Tailor-Made Branch Reconstruction by Intracranial to Intracranial Bypass During Clipping Surgery for Middle Cerebral Artery Aneurysms

Background: In clipping surgery, it can be advantageous to dissect an adherent artery from the aneurysmal dome to achieve complete clipping. Bypass surgery can be useful to reconstruct an adherent artery when dissection of the artery is technically difficult or risky. We report the effectiveness of tailor-made intracranial (IC)–IC bypass to reconstruct an adherent artery in clipping surgery for middle cerebral artery (MCA) aneurysms. Methods: A retrospective review of 384 consecutive patients who had presented with MCA aneurysms from 2008 to 2016 had identified 4 patients who had undergone an IC–IC bypass during clipping surgery for reconstruction of an adherent artery. We analyzed the preoperative radiological findings, methods of bypass surgery, surgical complications, and clinical outcomes in the present study. Results: Preoperative angiography showed that the temporal cortical artery coursed along the aneurysmal dome in all cases. These cortical arteries exhibited tight adherence to the aneurysmal body intraoperatively, proving them to be difficult to dissect from the aneurysm. The adherent artery was injured during dissection in 2 cases. These arteries were reconstructed by IC–IC bypass, after which neck clipping was completed. The methods of IC–IC bypass included end-to-end anastomosis in 2 patients, end-to-side anastomosis in 1, and side-to-side anastomosis in 1 patient. Postoperative computed tomography and magnetic resonance imaging revealed neither hemorrhagic nor ischemic complications. The postoperative course was uneventful in all the patients. Conclusions: During clipping surgery for MCA aneurysms, tailor-made IC–IC bypass is one of the useful options to reconstruct tightly adherent branch arteries, especially when an external carotid artery graft has not been prepared in advance.