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

BACKGROUND: 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. METHODS: This was a retrospective study of patients treated endovascularly for PAAs from December 2007 to January 2019. RESULTS: 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. CONCLUSIONS: 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.