Volume 4 - Número 2

The authors discuss the use of cardioplegic solution as well as its composition. The immediate stop of the heart beats can be obtained with cardioplegic solutions whether they are crystalloid or blood-cardioplegia, oxygen-enriched or not, either in association or alone; hypotermia also can be used or not. The agents to stop the heart can be potassium, magnesium, procaine or calcium blockers. Caution is needed in regard to hypotermia since low temperature itself is not enough to protect myocardium for long periods. Substrates like glucose and oxygen must be supplied during the aortic clamping period, to provide some aerobic metabolism. The addition of other substrates like aspartate, glutamate and lactate as well as ATP and/or phosphate creatine, Krebs cicle intermediates can improve the myocardium salvage. The cell membrane, with all its structural, selective and secretory functions, is the most sensible region to ischemic injure. The retrograde cardioplegy allows a better difusion of the solutions. We believe that it should be part of any cardiac surgery, although we must be aware of its limitations. Perfusion is the most important step of the myocardium salvage when the delivery of free radicals occurs, so the use of scavengers can improve the results of reperfusion. The normotermic blood oxygenated cardioplegy in enriched with substrates was used initially in extremely severe cases of muscle dysfunction, in severe myocardium ischemia or for lack of adequate protection during ischemia and/or reperfusion, and now has been extended to all cases. It is advisable to have the heart chambers always drained, avoiding any increase of tension on the walls which would lead to a higher oxygen consumption. The authors describe the technique and the solution for cardioplegy used in the Cardiac Service of IMC and the results achieved with its use. They conclude that the use of blood modified normotermic cardioplegy aminoacid-enriched and asystolic reperfusion are satisfactory in myocardium salvage and for reverting the ischemic injures. Keywords: myocardial protection, cardioplegia; calcium blockers; free radicals

The current scarcity of satisfactory human heart transplant donors has led to the use of distant procurement of donor organs with prolonged total ischemic times (TIT). The effect of TIT is controversial and is important that the safe limits of TIT are determined. The effect of increasing TIT on cardiac index during the first 3 operative days (CI/1-3), total period of dopamine and dobutamine (D + D/Kg), maximum inotropic requirements and peak CPK-MB levels were assessed in 96 consecutive heart transplant recipients, at the University of Minnesota, to determine the relatiosnhip of these variables to TIT. TIT ranged from 61 to 288 min (mean 171.7 min). The population was divided into groups representing 30 minutes increments of IT. Although reduced levels of peak CPK-MB were evident in the lower TIT groups, cardiac function, support times and inotrope requirements were not different. We conclude that ischemic times of up to 5 hours are well tolerated and that other factors, such as donor heart function prior to harvest and possible ischemic damage during harvest and implantation, are more important determinants of early post-transplant function. Keywords: heart transplantation, human, myocardial ischemia; heart transplantation, human, postoperative period; heart transplantation, human, donors

This is a prospective study performed from August 1987 to September 1988, including 80 adult patients who underwent elective cardiac surgery with cardiopulmonary bypass, for the purpose of assessing the efficacy of autodonation (AD) and autotransfusion (AT) in reducing the use of homologous blood and blood products (SDH). The Control Group (GC) did not undergo autodonation (n=38). Pre-operative collection of flood was performed in 42 patients, forming the autodonation Group (GAD), beginning from I to 7 days pre-operatively (GAD I; n=29), and from 8 to 14 days pre-operatively (GAD II; n = 13). Groups GC and GAD had very similiar "pre", "intra" and "post-operative" parameters. The results showed that the use of blood and blood products was similar in the various groups. Nevertheless, the number of patients exposed to SDH (GC 27 (71%) x GAD 10 (23.8%) - p < 0.001), the mean volume of SDH (GC 1241 x GAD 412 ml - p < 0.003) and the mean number of Homologous Units used (GC 6.31 x GAD 1.95 - p < 0.001) demonstrated that AD and AT were efficacious, reducing in 64% the mean volume of SDH, diminishing the exposure to Homologous Units and minimizing the number of patients exposed. The GAD II attained the best indexes, not reaching, however, statistical significance when compared to GAD I, possibility due to the small number of patients. We believe that AT & AD should de encouraged in elective cardiac surgery. Keywords: blood, autodonation; blood, autotransfusion; blood, conservation; extracorporeal circulation

During the period of October 1986 to January 1989 we executed 445 sternotomies; 158 of these were for myocardial revascularization. In 92 cases the left internal mammary artery (LIMA) was used. Of 445 cases, 7 patients developed sternal infection in the immediate post operative period. The average time for the infection to appear was 8.7 days (4-15 days). Of these, 6 patients were male with an average age of 48.8 years (35-60 years). All cases were first operations; complicating factors were diabetes (1 case), pulmonic emboly with respiratory insufficiency (1 case), low output syndrome (3 cases), prolonged surgery (1 case) and LIMA dissection (6 cases). With the use of plastic surgery techniques and myocutaneous and muscular flaps, complications were corrected and permitted a more rapid patient recovery, avoiding deaths in this period. The esthetic and functional results were considered excellent. Three small dehiscences were treated in the out-patient clinic. Also of great importance was the identification of the germes by cultures and the treatment based on antibiograms in conjunction with the surgical techniques aplied. In conclusion, we judged that in sternal infections, rapid and aggressive surgery avoided deaths. Keywords: sternal infections; myocardial revascularization, complications

