Occipital Artery-Posterior Inferior Cerebellar Artery (PICA) Bypass for the Treatment of a Ruptured Fusiform Aneurysm of the Left PICA: 2-Dimensional Operative Video.

Posterior inferior cerebellar artery (PICA) aneurysms are usually complex to treat because of their deep location, frequent entanglement with the lower cranial nerves, the presence of perforating arteries to the brainstem, and their often dissecting or fusiform morphology.1 These aneurysms can require revascularization of the PICA.2 The length and size of the occipital artery (OA) make it an excellent donor.3,4 Video 1 shows the technical nuances of an OA-PICA bypass for the treatment of a ruptured fusiform aneurysm of the left PICA. The patient is a 34-year-old male presenting with an abrupt headache and confusion (Hunt and Hess grade III and World Federation Neurology Surgeons grade II). Computed tomography of the brain revealed hydrocephalus and subarachnoid hemorrhage (Fisher IV) and digital subtraction angiography revealed a fusiform aneurysm on the tonsillomedullary segment of the left PICA. Given the dissecting nature of this aneurysm and the fact that it was ruptured, we felt it would be safer to be prepared to perform revascularization and to secure the aneurysm using an open surgical approach.5 There were no complications associated with this procedure. The patient remained neurologically intact, and imaging showed good flow through the bypass and no evidence of stroke. OA-PICA bypass is a useful strategy to treat ruptured fusiform PICA aneurysms since it avoids sacrificing the PICA and the use of dual-antiplatelet therapy. This video is one of the few videos published on OA-PICA bypass.6,7 It explains the technical aspects, open and endovascular alternatives, and rationale for this procedure.