POSTOPERATIVE SUBARACHNOID CLOTS AND THE PATTERN OF CEREBRAL-ISCHEMIAASSOCIATED WITH SYMPTOMATIC VASOSPASM

OBJECTIVE We retrospectively evaluated the presence of subarachnoid cl ots and the development of symptomatic vasospasm in 125 patients who h ad early surgical treatment of a ruptured cerebral aneurysm. SUBJECTS AND METHODS We studied 16 patients (aged 35-86 years; mean, 58.7 years ) who underwent surgery 0 to 6 days (mean, 2.1 days) and then manifest ed symptomatic vasospasm on day 5-12 (mean, day 7.4), and 57 patients (aged 13-79 years; mean, 52.0 years) who underwent surgery 0-8 (mean, day 2.9) and did not manifest symptomatic vasospasm. The volume and lo cation of subarachnoid clots were evaluated with computed tomographic (CT) scanning. Cerebral ischemia was evaluated clinically and also, in eight patients, by measurement of cerebral blood flow (CBF) using xen on-enhanced CT. Angiographic evaluation was performed only on one pati ent. RESULTS Of the 16 patients with symptomatic vasospasm, the subara chnoid clots were localized, distributed thickly, or associated with i ntracerebral hematomas in 15 and thin in 1 at the time of admission. F ifteen patients had CT evidence of a subarachnoid clot during vasospas m. Most of the clots were near the ruptured aneurysms, but in three ca ses, clots were located in the remote cisterns, which were not accessi ble operatively. The clinical manifestations of vasospasm in these thr ee patients correlated with the site of the clot. CBF was reduced in t he territory of the involved artery in all eight patients in whom it w as measured. In two of the eight cases, the reduction occurred in the territory of a contralateral artery. In contrast, in the 57 patients w ithout symptomatic vasospasm, the subarachnoid clots were already gone or disappeared soon after surgery in most patients. CONCLUSIONS The c ontinued presence of subarachnoid clots is an important risk factor fo r symptomatic vasospasm after the rupture of a cerebral aneurysm. The clot is not always located near the ruptured aneurysm, and the clinica l course may be unpredictable. (C) 1998 by Elsevier Science Inc.