Volume 8 - Número 2

Between February 1984 and March 1992, 10 patients with aortic coarctation undetwent surgical correction with the technique of subclavian aortoplasty with preservation of arterial flow to the left upper limb. Eight of the patients were male and 2 were female. Their ages ranged from 2 months to 25 years (mean 6.3 years) and the weight ranged from 3.1 to 60 kg (mean 21.2 kg). Surgical technique basically consisted of detachment of the left subclavian artery with subsequent reimplant as a ceiling over the constricted aortic area, thus preserving the arterial flow to the left arm. In this procedure two steps are fundamental: a) wide dissection of aorta and the left subclavian artery in order to allow full mobilization of those vessels, and b) anterior aortic incision should be large to allow reimplant of the subclavian proximal flap well beyond the constricted area. This will produce a wide anatomic reconstruction without tension on the suture lines. Two modifications of the original technique have been utilized: a) resection of a segment of anterior aortic wall the base of the subclavian artery. This will allow a good aortoplasty for patients with well formed isthmus with less dislodgement of the original subclavian insertion, and b) resection of the coarcted segment, end to end anastomosis of the posterior wall and anterior widening with the previously detached and posteriorly incised subclavian artery. This modification is best indicated for small children since it will remove the adjacent ductal tissue. The original technique was utilized for three patients; the modification with and anterior aortic flap was employed in 2 patients and the technique with simultaneous resection of the coarcted area was utilized in the other 5 patients. There was a single operative death, not related to the technique. Nine patients were followed for 1 to 8 years post-operatively (mean 3.9 years). All patients remained asymptomatic, with normal arterial blood pressure and normal pulses in the second day and six years (mean 1.6 years), and demonstrated an excellent aortic widening with preservation of arterial flow to the left arm in 8 patients. One patient had a small circular constriction which produced a 20 mmHg gradient. In conclusion, the subclavian-aortoplasty with preservation of arterial flow to the left arm (basic or combined technique) allows an adequate anatomic correction, permits the subsequent aortic growth and can be utilized in the vast majority of cases of aortic coarctation treated during the pediatric age. Keywords: aortoplasty, subclavian; aortic coarctation, surgery

Mitral valve replacement has been performed for the last 30 years using an aortic designed valve, to fulfil specific requirements of the left ventricle. The clinical results obtained by such devices have been generally favorable, although specific restrictions are obvious because of their design. The knowledge and experience acquired by Biocor Laboratories in the last two decades, in production of biological heart valve substitutes, contributed positively to the research, development and manufacture of the heterologous mitral valve substitute. This stentless heterologous mitral valve was implanted in 38 patients, without hospital mortality. Their mean age was 29 years. Female gender predominated (69%). The most common mitral dysfunction was the double mitral valve lesion (53%). Eighteen (47%) patients were in functional class III and 20 (53%) in class IV of the NYHA. There was one valve related complication (our first patient), due to disproportion of patients, large annulus and the incorrectly size chosen. This complication led us to the strict adherence of our protocol, which is based upon animal experimentation. The satisfactory operatory and clinical results, throughout this 12 months of follow-up, confirm that the stentless heterologous mitral valve is the natural mitral substitute, when considering mitral valve replacement. This first natural mitral valve substitute, tanned with a non-aldehyde tissue treatment, proved to avoid calcification and to produce no foreign reaction, hence it may be the best choice in order to obtain better quality of life and the desired valve durability. Using both, the natural design mitral valve and the non-aldehyde treatment, the last 6 patients of this series received this devicxe and is certainly hoped that, due to the more natural model and the non-calcificant and inhert tissue, patients own cells will be responsible to greatly delay tissue degeneration, providing longterm durability. Keywords: heart valves, mitral, surgery; heart valves, surgery

It was previously shown that topical application of heparin produces enhanced bleeding from small vesseis and capillaries. Adenosine triphosphate at low concentrations is able to disalodge heparin bound to a receptor, counteracting its antihemostatic activity. This results led us to measure the amounts of heparin remaining in the blood after protamine neutralization of the patients subjected to cardiopulmonary bypass operation and to test the topical application of the nucleotide denosine triphosphate at a concentration of 10-4 mol/L significantly reduces the blood volume (p<0,005) oozed from the thoracic cavity of the patients (mean 288 ± 188 ml) when compared with controls (mean 564 ± 288 ml). Adenosine triphosphate at 5 X 10-5 mol/L reduces the blood loss to a mean of 370 ± 155 ml in the patients tested (p<0.08). About 10% of heparin of low molecular weight (< 6.0 Kda), which is also found in the oozed blood, is not neutralized by protamine. We suggest that the excessive blood loss of the patients is probably produced by low molecular weight heparins in the commercial preparations that are not neutralized by protamine. Keywords: bleeding in heart surgery

