Effect of the hemodinamic overload on the arterial wall of the aortic bifurcation of rats Wistar: development of a model of aneurismatic structural fatigue by means of arterial hypertension and modification of the bifurcation angle

Abstract

The spontaneous Subarachnoid hemorrhage (SAH) represents up to 40% of the cerebral vascular accidents in lesser population of 45 years, with a tax of mortality of 3.5/100.000 and generates expenses of 1.7 billion dollars/year in the United States. The saccular aneurisms are responsible for 90% of the cases. The etiology, the mechanisms of development and the causes of rupture of the saccular aneurisms have been studied in extensive way, however, do not exist consensus in its pathogenesis. To clarify the etiology of the cerebral aneurisms, the mechanisms of initiation, growth and rupture they will have to be studied in sequential way. By this it is essential an experimental model that reproduces its development. By means of micron-surgical technique and through laparotomy will be made left nephrectomy and coagulation of the renal artery posterior right in male Wistar rats of 200grs. In some of these species, during the same surgical procedure, will be made the modification from the angle of aortic bifurcation by means of tunneling of the left iliac artery in the iliolombar muscle. 9 months later the species will be submitted to a new procedure of exploring laparotomy, registering the morphologic and histopathological changes in the aortic bifurcation. The hemodynamic features will be determined in the pre and postoperatory period by means of direct manometry. The results of our pilot study indicate that it is possible to develop a model of structural aneurismatic fatigue of the vascular bifurcations without direct injury of the wall. This not described model previously will allow the biofisical characterization of the development mechanisms, growth and rupture of the intracraniais aneurisms. (AU)