Pseudoaneurysm presenting around polytetrafluoroethylene fiber following microvascular decompression: A case report and literature review.

We report the first case of pseudoaneurysm associated with polytetrafluoroethylene fiber used in microvascular decompression (MVD). A 62-year-old female who had undergone MVD for hemifacial spasm 30 years ago presented with a 4-month history of progressive facial palsy. Computed tomography angiography revealed a large thrombosed aneurysm originating from the right posterior inferior cerebellar artery and having a mass effect upon the pons. The aneurysm was treated by trapping and bypass procedure. Intraoperatively, the pseudoaneurysm adhered to the dura mater, and the thrombus contained a large amount of polytetrafluoroethylene fiber. The cause and management of pseudoaneurysm after MVD is discussed.