A 45-year-old man was admitted for a progressively worsening headache over 2 weeks. He denied history of recent head trauma or anticoagulation and antiplatelet medication. General and neurologic examinations were not remarkable on admission. Routine laboratory investigations including coagulation profiles and platelet function were within normal limits. Head computed tomography (CT) on admission revealed an isodense CSDH on the right hemisphere with mild midline shift (Fig. a). A CT angiography (CTA) was performed to rule out any intracranial vascular malformation. A DAVF was noticed at the transverse sinus with dilated cortical venous drainage (Fig. b). So, a digital subtraction angiography (DSA) of the external carotid artery and DAVF embolization was planned.\nNo anomaly was noticed during selective angiography of the internal carotid and vertebral arteries and the left external carotid artery. Selective angiography of the right external carotid artery showed that the DAVF was located at the transverse sinus and fed by posterior branch of the middle meningeal artery (MMA), the occipital artery, and the posterior meningeal artery and drained to the occipital cortical veins with venous ectasia (Fig. a-b). The DAVF was classified as type IV according to the Cognard classification. The embolization was performed via the MMA. The Headway duo catheter was used and accessed to the DAVF, and Onyx was injected until the shunt disappeared (Fig. c-d). The patient experienced an uneventful recovery. His CSDH gradually resolved in 1 month (Fig. ). No neurologic deficit was noticed.\nA PubMed search of published studies written in English and Chinese was conducted on June 30th, 2017. The following key words were used in relevant combinations: dural arteriovenous fistula, dural arteriovenous malformation, subdural hematoma, subdural haematoma, subdural hemorrhage, and subdural haemorrhage. The reference lists of the identified articles were also manually searched for additional studies. Studies of which full text could not be obtained or those without sufficient individualized description of the isolated SDH cases mixed in larger case series were excluded.\nFinally, 13 articles containing 14 patients were identified [–]. In all 15 patients (9 females, 60%) including 1 case in our institution were included for the final interpretation (Table ). The inflicted patients were aged from 27 to 82 years (55.5 ± 8.6).Of note, 12 (80%) of the 15 patients were aged between 40 and 60 years of age, and 8 (53.3%) patients were between 50 and 60 years. Sides of the DAVF or SDH were obtained in 13 patients with 9 (69.2%) located at the left side and 4 at the right side. The intracranial locations of DAVF were anterior fossa (2), middle fossa (2), frontal region (2), parietal region (3), temporal region (2), and occipital region (2). The types of SDH were CSDH (7/15), acute SDH (ASDH) (7/15), and undefined SDH (1/15). Of the 12 patients feeding artery could be identified, MMA was the commonest feeding artery (8/12, 66.7%). Multiple feeding arteries were identified in 3 (25%) patients. The causes of DAVF were only defined in 3 patients (2 iatrogenic and 1 traumatic), with the rest undefined or not mentioned. Cognard classifications (Table ) of the DAVF were reported or deduced from the reports in 12 patients, with type I, type III, and type IV in 7, 2, and 3 patients respectively. The treatment strategies included hematoma evacuation (2/15), CSDH drainage and DAVF embolization (5/15), craniotomy and DAVF resection (3/15), DAVF embolization and hematoma evacuation (1/15), DAVF embolization (2/15), and not applicable or not mentioned (2/15). Of the 12 patients with direct description of outcome, 7 (58.3%) patients were neurological intact, 3 (25%) patients with neurological deficits, and 2 (16.7%) died.
A 59-year-old male with a recent fall and closed head injury presented with progressively worsening headaches. The fall occurred 9 days before presentation. On examination, no neurologic deficits were found. Noncontrast head CT demonstrated a 5 mm left convexity CSDH []. He underwent burr hole evacuation and was discharged on the subsequent day. He presented again on postoperative day 6 with recurrence of his headaches. Noncontrast head CT demonstrated recurrence of the left convexity subdural hematoma []. He subsequently underwent a left craniotomy for evacuation. He was discharged on postoperative day 2 with no postprocedural complications. At 1-month follow-up, he continued to complain of severe headaches. Surveillance CT demonstrated a new 27 mm right convexity mixed density subdural hematoma [ and ]. He subsequently underwent right MMA embolization as primary treatment. Intraprocedural digital subtraction angiogram revealed a Cognard Grade III cribriform plate DAVF supplied by the right ophthalmic artery draining into a right frontal cortical vein [ and ]. The right MMA temporoparietal and frontal branches were embolized with n-BCA glue. Follow-up was arranged to treat the DAVF at a later date and he was discharged the following day. The patient was subsequently lost to follow-up, but presented to the emergency department 4 months later with diplopia and a right abducens nerve palsy. Noncontrast head CT demonstrated significant reduction in size of the previously embolized right convexity subdural hematoma. He was admitted and underwent attempted endovascular treatment of the DAVF. Catheterization of the arterial and venous sides of the fistula achieved suboptimal positioning for liquid embolic embolization and so he underwent a right craniotomy for surgical ligation of the fistula. The patient experienced no postprocedural complications. At 2-week follow-up, there was complete resolution of his presenting symptoms and surveillance CT demonstrated no residual SDH.