ABSTRACT
OBJECTIVE: This study aimed to investigate factors associated with incomplete occlusion of a cerebral aneurysm detected by indocyanine green videonangiography (ICG-VA) following aneurysm clipping. METHODS: We performed surgery on 135 patients with 151 intracranial aneurysms over a 1-year period. Included was an aneurysm more than 3 mm in size, the dome of which was sufficiently exposed and clipped permanently with one clip. Following ICG-VA, aneurysms were divided into a delayed-filling group and a no-filling group. Retrospective comparisons of the clip force, blade length and width, neck and dome size of the aneurysm, diameter of the parent artery, presence of atherosclerosis in the aneurysm neck, and systolic blood pressure during ICG-VA were made between the two groups. RESULTS: Eight of 31 aneurysms in 29 patients showed delayed filling of contrast. The clip force in the delayed-filling group was lower than in the no-filling group and the atherosclerosis of the aneurysm neck differed between the two groups (P<0.05). Blade width in the delayed-filling group was also significantly lower than in the no-filling group (P<0.05). Following adjustment for atherosclerosis of the aneurysm neck, clip force and blade width in the delayed-filling group was even lower. Incomplete passage of the clip tip was observed in four aneurysms, weak clip force in three, and a slit between clip blades in one. After booster clipping or clip reposition, neither aneurysm regrowth nor recanalization was observed during 6 months of follow-up. CONCLUSION: Closing force, blade width, tip position, and remnant slit are important for incomplete occlusion of an aneurysm.