[Dural arteriovenous malformation in the falx with subarachnoid hemorrhage].

A case of falx dural arteriovenous malformation was reported. A 62 year old man was admitted to Nakamura City Hospital on August 15, 1989, with severe headache as his chief complaint. On admission, his consciousness was lethargic. CT scan showed subarachnoid hemorrhage with ventricular perforation and hematoma of the corpus callosum. Angiograms demonstrated a dural arteriovenous malformation (DAVM) in the frontal falx, which was fed by bilateral middle meningeal arteries and the left anterior falx artery and drained into the superior sagittal sinus via the dural vein. Bifrontal craniotomy was performed. At first, bilateral middle meningeal arteries were coagulated, and the frontoparietal dura was excised widely. Then, the falx was cut at the crista galli. The DAVM was found in the falx, including a vascular sac embedded in the brain tissue. The DAVM was coagulated as much as possible. Carotid angiograms revealed complete disappearance of the DAVM, 4 months after the operation. Although angiograms performed after only one month still showed a small residual DAVM. On reviewing the literature we found only 5 patients with the DAVM in the falx. In 6 cases including our own, intracranial hemorrhage occurred in 4 cases (3 cases were subarachnoid hemorrhage). Vascular sacs were seen in 4 cases, and drainage to the pial vein was noted in 3 cases. It seemed to be rare that the DAVM drained into the dural vein. In our particular case, operative findings showed the DAVM drained into the dural vein without the pial vein, and intracranial hemorrhage was attributed to rupture of the vascular sac.