Volume 14 - Número 1

Keywords:

Keywords:

Thirty patients with diagnosis of aortic aneurysm or dissection were submitted to surgery and randomized into two groups. Group I, consisting of 15 patients underwent retrograde cerebral perfusion (RCP) and Group II, also with 15 patients in which the RCP was not utilized. Eleven (36.7%) patients had ascending aorta aneurysm and aortic arch, 7 (23.3%) had acute aortic dissection type I, 6 (20%) suffered from chronic dissection of the ascending aorta and the remaining 6(20%) had other ungroupable diagnosis. The following independent variables were analyzed in the two groups: age, sex, extra-corporeal time span, duration of circulatory arrest, diagnosis and previous complications. Immediate mortality in Group I was 4/15 (26.6%) and in Group II 3/15 (20.0%) p = 1.00. The rate of neurological complications in Group I was 3/15 (20%) and in Group II, 2/15 (13.3%) p = 1.000. Causes of death were: respiratory insufficiency in 4 patients, neurological changes, hyperpotassemia and myocardial infarct, respectivelly in the last three. In this study, we concluded that the association of RCP does not provide more effective cerebral protection than circulatory arrest with deep hypothermia for the ischemic period studied. Keywords: Perfusion, methods; Cerebrovascular circulation; Aortic diseases, surgery; Perfusion, cerebral, methods

Purpose: With the improvements in the hemodynamic treatment of coronary artery lesions, myocardial revascularization using minimally invasive technique is a compelling option. The objective of this study is to report our three-year experience with this technique, evaluating the use of a suture mechanical stabilizer, the access routes and the results obtained. Material and Methods: One hundred and twenty patients were operated on, 86 were male, with ages ranging from 30 to 83 years, mean 61.2 years. All of them had obstructive coronary lesions greater than 80%. Of those with single artery lesions, 79.2% anterior interventricular branch (AIB) lesions, 1.6% had diagonal branch (Dg) lesions and 0.8% right coronary artery (RCA) lesions. Those with associated artery lesions had 17.6% of AIB and Dg lesions and 0.8% of AIB and left marginal circumflex artery (LMg) lesions. Two access routes were used: for single AIB lesions an 8 cm anterior minimal thoracotomy was performed in the fourth left intercostal space. For associated AIB/Dg lesions a 10 to 12 cm median longitudinal incision was used, with total section of the sternum and removal of 5 to 6 cm of the borders. Intravenous beta-blockers and vasodilators were used, and for anastomoses, proximal tourniquets were used in all of the cases, in addition to CO2 to maintain the surgery field bloodless. In the last 82 patients a suture mechanical stabilizer was used for the regional reduction of heart beats. In 22 (18.4%) patients, the left internal mammary artery (LIMA) was elongated using a saphenous vein segment, radial or epigastric arteries. For AIB and Dg revascularization an artificial Y was used from the LIMA with venous or arterial graft. A coronary cineangiography was carried out between postoperative days 1 and 3 in 84 (70%) patients, who were evaluated based on the following findings, according to their anastomosis status: Grade A - no obstruction; Grade B - obstruction > 50%; Grade C - occlusion. This evaluation was performed in 2 different periods: in the first period, without a suture stabilizer and in the second period with a stabilizer. Results: Coronary cineangiography showed the following anastomosis status: in the first period (38 anastomosis), Grade A - 79%, Grade B - 5.2% and Grade C - 15.8%. In the second period (62 anastomosis), Grade A - 90.4%, Grade B - 6.4% and Grade C - 3.2%. The thoracic or mediastinal drains were removed in up to 33.1 h, mean 22.4 hs. There were 6.4% of reoperations, of which 3.2% were related to anastomosis, 2.4% of early and 0.8% reoperations and 3.2 were not related to anastomosis, 2.4% early and 0.8% late reoperations. In 99.2% of the cases there were no ischemic complications in the early postoperative and 118 (98.4%) were discharged. Of these patients, 115 (95.8%) were discharged after 2 to 9 days, mean 4.6 ± 1.8 days and 3 (2.4%) patients had prolonged hospitalization periods due to pulmonary infection. Overall morbidity was 14.2% of which 4.0% was wound infection; 3.2% pulmonary atelectasia; 3.2% subcutaneous emphysema; 2.4% bleeding and 2.4% bronchopneumonia. Conclusions: Minimally invasive coronary artery bypass graft has shown to be a good alternative for some groups of patients. It showed better esthetics and faster postoperative recovery. The anastomosis results were better when a suture mechanical stabilizer was used. Keywords: Myocardial revascularization, methods; Surgical procedures, minimally invasive, methods; Arterial occlusive diseases, surgery; Coronary vessels, surgery