Ortothopic heart transplantation (OHT) was performed in 110 patients at the Heart Institute, between march 1985 and february 1993 for treatment of terminal cardiomyopathy. From these patients, 24 had a survival period of more than 36 months and were selected for a long term analysis of the left ventricular function. They were observed in a 56 months average follow-up. The patients were 44.3 years old average, being 21 (87.5%) male. The ethiology of the cardiac diseases was dilated cardiomyopathy for 13 (54.2%) patients, ischemic for 8 (33.3%) patients and Chagas' Disease for 3 (12.5%) patients. All patients were initially in functional class IV (NYHA). They were evaluated by cinecoronariography, hemodynamic and echocardiographic studies preoperatively, and every year in a 5 years follow-up. The results suggest that: 1) all patients presented left ventricular hipertrophy as an adaptative mechanism; 2) the arterial hypertension was observed since the first year of follow-up; 3) the acute rejection episodes and the myocardiopathy ethiology did not interfere on the left ventricular function; 4) the acelerated atherosclerosis had a negative effect on left ventricular function; 5) the echocardiographic and hemodynamic evaluation showed a left ventricular function stability of 5 years after surgery; nevertheless, it was observed an important reduction of the cardiac index associated with a crescent increase of abnormal measures results, suggesting a late reduction of the left ventricular performance. Keywords: heart transplantation, ortothopic; heart transplantation, left ventricular function

From January 1980 to December 1989, 48 consecutive patients with chronic aortic dissection and aortic valve insufficiency underwent operation. They were analyzed in 2 groups (24 patients each) to evaluate the late clinical and echocardiography outcome of those in whom the aortic valve was preserved (Group A) compared with those having valve replacement (Group B). The overall preoperative characteristics of the two groups were similar except for the age (Group A 47.9 ± 10.8 versus Group B 40.2 ± 9.5 years, p=0.03). In the preoperative echocardiographic evaluation, Group B patients had significantly higher aortic root and left ventricle systolic and diastolic diameters (p<0.03), and aortic insufficiency grade (p=0.02). The hospital mortality was 12.5% in Group A and 4.2% in Group B and the seven years actuarial survival rate was respectively 75.7% ± 9.8% and 82.7% ± 7.9%. Postoperatively there was, in both groups, a significant improvement in all clinical parameters evaluated (dyspnea, chest pain, arterial hypertension, aortic insufficiency murmurs (p<0.001). There was also a marked reduction in the aortic root and left ventricle diameters in all patients compared to preoperative values (p<0.05) without statistical difference between the groups. Echocardiographic mild aortic insufficiency remained in 20% of the patients in whom the valve was preserved, without long term hemodynamic or clinical repercussion. Hence, we conclude that aortic insufficiency in chronic dissection can be equally treated with both techniques. Aortic valve preservation should, whenever possible, be attempted and considered as the procedure of choice. Keywords: heart valves, aortic, surgery; heart valves, surgery

An aortic stentless bioprosthesis (Biocor Ind.) was implanted in 17 patients with difficult aortic annulus due either to endocarditis orto a previous aortic valve replacement. Native valve endocarditis was present in 3 patients and prosthetic valve endocarditis in 5; 9 patients had one or more previous aortic valve replacements showing a wheakened aortic rim. The stentless bioprosthesis was implanted with a two layers suture technique similar to a homograft implant. The ascending aorta was enlarged with a patch of bovine pericardium in 11 ocasions; mitral valve replacement was concomitantly performed in 3 patients. There was one hospital death secondary to multiple organ failure in a patient with acute endocarditis and a preoperative cerebro-vascular accident. One patient who was pacemaker dependant had a sudden death in the 6 th postoperative month. All other 15 patients are in regular follow-up with periodic ecocardiographic analysis. One patient had partial deiscense of the lower suture line which generated a gradient in the left ventricular outflow tract; he was reoperated upon and the valve was refixed with flow normalization. In all patients the valve has shown an excellent performance with very small gradients (mean = 10.6 mmHg) and abscence of significant aortic regurgitation. No case of reinfection was observed in the patients with endocarditis. The stentless aortic bioprosthesis proved to be an excellent heart valve substitute in this difficult group of patients. Keywords: heart valves prosthesis, aortic, surgery

