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Biomedical subjects

J Boivin

Publications and source records attributed to J Boivin.

47 records · Page 3Linked to original sources

[Prognosis following mitral valve replacement with the Starr-Edwards 6120 prosthesis].

Between 1970-78, 302 mitral valve replacements with the SE 6120 prosthesis were performed, with an average postoperative follow-up of 50,7 months, using the 3 M size (206 cases) and 2 M (96 cases with small left ventricles). Early postoperative mortality was 5,6%, late postoperative mortality: 17,2%, the 5 year actuarial survival rate: 77,4% and the 9 year survival rate 71,8% (early mortality included). There was no significant difference in survival after mono- (143 cases) and polyvalvular replacement (159 cases); only a voluminous left atrium (p less than 0,05) and left atrial thrombosis (p less than 0,01) were statistically significant prognostic factors of global mortality. Late haemorrhage due to anticoagulant therapy (3%) (0,6 per 100 patient years). The most common complication was systemic embolism (3,7 per 100 patient years). Actuarial studies showed that 86,6% at 5 years and 80,1% at 9 years, escaped this complication. Statistically the favorising roles of permanent atrial fibrillation (p less than 0,05), the size of the left atrium (p less than 0,02) of isolated demonstrated. 90,4% of the survivors were clinically improved: the functional result was better when that 86,6% at 5 years and 80,1% at 9 years, escaped this complication. Statistically the favorising roles of permanent atrial fibrillation (p less than 0,05), the size of the left atrium (p less than 0,02) of isolated demonstrated. 90,4% of the survivors were clinically improved: the functional result was better when that 86,6% at 5 years and 80,1% at 9 years, escaped this complication. Statistically the favorising roles of permanent atrial fibrillation (p less than 0,05), the size of the left atrium (p less than 0,02) of isolated demonstrated. 90,4% of the survivors were clinically improved: the functional result was better when the valve replacement was not a reoperation (p less than 0,02), when the patient was not in functional Class IV (p less than 0,01), in permanent excessively dilated (p less than 0,01) and in patients without severe tricuspid regurgitation (p less than 0,01). There was no significant difference in global mortality, the percentage of embolic events and the quality of the functional postoperative result between patients with the 3 M and those with the 2 M SE 6120 prosthesis.

Adult↗

[Myocardial metabolism during coronary perfusion at 10 degrees C with or without cardioplegia associated with potassium].

Myocardial metabolism was studied during coronary perfusion at 10 degrees c with haemodiluted blood by sampling the coronary sinus blood of 20 patients undergoing aortic valve replacement. The patients were divided into four groups : Group 1 with continuous coronary perfusion at 10 degrees c ; Group 2 : continuous perfusion at 10 degrees c with Potassium cardioplegia ; Group 3 : discontinuous coronary perfusion at 10 degrees c ; Group 4 : discontinuous perfusion at 10 degrees c with Potassium cardioplegia. In groups 1 and 2, coronary blood flow remained constant at an average of 200 ml/mn. Cardioplegia did not affect the peripheral coronary resistances at this temperature. During coronary perfusion the average myocardial oxygen consumption was 1.38 vol/mn (Group 1) and 0.18 vol/mn (Group 2), p < 0.01. This reduced oxygen consumption results in a fall in the average amount of oxygen extracted from 4.8 p.100 (Group 1) to 1.2 p.100 (Group 2) p < 0.01. At the end of coronary perfusion lactic acid production was not observed in Groups 1 and 2. Ten minutes after coming off bypass, the percentage of oxygen extraction was nearly the same in both groups (Group 1 : 38.4 p.100 ; Group 2 : 43.2 p.100). Systemic arterial lactic acid levels tended to be higher than those of coronary sinus blood in both groups. With discontinuous coronary perfusion and an average period of myocardial anoxia of 45 mn, metabolic acidosis was observed, greater in Group 3 than in Group 4 (p < 0.05) when the aorta was unclamped. Ten minutes after the end of bypass, despite normal levels of oxygen extraction, myocardial lactate production was observed in both groups. The enzyme levels, in particular the CPK MB isoenzyme, in the coronary sinus blood, remained low throughout operation in all four groups. Deep, stable and constant myocardial hypothermia (10 degrees c) induced by coronary perfusion with haemodiluted blood, affords excellent myocardial protection ; it was not possible to show the complementary benefits of Potassium cardioplegia at such low temperatures.

Aortic Valve↗

[Comparative study of myocardial protection by coronary perfusion in deep hypothermia (10 degrees C) with or without potassium cardioplegia. Clinical, electrocardiographic, enzymatic results; biochemical and histological controls].

