Background: The management of the unruptured AcomA aneurysm associated with atherosclerotic occlusion of the unilateral internal carotid artery (ICA) raises several strategic dilemmas.
Methods: Two such patients with unruptured aneurysm on the AcomA, which supply cross-flow toward the hemisphere with ICA occlusion, are presented.
Results: Both patients were treated with STA-M2 bypass followed by clipping of the unruptured AcomA aneurysm in 1 stage through the transsylvian route. Both patients were doing well without neurological deficit nor cognitive impairment at 1 year follow-up.
Conclusions: In the surgical treatment of unruptured AcomA aneurysm with atherosclerotic ICA occlusion, preceding bypass would be ideal in case of intraoperative rupture as well as to reduce perioperative ischemia if the bypass procedure itself could be performed with minimal risk. Enough and atraumatic exposure of the sylvian fissure contributed to reduce brain retraction during the clipping of AcomA aneurysm and, in addition, to ease the STA-M2 bypass.