In our practice, we no longer use the terms of double-outlet right ventricle, Taussig-Bing anomaly, double outlet left ventricle, or transposition of the great arteries when associated with a ventricular septal defect. We call anomalous ventriculo-arterial connection any connection different from that of a normal heart. In these anomalies the aim of the repair is to connect theleft ventricle to the aorta and the right ventricle to the pulmonary trunk. The strategy we have chosen, for empirical reasons, is based on the hypothesis that the simplest methods which require no prosthetic conduit, no translocation of the coronary arteries and no complex partition of the ventricular cavity offer the best chances of optimal long term results. The feasibility of anatomic repair was investigated in 197 patients who underwent an operation for anomalies of ventriculo-arterial connection associated with ventricular septal defect. Three types of anatomic repair were used: intraventricular rerouting (35 patients), R.E.V. (association of intraventricular rerouting with translocation of the pulmonary arterial trunk on the right ventricle) in 78 patients, and Jatene's operation with closure of the ventricular septal defect (49 patients). Our repair of choice is intraventriclar repair when it is possible to construct a straight and direct tunnel from the left ventricle to the aorta. Thus, the basic question is the feasibility of a simple intraventricular repair. We presently base our strategy in all types of anomalous ventriculo-arterial connection on the preoperative measurement of the minimal distance between the tricuspid valve and the pulmonary valve. Either this distance is significant (at least equal to the diameter of the aortic orifice) and the intraventricular repair is feasible, or it is shorter and another type of repair is indicated. We then perform a R.E.V. in cases associated with pulmonary stenosis or Jatene's operation in cases with increased pulmonary blood flow. Our present experience suggests that the measurement of intervalvar distances is, from a surgical standpoint, the most important information adequately to choose the of repair for the anomalies of ventriculoatrial connection. This approach is not in contrast with the usual classifications based on the position of the great arteries and/or the situation of the ventricular septal defects. It gives information which is directly related to the feasibility of intraventricular repair. Keywords: ventriculo-arterial connection, surgery

The knowledge of the different anatomical types of the Thebesius valve should clarify some problems observed in coronary sinus catheterization. Ninety-four human normal hearts were analysed by an incision in he right atrium from the inferior vena cavae through the terminal groove, allowing inspection of the coronary sinus. Based on the anatomical features of the Thebesius valve, we identify 5 different groups, i.e.: 1) absent valve (16%) when no valve exists; 2) residual valve (33%) when there was only a small membrane occluding less than 15% of the sinus diameter; 3) partial valve (43%) when a membrane occludes more than 15% of the sinus diameter; 4) trabeculated valve (7%) when there was no membrane but trabeculation over the sinus; 5) double valve (1%) when there were 2 membranes over the sinus in different positions. In all cases we tried to perform catheterization of the coronary sinus with 2 different types of catheters commonly used in hemodynamic studies. We observed more difficulty to catheterize the coronary sinus with partial or trabeculated valves. There was no statistical relationship between the different valves and age, sex or race. Keywords: Thebesius valve, anatomy

Seventy patients ranging in age from 14 days to 49 years (mean 7.5 yrs.) were submitted to surgical repair of coarctation of the aorta. Twenty-six (37.1%) were in the first year of life. Surgical techniques performed included patch aortoplasty in 30 cases, subclavian flap angioplasty in 28, resection and end-to-end anastomosis in 9, resection and interposition of a Dacron tube graft in 2 and subclavian aortoplasty with preservation of arterial blood flow to the left arm in 1. There were 6 (8.5%) early and 2 (2.8%) late deaths, not related to the type of repair. Early mortality was clearly related to young age, associated anomalies and severe pre-operative heart failure. All surviving patients present good long-term results and no instance of recoarctation has occurred. No late aneurysm formation was seen in the group of patients submitted to patch aortoplasty probably due to the use of biological patchs in the majority of cases. At present, the authors try to individualize the operation, performing the more suitable technique for each case. Therefore, it is tried to use sublavian flap aortoplasty as much as possible in children below the age of 5 and end-to-end anastomosis or patch aortoplasty in older patients. Keywords: coarctation of the aorta, surgery

A case never described in adults before is here reported. A 35-year-old patient who had referred precordial pain in effort for seventeen years was investigated after having been submitted to correction of coarctation of the aorta, and had the following diagnosis: anomalous origin of the circunflex artery. In the intraoperatory, the latter was found to proceeed from the right pulmonary artery. The anomalous ostio was sutured and a free graft was made, from the right internal thoracic artery to the circunflex coronary. In addition to the unusualness of such pathology, some physiopatologic considerations related to the coarctation of the aorta may be made, in this particular case. Keywords: circunflex artery, anomalous origin