and Importance: Cerebral arteriovenous malformations (CAVM) are characterized by altered hemodynamics and associated with angioanatomical changes, such as aneuryms. We encountered a patient with a CAVM-associated dissection of the medial trunk of the posterior inferior cerebellar artery (PICA) instead of an aneurysm.
We report the case of a 56-year old male patient with spontaneous subarachnoid hemorrhage within the cisterna magna and fourth ventricle. Digital subtraction angiography (DSA) revealed a cerebellar AVM located within the inferior semilunar lobule, however anatomically not matching the bleeding pattern. The left PICA, serving as primary feeding artery, showed a dissection of the proximal portion of the medial trunk with precise anatomical association to the blood in the telovelotonsillar space. CAVM induced hyperdynamic flow through the feeding vessel is the most plausible pathophysiological explanation for the dissection. Complete microsurgical resection of the CAVM was performed and three months follow-up DSA showed complete regression of the dissection, disappearance of the irregularities and significant caliber reductions of the medial PICA trunk.
This is the first report of a hyperdynamic flow-related dissection of a CAVM-associated feeding vessel. Microsurgical resection of the CAVM allowed for spontaneous resolution of the dissected area by restoration of normal rheodynamics.