Abstract 412: Beyond Clipping and Coiling: Multimodal Rescue of a Ruptured Giant Middle Cerebral Artery Aneurysm: Integrating Bypass, Endovascular Therapy, and Decompression

Introduction Giant middle cerebral artery (MCA) aneurysms are uncommon, accounting for 10% of MCA aneurysms. They carry a worse prognosis than other anterior circulation aneurysms, with an estimated annual rupture rate of 33%. Factors associated with rupture include irregular morphology, a height‐to‐width ratio >1, size >7mm, and MCA bifurcation location. Their unique anatomy complicates endovascular treatment and risks distal ischemia. Thus, in cases with large intracerebral hemorrhage (ICH), decompressive craniectomy (DHC) with hematoma evacuation and microsurgical clipping remains the standard of care. When clipping is not feasible, superficial temporal artery‐MCA (STA‐MCA) bypass and encephaloduroarteriomyosynangiosis (EDAMS) can augment distal flow before aneurysm occlusion, though these revascularization techniques have not historically been applied acutely or in combination with coil embolization. Here, we report a unique multimodal approach combining DHC, double‐barrel STA‐MCA bypass, endovascular coil embolization, aneurysm decompression, and EDAMS to treat a ruptured giant MCA aneurysm. Methods Case report. Results A middle‐aged male with a history of hypertension and two transient episodes of aphasia within the previous one year presented to the emergency department for acute‐onset global aphasia and a right facial droop (NIHSS score four). CT demonstrated a large thrombosed mass in the left Sylvian fissure with a large insular ICH (ICH score two), diffuse subarachnoid blood (Hunt & Hess II, Modified Fisher IV), intraventricular hemorrhage, uncal herniation, a pontine Duret hemorrhage, and 1cm midline shift. Emergent cerebral angiography demonstrated a 6x6x6cm giant, partially thrombosed, fusiform M2 inferior division aneurysm. A balloon test occlusion of the M2 proximal inferior division was unsuccessful. Flow disruption was not feasible given the aneurysm's fusiform morphology. Emergent left DHC and double‐barrel STA‐M4 bypass were performed. Due to significant cerebral edema, coil embolization was performed over clipping. Aneurysmal decompression and EDAMS were additionally performed. Postoperatively, he developed focal to bilateral tonic‐clonic seizures requiring anti‐seizure medications. Repeat cerebral angiography on post‐operative day nine demonstrated complete aneurysmal occlusion and bypass patency. He was discharged to rehabilitation on post‐operative day 26 partially oriented, following commands, hypophonic, and moving all extremities antigravity. Dysarthria, strength, and dysphagia were improved at three‐month follow up. Conclusion This is, to our knowledge, the first report of acute, simultaneous application of DHC, double‐barrel STA‐MCA bypass, EDAMS, and coil embolization for a ruptured giant MCA aneurysm. Our case illustrates the feasibility of an aggressive multimodal strategy. We further highlight the clinical‐radiographic discordance between our patient's extensive imaging pathology and relatively mild NIHSS and symptoms. image