Internal Maxillary Artery Bypass with Radial Artery Graft Treatment of Giant Intracranial Aneurysms.

Background: Giant intracranial aneurysms (GIAs) can be approached via microsurgical and endovascular techniques. Use of flow diversion devices has yielded favorable outcomes, and indications for cerebral revascularization have dramatically decreased.

Objective: To evaluate the safety and validity of using internal maxillary artery (IMA) bypass with an interposed graft to treat GIAs.

Methods: During a 6-year period, high-flow IMA bypass procedures were performed in 32 patients with GIAs at our institute. Intraoperative Doppler sonography, indocyanine green, and postoperative angiography were used to assess the patency of the graft conduit and the stability of the aneurysm. Neurologic function was assessed with the modified Rankin Scale.

Results: The mean GIA size was 33.7 mm (range, 25.3-64 mm), and all showed a nonsaccular morphology, except for 1 patient who underwent a first attempt at surgical clipping of a saccular aneurysm. Complete occlusion (65.6%, n = 21) or great diminishment (28.1%, n = 9) of the GIA was shown in 30 patients and the graft patency rate was 90.6% (n = 29). No deaths resulting from bypass surgery occurred. Functionally favorable outcomes (modified Rankin Scale score of 0-2) were recorded in 65.6% of patients at discharge, and the rate increased to 71.9% at the most recent follow-up (mean, 40.6 months). Surgical-related complications involving hydrocephalus and ischemic and hemorrhagic episodes were encountered in 5 patients, but 4 had complete regression of their neurologic symptoms.

Conclusions: Considering the grave natural history and treatment complexity of these lesions, this study showed satisfactory results in the treatment of GIAs with IMA bypass.