Volume 8 - Número 1

From July 1986 to July 1993, 22 consecutive patients with Type A Aortic Dissecation were surgically treated using total cardiovascular arrest with deep hypothermia (18ºC). Fifteen cases had acute dissecations and 7 were chronic cases. In 14 cases (64%), the ascending aorta was reconstructed using a straight Dacron graft. In 5 of these, the aortic valve was repaired. The aortic arch was reconstructed in 8 cases (36%) and in 3 of these, the arch branches were reimplanted. The average time of the cardiovascular arrest was 43 minutes and the hospital mortality was 18%. The most frequent complication was respiratory infection, 5 patients (22.7%) showed neurologic damage, 4 of them transient and reversible. In summary, the cardiovascular arrest with deep hypothermia technique for the treatment of Type A Aortic Dissection can be used with reasonable mortality and morbility allowing a safe cerebral protection, good exposure of the dissected aorta and prevents damage to the aortic wall by the cross clamping. Keywords: aorta, dissection, surgery; circulatory arrest; hypothermia, deep

The type of circulation and the predominance of the coronary arteries have a great interest in Cardiology as well as in Cardiac Surgery. There is a close relationship between the type of circulation and the risk of myocardial injuries after coronary obstruction. We carried out 50 normal hearts (35 males and 15 females) of 28 Caucasian and 22 non-caucasian individuals. The arteries were injected with colored gelatine. The average cardiac weight was 291 g and the ventricular length was 97 mm. The right coronary predominance was the most common pattern of distribution (72%) and is followed in incidence by a left coronary predominance (16%) and least frequently by a balanced circulation (12%). The incidence of branches crossing the crux cordis ranged from 1 to 5 (average 2,2) in right coronary predominance. On the other hand, in the left coronary predominance we found one branch in two hearts. The most frequent branch reaching the diaphragmatic from the sternocostal surface was the interventricularis anterioris ramus (50%). Keywords: coronary arteries, morphology; coronary arteries, anatomy

Obstruction of the right ventricle outlet tract (RVOT) has been the object of arguments regarding its surgical correction, while there are different criteria for reconstruction. Thus two kinds of prostheses were developed from the pig pulmonary trunk (PT). 1) One with two valves of the pulmonary valve (PV), named bivalvular graft, and could be used for correction of Fallot with pulmonary ring hypoplasia. 2) The other, with a tubular form, containing the pig PV itself and named valved conduit, could be used in RVOT reconstruction for patients with pulmonary atresia (PA). These prostheses were tested in an experimental model: implant of the bivalvular graft was performed in 16 sheep with the aid of extracorporeal circulation (ECC). The surgical technique consisted of resection of the two valves of the PV and of the anterior wall of the infundibulum; this condition was similar to Fallot correction. Implant of the valvular conduit was carried out in 12 sheep, without ECC, by direct clamping of the RV infundibulum. The PT was then ligated, deviating blood flow through the conduit. Intraoperative hemodynamics and echodoppler evaluation of the bivalvular graft showed good PV competence and only 1 case of gradient higher than 10 mmHg. Because of frequent pulmonary hemorrhage followed by death due to ECC, this group was not evaluated in the postoperative period. Intraoperative hemodynamic measurements of the valvular conduit were carried out showing good valvular competence and gradient higher than 10 mmHg in 3 cases. There was no operative mortality. Seven sheeps were followed-up during the late postoperative period with a control echodoppler on days 99 and 135 of follow-up. Gradients ranged from 9.85 to 49 mmHg (mean = 19.7). Four sheep underwent hemodynamic studies at six months of follow-up. There was a slight increase in the gradient between RV and PT (mean = 22.3 mmHg), no gradient being observed inside the conduit. Anatomopathological evaluation was performed. Clinical applications of the bivalvular prostheses was performed in 3 patients with tetralogy of Fallot and hypoplasia of the pulmonary ring (2 cases) and PV absent (1 case); they were 16,2 and 7 years old. The postoperative echodopplercardiogram showed gradients between 10 to 20 mmHg and mild pulmonary valve insufficiency. Clinical application of the valvular conduit was performed in 2 patients: 1 with pulmonary atresia and ventricular septal defect (VSD), the other with corrected transposition of the great arteries, VSD and subpulmonary stenosis (10 and 6 years old, respectively). The postoperative echodopplercardiogram showed gradients between 15 to 18 mmHg. Although the results of the experiment may be considered acceptable, reconstruction of the RVOT with the newly developed prostheses, obviously requires to be tested over time to better evaluate their resistance to calcification, infection, obstruction and rupture. Keywords: heart valves, pulmonary, surgery; heart valves prostheses, biologic, surgery

Between January 1978 and December 1990, 3659 autopsies were performed in our Institution, of which 106 of the patients were > 80 years old. Of these patients, 55 (51.88%) were male and 51 (48.11%) female, and the mean age was 83.66 (80 to 93) years old. The main symptoms presented prior to death were: angina in 40.56%, dyspnea in 25.47%%, and syncope in 8.49% of the patients. In 47.16% the symptoms had begun more than six months before. The systems related to the cause of death were found to be: cardiovascular in 74.52%, respiratory in 10.37%, digestive in 9.43%, nervous in 1.88%, urinary in 1.88% and others in 1.88%. Among the cardiovascular deaths: 56.96% were due to coronary artery disease, 12.65% due to myocardiopathy, 10.12% due to thoracic aortic aneurysm and 8.86% were atributed to arrythmias. It was considered that: the cardiovascular system was the major determinant of death in 74.52%, coronary disease was responsible for 56.96% of the cardiovascular deaths, standard revascularization in this group has a mortality rate of 8.5% and that primary angioplasty has had a success rate of 93.2%. It was therefore concluded that the patients of at least 80 years old should be maintained near their physician or the time between their medical check-up be reduced in order to significantly improve their quality and expectancy of life. Keywords: necropsies, elderly patients

A method of surgical correction for patients with acquired aortic stenosis involving calcification of the aortic valve and the ascending aorta has been described. A prosthesis to a 21 mm biological valved conduit, interposed between the left ventricular apex and descending thoracic aorta, permits the left ventricle to bypass the obstruction and eject directly into the aorta. The pressure gradient across the aortic valve was decreased from 75 to 31 mmHg, with a 13 mmHg gradient between the left ventricle and the valved conduit. The patients remains assymptomatic four mounths after the operation, without fatigue or shortness of breath. Keywords: heart valves, aortic, surgery; ascending aorta, surgery; valved conduit, biologic, surgery

We report the surgical procedure which was adopted in two patients exhibiting thrombosis of mechanical prosthesis, a rare procedure and unprecedent in our Institution. A 19 years old male patient with a history of rheumatic fever in childhood, who had been submitted to two mitro-aortic substitutions, two metalic prostheses, having been introduced in the last surgery, which occurred in 1988. The patient, having of his own free will discontinued taking the anticoagulant, was admitted into the Emergency Department whith a condition of acute pulmonary oedema, with a diagnosis of thrombosis of the prosthesis. He was directed to the Surgical Centre where surgical depletion of the prosthesis was opted for, thus reducing the period of extracorporeal circulation of the patient in an extemely critical condition. Another patient, a two and a half years old female with a diagnosis of mitral insufficiency resulting from mixomatous degeneration, underwent mitral valve substitution for a mechanical prosthesis, on October 13, 1992. Despite satisfactory anticoagulation, the patient exhibited thrombosis of the prosthesis on January 12, 1993, and was also submitted to surgical thrombectomy. Both patients presented satisfactory pastoperative evolution. Three months following the thrombectomy, the second above mentioned patient exhibited a further acute thrombosis, which was followed by sucessful streptokinase. Surgical thrombectomy could be a satisfactory surgical option in high risk surgical patients exhibiting thrombi in metal prosthesis. Keywords: heart valves prostheses, thrombectomy; heart valves prostheses, surgery

We present an original surgical instrument, the ADL Holder, used in valve replacement surgery, in any position: aortic, mitral or tricuspid, for biologic or mechanic prosthesis. This holder was already used in 33 patients during valve replacent (19 mitrals and 14 aortics), and has been showed advantageous for this tipe of surgery. Keywords: heart valves prostheses, surgical instruments; heart valves, surgery