The safety of Pipeline flow diversion in fusiform vertebrobasilar aneurysms: a consecutive case series with longer-term follow-up from a single US center

OBJECTIVE Pessimism exists regarding flow diversion for posterior circulation aneurysms because of reports of perforator territory infarcts and delayed ruptures. The authors report the results of patients who underwent Pipeline Embolization Device (PED) flow diversion using novel strategies for treatment of fusiform posterior circulation aneurysms, and compare these results with those from previously reported series. METHODS The authors conducted a retrospective review of data from consecutive patients with fusiform vertebrobasilar artery aneurysms treated with the PED. RESULTS This review resulted in the identification of 12 such patients (mean [+/- SD] age 55.1 +/- 14.1 years). Eleven patients had symptoms; 1 had a dissecting aneurysm identified on imaging for neck pain. The average aneurysm size was 13.25 +/- 4.5 mm. None of the aneurysms were ruptured or previously treated. The average clinical follow-up duration was 22.1 +/- 10.7 months and radiological follow-up was 14.5 +/- 11.1 months from the index PED treatment. One patient suffered a perforator stroke and had a modified Rankin Scale (mRS) score of 4 at last follow-up. Another patient had a retained stent pusher requiring retrieval via surgical cut-down but recovered to an mRS score of 0 at last follow-up. Eleven (91.7%) of 12 patients recovered to an mRS score of 0 or 1. Two patients had aneurysmal remnants at 7 and 10 months, respectively, after the index PED, which were retreated with PEDs. At last follow-up, all 12 aneurysms were occluded and PEDs were patent. The minimum follow-up duration was 12 months from the index PED treatment; no patient experienced delayed hemorrhage, stroke, or in-stent stenosis. CONCLUSIONS Flow diversion with selective adjunctive techniques is evolving to become a safer treatment option for posterior circulation aneurysms. This is the longest clinical follow-up duration reported for a single-center experience of flow-diversion treatment of these aneurysms.