Volume 10 - Número 1

Keywords:

Dynamic cardiomyoplasty has been proposed as an alternative to heart transplantation in the treatment of severe cardiomyopathies. In this investigation, its results were investigated in 34 patients with idiopathic dilated cardiomyopathy submitted to this procedure from May 1988 to September 1994. Twenty seven patients were in New York Heart Association functional class III and 7 were in class IV before the operation, despite the use of maximal medical therapy. Hospital mortality was 2.9% and 1 patient presenting heart failure progression was submitted to urgent heart transplantation 42 days after cardiomyoplasty. The other patients were followed-up from 2 to 73 months (mean, 27.4 months). At 6 months of follow-up, 12 patients were in functional class 1,15 patients in class II and 3 patients in class III (p=0.001, in relation to preoperative data). Similar findings were observed from one to four years of follow-up. On the other hand, 14 patients died up to 5 years after the operation and the survival rates were 84.7% at 1 year, 67.7% at 2 years and 39.9% at 5 years of follow-up. The cause of death was progression of heart failure in 9 patients and 5 patients died suddenly. By stepwise Cox regression method, patients operated in functional class IV had relative risk of death 5.5 times higher than class III patients (p=0.006), whose survival rate was 52.7% at 5 years of followup. Regarding cardiomyoplasty influence on ventricular function, radioisotopic left ventricular (LV) ejection fraction improved from 19.8 + 3.1% to 23.6 + 6.2%, at 6 months of follow-up. Doppler-echocardiography documented similar changes in LV wall shortening. Also, right heart catheterization showed significant increases in mean arterial pressure, stroke index and LV stroke work index, which were associated with the decrease of mean pulmonary wedge pressure. On the other hand, it was not found any significant postoperative change in ventricular arrhythmia and atrial fibrillation incidence. At the late postoperative period, the hemodynamic improvement was maintained up to 5 years of follow-up, while LV ejection fraction and wall shortening tended to decrease after the second postoperative year returned to the preoperative levels. Finally, 3 of the 5 patients who completed 5 years of follow-up died due to heart failure progression and other died suddenly up to 73 months after the operation. Furthermore, histological examinations showed important fat tissue infiltration in the skeletal muscle flap of 9 patients submitted to necropsy studies from 20 to 73 months of follow-up. These histological changes were more severe in patients with longer follow-up. In conclusion, dynamic cardiomyoplasty improves congestive heart failure and LV function in patients with idiopathic dilated cardiomyopathy. However, long-term survival after this procedure is limited in patients operated upon in functional class IV. Furthermore, the cardiomyoplasty benefits on left ventricular function appear to be limited to a midterm period and this fact may be associated with late muscle flap degeneration. Keywords: Cardiomyoplasty; Heart failure, cardiomyopathy, surgery; Cardiomyopathies, surgery

The "Maze" procedure for surgical treatment of chronic atrial fibrillation (AF) described by Cox was performed in 34 patients (pts) from July 91 to October 94; 26 were female and the ages ranged from 35 to 68y (50.2y). All pts had mitral valve disease (MVD) and chronic AF (> 1 year). Thirty one pts had surgical rheumatic MVD (mitral stenosis in 21; mitral double disfunction in 9) and 3 had mixomatous MVD with severe regurgitation. Twenty eight pts were in FC (NYHA) IV and 6 in FC III preoperatively. Left atrium diameter varied from 4.4 to 6.5 cm (5.5 cm). In 21 pts the surgical treatment was performed following the original "Maze" technique and in 13 pts with the modifications proposed by Cox. The surgery was completed with 17 mitral conservative procedures and 17 mitral valve replacements (bovine pericardium bioprostheses). Eight pts had left atrial thrombosis. There were 2 (5.8%) immediate deaths (low cardiac output and severe liver disfunction) and 1 patient died in the 48th day with infeccious complications. The first patient required reoperation for bleeding review. Atrial arrhythmias were observed in 6 pts and 14 required temporary pace-maker. Regular "sinus" rhythm was observed in all pts. No other major complications were observed. In 30 pts with more than 6 months of follow up, 27 (90%) were in regular rhythm (heart rate from 55 to 87bpm), with no antiarrhythmic drugs and atrial contraction demonstrated by ECHO. In conclusion, the "Maze" procedure showed effective to treat AF even in pts with big atrium and MVD, with acceptable immediate and late results. Longer observation is required to a definitive conclusion. Keywords: Cox operation, late follow-up; Atrial fibrillation, surgery

