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V Bomfim

Publications and source records attributed to V Bomfim.

30 records · Page 2Linked to original sources
PubMed1982

Normothermic ischaemic arrest in one-vessel coronary artery surgery.

Cardiac metabolism following normothermic ischaemic arrest was studied in 14 patients undergoing coronary bypass surgery for single vessel coronary artery disease. Simultaneous blood samples were taken from the radial artery and from the coronary sinus before and during the first 60 min after aortic crossclamping. O2-saturation and content, potassium, lactate and the isoenzyme MB of the creatine kinase (CK-MB) were assessed. In addition, CK-MB was followed in peripheral venous blood for 8 hours after operation. Analysis of the results revealed decreased oxygen extraction by the heart immediately after the release of the aortic crossclamping and marked lactate and potassium release with delayed metabolic recovery of the myocardium despite the very short aortic occlusion time. Increased postoperative CK-MB serum activity was also seen. We concluded that the use of normothermic ischaemic arrest is hazardous even in such surgical procedures requiring aortic occlusion times as short as 15 min and should be avoided at least by the less experienced surgeon.

Coronary Artery Bypass↗
PubMed1981

Myocardial protection during aortic valve replacement. effects of mannitol in the cardioplegic solution on cardiac metabolism and enzyme release.

Myocardial substrate metabolism and enzyme release following hypothermic potassium cardioplegia with and without the addition of mannitol in the cardioplegic solution were studied in two series of patients undergoing isolated aortic valve replacement. Measurements were made of PO2. O2-saturation and content, PCO2, pH, glucose, lactate, pyruvate, potassium, myoglobin, creatine kinase (CK), its isoenzyme MB and aspartate aminotransferase (ASAT) simultaneously in arterial and coronary sinus blood before cardioplegia and during the first 60 min after the release of aortic cross-clamping. In addition, myoglobin and enzymes were followed in peripheral venous blood for 72 hours after cardioplegia. Analysis of the results revealed no striking difference between the groups. Nevertheless, with the addition of mannitol, there was a slightly lower release of lactate and myoglobin probably indicating a more rapid metabolic recovery of the myocardium.

Aortic Valve↗
PubMed1981

Myocardial protection during aortic valve replacement. Comparison between sanguineous and Asanguineous Cardioplegic Solutions.

Myocardial substrate metabolism and enzyme release following hypothermic potassium cardioplegia were studied in two series of patients undergoing isolated aortic valve replacement. In 15 patients blood was used as cardioplegia vehicle (blood cardioplegia group) and a plain electrolyte solution was used in a control group of 17 patients. Simultaneous blood samples were drawn from arterial and coronary sinus blood before and during the first 60 min after release of aortic cross-clamping. Blood samples were analyzed for PO2. O2-saturation and content, PCO2, pH, lactate, pyruvate, glucose, potassium, myoglobin, creatine kinase (CK), its isoenzyme MB and aspartate aminotransferase (ASAT). In addition, myoglobin and enzymes were followed in peripheral venous blood for 48 hours. The pattern of metabolic changes after cardioplegia was similar in both groups, but some differences were encountered in the degree of the changes in potassium, myoglobin and CK-MB between the groups. The differences were nevertheless small and cell damage was probably of reversible nature in all patients, but the myocardial protection afforded by single dose blood cardioplegia was not unquestionably better than that of the control group.

Aortic Valve↗
PubMed1981

Myocardial protection during aortic valve replacement. Cardiac metabolism and enzyme release following continuous blood cardioplegia.

Cardiac metabolism following hypothermic potassium cardioplegia with blood as cardioplegia vehicle was studied in two groups of patients undergoing aortic valve replacement. In 15 patients, blood was given as single dose infusion (single dose group) and in 18 patients the same initial bolus was followed by a continuous perfusion (25-30 ml/min) with modified blood from the heart-lung machine (continuous blood group). Simultaneous samples were drawn from arterial and coronary sinus blood before and during the first 60 min after cardioplegia. In the continuous blood group, samples were also drawn during the period of cardioplegic perfusion. The samples were analyzed for PO 2, O2-saturation and content, PCO2, pH, lactate, pyruvate, glucose, potassium, myoglobin, creatine kinase (CK), its isoenzyme MB, and aspartate aminotransferase (ASAT). In addition myoglobin and enzymes were followed in peripheral venous blood for 24 hours. Myocardial biopsies were taken from the left ventricle at the beginning and end of cardioplegia and analyzed for adenosine triphosphate (ATP), creatine (C) and creatinephosphate (CP). The pattern of metabolic changes after cardioplegia was similar in both groups with decreased myocardial oxygen extraction, marked lactate and potassium release, increased glucose uptake and significant enzyme and myoglobin release. However, the degree of changes was significantly smaller in the continuous blood group. The myocardial biopsies also showed significantly less ATP and CP decrease in the continuous blood group, suggesting, together with the other metabolic results, that the myocardial protection afforded by continuous blood cardioplegia was superior to that of the single dose group. Furthermore, continuous perfusion permitted easy control of myocardial temperature during the period of aortic cross-clamping.

Aortic Valve↗
PubMed1981

Detachment of the septal tricuspid leaflet during transatrial closure of isolated ventricular septal defect.

