Background and purpose The aim of our study was to evaluate the safety and efficacy of the pipeline endovascular device for the treatment of anterior circulation aneurysms at the level of the circle of Willis and beyond.

Methods A consecutive series of 25 patients (24 unruptured and one ruptured) with anterior circulation aneurysms treated with a pipeline endovascular device were included in the analysis.

Results We found two minor clinical events (resolved within 7 days of the procedure), one major event (symptoms present after 7 days), and no mortality. There were no aneurysm ruptures or parenchymal hemorrhages during follow-up. The modified Rankin Scale (mRS) scores at 3 and 6 months did not change from the prior mRS score for all cases except 1. There was one asymptomatic periprocedural event. There were three intraprocedural complications which resolved without clinical consequences. Six month follow-up angiograms were obtained for 22 aneurysms, showing complete occlusion in 14 (64%) and significantly decreased residual filling in 8 (36%). The status of branches originating from the aneurysm sacs was evaluated in 14 angiograms: 11 were patent (79%), 2 had moderate reduction (14%) and 1 (7%) was occluded. We found six cases of in-stent stenosis (27%) on 6 month DSA, with only one symptomatic case.

Conclusions The pipeline embolization device provides a feasible and technically safe solution for aneurysms at and beyond the circle of Willis. Preliminary results are promising but larger series with longer term follow-up examinations are required to show the long term safety and durability of this treatment alternative.