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Biomedical subjects

R Prêtre

Publications and source records attributed to R Prêtre.

At least 19 recordsLinked to original sources
PubMed1998

Surgical management of hemorrhage from rupture of the aortic arch.

BACKGROUND: Control of hemorrhage in patients with active bleeding from rupture of the aortic arch is difficult, because of the location of the bleeding and the impossibility of cross-clamping the aorta without interfering with cerebral perfusion. A precise and swift plan of management helped us salvage some patients and prompted us to review our experience. METHODS: Six patients with active bleeding of the aortic arch in the mediastinum and pericardial cavity (5 patients) or left pleural cavity (1 patient), treated between 1992 and 1996, were reviewed. Bleeding was reduced by keeping the mediastinum under local tension (3 patients) or by applying compression on the bleeding site (2 patients), or both (1 patient) while circulatory support, retransfusion of aspirated blood, and hypothermia were established. The diseased aortic arch was replaced during deep hypothermic circulatory arrest, which ranged from 25 to 40 minutes. In 3 patients, the brain was further protected by retrograde (2 patients) or antegrade (1 patient) cerebral perfusion. RESULTS: Hemorrhage from the aortic arch was controlled in all patients. Two patients died postoperatively, one of respiratory failure and the other of abdominal sepsis. Recovery of neurologic function was assessed and complete in all patients. The 4 survivors are well 8 to 49 months after operation. CONCLUSIONS: An approach relying on local tamponade to reduce bleeding, rapid establishment of circulatory support and hypothermia, retransfusion of aspirated blood, and swift repair of the aortic arch under circulatory arrest allows salvage of patients with active bleeding from an aortic arch rupture.

Aged↗
PubMed1998

Performance of a safe proximal anastomosis in aortic dissection.

Because of the increased fragility of a freshly dissected aorta, the anastomosis between the aortic root and a tubular prosthesis is not forgiving of technical imperfections and may lead to troublesome bleeding. Providing an appropriate everting surface of contact and a homogeneous distribution of tension between the graft and aorta, as described here, should help obtain a hemostatic suture line.

Anastomosis, Surgical↗
PubMed1998

Improved exposure of the pulmonary arteries for thromboendarterectomy.

Pulmonary thromboendarterectomy is a surgical technique for treating pulmonary hypertension caused by unresolved pulmonary embolism. It has been recommended to perform this procedure under deep hypothermic circulatory arrest. Here we describe two technical modifications: (1) improved exposure to the right pulmonary artery by division of the superior caval vein and (2) thromboendarterectomy in normothermic cardiopulmonary bypass, with beating heart or electrically induced ventricular fibrillation. These modifications allow complete endarterectomy of both pulmonary arteries under normothermic conditions, thus avoiding hypothermic circulatory arrest, which results in short cardiopulmonary bypass times and reduces the morbidity and mortality of this procedure.

Cardiopulmonary Bypass↗
PubMed1998

Endothelial cell injury in cardiac surgery: salicylate may be protective by reducing expression of endothelial adhesion molecules.

OBJECTIVE: Cardiac surgery with cardiopulmonary bypass induces ischemia to the heart, hypoxemia to various tissues and release of endotoxins. The endothelial cell may suffer from hypoxia and trigger cascades of adverse reactions by activation of neutrophils through adhesion molecules. The authors measured expression of intercellular adhesion molecule-1 (ICAM-1), during hypoxia and normoxia and hypothesized that salicylate, which inhibits the nuclear factor-kappaB (NFkappaB), an hypoxia-dependent transmission factor, could reduce this expression. METHODS: Human umbilical vein endothelial cells were cultured and exposed to normoxia and hypoxia in the presence of lipopolysaccharide (LPS). The endothelial cells were thereafter treated with salicylate or indomethacin under the same conditions. The surface expression of ICAM-1 was measured by whole cell enzyme-linked immunosorbent assay (ELISA) and the NFkappaB expression by Western blotting. RESULTS: In the presence of LPS and under hypoxic conditions, the endothelial cells produced a 300 +/- 41% increased expression of ICAM-1 compared with normoxia. The addition of salicylate (0.02-20 mM) completely inhibited the enhanced expression of ICAM-1, the addition of indomethacin at equivalent concentrations did not reduce ICAM-1 expression under either condition. CONCLUSION: ICAM-1 expression is greatly enhanced by the hypoxic endothelial cell in the presence of circulating endotoxin. Pre-treatment with salicylate completely abolishes the enhanced expression. The study suggests that salicylate administered before cardiopulmonary bypass might protect the heart against ischemic/reperfusion injuries and reduce the load of the overall inflammatory reaction.

Blotting, Western↗
PubMed1998

[Approach to upper limb edema secondary to subclavian vein occlusion situated distal to an arteriovenous fistula].

AIM OF THE STUDY: To analyse the course of upper limb edema in patients with an arteriovenous fistula used for dialysis and to analyse the available therapeutic options. STUDY DESIGN: Retrospective study of patients with this type of edema, who were treated in our institution from 1992 to 1996. PATIENTS AND METHODS: Seven consecutive patients with an arterioveinous fistula treated for edema of the upper extremity, were reviewed. The fistula was created at the elbow in 6 patients and at the forearm in 1. The edema appeared immediately after operation in 4 patients and after a delay in 3 patients. Stenosis (3 patients) or occlusion (2 patients) of the subclavian vein was documented in 5 patients who were investigated by angiography. RESULTS: The edema regressed spontaneously in 4 patients because collaterals developed in 3 patients, and the fistula thrombosed in 1 patient. Surgical intervention allowed regression of the edema in the other 3 patients: excessive output of the fistula was reduced in 2 patients and an axillojugular bypass was performed in 1 patient. The fistula remained effective in 6 patients. Another fistula was performed on the contralateral arm in 1 patient. CONCLUSION: Non-operative management is recommended in patients who develop edema immediately after creation of the fistula, because spontaneous regression is likely. Measures aimed at reducing the output of the fistula or enhancing the venous capacities of the arm are required when edema appears at a later stage. The fistula can be saved in the majority of cases.

