Surgery for distal anterior cerebral artery aneurysms

Because DACA aneurysms are located in the narrow interhemispheric space surrounded by the corpus callosum and bilateral cingulate gyri with intervening falx cerebri, they are considered some of the most difficult anterior circulation aneurysms to surgically treat. Moreover, because of their rare occurrence and the emerging nonsurgical treatment options, neurosurgeons are limited in their ability to surgically treat DACA aneurysms due to their lack of experience. This article describes details of the preoperative considerations, operative techniques, and surgical results for DACA aneurysms.

Medical records, including imaging studies, surgeon's hand drawings and descriptions of microsurgical findings, microphotographs, and video records of operative procedures, were reviewed.

Among 3577 patients with intracranial aneurysms treated since 1975, 126 (3.5%) patients with DACA aneurysms were identified. They were treated either by surgery (117 patients) or endovascular treatment (9 patients). The results of surgical treatment for the 117 patients with DACA aneurysms were favorable in 94% (90.6% good and 3.4% fair) and unfavorable in 6% (5.1% poor and 0.9% dead). All unfavorable outcomes occurred in patients who were of preoperative grades 4 or 5.

Successful surgical management of DACA aneurysms depends on precise understanding of their unique microsurgical anatomy, avoidance of pitfalls, and the surgeon's experience. Sufficient brain relaxation, accurate localization of the aneurysm, early identification of the proximal A2 segment, and preservation of the major draining veins are necessary for a safe surgery.