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J O Defraigne

Publications and source records attributed to J O Defraigne.

At least 19 recordsLinked to original sources
PubMed1998

Comparative effects of University of Wisconsin and Euro-Collins solutions on pulmonary mitochondrial function after ischemia and reperfusion.

BACKGROUND: The aim of this study was to compare the effects of Euro-Collins and University of Wisconsin solutions on pulmonary mitochondrial function after cold ischemia and subsequent warm reperfusion. METHODS: Seventeen pigs underwent lung harvesting after classical lung flush with either University of Wisconsin or Euro-Collins solutions. The mitochondria were isolated from fresh swine lungs, from swine lungs subjected to 24 hr of cold ischemia, and from swine lungs subjected to 24 hr of ischemia followed by 30 min of subsequent ex vivo reperfusion at 37 degrees C with Krebs-Henseleit buffer solution and air ventilation. Mitochondrial oxidative phosphorylation parameters were determined in isolated mitochondria by in vitro measurement of oxygen consumption rates. During reperfusion, the lung function was assessed by the pulmonary aerodynamic parameters and the pulmonary vascular resistance. RESULTS: Relative to controls, mitochondria submitted to cold ischemia showed an alteration in the oxidoreductase activities of the respiratory chain. However, the yield of oxidative phosphorylation was conserved. After reperfusion, pulmonary mitochondria underwent a significant worsening in the oxidoreductase activities of the respiratory chain, and a decrease in the respiratory control and the efficiency of oxidative phosphorylation. Meanwhile, the reperfused lungs showed evidence of early dysfunction, assessed by the aerodynamic parameters and pulmonary vascular resistance. In this model, there was no advantage of University of Wisconsin solution over Euro-Collins solution. CONCLUSIONS: The mild mitochondrial alterations after cold ischemia were not sufficient to explain the limited tolerance of lung to ischemia. After reperfusion, the mitochondrial damage was more severe and could be involved in the posttransplant lung dysfunction.

Adenosine↗
PubMed1998

Effects of PEEP on systemic venous capacitance.

The aim of the present study was to determine effects of positive end expiratory pressure (PEEP) application on peripheral venous capacitance and relate them to concomitant central hemodynamic disturbances. The venous volume-pressure (V/P) relationships were studied in 6 intact anesthetized pigs to describe the effects of PEEP on systemic venous compliance (computed as the slope of the V/P relationship) and unstressed volume (referred to as the extrapolated volume intercept). Cardiac volumes as well as partitioning of circulating blood volume between central (ITBV) and peripheral (PBV) compartments were assessed by thermo-dye dilution techniques. During a 15 cm H2O PEEP application, venous compliance was reduced by 48%, while unstressed volume was increased by 25% and peripheral blood pooling increased from 63 to 74%. As a result, left heart and right ventricular end diastolic volumes were decreased by 8% and by 44%, respectively. It is concluded that increased venous unstressed volume and reduced compliance depicted the distension of the venous tree secondary to PEEP which acted as an impediment to venous return. As a consequence, cardiac output was reduced because of decreased preload.

Animals↗
PubMed1998

[Cardiac assistance using transformed striated skeletal muscle: cardiomyoplasty].

The biomechanical potential of transformed skeletal muscle used for cardiocirculatory assistance is the keystone of this surgical concept. This underscores the necessity to modulate type II to type I transformation to premise the muscle bulk, shortening velocity, and, therefore, power. It is only if an efficient autologous engine is available that optimal surgical configuration (i.e. aortomyoplasty) will provide active cardiocirculatory support.

Aorta↗
PubMed1998

[From the study of biochemical changes in ischemic and reperfused skeletal muscle to the controlled reperfusion of limbs in patients with acute severe ischemia].

The reperfusion of a limb which has been submitted to a severe and prolonged period of ischemia may be followed by dramatic local and systemic complications. The results of several experimental studies have given insights on the biochemical and physiopathological alterations occurring in the ischemic and reperfused skeletal muscle. Therefore the technique of the controlled limb reperfusion has been developed. we present the results obtained in two patients with this technique. Two patients were admitted for a limb-threatening ischemia consecutive to embolism. After removal of the thrombi with a Fogarty's catheter and before reperfusion with the normal blood, a controlled limb reperfusion was performed by mixing the systemic blood with a crystalloid solution in order to obtain a hyperosmolar, hypocalcemic, alcalotic and substrate-enriched (aspartate and glutamate) reperfusate. This reperfusate was infused during 30 min with a roller pump into the deep and superficial femoral arteries. The delivery conditions (temperature, flow and reinjection pressure) were closely monitored. In both cases, no post-operative complication was observed and the pedal pulses were restored after the operation. Complete recovery of the motor and sensitive functions were observed and the patient were discharged at the 10th post-operative day.

Acute Disease↗
PubMed1998

Local and systemic consequences of severe ischemia and reperfusion of the skeletal muscle. Physiopathology and prevention.