Aged↗
PubMed1998

[The significance of endothelial adhesion molecules in heart surgery].

Myocardial ischemia and reperfusion is a common event in cardiovascular surgery patients. The endothelium has been shown to play a key role in the injury suffered after ischemia and reperfusion. When endothelial cells became hypoxic followed by reoxygenation they become activated to express endothelial adhesion molecules followed by the migration of neutrophils into the tissue. These changes may contribute to the early postoperatively myocardial dysfunction. An increased understanding of the interaction between leukocytes and endothelium may allow to develop new therapies in future.

Animals↗
PubMed1997

Aortic dissection.

Explore the source record for details and available documents.

Aortic Dissection↗
PubMed1997

Blunt injury to the supra-aortic arteries.

BACKGROUND: Blunt trauma causing injury to the vessels of the aortic arch is uncommon but may be attended by serious consequences. Most surgeons will experience only an occasional case and will need to rely on published literature for guidance. METHODS: A Medline search over 1986-1995 was carried out using the following keywords: brachiocephalic trunk, common carotid artery and subclavian artery; injury was used as a subheading. RESULTS AND CONCLUSION: After the aortic isthmus, the innominate is the most commonly injured artery in the chest. Whatever the site of an arterial lesion, however, angiography is the diagnostic test of choice. Some vascular lesions are relatively benign and may be managed without operation; this form of management may also be appropriate if there is severe associated neurological injury. Otherwise, operation using an approach and technique suited to the site of the injury is advocated.

Aorta, Thoracic↗
PubMed1996

Operative injury to the hepatic artery. Consequences of a biliary-enteric anastomosis and principles for rational management.

Although the interruption of the hepatic arterial flow usually is well tolerated, this is not always the case, and it is important to predict in which circumstances complications are likely to occur. The main determinants that should guide the surgeon confronted with this problem are (1) whether the portal circulation is normal, (2) whether structures carrying collateral blood supply have been interrupted, and (3) whether some form of biliary reconstruction is needed. We present our experience with three patients in whom the hepatic artery was damaged at operation as examples of how this injury can be dealt with in practice and discuss the measures to prevent or treat the complications that developed.

Adult↗
PubMed1996

Blunt injury to the ascending aorta: three patterns of presentation.

BACKGROUND: Injury to the ascending aorta is a rare lesion that may present in various forms. A thorough analysis of this lesion is lacking in the literature. This study was undertaken to delineate the prevalence and modes of presentation of injuries to the ascending aorta after blunt trauma and to suggest guidelines for management. METHODS: A retrospective analysis of autopsies performed in our department of forensic medicine on blunt trauma victims from 1984 to 1993 and a literature review of autopsy series were undertaken to delineate the prevalence and relevant characteristics of this injury. A cash report from our institution and a review of the literature were used to provide information regarding clinical presentations of this injury and treatment approaches. RESULTS: Three modes of presentation were encountered. (1) Presentation at autopsy: The prevalence of injury to the ascending aorta after a traffic accident was 2% in our autopsy series. Among 13 patients with this injury 12 had other associated, potentially lethal lesions. A massive hemopericardium was present in two patients only. In autopsy series the incidence of injury to the ascending aorta in patients with an injury to the aorta ranged from 0% to 23%. (2) CLINICAL PRESENTATION: Twenty-one patients were treated surgically and reported in the literature. Fourteen presented with a pseudoaneurysm and seven with a chronic sinus of Valsalva fistula. One patient with a pseudoaneurysm presented with signs of cardiac tamponade and required immediate decompression; the others were hemodynamically stable. Seven patients had a cardiac lesion (valve tear in six and cardiac contusion in one), and three had an arch vessel lesion. Aorta repair was performed under cardiopulmonary bypass in every patient. (3) Incidental presentation: Seven patients with a traumatic tear of the aortic valve presented an incidental lesion of the ascending aorta. It was a subadventitial hematoma in three patients and an intimal and medial tear in four patients. Aortic tears were reinforced by direct suture. CONCLUSIONS: Injury to the ascending aorta after blunt trauma is rare but lethal mostly from associated injuries. Survivors may appear in stable condition and present mostly with pseudoaneurysms of the ascending aorta or sinus of Valsalva fistula. Associated lesions to the heart and arch vessels should be looked for. Repair of the ascending aorta injury is performed under cardiopulmonary bypass.

Adolescent↗
PubMed1996

Preoperative inhibition of angiotensin-converting enzyme improves systemic and renal haemodynamic changes during aortic abdominal surgery.

We studied 22 patients undergoing aortic surgery, allocated randomly to receive, before induction of anaesthesia, a single i.v. dose of enalapril 50 micrograms kg-1 or saline. During infrarenal aortic cross-clamping, we observed similar reductions in oxygen uptake in the two groups, despite greater systemic oxygen delivery in enalapril-treated patients; angiotensin-converting enzyme inhibition prevented the reduction in cardiac output and attenuated the decrease in glomerular filtration. Changes in glomerular filtration secondary to aortic clamping were related positively to changes in renal plasma flow (r = 0.83 (saline group) and r = 0.65 (enalapril group)). Creatinine clearance on the first day after operation was significantly higher in the enalapril compared with the saline group. We conclude that enalapril pretreatment is effective in improving systemic oxygen delivery, renal plasma flow and glomerular filtration during aortic abdominal surgery.

Aged↗