Between January 1984 and December 1992, 8 patients with acute massive pulmonary embolism (PE) underwent pulmonary embolectomy under cardiopulmonary bypass. The age ranged from 36 to 70 years (average 56.6 years). There were 6 men and 2 women. A causative factor for pulmonary embolism was found in 6 (95%): myocardium revascularization in 3, abdominal lipoaspiration in 2 and hemorrhoidectomy in 1. All patients where severely hypoxic with mean arterial PO2 of 55%. The diagnosis of PE was established by pulmonary angiogram in 6 (75%) and surgery in 2. Hospital mortality was 50% (4 patients), two of them had previous cardiac arrest, 1 patient died of acute respiratory distress syndrome, 1 of neurologic complication, 1 of pulmonary infection and 1 of myocardial failure. Among the survival patients, 3 are without symptoms and 1 complains of discrete exertional dyspnea (NYHA class II). This study demonstrates that: 1) the mortality rate was higher in patients with previous cardiac arrest; 2) the time between diagnosis and surgery was a predictive factor; 3) the high mortality rate reflects the gravity of the situation; 4) the long term results in surviving patients have been favorable. Keywords: pulmonary embolism, surgery

The association of intracardiac lesions with coarctation of the aorta (CoAo) is a situation that could be repaired in only one surgery by anterior midline approach, despite of sugestión of increased risk if compared with two stage repair. Our experience with this approach is a group of 22 children, with ages ranging from 12d to 18y (48.9m), being 12 male, from Jun 88 to Dec 92. All children had CoAo associated whith different intracardiac lesions like VSD in 12 (isolated in 6; with mitral and subaortic stenosis in 3; with subaortic stenosis in 2 and 1 with mitral regurgitation); aortic and subaortic stenosis in 5, mitral stenosis in 2. All children were operated on by anterior midline approach using cardiopulmonary bypass and profound hypothermia to repair first the CoAo and after the intracardiac lesion. In 17 children the CoAo zone was excised with end to end anastomosis; in 4 the left subclavian flap was used and in 1 a Dacron graft was used. No deaths were observed and the main immediate complications were low cardiac output syndrome in 3 and pneumonia in 2 children. In a follow up period from 1 to 50m (17.7%), 16 children are well and assymptomatic and 4 have incaracteristic chest pain. In the same period, the CoAo repair was evaluated by ECHO with no residual stenosis. In conclusion, the concomitant repair showed good results with low morbidity and no mortality in children with different ages and diagnosis. Keywords: intracardiac surgical lesions; aortic coarctation, surgery

Patients with complete atrioventricular septal defects (CAVSD) frequently present with severe heart failure which cannot be controllable medically and pulmonary hypertension in infancy. Just a small number survives without early surgical treatment. For this reason the definitive repair is indicated to improve the disease's natural history. However many factors are responsible for a still high surgical mortality in this condition. In the present study the surgical experience in the correction of CAVSD is reviewed in order to identify potential statistically important risk factors for operative death. Between January 1974 and December 1990,52 patients with complete atrioventricular septal defects underwent definitive surgical repair at The Royal Brompton and National Heart and Lung Institute. They were retrospectively studied and the following variables analysed: age, weight, sex, year of the operation, Down's syndrome, atrioventricular valve regurgitation, previous pulmonary artery banding, associated anomalies, systolic pulmonary artery pressure, double "mitral" valve orifice, Rastelli's classification, circulatory arrest, and the surgical technique (1 x 2 patches). All this variables were studied by the univariate analysis and, to determine which factors were independently responsible for the operative risk, multivariate analysis with logistic regression was applied. Multivariate analysis showed that the low weight at operation an 1 patch technique significantly increased surgical mortality. Keywords: atrioventricular septal defect, surgery, risk factors

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 interventricuiaris anterioris ramus (50%). Keywords: coronary arteries, morphology; coronary arteries, anatomy

Submitral left ventricular aneurysm is a poorly known entity in our country; it has been described mainly in the southern and western African black populations. It appears to be related to a ventricular wall weakness in the area of implantation of the posterior mitral valve leaflet. A 20-year-old white man was admitted with complaints of dyspnea and palpitation. On admission he was in NYH A class IV. After medical treatment the cardiac area was very enlarged and there was a systolic murmur +++/++++. The twodimensional echocardiography as well as the angiocardiography revealed annular submitral left ventricular aneurysm associated with severe mitral regurgitation. He was operated upon on October 20, 1986. We closed the neck of the aneurysm with a pericardial patch. The mitral valve was replaced due to a severe distortion. The patient is well, six years after the surgery. Keywords: aneurysms, left ventricle, submitral, surgery