Pial-Dural Intracranial Arteriovenous Fistula with Flow-Associated Aneurysmal Rupture-Case Report with Review of Literature and Proposal on the Mechanism of Hemorrhage and Treatment Options.

BACKGROUND: Vascular anomalies in the form of dural arteriovenous fistulas (DAVFs), arteriovenous malformations, and aneurysms are well described in the literature. Pial arteriovenous fistulas (PAVFs) are described to a lesser extent in the literature. When these anomalies are combined, diagnosis and treatment become complex.

CASE DESCRIPTION: A 55-year-old man presented with PAVF/DAVF with a ruptured flow-related aneurysm in the distal left posterior inferior cerebellar artery, which required surgical clipping and disconnection. We performed a PubMed search of all identifiable cases of PAVFs in adults. We then identified which cases had components of DAVFs and flow-related aneurysms. We identified 51 PAVF cases and identified which patients presented with hemorrhage and the treatment modalities of all cases. Of 51 cases identified, 4 were a DAVF/FRA, and 5 were a PAVF/DAVF. One case of PAVF/DAVF/FRA was identified.

CONCLUSIONS: The exact mechanism of PAVF/DAVF formation is unknown. Hemorrhage predilection of PAVF/DAVF is more difficult to predict than a sole fistula, likely secondary to the complex flow dynamics. To our knowledge, this literature review is the largest review to date regarding PAVFs in adult patients and can provide insight into decision making when evaluating treatment options.