Surgical Strategies and Clinical Results of Site-Specific Treatment Using High-Flow Bypass for Ruptured Blood Blister–Like Anterior Wall Aneurysms of the Internal Carotid Artery

Abstract

Surgical treatment of ruptured blood blister-like aneurysms (BBAs) arising from the internal carotid artery (ICA) is challenging. We retrospectively reviewed the results of our surgical strategies tailored for each aneurysm site. All ruptured ICA BBAs treated between 2003 and 2015 were reviewed. Aneurysms on the lateral side of the ICA were classified as type A, on the medial side of C2 as type B, and on the medial side of C1 as type C. The principal strategy was high-flow bypass (HFB) by use of a radial artery graft, with clipping, trapping, or proximal occlusion selected on the basis of aneurysm type. The results of each treatment were examined. This study included 20 patients. There were 11 type A aneurysms (55%), 2 type B (10%), and 7 type C (35%). HFB was used in 13 patients (65%) and low-flow bypass in 4 (20%). Except for 1 case, no other cases of rerupture or recurrence occurred. Severe ischemia due to cerebral vasospasm was confirmed in 4 of 20 patients (20%), 3 of whom had not received HFB. Modified Rankin Scale score was 0-2 in 16 of 20 patients (80%). Inadequate cerebral blood flow is a distinct possibility even with HFB, so parent artery flow should be preserved to protect against ischemia whenever possible. However, if preservation of the anterior choroidal artery or posterior communicating artery during clipping or trapping is difficult, HFB combined with occlusion of the proximal portion of the ICA in the neck is a feasible option.