Treatment of Therapy-Refractory, Symptomatic Vasospasm in a Radial Artery Bypass Graft With Balloon Angioplasty in a Patient With Severe Subarachnoid Hemorrhage: A Case Study

BACKGROUND AND IMPORTANCE: This case highlights the effectiveness of endovascular balloon dilatation (percutaneous transluminal angioplasty (PTA)) for treating vasospasm in a radial artery (RA) bypass graft from the internal carotid artery to the M2 branch of the middle cerebral artery in a patient with severe subarachnoid hemorrhage. CLINICAL PRESENTATION: A 69-year-old woman with severe subarachnoid hemorrhage due to a ruptured giant aneurysm in the ophthalmic segment of the right internal carotid artery underwent an extracranial-intracranial high-flow bypass with a RA graft, followed by trapping of the aneurysm. During her intensive care unit stay, vasospasms developed primarily in the intracranial radial graft and M2 branches. These spasms showed only minimal improvement after standard care and intra-arterial vasospasmolysis with nimodipine. Thus, after systemic anticoagulation, balloon PTA was performed, treating both the intracranial and extracranial sections of the graft, including areas near the anastomosis. The procedure was complication-free, with immediate morphological success and significant improvement in perfusion to the middle cerebral artery territory. CONCLUSION: Endovascular balloon PTA should be considered a rescue measure for vasospasm in extracranial-intracranial bypasses, particularly with RA grafts post-SAH. Owing to its muscular structure, the RA graft is especially prone to spasm, potentially compromising graft patency. When pharmacological treatments fail, balloon PTA offers a targeted intervention to restore vessel caliber, stabilizing blood flow and preventing ischemic complications, thus supporting the bypass's long-term success.