Successful treatment of a case of tentorial dural arteriovenous fistula causing subarachnoid hemorrhage with invagination of the brainstem by huge and multiple venous pouches

Background: We present a case of tentorial dural arteriovenous fistula (TDAVF) causing subarachnoid hemorrhage with mass effect of large venous pouches, which was struggling to diagnosis and management due to complex vasculature and severe general condition. Case Description: A 43-year-old man was transferred to our hospital due to sudden consciousness disturbance. A neurological examination revealed tetraparesis and pupil dilatation with no light reflex. Imaging findings showed a large lesion in the brainstem with subarachnoid and intraventricular hemorrhage. Since there were multiple feeding arteries and large and multiple venous pouches on vascular imaging, we diagnosed the patient with TDAVF. Because of a high-flow arteriovenous shunt and the presence of large venous pouches, it appeared to be very difficult to approach the shunting point by direct surgery. Therefore, we first performed transarterial endovascular treatment with 25% n-butyl-2-cyanoacrylate to shrink the venous pouches and to reduce the pressure of the posterior fossa, followed by direct radical interruption of the shunting point using the craniotomy maneuver. Postoperative vascular imaging revealed disappearance of abnormal feeding arteries, draining veins, and venous pouches. The patient was discharged and transferred to a rehabilitation hospital with a modified Rankin Scale Score of 3. Accurate interpretation of the detailed vasculature preoperatively and an appropriate treatment strategy using endovascular and direct surgical technique are required to achieve a satisfactory outcome for difficult-to-treat dural arteriovenous fistulas. Conclusions: This combined maneuver with endovascular embolism as complementary pretreatment for radical surgery is useful for a case with high-flow shunting and large venous pouches.