In order to evaluate the effects of pulsatile flow in the pulmonary artery of patients undergoing bidirectional cavopulmonary shunts (BCS), we reviewed the data of 36 patients operated upon from October 1990 to July 1994. Age at operation ranged from 11 months to 14 years (mean 4.4 ± 3.4 years) and diagnoses were as follows: tricuspid atresia (18), single ventricle (16), mitral atresia (1) and pulmonary atresia with intact ventricular septum (1). A total of 19 (52.8%) patients had a prior palliative operation done. Cardiopulmonary bypass was used in every case, with mild hypothermia in 11 cases and profound hypothermia and circulatory arrest in the remaining. The surgical technique was an anastomosis between the superior vena cava and the ipsilateral pulmonary artery in an end-to-side fashion. The main pulmonary artery was ligated only if the mean pressure taken at the site of the anastomosis was higher than 15 mmHg but in 2 recent cases with a very high mean pulmonary pressure, the main pulmonary artery was banded, adjusting the pressure to the desirable levels. The overall hospital survival was 91.7% (33 patients). One patient required a systemic to pulmonary shunt due to persistent low arterial oxygen saturation, 7 days after the BCS. Twenty-eight patients were followed for a mean of 1.8 ± 1.2 years (3 months to 4.1 years) and were divided in 2 groups: A - 18 patients without pulsatile flow in the pulmonary artery, and B - 10 patients with pulsatile flow. In Group B, the mean arterial saturation has ranged from 80% to 90% (mean 86 ± 3.8%) and is significantly higher than in Group A (68 to 85%, mean, 77.6 ± 5.5) (p<0.001). Two patients of Group A are in NYHA functional class III, whereas all patients of Group B are in class I or II (p=0.05). There was one late death and one patient required a subsequent Fontan procedure, both of Group A. Thus, the presence of pulsatile flow in the pulmonary artery improved the arterial oxigen saturation and exercise tolerance in patients submitted to a cavopulmonary shunt, without adverse effects on pulmonary circulation. Keywords: Glenn operation; Pulmonary artery, surgery

A novel perfluorocarbon emulsion (Oxygent^TM - Alliance Pharmaceutical Corp., San Diego, CA 92121, USA) was tested during hypothermic (32ºC) cardio pulmonary bypass (CPB) under severe hemodilution (Hto = 12%). Forty-two mongrel dogs were allocated to 4 groups. Group 1 (n=12) was not given Oxygent and served as control whereas Groups 2, 3, and 4 (10 animals each) were given a bolus dose of the emulsion (1.5,3.0, and 6.0 ml/kg, respectively) at the onset of CPB. O₂ metabolism variables were then studied at 6 randomized pump flow rates (Q) ranging from 0.25 to 3.0 l/min/m². After rewarming CPB was discontinued and the animals were followed-up for one hour and then killed by IV KGI injection. Differences between groups were evaluated by the least squares means and Duncan's tests and considered significant for p<0.05. Fluorocrit values remained stable on CPB Group 2 -1 %, Group 3 - 2%, and Group 4 - 3%). Although somewhat elevated, Group 4 arterial blood O₂ partial pressure and content (C_aO₂) didn't reach statistical significance versus control. Group 4 mixed venous blood O₂ partial pressure (PvO₂) regressed against Q was significantly higher (p < 0.03) than control, but there was no statistical difference when this variable was regressed against O₂ delivery rate. Groups were similar regarding total as well as dissolved O₂ consumption and systemic and transmyocardial lactate gradients. A trend towards lower mortality rates was noticed in Groups 3 (20%) and 4 (10%) versus control (41.6%). Group 4 trend towards both reduced mortality and higher C_aO₂ as well as its significant PvO₂ rise against Q suggest a beneficial, yet speculative, Oxygent dose dependent effect on O₂ metabolism. Keywords: Perfluorocarbons, in extracorporeal circulation; Oxygen metabolism; Extracorporeal circulation

