An Improved Canine Model of Subarachnoid Hemorrhage Using Intrathecal Indwelling Catheters.

Abstract

ABSTRACT. In the present study, the feasibility of intrathecal indwelling catheters in the preparation of a repeated subarachnoid hemorrhage (SAH) model in dogs, as well as chronic intrathecal administration of therapeutic 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 show: i) the injected blood effectively formed a subarachnoid clot in the prepontine cistern, invariably leading to the occurrence of severe cerebral vasospasm of the basilar artery; ii) the fluid injected by the osmotic pump was evenly distributed in the cisterns around the brain stem; iii) on post mortem pathological examination, no injury of the brain or the major arteries ascribable to the placement of catheters was found. Therefore, the present model is considered to be useful for both the investigation of pathophysiology and therapy of cerebral vasospasm following SAH, to be more favorable from the standpoint of animal protection, and more convenient and reliable than those used until now. -KEY WORDS: canine, cerebral vasospasm, osmotic pump.J. Vet. Med. Sci. 59(9): 825-828, 1997 complied with the "Principle of Laboratory Animal Care" and the "Guide for the Care and the Use of Laboratory Animals" issued by the National Institute of Health (U.S.A. DHHS publication No. [NIH] 85-23, revised 1985).Under general anesthesia (sodium pentobarbital 30 mg/ kg, i.v.) and mechanical ventilation, the head of each dog was placed in a supine position using a stereotaxic device (Takahashi Co., Ltd., Tokyo, Japan). Arterial blood gas levels were monitored to safeguard against pO 2 fluctuation in the dimentions of the cerebral artery due to variations in pCO 2 . Rectal temperature was kept within the normal range using a feedback-regulated heating pad. With an aseptic technique, the right vertebral artery was exposed in the lower neck and cannulated with a polyethylene catheter (0.86 mm). The dog was turned to the prone position, and an initial angiogram (pre-day 0) was obtained using 8 ml meglumine diatrizoate at a rate of approximately 3 ml/sec via a catheter inserted into the right vertebral artery. In the P-SAH and the sham groups, the occipital skin was surgically prepared, and a 4 cm skin incision was then made caudally starting from the external occipital protuberance. The occipital neck muscles were divided at the midline, and the atlantooccipital membrane was exposed. Through a small incision made in the membrane, two silicon catheters were separately inserted into either side of the cerebellomedullary cisterns; one (1 mm in diameter, 5 cm long) was ...

Effects of Electrical Stimulation of theGasserian Ganglion on Regional Cerebral Blood Flow after Induced Subarachnoid Hemorrhage in Pigs Evaluated by 99mTc-HMPAO-SPECT

“…Furthermore, a granulocytic reaction in the subarachnoid space with a secondary migration of granulocytes into the brain parenchyma was found. The granulocytic invasion must be interpreted as a reactive aseptic meningoencephalitis and is in accordance with the findings described by others [23].…”

Standard intracranialin vivoanimal models of delayed cerebral vasospasm

“…163 The features in common with human cerebral vasospasm and the relatively simple surgical procedure for inducing SAH increased the popularity of the model. Subsequently proposed modifications of the double-hemorrhage model, such as adding a third injection 164 , installing an in-dwelling cisterna magna catheter 165 , or using a microcatheter for blood placement into the ventral cisterna magna 166 , did not significantly alter established characteristics of the original method and were rarely applied. The time course of vasospasm in the canine double-hemorrhage model is extremely well documented.…”