Coil embolization of overwide and undertall small intracranial aneurysms with double microcatheter technique

Background: Overwide and undertall small intracranial aneurysms remain a challenge for coil embolization. The purpose of this study is to evaluate the feasibility and results of intrasaccular double microcatheter endovascular coil embolization of overwide and undertall small intracranial aneurysms. Methods: Small (<7 mm), overwide (dome-to-neck ratio [DNR] ≤1.2), and undertall (ASPECT ratio ≤1.2) aneurysms which were treated with double microcatheter technique were selected. For the double microcatheter technique, two microcatheters were selected simultaneously into the aneurysm sac and coil insertion was performed alternatingly. The initial results, ASPECT, DNR ratios, complications, and follow-up results were assessed. Results: Twenty small (mean, 3.8 mm), overwide (mean DNR, 1.1), and undertall (mean ASPECT, 1.0) aneurysms were treated with the double microcatheter technique. Overall, complete or near complete occlusion was achieved in 19/20 cases. This was achieved with only the double microcatheter technique in 16/20 cases (ASPECT mean, 1.0; DNR mean, 1.1). Adjuvant balloon remodeling was performed in 4/20 cases (ASPECT mean, 0.8; DNR mean, 1.1). The ASPECT ratio was significantly lower in the adjuvant balloon remodeling cases (p = 0.027). Coiling failed in one patient with both DNR and ASPECT ratio <1.0. Overall, one patient developed a focal visual field defect after the procedure. No other patients developed neurologically significant complications. Conclusions: Double microcatheter technique may be a safe and effective method for the treatment of overwide and undertall small intracranial aneurysms.