There is evidence of the advantage and impact on the prolongation of life in revascularized patients using the internal thoracic artery. Other grafts have been introduced. The scope of the present report is to show the advantages of myocardial revascularization using composite grafts and to analyze the results over the short and medium term. Between June 1992 and December 1997 fifty patients were submitted to complete myocardial revascularization surgery with composite arterial grafts. Age ranged from 41 to 88 years (average 56). In this group 44% of the patients had previous MAI and 20% unstable angina. In all cases ITA was used with prolongation of saphenous vein in 6%, saphenous vein in "Y" in 24%, radial artery in "Y" in 40% and in 30% with "Y" of the ITA itself. Post-operative follow-up included clinical exam, exercise tests proves and/or myocardial scintigraphy. In 14% coronary arteriography was accomplished. Postoperatively the highest mortality was in females with diabetes mellitus. Hospital mortality was 2%. Only one patient demonstrates class II angina (CCS - Canadian Cardiology Society). This study demonstrates that myocardial revascularization with composite grafts is possible with low mortality, it permits a greater number of anastomoses and provides excellent postoperative progress over the short and medium term. Keywords: Myocardial revascularization, methods; Thoracic arteries, surgery; Radial artery, surgery

A retrospective study of thirty seven patients with myocardial infarction who underwent myocardial revascularization surgery was accomplished. Two groups of patients were established for the comparative study. The first group consisted of patients operated on within 30 days of the myocardial infarction and the second group was composed of patients operated on after that time. Both groups had similar characteristics: age, sex, affected heart region, coexistence or not of diabetes mellitus or arterial hypertension, and cardiogenic shock. Overall surgical mortality was 13.5% (4 deaths out of 18 patients in group I and 1 death out of 19 patients in group II - p = 0.180). When patients operated on within the first 72 hours of myocardyal infarction were excluded and both groups were compared, overall mortality was 5.9% (one death out of 15 patients in group I; one death out of 19 patients in group II - p = 1.0. Based on previous reports, it is believed that surgery for myocardial revascularization can be safely accomplished especially after the first 72 hours of the ischemic event. Keywords: Myocardial revascularization; Myocardial infarction, surgery; Myocardial revascularization, mortality

The purpose of this study is to analyze long-term results with valve replacement in the elderly with bovine pericardial bioprostheses developed by the Heart Institute of São Paulo. Between March 1982 and December 1995, 463 FISICS-INCOR bovine pericardial bioprostheses were implanted in 432 patients over 65. The average age was 70.3 ± 4.3 years, and 58.1% were male. We performed a total of 286 aortic valve replacements, 144 mitral replacements, 16 double replacements (mitral and aortic) and 1 tricuspid replacement. There were associated procedures in 158 patients (36.6%) and the most frequent was myocardial revascularization (19.2%). Hospital mortality was 12.2% (53 patients), 18.7% for the mitral group, 7.7% for the aortic, and 18.8% for the double valve replacement. The linearized rates for calcification, thromboembolism, rupture, leak and endocarditis were 0.4, 0, 0.8, 0.1 and 0.1% patient-year. The actuarial survival curve for the aortic group was 32.4 ± 15.5% in 12 years, freedom from endocarditis was 100%, freedom from calcification was 98.3 ± 1.7%, freedom from rupture was 91.6 ± 4.8%, freedom from leak was 99.5 ± 0.5% and freedom from reoperation was 89.6 ± 4.9% in 12 years. The actuarial survival curve for the mitral group was 14.5 ± 11.5% in 12 years, freedom from endocarditis was 97.8 ± 2.2%, freedom from calcification was 98.0 ± 2.0%, freedom from rupture was 91.7 ± 5.0%, freedom from leak was 100% and freedom from reoperation was 87.9 ± 5.5% in 12 years. There was no thromboembolism. In the late post-operative period, 293 patients (87.7%) were in functional class I (NYHA). We conclude that late results with FISICS-INCOR bovine pericardial bioprostheses were satisfactory in the elderly group of patients. Keywords: Bioprosthesis; Heart valve prosthesis

Since the appearance of new surgical techniques such as Cox surgery employed for the treatment of cardiac arrhythmia, especially for atrial fibrillation, the knowledge of coronary artery characteristics and courses has been of increasing importance. The aim of this study was the analysis of this circulation and definition of atrial irrigation patterns. Hence, the coronary arteries of 30 normal human hearts were injected with colored resin and carefully dissected. After macroscopic evaluation of the hearts, no atrial irrigation patterns were found. However, when only the sinus atrial node was analyzed, it showed origin patterns as well as course patterns. Seven origin and route patterns of this artery are described, considering the anatomical structure of the atria as reference points. The described patterns, differently from others found in the literature, are easy to understand and apply in surgical techniques which deal with the atria. Keywords: Coronary circulation, physiology; Atrial fibrillation, surgery; Heart atrium, physiology; Sinoatrial node