There are still controversies about the treatment of associated coronary artery disease and carotid artery obstruction. Between 1979 and 1994, 10940 patients were operated on for myocardial revascularization. Combined operations (myocardial revascularization and carotid endarterectomy) were done in 46 (0.43%) patients, during the same period. Patients age ranged from 48 to 76 years with an average of 65.2 yrs; 80.4% were male; 23 had had previous myocardial infarction. Associated diseases were diabetes mellitus in 10 patients, chronic renal insufficiency in 5; 29 were in functional class 111 or IV for angina; 4 patients had congestive cardiac insufficiency: left main carotid obstruction, and in 4 of them one carotid artery was completaly obstructed; 23 patients had had transient cerebral ischemic attack and 2 had had stroke with sequelae. Hospital mortality was 8.6% (4/46). Permanent stroke did not occur in the operative period; 3 of the 4 deaths occurred in patients 70 years or older. Carotid endarterectomy was done just before cardiopulmonary bypass in 42 patients and in 4 patients with one of the carotid arteries occluded, done after cardiopulmonary bypass was established and the patient temperature was 25ºC. Considering that no patient had perioperative stroke, we think that this strategy is adequate for this association of diseases. Keywords: Myocardial revascularization, surgery; Carotid artery, endarterectomy

Between January 1980 and December 1993, 291 patients underwent valve replacement with mechanical valves in the Heart Institute of HCFMUSP. One hundred and eighty seven (64.3%) patients were male, aged between 2 months and 78 years (average 38.3 +/-18.5). The ethiology was rheumatic in 132 patients (45.4%). Were inserted 315 mechanical valves, 201 aortic, 77 mitral, 15 double aortic-mitral, 2 tricuspid, 1 double mitral-tricuspid, and 1 triple mitral-aortic-tricuspid. There were associated procedures in 164 patients (56.4%), the most frequent was replacement of ascending aorta in 49 (16.8%). One hundred and forty one patients (48.4%) underwent previous heart valve surgery. Follow-up data are reported concerning functional status (NYHA) and valve related complications. Early mortality rate was 12.4% (36 patients). Followup totaled 10078 months/patient (159 patients), with a mean follow-up period of 40.6 months. The linearized rates of thromboembolism, hemorrhage related to antithrombotic therapy, late death, endocarditis, paravalvular leak and hemolysis were 1.33%, 0.95%, 1.9%, 0.19%, 0.57% and 0.57% patients/year, respectively. Fourteen year survival rate was 63.8%. Eighty two percent of the patients were in functional class I in the postoperative period. It was possible to conclude that the patients submitted to mechanical valve replacement had a satisfactory clinical evolution. Keywords: Heart valves prostheses, surgery, late follow-up; Heart valves, surgery

A thirty nine-year-old patient presenting arterial hypertension was operated upon for type I acute aortic dissection. Due to important alterations in the ascendent aorta with involvement of the right coronary ostium, the surgical procedure included resection of the segment of aorta containing the intimal tear and replacement with a Dacron prosthesis, suspension of the aortic valve and ligadure of the right coronary ostium. Technical difficulties brought the necessity of a different approach for the myocardium revascularization. Instead of the traditional described procedures, an intercoronary venous graft was put between the anterior interventricular artery (branch of the left coronary artery) and the right coronary artery. The intercoronary graft presented a good flow since the begining, keeping a good myocardial contratility. Patient left the hospital in a good clinical condition, with preserved myocardial function. Intercoronary graft should be an efficient alternative for revascularization of a corohary artery involved by aortic dissections. Keywords: Aortic dissection, surgery; Myocardial revascularization, surgery