Endovascular management of symptomatic spasm of radial artery bypass graft: Technical case report

Objective: To describe the technique of endovascular access for treatment of vasospasm of a radial artery bypass graft from the occipital artery to the M3 branch of the middle cerebral artery (MCA) in a patient with moyamoya disease. CLINICAL PRESENTATION: A 32-year-old woman presented with recurrent right-sided ischemic symptoms in the territory of a previous stroke. Angiographic findings were consistent with moyamoya disease, and a perfusion deficit was identified on computed tomography (CT) perfusion imaging. TECHNIQUE: The patient underwent a left MCA bypass graft for flow augmentation. She returned with an occluded bypass graft, collateralization of the anterior MCA territory through a spontaneous synangiosis, and a severe perfusion deficit in the posterior MCA territory. She underwent a revision bypass graft procedure with the radial artery from the occipital artery stump to the MCA-M3 branch. She developed repeated symptomatic vasospasm of the radial artery graft postoperatively. After systemic anticoagulation, the graft was accessed through the occipital artery, and intra-arterial verapamil was injected. When this failed to resolve the graft spasm, the radial artery graft was accessed with a 0.14-inch Synchro-2 microwire (Boston Scientific, Natick Massachusetts), and sequential angioplasties were performed using over-the-wire balloons from the proximal to distal anastomosis and in the occipital artery stump. A nitroglycerin patch was applied cutaneously over the graft to relieve the vasospasm. Results: No complications occurred. Graft patency with robust flow was observed on the 5-month follow-up angiogram. Conclusion: Endovascular techniques can be safely used for salvage of spastic extracranial-intracranial grafts.