From Oct/90 to Dec/97, 49 patients with complex cyanotic congenital heart disease underwent bidirectional Glenn anastomosis (BGA). Age at operation ranged from 7 months to 25 years (mean = 4.0 ± 4.8 years). The most frequent malformation was tricuspid atresia (53.1%). Palliative procedures were previously performed in 25 (51.0%) patients. Preoperative pulmonary artery pressure ranged from 6 to 33 mmHg (mean = 13.1 ± 4.8). All operations were done with cardiopulmonary bypass and circulatory arrest was used in 49% of patients. In 21 (42.9%) patients the native pulmonary blood flow was maintained to assure pulsatility. Additional procedures were used in 16 occasions. The overall hospital survival was 91.8%; 45 patients were followed for a mean period of 3.2 ± 1.4 years (4 months to 7 years). There were two early deaths (tromboembolism and "take-down" tentative). Two patients with severe stenosis of the left pulmonary artery, corrected at the same time as the BGA, developed exclusion of the pulmonary branch after 2 and 3 years postoperatively. Twelve patients underwent a second procedure for conversion to total cavopulmonary anastomosis with two early deaths and one late death. Two patients are waiting for total correction. There are presently 27 patients with the primary operation (BGA) in good clinical condition. Considering reoperations good results have been achieved in 73.4% of the patients. Keywords: Surgical anastomosis, methods; Heart defects, congenital, surgery; Surgical anastomosis, adverse effects

A better cosmetic effect may result from minimally invasive techniques available for the surgical correction of congenital cardiopathies. Amongst the possible accesses for the correction of an interatrial communication, we selected a partial sternotomy which we performed in 20 pediatric patients. When analyzed, this group of patients demonstrated that this approach is a safe and easy one, and that the cosmetic result is very satisfactory. No complications specifically related to the surgical access were observed. Keywords: Heart septal defects, atrial, surgery, child; Surgical procedures, minimally invasive, methods

Due to continuously improved technologies, the present generation of implantable cardioverter-defibrillators (ICD) guarantees a high degree of safety and efficacy for detecting and terminating ventricular tachyarrhythmias. This paper summarizes the clinical results obtained with 1058 single-chamber ICD (Phylax 6, Phylax XM, Biotronik) employing single-lead and active housing technology (SPS and Kainox RV (single coil), SL-ICD and Kainox SL (double coil, Biotronik). In all but 3 patients (> 99%), reliable low-energy defibrillation was achieved using transvenous leads only. This has led to the trend to replace DFT testing by a short function test during implantation in order to minimize the risks associated with repeated induction of fibrillation and extended anesthesia. Keywords: Defibrillators, implantable; Tachycardia, ventricular, therapy; Ventricular fibrillation, therapy

Background: Dual Chamber Implantable Cardioverter Defibrillator (ICD) in addition to providing hemodynamically improved bradycardia support can also reduce the incidence of inappropriate ventricular shocks owing to episodes of Supraventricular Tachycardia (SVT), with reported incidence of up to 41% of patients. An atrio-ventricular (AV) discrimination algorithm is needed in dual chamber implantable cardioverter-defibrillators (ICD) to avoid these inappropriate shocks. Methods: An AV discrimination algorithm, SMART DetectionTM, has been developed to differentiate between episodes of ventricular tachycardia (VT) and SVT. It relies on the concept that the chamber with the higher rate is the origin of the tachycardia. The ventricular rate stability criterion is also used to detect concurrent VT during an episode of SVT. Other parameters used in the discrimination algorithm are: atrial and ventricular rhythm multiplicity, P-R regularity, sudden onset. The SMART DetectionTM algorithm has been implemented in the Biotronik Phylax® AV dual chamber ICD. The original SMART DetectionTM has been improved recently with the addition of active detection in the case of 1:1 AV conduction. Results: 10 patients were implanted with Phylax® AV's at the Bakoulev Institute. Analyses of stored dual chamber intracardiac electrogram (IEGM) indicate that all episodes of VTs and Ventricular Fibrillations (VF) were terminated following appropriate therapies. No episode of Atrial Flutter (Afl) or Atrial Fibrillation (AF) was treated even though the majority of patients have a history of SVTs. In one patient, an episode of Sinus Tachycardia (ST) was inappropriately treated. Increasing the sudden onset criterion, which is used only in the case of stable 1:1 rhythms, was sufficient to prevent recurrence of inappropriate therapy. To avoid the necessity of setting the, not very reliable, sudden onset criterion an active detection procedure was developed. Isolated Premature Ventricular Stimuli were used to test the hypothesis of VT with retrograde atrial conduction in the 1:1 AV rate case. Results of acute tests of this active detection improvement are reported in this paper. Conclusion: The SMART DetectionTM algorithm, with is active detection improvement in the case of 1:1 AV rate, should prove to be an effective AV discrimination algorithm in dual chamber ICD which will offer freedom from unnecessary shocks in response to SVTs. Keywords: Tachycardia, supraventricular; Defibrillators, implantable; Tachycardia, ventricular; Cardioversors, implantable; Algorithms