Objectives The aim of this study was to examine the feasibility, technique, and clinical and angiographic outcomes of endovascular coiling to treat a cerebral aneurysm with a branch incorporated into the aneurysmal wall. Methods From 2012 to 2016, 25 patients with 26 cerebral aneurysms having a branch incorporated into the aneurysm (9 unruptured, 17 ruptured) were treated to prevent rupture or re-bleeding from the sac while preserving the incorporated branch by using single-catheter ( n = 18), balloon-remodeling ( n = 4), stent-assisted coiling ( n = 3), or double-catheter ( n = 1) techniques. Results Endovascular coiling was conducted in 26 procedures without angiographic occlusion of the incorporated branch. Post-embolization angiography revealed near-complete occlusion ( n = 8; 30.7%), neck remnant ( n = 13; 50%), and incomplete occlusion ( n = 5; 19.3%) aneurysms. Thromboembolisms were observed in four (15.4%) patients during or after the procedure. A procedure-related neurological deficit was observed in one (3.8%) patient. When patients with a preictal modified Rankin Scale (mRS) score of 3 presenting with grade 5 subarachnoid hemorrhage were excluded, all patients had favorable outcomes (mRS 0-2). Six (23.1%) recurrent aneurysms were observed during follow-up, five of which were treated endovascularly at 5-22 months without complication. The location of an aneurysm at the ICA-posterior communicating artery associated with the dominant-type posterior communicating artery was significantly associated with recurrence ( p = 0.041). Conclusions Cerebral aneurysms with an incorporated branch were safely treated using conventional endovascular coiling. However, treatment durability was unsatisfactory, especially for dominant-type ICA-posterior communicating artery aneurysms.
Keywords: Endovascular embolization; branch incorporation; cerebral aneurysm; recurrence.