Delayed venous hemorrhage after endovascular treatment for a petrous ridge dural arteriovenous fistula.

Endovascular treatment (EVT) is the first-line treatment for petrous ridge dural arteriovenous fistulas (DAVFs). However, EVT is associated with complications. Among these complications, delayed venous hemorrhage is fatal. Here, we report such a case in a 59-year-old male with a 1-month history of dizziness. Previously, the patient was healthy. Physical examination showed no abnormalities. Computed tomography (CT) angiography revealed a petrous ridge DAVF that was draining via the superior petrosal venous complex and superior petrosal sinus, venous drainage involving the venous system of the brainstem, and 2 aneurysmal dilatations on the brainstem vein. EVT was performed via the ascending pharyngeal artery to cast Onyx-18, and the DAVF was obliterated. During EVT, the venous system of the brainstem was impaired by the occlusion of the aneurysmal dilatation. Postoperatively, the patient awoke. Twenty hours after EVT, he experienced left hemiplegia, and CT revealed no hemorrhage. However, thirty hours after EVT, the patient fell into a deep coma, and CT revealed hemorrhage of the brainstem and cerebellum into the ventricle system. Delayed venous hemorrhage was considered. After receiving conservative treatment for 10 hours, the patient died. This case demonstrates that excessive occlusion of the draining vein of a DAVF may result in fatal delayed venous hemorrhage. To decrease this risk, staged embolization may be useful after occluding the high-risk draining vein or reducing the DAVF blood flow. In conclusion, during EVT for petrous ridge DAVFs, care should be taken not to impair the venous system of the brainstem, to prevent venous hemorrhage.