Revascularization of a limb after a severe and prolonged period of ischemia may be associated with high rates of mortality and amputation, because of the development of a postrevascularization syndrome, regardless the cause of occlusion (ischemia, trauma, iatrogenic) or the methods used to achieve reperfusion (fibrinolysis, surgery, resuscitative therapy). This "revascularization" syndrome includes several complications, both local (explosive swelling of the limb, compartment syndrome and skeletal muscle infarction (rhabdomyolysis) and general (acidosis, hypercalcemia, hypovolaemic shock, renal, hepatointestinal and pulmonary failures, arrhythmias and cardiac arrest (multiple organ dysfunction). Current therapies are directed against complications after they occurred, once revascularization is completed: fasciotomy, mannitol and diuretics administration for forced diuresis, fluid administration to correct hypovolaemia, use of resins, insulin and glucose or haemodialysis to deal with hypercalcemia, administration of buffers (THAM, bicarbonate) to correct acidosis, control of hypercalcaemia with orthophosphates and calcitonin.... Nevertheless, a substantial percentage of the injury is generated upon reperfusion and the muscle may remain viable after prolonged period of ischemia. Intra and extraacellular swelling, tissue acidosis, free radical mediated damage, loss of adenine nucleotide precursors, and intracellular calcium overload have been suggested to be the mechanisms responsible for reperfusion injury. Careful control of both the composition and the physical conditions of the initial reperfusion (controlled reperfusion) may result, in selected cases, in improvements in the metabolism, structure and function of the limb after reperfusion.

Acute Kidney Injury↗
PubMed1997

Advantages of inferior vena caval flow preservation in combined transplantation of the liver and heart.

Only a few cases of combined liver and heart transplantation have been reported in the literature, and no standard surgical procedure has yet been established. We report the successful transplantation of both liver and heart in a 28-year-old patient suffering from homozygous beta-thalassemia. We used Belghiti's technique of inferior vena caval flow preservation for liver transplantation, which avoids inferior vena cava occlusion by a side-to-side caval anastomosis. Applied to combined liver and heart transplantation, preservation of caval flow during liver transplantation may allow early discontinuation of cardiopulmonary bypass and, thus, minimize the general consequences of prolonged bypass.

Adult↗
PubMed1997

Successful controlled limb reperfusion after severe prolonged ischemia.

Controlled limb reperfusion was performed in two patients who were admitted for lower limb-threatening ischemia as a result of embolism. After embolectomy, the inflow blood was drained with a cannula and mixed with a crystalloid solution to obtain an hyperosmolar, hypocalcemic, alkalotic, and substrate-enriched (aspartate, glutamate) reperfusate. This reperfusate was reinjected with a roller pump for 30 minutes through two cannulas inserted in the profunda and superficial femoral arteries. Temperature, intraarterial pressures, and flow were closely controlled. No complications occurred, and complete recovery of motor and sensory functions were observed, with restoration of pedal pulses.

Aged↗
PubMed1997

Comparison between three- and four-element Windkessel models to characterize vascular properties of pulmonary circulation.

In 11 anaesthetised pigs the accuracy of the three-element (WK3) and the four-element (WK4) Windkessel models to describe hemodynamic properties of the pulmonary circulation was compared during six different experimental conditions increasing pulmonary arterial pressure: increase in left atrial pressure, increase in alveolar pressure, increase in pulmonary blood flow, endotoxin shock, mechanical obstruction of left pulmonary artery or histamine infusion. Our results showed that WK4 fitted better the data than did WK3 because values of 1-R2 decreased from 6 percent (WK3) to 1.4 percent (WK4) when WK4 was used (P < 0.0005). 1-R2 was an adequate marker of the accuracy of the linear regression used to solve equations of both models. Compliance values estimated by WK4 were decreased by 5% comparatively to WK3 (P = 0.008). However, this difference can be considered as not physiologically relevant. Values of characteristic resistance corresponding to R1 + (L/R2C) in WK4 and to R1 in WK3 were not different (P = 0.22). The relative changes in R1, R2, and C observed due to the different experimental conditions were comparable regardless of the model. In conclusion, the conversion of WK3 in WK4 by adding an inductance, whose physiological meaning is not clear, resulted in an increased statistical accuracy of the model, but did not seem to have relevant influence on parameters or their evolution during experimental conditions.

Animals↗
PubMed1997

Fatal mural endocarditis and cutaneous botryomycosis after heart transplantation.

Fatal mural endocarditis and botryomycosis occurred concurrently in a 62-year-old women 4 months after orthotopic heart transplantation. Subsequent to mild mitral regurgitation, infection developed on a left atrial thrombus and was complicated by cerebral embolization. Simultaneously, skin nodules manifested on both forearms. Histologic examination revealed typical aspects of early evolving botryomycosis with massive infiltration of the dermis and hypodermis by necrotic granulomas framed by grains of Gram-positive coccoid forms. Bacteria were decorated by a nonspecific polyclonal antibody to Mycobacterium bovis.

Endocarditis, Bacterial↗
PubMed1997

Ruptured aneurysm of the profunda femoral artery associated with polyaneurysmal disease.

A 73-year-old man was admitted for rupture of an atherosclerotic aneurysm of the profunda femoris artery associated to popliteal and bilateral axillary arteries aneurysms. The aneurysm of the profunda femoris artery was developed between the branches of the crural nerves. Considering the patency of the superficial femoral artery and of the leg arterie, and to avoid injury to the crural nerve, no reconstruction of the profunda femoris was attempted. The aneurysm was ligated proximally and buttress sutures were placed on the site of rupture to achieve thrombosis of the aneurysms. Most of the published cases of aneurysm of the profunda femoris artery are false aneurysms developed after various trauma. Atherosclerotic aneurysm of the profunda femoris artery is a rare lesion and rupture is exceptional.

Aged↗
PubMed1997

Successful management of acute aortic dissection in a heart transplant recipient.

A case of type III aortic dissection which occurred fourteen months after heart transplantation is presented. Medical therapy was instituted to achieve controlled hypotension. The evolution was favorable and the patient could be discharged after one month. Hypertension and increased ejection fraction after transplantation could have been predisposing factors via an increase of the shear stress in the aorta.

Aged↗