Superficial Temporal Artery-to-M2 Bypass and Clip Trapping of a Ruptured Fusiform MCA Aneurysm.

Fusiform intracranial aneurysms (IAs) can be challenging to treat, especially when ruptured.1-3 Clip trapping and bypass is an important treatment modality for complex IAs not amenable to endovascular approaches (i.e., stent-assisted coiling, flow diversion), which can be limited by low occlusion rates and anatomical constraints (e.g., tortuosity, proximity to branching vessels).4,5 Here we highlight the treatment considerations and technical steps for clip trapping and intracranial bypass of a previously ruptured middle cerebral artery fusiform aneurysm. A 76-year-old man with a history of atrial fibrillation presented with subacute progressive headaches and lower-extremity weakness one month after admission elsewhere for reported hypertensive hemorrhage. Imaging demonstrated a right-sided 4.3 × 3.0-mm fusiform IA involving the proximal nondominant anterior temporal M2 artery and subacute bilateral basal ganglia strokes, presumably from vasospasm; prior imaging showed a right peri-sylvian hemorrhage. He was neurologically intact, except for diffusely weakened lower extremities (4/5). Endovascular treatment options were dismissed because of small vessel size and his hesitance toward dual-antiplatelet therapies. Vessel sacrifice was not selected because of the stroke risk. A clip-trapping and flow-preserving bypass was selected for treatment, with superficial temporal artery (STA)-M2 selected because there was a large frontal STA donor branch and nondominant M2 recipient vessel. After uneventful surgery, postoperative imaging demonstrated complete aneurysm occlusion, a patent bypass filling the temporal M2, and no new strokes. The patient returned to his prehemorrhage baseline by 2-month follow-up. Flow-preserving cerebral bypass remains an important skill for the management of complex IAs in properly selected patients in the endovascular era.