Posterior Inferior Cerebellar Artery Double Reimplantation Bypass for Treatment of a Dolichoectatic Posterior Inferior Cerebellar Artery Aneurysm: A Technical Report.

background and importanceThe surgical management of posterior inferior cerebellar artery (PICA) aneurysms often poses a challenge because of tight surgical corridors, proximity to the lower cranial nerves, and the presence of perforators supplying the medulla. This report describes an excision and double reimplantation bypass for treatment of a dolichoectatic PICA aneurysm found on familial screening in a young man with a family history of aneurysmal subarachnoid hemorrhage. CLINICAL PRESENTATION: The patient underwent a right far-lateral craniotomy with excision of the dolichoectatic right PICA aneurysm with an additional outflow branch. An end-to-end reanastomosis was performed from the proximal PICA to the larger distal outflow PICA vessel, followed by an end-to-side anastomosis of the second outflow branch to the distal PICA; a salvage bypass with side-to-side V4-p2 reimplantation was later conducted because of thrombus formation at the initial end-to-end reanastomosis.

conclusionPICA aneurysms are uncommon and difficult to treat because of their location and complex anatomy, often requiring unique bypass techniques. This case was further complicated by a thrombus formation, which was likely caused by pathological aneurysmal tissue being incorporated in the bypass. This case required an unconventional bypass construct that proved to be effective.