Successful Clazosentan Therapy for Subarachnoid Hemorrhage after Coil Embolization of Ruptured Posterior Cerebral Artery Aneurysm in a Patient with Moyamoya Disease: A Case Report

Abstract

Moyamoya disease is a progressive steno-occlusive cerebrovascular disorder that may be complicated by intracranial aneurysms, particularly, in the posterior circulation, which are at higher risk of rupture than those in the general population. Clazosentan, a selective endothelin A receptor antagonist, has been approved in Japan for the prevention of cerebral vasospasm after aneurysmal subarachnoid hemorrhage. However, cerebral hemodynamics after subarachnoid hemorrhage and safety of clazosentan in patients with moyamoya disease remain unknown. We report the case of a 46-year-old man with bilateral moyamoya disease who presented with severe subarachnoid hemorrhage caused by a ruptured saccular aneurysm in the right P2 segment of the posterior cerebral artery. Coil embolization was successfully performed, and clazosentan (10 mg/hr), along with cilostazol, was administered to prevent vasospasm. Fluid balance was carefully managed, and no clazosentan-related adverse events were observed. Follow-up radiological examinations showed no evidence of cerebral vasospasm or ischemic lesions. The patient made a favorable recovery and was discharged with a modified Rankin scale score of 1. Four months later, revascularization surgery was performed to reduce hemodynamic stress and the risk of hemorrhage from choroidal collaterals. The aneurysm remained occluded, the choroidal channels regressed, and no recurrent strokes occurred during 1 year of follow-up. To the best of our knowledge, this is the first report of successful clazosentan therapy for aneurysmal subarachnoid hemorrhage in a patient with moyamoya disease. Careful perioperative management allowed the safe use of clazosentan without complications. Further studies are needed to evaluate its broader safety and efficacy in this population.

Keywords: clazosentan; endovascular treatment; moyamoya; subarachnoid hemorrhage; vasospasm.

Fig. 1

(A) Computed tomography reveals diffuse subarachnoid hemorrhage. (B, C) Right internal carotid artery angiography shows bilateral moyamoya disease and a saccular aneurysm in the right P2 segment of the posterior cerebral artery (arrow). (D) The aneurysm was successfully embolized using a simple coiling technique; a small neck remnant is visible (arrow). (E-G) Diffusion-weighted imaging and fluid-attenuated inversion recovery imaging on day 2 post-onset demonstrate primary brain injury in the right frontal lobe. Magnetic resonance angiography confirms bilateral moyamoya disease. (H) Single-photon emission computed tomography on day 7 shows no abnormal decrease in cerebral blood flow, except in the region of the primary brain injury.

Fig. 2

(A) Carotid and vertebral angiography on day 10 post-onset show no evidence of vasospasm in the major cerebral arteries. (B) Diffusion-weighted imaging on day 14 reveals resolution of the right frontal lobe injury, with no signs of delayed cerebral infarction. (C) Slab maximum-intensity projection magnetic resonance angiography demonstrates dilation and extension of the right choroidal collaterals reaching the level of the lateral ventricle body (arrows).

Fig. 3

(A) Intraoperative view of superficial temporal artery to middle cerebral artery anastomosis. Indocyanine green angiography confirms patency. (B) Postoperative magnetic angiography also demonstrates patency of the anastomosis (arrow). (C) Right carotid angiography 2 months after revascularization confirms complete aneurysm occlusion (arrow). (D) One-year postoperative slab maximum-intensity projection magnetic resonance angiography shows regression of the ipsilateral choroidal collaterals.