In 27 (18%) of the 151 patients who underwent transatrial closure of isolated ventricular septal defect (VSD) between 1966 and 1979, the tricuspid valve was partially detached in order to achieve better exposure. All 27 patients had defects of the membranous or paramembranous type situated behind the tricuspid septal cases, tight chordae tendineae crossed over the defect and inserted in the edge of the VSD. A 15 to 20 mm incision in the septal leaflet was usually needed to expose the defect sufficiently. There were two operative deaths among the 27 patients, both unrelated to the tricuspid incision. The remaining patients had uncomplicated postoperative courses. There were no long-term complications or instances of significant tricuspid valve incompetence, major residual shunt, or heart block at follow-up. Three patients, operated upon at the ages of 3, 3, and 6 years, respectively, had residual pulmonary hypertension. In one patient, who died 4 years postoperatively in a traffic accident, the tricuspid valve was intact and the previous incision could hardly be seen. It is concluded that detachment of the septal tricuspid leaflet is a safe procedure during transatrial closure of a VSD.

Adolescent↗
PubMed1980

Myocardial protection during aortic valve replacement. Cardiac metabolism and enzyme release following hypothermic cardioplegia.

Cardiac metabolism following hypothermic potassium cardioplegia was studied in 23 patients undergoing isolated aortic valve replacement. All had normal coronary arteries. Cardioplegia was induced by infusing 700-1 000 ml of cold Ringer's acetate containing 20 mekv K+ selectively into the left coronary artery. Simultaneous blood samples were taken from the radial artery, a central vein and from the coronary sinus before and after cardioplegia. The PO2, O2-saturation and content, PCO2, pH, lactate, glucose, potassium, myoglobin, total creatine kinase (CK), its isoenzyme CK-MB, aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) were assessed. Before bypass lactate was extracted by the heart. During the initial 10 to 20 min after cardioplegia there was a marked release of lactate in the coronary sinus. Myoglobin concentration and CK-MB serum activity peaked during the first 4 hours after the release of the aortic cross-clamping. In order to determine the best indicator of myocardial damage after cardioplegia, duration of extracorporeal circulation (ECC-time), aortic occlusion time (AOT), mean myocardial temperature (MMT) and the product of AOT and MMT, referred to as time-temperature area (TTA), were related to possible indicators of myocardial injury, such as enzyme and myoglobin release. The TTA was the best way of expressing the degree of exposure of the heart to ischaemia. The CK-MB to peak area (CK-MB max area) was the best indicator of the degree of ischaemic injury sustained by the heart during operation.

Aortic Valve↗
PubMed1979

Myocardial protection during aortic valve replacement. Selective infusion of cold cardioplegic solution into the left coronary artery.

A simple method for hypothermic cardioplegia during aortic valve surgery is described. Cold cardioplegic solution (Ringer's acetate with 16 mEq potassium added) was selectively infused into the left coronary artery after the aorta had been opened. This resulted in an even cooling of the left ventricle with a relatively small amount of cardioplegic solution. Local cooling with "soft ice" was then initiated and the heart isolated from its warmer surroundings with the aid of a specially designed pad of compressed plastic foam. Thus, the left ventricular temperature could be kept below 20 degrees C for more than one hour. One hundred and three (103) patients were operated on with this method during a one-year-period. Only one patient died (1%). There were few early and/or late complications. Postoperative heart function was excellent in 23 patients subjected to a special study. Peak aortic pressure during the first 16 postoperative hours was 130 (+/- 22) mmHg, mean left atrial pressure 12 (+/- 2) mmHg, mean right atrial pressure 10 (+/- 2) mmHg and all patients were in sinus rhythm. There was a brief and limited release of myocardial enzymes postoperatively, indicating slight intra-operative myocardial damage. Apart from the cardioplegic technique, there are certain factors of importance for the efficacy of myocardial protection during aortic valve replacement. Among them may be mentioned avoidance of ventricular fibrillation, gentle reperfusion after release of the aortic cross-clamping, avoidance of left ventricular distension and administration of calcium intravenously before termination of bypass.

Adult↗
PubMed1978

Myocardial protection during aortic valve replacement. Physiological and metabolic effects of selective coronary perfusion on the fibrillating heart.

The physiological effects and certain aspects of cardiac metabolism were studied in 14 patients undergoing primary aortic valve replacement. The operations were performed under moderate hypothermia (30 degrees +/- 2 degrees C) and blood for coronary perfusion was taken from a sidebranch of the arterial line. The majority of the hearts went spontaneously into ventricular fibrillation at some stage of the operation. In spite of the high resistance measured in the coronary perfusion cannulae, an intraluminar coronary blood flow of 380 ml/min was recorded. The myocardial oxygen uptake decreased to 6.0 ml/min at 29 degrees C compared with 20.0 ml/min at 36 degrees C. The elevated coronary sinus lactate throughout the period of coronary perfusion and the increasing level of ASAT-enzyme indicated that this technique could not fully protect the myocardium from ischaemic changes. One patient died of myocardial infarction and two others needed vasopressor support postoperatively, in spite of documented effective coronary perfusion throughout the procedure. Cannulation of the coronary sinus is a valuable adjunct for the study of cardiac metabolism during ECC and it was accomplished without complications.

Adult↗
PubMedDate not supplied

[Myelomeningocele: surgical treatment and results].

The authors made a retrospective study of 72 patients with myelomeningocele treated at a pediatric hospital in Rio de Janeiro, Brazil. 65 (90.2%) lesions involved the inferior segments of the spine and 87.5% of the patients needed shunt procedures for hydrocephalus control. Shunt infections in spina bifida cystica patients were more frequent than in any other group of hydrocephalic patients treated at the institution. There was a great incidence of postoperative complications such as wound infections and skin necrosis. 11 (15.3%) patients developed signs and symptoms related to Chiari II malformation. The overall mortality was 8.3%, and in most of the cases, ascribed to the Chiari malformation.

English Abstract↗