Ruptured, dissecting posterior inferior cerebellar artery aneurysms: endovascular treatment without parent vessel occlusion

Introduction Treatment of a dissecting aneurysm of the medullary segments of the posterior inferior cerebellar artery (PICA) usually entails trapping of the diseased arterial segment with possible sacrifice of brainstem perforators. The goal of the work was to review our experience with selective coiling of ruptured, dissecting aneurysms of the anterolateral segments of the PICA without parent vessel occlusion. Methods Eleven consecutive patients (9 women, 2 men, mean age 47.2 years) were retrospectively reviewed from a prospectively acquired neuroradiological database. On admission three patients had Hunt and Hess (HH) grade I, three HH grade II, two HH grade III, and one HH grade IV. Outcome was evaluated according to the modified Rankin scale (mRS) score. Follow-up (mean:19.4 months) consisted of magnetic resonance angiography and/or digital subtraction angiography in ten patients. Results Ten patients had mRS score 0 and one mRS score 2. No treatment failure occurred. The aneurysm was completely occluded in seven patients, a neck residue was present in two, and a loose coil mesh was present in two. Recurrence occurred in three patients, and all were successfully retreated for a total of 13 procedures. Procedure-related complications were all without clinical consequences and included a coil perforation in one procedure and stagnant filling of the parent vessel in six procedures. PICA occlusion did not occur in any patient. Conclusion Coiling of ruptured, isolated dissecting aneurysms of the PICA without parent vessel occlusion is feasible, relatively safe and effective in preventing early/medium-term rebleeding. A strict angiographic follow-up program is, however, necessary to detect recurrence.