AN IMPROVED CANINE MODEL OF SUBARACHNOID HEMORRHAGE USING INTRATHECALINDWELLING CATHETERS

In the present study, the feasibility of intrathecal indwelling cathet ers in the preparation of a repeated subarachnoid hemorrhage (SAH) mod el in dogs, as well as chronic intrathecal administration of therapeut ic agents against the ensuing cerebral vasospasm was examined. Briefly , through a small suboccipital incision, two catheters were introduced into the subarachnoid space so that their tips were positioned in the prepontine cistern. One was used to induce SAH by infusing autologous blood, and the other to administer pharmacological agents (saline and /or saline containing a dye in this study) by means of an osmotic pump . The occurrence of cerebral vasospasm was followed by angiography via the catheter placed in the vertebral artery. The obtained results sho w: i) the injected blood effectively formed a subarachnoid clot in the prepontine cistern, invariably leading to the occurrence of severe ce rebral vasospasm of the basilar artery; ii) the fluid injected by the osmotic pump was evenly distributed in the cisterns around the brain s tem; iii) on post mortem pathological examination, no injury of the br ain or the major arteries ascribable to the placement of catheters was found. Therefore, the present model is considered to be useful for bo th the investigation of pathophysiology and therapy of cerebral vasosp asm following SAH, to be more favorable from the standpoint of animal protection, and more convenient and reliable than those used until now .