[Nontraumatic acute subdural hematoma caused by the rupture of transdural anastomotic vessels in moyamoya disease].

A case of nontraumatic acute subdural hematoma caused by the rupture of transdural anastomotic vessels in a patient with Moyamoya disease is reported. The patient was a 55-year-old woman who was admitted to our hospital in a comatose state. A diagnosis of acute subdural hematoma associated with Moyamoya disease was made on the basis of CT and angiographic findings. No lesions suggestive of trauma, such as cerebral contusion, could be detected during surgery. Although total evacuation of the hematoma was performed, she developed the apallic syndrome and did not recover consciousness. Judging from the angiographic and operative findings, it appears that subarachnoid hemorrhage occurred first and stretched the transdural anastomotic vessels which supplied the collateral circulation. This led to tearing of some of the vessels, and their proximal ends were consequently exposed in the subdural space. The surgical treatment of acute subdural hematoma associated with Moyamoya disease requires the closest attention to avoid damage to the collateral circulation. Although we carefully arrested the bleeding without using a coagulator in order to spare the collateral vessels, the transdural anastomosis was no longer visible on postoperative angiograms. Our experience suggests that hematoma irrigation with trephination therapy, which may minimize the damage to the collateral circulation, may be the most appropriate treatment for acute subdural hematoma associated with Moyamoya disease. Furthermore, cerebral revascularization should be performed for the treatment of the circulatory disturbance intercepted by the hematoma itself or by operative manipulation.