A technique of coronary perfusion with diluted blood, giving homogenous myocardial cooling (10-12 degrees C) under lignocaine perfusion, with or without potassium (K) cardioplegia is presented. The first 75 operated cases were used to adjust the optimal lignocaine (5 mg/min) and K (2 meq/min in continuous coronary perfusion, 5 meq/min in discontinuous coronary perfusion) dosage in the myocardial protection circuit. Then, 123 operated patients (78 aortic valve replacement, 30 mitro-aortic double valve replacement, 15 other operations on the ascending aorta) were classified into four groups prospectively: 1. Continuous coronary perfusion 10 degrees C, 2. Continuous coronary perfusion 10 degrees C with associated K cardioplegia, 3. Discontinuous coronary perfusion 10 degrees C, 4. Discontinuous coronary perfusion 10 degrees C with K cardioplegia. The best return of cardiac activity was observed in Group 1 and this was statistically significant with a high percentage of spontaneous heart beating after declamping the aorta (average 10 minutes), immediate efficacity of left ventricular contraction, and absence of arrhythmias, especially the transient conduction defects observed with K cardioplegia. In Group 1, during mitro-aortic valve replacement, after over 60 minutes aortic clamping, no significant reduction of ATP or myocardial phosphocreatinine or changes of hexosemonophosphates were observed, contrary to the findings after 15 minutes aortic clamping at 28 degrees C in a control group of mitral valve replacements (n = 10). Myocardial changes on electron microscopy in the subendocardial region of the left ventricle were minimal or absent, especially with respect to the mitochondria. The early post-operative course was the same in all four groups: of the 123 patients operated, early mortality was 2.4 p. 100 (1.6 p. 100 from intercurrent causes), severe arrhythmias were observed in 1.6 p. 100, supraventricular arrhythmias in 4.9 p. 100, myocardial infarction in 0.8 p. 100, electrocardiographic ischaemia in 0.8 p. 100, and atrioventricular block in 0.8 p. 100. The average enzyme level (CPK, SGOT, LDH) in the early postoperative period were low, with no correlation with the duration of aortic clamping.

Chemical Phenomena↗

[Factor analysis fever in the early postoperative period following cardiopulmonary bypass surgery in adults. Correlation with bacteriological data. Statistical study of 518 case histories by computer].

The results of a continuous series of 518 adults undergoing cardiopulmonary bypass surgery, operated on by the same surgeon, comprising valvular replacement and aorto-coronary bypass surgery with a peroperative protocol of asepsis and a short prophylactic course of Penicillin and Streptomycin, a preoperative and postoperative bacteriological study, were treated by computer. The postoperative temperature chart showed a progressively decreasing pyrexia in the first 8 days after cardiopulmonary bypass. The nature of the operation, the bypass time, the quantity of blood used during operation and the blood loss were statistically significant factors. Patients with a clinical infection had significantly higher temperatures from the first on. 8,9% of patients had a febrile reaction which continued after the 10th day after cardiopulmonary bypass. The cause was not always apparent but the appearance of their temperature graphs was distinguishable after the first week. Analysis of the systematic bacterial specimens showed bacterial contamination of nearly 10% of drains, 10% of blood cultures, over 15% of intravenous infusion catheters and 70% of urinary catheters. The significance of these results is discussed. The normal appearance of the temperature chart after cardiopulmonary bypass surgery in the absence of clinical complications and bacterial contamination has been established.

Bacterial Infections↗

[Results of mitral-aortic valve replacements].

Seventy-five combined mitral and aortic valve replacements were done between 1970 and 1976 with a minimum follow-up of 12 months and a mean of 3.72 +/- 17 months using à Björk prosthesis in the aortic position and the Starr 6120 prosthesis in the mitral position. The early post-operative mortality was 5.3% and the late mortality 8.4%. The actuarial survival curve projected a mortality of 16% at 6 years, including the operative mortality. The survival at 6 years did not differ from that of mitral valve replacement alone during the same period, though it was less than the survival of aortic valve replacement for aortic regurgitation. Among the post-operative complications only 3 embolic complications were seen. Surprisingly, the degree of heart failure, the radiological heart size, and the haemodynamic data showed no satistically significant influence on the post-operative mortality. All of the survivors except one showed a functional improvement. Haemodynamic checks in 13 patients showed a significant reduction in mean pulmonary arterial pressure, in mean capillary wedge pressure and in arteriovenous oxygen difference, but not in the cardiac index. The radiological heart size was significantly reduced but this reduction was usually limited.

Adult↗

[Significance of Alfatesine in anesthesia for multiple dental extractions before major cardiac surgery].

This technique of anaesthesia used for oral surgical operations such as, multiple dental extractions, apical resection, carried out in cardiac patients before major cardiac surgery under extra-corporeal circulation, for insertion of valvular prostheses or aorto-coronary by-pass operations, has passed by various stages. The present technique associating phenoperidine-alfatesine-suxame-thonium-N2o-o2, was used in the last 58 cases. It presents a certain number of advantages compared with previous techniques: -very stable level of anaesthesia whatever the duration of the operation, -satisfactory cardio-vascular stability, -almost constant absence of hypo-excitability of the myocardium even in patients in poor cardiac condition before the operation with uninterrupted treatment with digitalis and diuretics, -good quality of awakening.

Adolescent↗