Effect of nimodipine on vasospasm of cortical arteries. Experimental study]

The efficacy of the calcium channel blocker Nimodipine (N) in prevention and treatment of chronic cerebral vasospasm (V.S.) after subarachnoid haemorrhage (S.A.H.) was tested in a blind randomized experimental study. Twenty seven dogs (French Grande Venerie) weighing between 40 to 50 kg, were randomly assigned in three groups. Under general anesthesia, each animal underwent baseline angiography, followed by right frontotemporal craniectomy. A retractor was placed under the temporal lobe and the arachnoid membrane over the internal carotid artery was dissected. 10 ml of autologous arterial blood was placed around the internal carotid artery, and 5 ml of arterial blood was injected into the cisterna magna. Group I was placebo group: ten randomly pre selected animals received a placebo. Group II was preventive group: seven animals received N (5 mg/kg) per os each day, from D0. Group III was curative group: ten animals received N (5 mg/kg) per os each day, from D2. At Day 2 and Day 5, all animals underwent a control angiography. The basilar artery, the internal carotid artery were measured. The craniectomy was reopened and the cortical arteries were measured with a calibrated optical micrometer. Intergroup comparisons at Day 0, Day 2 and Day 5, were made by analysis of variance. The level of significance was n < 0.05. V.S. was defined as a reduction in vessel caliber of 10% or greater, compared to baseline value. In the placebo group (Group 1), V.S. of the basilar and cortical arteries was present in all cases, from D2 to D5.(ABSTRACT TRUNCATED AT 250 WORDS)