Lessons Learned from Endovascular Coil Embolization of Pericallosal Artery Aneurysms and Adoption of Flow Diversion: A Retrospective Cohort Assessment of the Efficacy of Coiling and Flow Diversion

Abstract

The adoption of endovascular techniques for treatment of pericallosal artery aneurysms (PAAs) has been comparatively gradual due to anatomic and technological factors. We conducted a retrospective cohort study to evaluate the outcomes of PAA treatment with coiling and flow diversion at our institution. This was a retrospective study of patients treated endovascularly for PAAs from December 2007 to January2019. In total, 33 patients with 34 aneurysms were included (25 aneurysms ruptured, 9 unruptured or recurrent). Of the ruptured group, 22 were coiled (88%) and rest treated with flow diversion. Initial angiographic follow up rate was 72%, at median of 159 days. Overall recurrence rate was 40% (10/25) at median of 376 days, all among coiled aneurysms. 6 recurrent aneurysms were retreated with further coiling (2) and flow diversion (4). Of the unruptured/recurrent group, 5 were coiled (55%) and remainder treated with flow diversion. Angiographic follow-up rate was 100% at median of 267 days. Recurrence rate was 22% (2/9), both in coiled aneurysms. Overall, 27 aneurysms were coiled, 9 treated with flow diversion and 3 with "partial" flow diversion. All aneurysms treated with pipeline flow diversion achieved 100% occlusion. No re-rupture or new rupture was observed. Good clinical outcome (modified Rankin Scale 0-2) was seen in 79% of patients. Our study demonstrates that endovascular coiling for PAAs is associated with a definite rate of recurrence, which has to be monitored with timely angiography. We also demonstrate the excellent effectiveness of flow diversion for PAAs with either presentation.