Endarterectomy of the Aneurysm Sac in Open Abdominal Aortic Aneurysm Repair Reduces Perigraft Seroma and Improves Graft Incorporation

Background: Fluid around the graft in the original aneurysm sac after open abdominal aortic aneurysm (AAA) repair is a poorly researched phenomenon. If large, such perigraft seroma can cause symptoms of compression, and cases of rupture have even been described. We assessed whether endarterectomy of the aneurysm sac reduces the incidence of perigraft fluid and improves graft incorporation. Design and methods: Starting in July 2005, all patients with elective open AAA repair were alternately treated either with conventional thrombectomy or thrombectomy plus endarterectomy of the aneurysm sac. All patients were treated with a polytetrafluoroethylene (PTFE) graft. The maximum axial width of the perigraft fluid collection was measured on computed tomography (CT) scans 1year after operation. Results: The CT scans of 115 patients were available; 56 had endarterectomy of the aneurysm sac and 59 did not. Fluid collections were significantly smaller in patients with endarterectomy (median width 4.0 versus 8.0mm; P=0.0001). Eight patients with endarterectomy had a fluid collection wider than 10mm compared to 28 patients without endarterectomy (OR 0.18, 95% CI 0.07-0.46). After endarterectomy, 17 patients had radiological signs of complete graft incorporation in comparison to only 6 patients without endarterectomy (OR 3.85, 95% CI 1.39-10.66). No patients were symptomatic or reoperated for perigraft seroma. Conclusions: Endarterectomy of the aneurysm sac in open AAA repair appears to improve graft incorporation. The high rate of asymptomatic perigraft seroma is surprising, and its clinical significance is unknown. Ultrafiltration of PTFE grafts may be an underlying mechanis

Cycloadditions 1,3 dipolaires asymetriques - nouvelle methode de generation d'ylures d'azomethine

SIGLEINIST T 71072 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Synthèse d analogues de la cytisine, ligands des récepteurs cholinergiques nicotiniques

CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF

Acides de Brønsted chiraux (Synthèses et applications en organocatalyse asymétrique)

L'organocatalyse a émergé récemment comme une approche complémentaire aux métaux de transitions dans le domaine de la catalyse asymétrique. Plus particulièrement, l utilisation d acides de Brønsted chiraux est devenue depuis 2004 une contribution importante et très originale. Au cours de ce projet, la synthèse d'acides originaux phosphoriques et phosphorodithioiques dérivés du BINOL a été réalisée afin de moduler les propriétés intrinsèques de cette classe de catalyseurs (acidité et encombrement stérique). Ces acides ont été développés afin de résoudre plusieurs problèmes associés aux réactions asymétriques de Nazarov, de Mannich et d aldolisation. Les acides phosphoriques se sont révélés plus sélectifs que les acides phosphorodithioiques, qui ont cependant montré une acidité accrue. La première réaction d'aldolisation directe énantiosélective catalysée par des acides de Brønsted chiraux a été étudiée. Un acide phosphorique chiral très encombrés a catalysé l addition de différentes cétones sur le glyoxalate d'éthyle (ee jusqu'à 89% et rd jusqu'à 95:5). L utilisation de substrats complémentaires vis-à-vis de la catalyse énamine, associée à une diastéréosélectivité syn observée, rendent cette approche particulièrement originale. L'ensemble de cette étude confirme le potentiel des acides phosphoriques en tant que catalyseurs chiraux efficaces pour de nombreuses réactions énantiosélectives.Organocatalysts has recently emerged as an alternative to transition metals for enantioselective catalysis. Since 2004, chiral Brønsted acids appeared as an important contribution to this area of research. In this work, a range of novel phosphoric and phosphorodithioic acids derived from BINOL have been synthesized to modulate the acidity and the steric hindrance of the catalysts. These acids have been used to investigate asymmetric Nazarov, Mannich and aldol reactions. The phosphoric acids appeared as more selective catalysts whilst the phosphorodithioic acids were shown to be more acidic. A syn-enantioselective aldol reaction has been developed using a strongly hindered phosphoric acid. This reaction is the first example of an enantioselective direct aldol reaction using Brønsted acid catalysis. This method affords the asymmetric synthesis of various b-hydroxyketones, some of which could not be synthesized using enamine organocatalysis. This confirms the potential of phosphoric acids as chiral catalysts in enantioselective reactions.CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF