NORMAL PERFUSION-PRESSURE BREAKTHROUGH SYNDROME IN GIANT ARTERIOVENOUS-MALFORMATIONS

The treatment of large, high-flow cerebral arteriovenous malformations is one of the most difficult operations which neurosurgeons encounter because of the complex surgery and the post-operative effects on the brain. We have evaluated 10 patients with large, high-flow AVMs who un derwent surgical resection. Patients were investigated with contrast-e nhanced computed tomography and magnetic resonance imaging, 1231-IMP s ingle photon emission computed tomography (SPECT) studies of cerebral flow and cerebral vasodilatory function, intraoperative Laser Doppler flowmetry (4 or 10 patients), and conventional angiography. The volume of the arteriovenous malformation nidi ranged from 32.8 to 210.5 cc. SPECT imaging performed on the first post-operative day hewed ma, ked hyperperfusion in the brain tissue surrounding the resected nidus, and these regions were normal on images on the 7th post-operative day. La ser Doppler flowmetry showed sudden, and marked increase in CBF immedi ately following placement of temporary clips on the main feeding arter y. Angiograms done on 7-14 days following surgery showed a stagnating artery, fragile vessel, and a prolonged circulation time. Our results indicate that pre- and postoperative SPECT study, especially a dynamic SPECT study done on the first post-operative day, was the most useful examination for ascertaining the post-operative normal perfusion pres sure breakthrough.