FALSE ANEURYSM ASSOCIATED WITH RUPTURE OF AN ARTERIOVENOUS MALFORMATION IMPLICATIONS FOR TREATMENT - CASE-REPORT

THE MORPHOLOGICAL FEATURES associated with cerebral arteriovenous malf ormations have been under increasing scrutiny since the advent of high -definition and superselective angiography; certain features may be as sociated with an increased risk of rupture. In the systemic circulatio n, the presence of a false aneurysm after the rupture of a vessel has been described; however, no similar phenomenon has been reported in th e cerebral circulation. In this case report, we describe a false aneur ysm in a young man who had an arteriovenous malformation that hemorrha ged in the posterior fossa. Computed tomography and magnetic resonance imaging revealed a posterior fossa hematoma in the lower brain stem a nd cerebellum. Angiography indicated that the arteriovenous malformati on was fed primarily by the left posterior inferior cerebellar artery. The mass effect of the hematoma was visible as a hypodense region. In the middle of the hematoma, on the distal portion of the posterior in ferior cerebellar artery, was a dilatation, measuring 4 x 5 mm, with a stagnation of the contrast medium that was pathologically consistent with a false aneurysm. The patient with a false aneurysm, such as the man we describe, runs a significant risk of hemorrhage at the time of resection of the arteriovenous malformation, with additional implicati ons for endovascular treatment. The volume of embolic injections of th e involved vessel should be limited to avoid raising the intra-arteria l pressure, and the choice of embolic material must be tailored indivi dually. Recognizing the presence of false aneurysm is important in the choice and timing of therapy.