Angiographic cerebral vasospasm and delayed ischemic deficit on anterior part of the circle of Willis. Usefulness of transcranial Doppler.

BACKGROUND AND PURPOSE: After subarachnoid hemorrhage (SAH), cerebral vasospasm (VS) may be revealed by cerebral angiography, during follow-up clinical examination with the occurrence of delayed ischemic deficit (DID). Moreover, transcranial Doppler (TCD) could be useful in determining the level of the velocimetric threshold. The aims of the study were, on a prospectively collected series of 460 patients, to assess angiographic VS incidence, to determine possible risk factors, and to evaluate diagnostic sensitivity and specificity of TCD.

PATIENTS AND METHOD: A total of 460 patients consecutively operated on for an aneurysm located on the anterior portion of the circle of Willis (mean age 47.2 +/- 14 years, sex ratio F/M=1.18) were included in the study. Preventive treatment against VS was administered in all patients. On the 10(th) day, we performed the following routine examinations: cerebral angiography, CT scan and TCD.

RESULTS: Angiographic VS occurred in 38.5% of the patients, and the single risk factor was delayed admission (p=0.02, Mann-Whitney test). DID occurred in 15.6% and was complicated by cerebral infarct in 4.7%. The risk factors were admission date (p=0.001, Mann-Whitney test) and severity of arterial narrowing (significant tendency). Diagnostic sensitivity of TCD decreased from 83.6% for MCA aneurysms, to 66.6% for ICA aneurysms and 40.6% for AcoA aneurysms. Diagnosis specificity remained between 88.6% and 97.6% for the 3 locations.

CONCLUSION: The unique risk factor for angiographic VS and DID was the admission date. TCD demonstrated high specificity but its sensitivity was too low for the aneurysms located far from the middle cerebral artery bifurcation.