Posterior Inferior Cerebellar Artery (PICA) Reanastomosis After Excision of a Ruptured p2-PICA Aneurysm: 2-Dimensional Operative Video.

Posterior inferior cerebellar artery (PICA) aneurysms have an increased tendency towards a fusiform morphology precluding primary clip reconstruction. The management of these complex aneurysms might require cerebral revascularization to preserve flow in a distal PICA territory. This video illustrates a case of a ruptured p2-PICA aneurysm excision followed by a PICA reanastomosis. A 54-yr-old male presented with a sudden-onset severe headache, diplopia, and complete left cranial nerve six (CN VI) palsy. Neuroimaging demonstrated diffuse subarachnoid hemorrhage in basal cisterns. A catheter angiogram shows a ruptured small fusiform aneurysm in the p2-PICA segment. After obtaining consent for surgery, the patient was placed in a three-quarter prone position. After a hockey stick skin incision and C1 laminectomy, a lateral suboccipital craniotomy was performed. The aneurysm was identified within the vagoaccessory triangle. Cerebral protection consisted of propofol-induced electroencephalography burst suppression during the clamp time for the bypass, without hypothermia or hypertension. After trapping the aneurysm and excising the diseased arterial segment, the distal end of the p2-PICA was reanastomosed to the proximal parent vessel in an end-to-end fashion. Indocyanine green angiography confirmed patency of the anastomosis. Postoperatively, the patient was neurologically at his baseline. The CN VI palsy had completely resolved at a follow-up visit. Reanastomosis is an effective modality for reconstructing PICA following the excision of the fusiform aneurysm. The redundancy of the tonsillomedullary segment of PICA allows for easier distal segment reapproximation in the inferior hypoglossal triangle. An intracranial-intracranial revascularization technique eliminates the need for harvesting the occipital artery. Additionally, it prevents iatrogenic ischemic injury to contralateral PICA, if used for a PICA-PICA bypass.1 © Barrow Neurological Institute, used with permission.