Trapping and revascularization for a dissecting aneurysm of the proximal posteroinferior cerebellar artery: technical case report and review of the literature

Abstract

Objective and importance: Subarachnoid hemorrhage caused by an isolated dissection of the proximal portion of the posteroinferior cerebellar artery (PICA) is a rare problem. The optimal treatment to use for patients presenting with this clinical scenario varies and therefore is controversial in the literature. We report a patient in whom this problem was treated effectively with trapping of the diseased segment and revascularization of the PICA. We report this case to review this rare topic and to present our perspective on the indications for and the effectiveness of trapping and revascularization for proximal PICA dissections that cause hemorrhage.

Clinical presentation: A 55-year-old man was transferred to our institution and admitted for Hunt and Hess Grade IV subarachnoid hemorrhage, which improved to Hunt and Hess Grade III after ventricular drainage. Imaging revealed the source of the hemorrhage to be a pseudoaneurysm related to the dissection of the proximal portion of the PICA.

Intervention: Three days after the initial bleeding episode, we operated on the patient. After the occipital artery was prepared for bypass, the diseased segment was trapped. The occipital artery-to-PICA anastomosis was then immediately performed distal to the trapped segment.

Conclusion: On the basis of our experience, the literature regarding this topic, and the anatomy of the perforators of the PICA, we think that the best treatment for a pseudoaneurysm located within the first three segments of the PICA is trapping of the diseased segment followed by revascularization distal to the trapped segment. This approach should prevent rehemorrhage and should avoid iatrogenic ischemic complications of the brainstem.