BACKGROUND: Aneurysms of the posterior inferior cerebellar artery (PICA) are rare, comprising 0.5% to 3% of intracranial aneurysms. Because their anatomic location relative to the PICA origin is variable, several endovascular techniques are used in their management.
OBJECTIVE: To evaluate and discuss endovascular techniques for the treatment of PICA aneurysms.
METHODS: We analyzed our prospectively maintained database to identify PICA aneurysms treated over a 12-year period from 1999 to 2011.
RESULTS: Twenty patients were assessed angiographically for endovascular treatment. Treatment was successfully performed in 17, but 3 were deemed unsuitable and were referred for surgery. Patients ranged in age from 15 to 82 years (mean, 60.5); 85% (17/20) were women. Thirteen (65%) presented with subarachnoid hemorrhage, and 3 (15%) had been previously treated surgically. Although the aneurysms were located at the PICA origin in 13 (65%), their involvement with the PICA and vertebral artery was variable. Some arose distinctly from the origin, and others incorporated the PICA itself. Five patients were treated for distal PICA aneurysms. Treatment techniques included direct coiling, vertebral artery balloon remodeling with coiling, PICA balloon remodeling with coiling, and parent vessel sacrifice of PICA with either coiling or glue embolization. Complete occlusion was initially achieved in 11 of 17 patients. Of the 6 remaining patients, 3 improved to complete occlusion at follow-up, 2 underwent re-treatment, and 1 remained stable. No patient experienced posttreatment hemorrhage.
CONCLUSION: A variety of endovascular techniques are required for the management of PICA aneurysms. Specific techniques vary according to the location of the aneurysm in relation to the PICA origin, distal course of the artery, and the vertebral artery.
ABBREVIATIONS: BRAT, Barrow Ruptured Aneurysm Trial
mRS, modified Rankin score
nBCA, n-butyl cyanoacrylate
PICA, posterior inferior cerebellar artery
SAH, subarachnoid hemorrhage
VA, vertebral artery