the clinical , angiographic , and histologic changes noted in the animal model include : abrupt clinical deterioration after a variable interval with some animals developing ptosis , afferent vessel dilatation and the development of prominent anastomotic channels , variable cerebral vessel histopathology -- related to duration and relative proximity to the shunt -- affecting all three vessel layers , plump , irregular , and clumped endothelium , denuded with adherent platelets , irregular , duplicated , and thinned internal elastic membrane , frayed with invasion of the intima by mesenchymal cells , vacuolization and necrosis of the media muscle , and invasion of adventitia by foreign cells and small blood vessels .
C0005847
vessel
C0162864
intima