved left ventricular function in the great majority of the patients. Based on the current analysis, it can be stated that reproducibility of the surgical technique and the excellence of the clinical follow-up may contribute favorably to a better quality of life and longer valve durability in patients requiring mitral heart valve replacement.

Replacement of the ascending aorta and aortic arch with bovine pericardial grafts. A preliminary report.

Bovine pericardial (BP) grafts have been clinical use at Biocor Hospital since 1989 for replacement or repair of the ascending aorta (AsAo) and initial segment of the aortic arch (AoAr). The main advantages of BP grafts that have justified their clinical application are much easier surgical technique, perfect hemostasis and low cost. From Feb/89 to Feb/94, 88 BP grafts were implanted in the AsAo or the AoAr. There were 33 valved conduits, 47 non-valved conduits and 8 patches. The main indication for the procedure was acute dissection of the aorta, accounting for 50% of the cases. The total hospital mortality was 20.4%. Follow-up was obtained in all but two patients. Patients who survived 2 or more years postoperatively (n = 31) underwent either an echocardiographic or an angiographic study in order to access the behavior of the graft, which was perfect in all of them. The current follow-up is short and complications such as calcification may still develop. However the present study has clearly shown the superior handling and better hemostasis of BP grafts compared to the classical Dacron prosthesis.

The new stentless aortic valve: clinical results of the first 100 patients.

From May 1990 to August 1993, 100 patients underwent aortic valve replacement using the stentless porcine aortic valve. There were 69 males and 31 females. The mean age was 36 (range 11-76) years. Of 70 patients under 40 years of age, 20 were less than 20 years old. Indications included rheumatic heart sequelae in 55 patients (first valve replacement), prosthetic failure in 20, endocarditis in 13, congenital aortic bicuspid valve in four, degenerative disease in four and senile calcified aortic valves in four. Twenty patients had aortic annular related pathology. There were 15 associated surgical procedures. Forty-three patients required aortic root enlargement. There were approximately equal numbers of patients in New York Heart Association (NYHA) functional classes III and IV. The hospital mortality rate was 6%; 14 patients who experienced hospital morbidity had a full recovery. Two late reoperations were performed in patients with primary valve endocarditis; their recovery was uneventful. Four late deaths were not valve related. Comparative echo Doppler analysis before and after operation demonstrated good improvement of left ventricular function in nearly all patients. The valve was competent in 96% of patients and the remainder displayed minor jets without haemodynamic significance. The valve coaptation was stable in all patients. Use of the stentless porcine aortic valve in this first 100 patients has provided excellent clinical results with a follow-up of 41 months. Further follow-up and close observation will be required to analyse the outcome of this new valve and procedure with time.

[Surgery for Wolff-Parkinson-White syndrome in the first year of life]. / Cirurgia para síndrome de Wolff-Parkinson-White no 1. ano de vida.

A case of surgical treatment for reentrant atrioventricular tachycardia in a 7 months old child is reported. Episodes of tachycardia were repetitive and long-lasting, often leading to signs of hemodynamic impairement, and were not controlled by antiarrhythmic drugs. The electrophysiologic study showed a circus-movement tachycardia utilizing a concealed accessory pathway located at the anterior septal aspect of tricuspid anulus. The child underwent successful surgical treatment by the endocardial technique. Few minutes after weaning from extracorporeal circulation, developed T wave inversion followed by acute right ventricular dysfunction and ventricular fibrillation. Others ischemic like episodes, maybe as a result of coronary artery spasm, occurring in the next 6 hours were successfully treated with isosorbide dinitrate. At 18 months follow-up, the child is free of tachycardia and has normal atrioventricular conduction.

Clinical results with the Biocor porcine bioprosthesis.

In order to evaluate our clinical results with the use of the Biocor prosthesis, a total of 1,101 patients were studied. Follow-up was from 1 to 96 months (mean 48); cumulative follow-up in the aortic group (385 patients) was 1,230 patient years and in the mitral group (716 patients) 3,018 patient years. Mitral patients had 102 late complications (14.24%), and aortic patients had 51 (13.2%). A total of 220 patients were under 20 years of age (176 mitral, 44 aortic). Intrinsic valve failure in this subgroup was found in 43% of mitral patients and 29% of aortic patients. Prosthetic endocarditis was more frequent in the aortic group (45%) than in the mitral group (29.9%). Sixty-two patients were reoperated, with a hospital mortality of 12.6%. Reoperation was more frequent in the mitral group and in patients under 20 years of age. The actuarial curve free mortality related to the bioprosthesis was 97.1% (32 patients). At the 8-year follow-up, 96.9% of the aortic versus 95.2% of the mitral group were free of valve dysfunction, and the majority were in Classes I or II of the New York Heart Association (NYHA) classification. The incidence of reoperation, although significant, is acceptable, especially since the bioprosthesis offers a safer alternative than mechanical prostheses followed for similar periods. Analysis of our results suggests the need for continued research for an ideal bioprosthesis.

The use of PTFE graft to correct anomalous drainage of persistent left superior vena cava.

A new technique to correct persistent left superior vena cava (LSVC) drainage into the left atrium is described in a 14-year-old patient with situs inversus, left atrial isomerism common atrium, and mitral valve regurgitation. During surgery, occlusion of the LSVC markedly increased the venous pressure, precluding its ligation. Because of the malposition of the heart and the unusual atrial anatomy, correction with an intra-atrial baffle was not attempted. After correcting the intra-cardiac anomaly, the LSVC was divided and anastomosed to the "right" atrial appendage using a segment of PTFE graft. The postoperative course was uneventful and an angiogram demonstrated excellent performance of the graft.