Long-term surgical outcomes of patients with delayed diagnosis of spinal dural arteriovenous fistula.

Spinal dural arteriovenous fistula (dAVF) is an extremely rare vascular entity that is usually misdiagnosed. We sought to determine the long-term clinical outcomes of patients undergoing microsurgical treatment for delayed diagnosis of spinal dAVF. This retrospective study identified patients with delayed diagnosed spinal dAVF at our institution from 2009 to 2018. Patients' data, including demographics, imaging, and follow-up data, were evaluated. This cohort included 65 consecutive patients with 68 dAVFs and a male-to-female ratio of 4:1 and a mean age of 53.5 ± 13.7 years. The presenting symptoms consisted of limb weakness (n = 42, 64.6%), paraparesis (n = 34, 52.3%), sphincter disturbances (n = 8, 12.3%), and pain (n = 13, 20.0%). The proportion of patients with each symptom significantly increased and patients experienced increased disability when the diagnosis was finalized. The mean length of delay of diagnosis was 20.7 ± 30.0 months. Surgery resulted in complete occlusion of the fistula on the first attempt in all patients. Three patients developed recurrent fistulas, and three died in the follow-up period. Improved motor function was achieved in 38 patients (59.5%). Other symptoms, such as sensory disorders, sphincter dysfunction, and pain, improved by 37.3%, 32.3%, and 66.7%, respectively. Patients with spinal dAVF usually exhibit progressive ascending myelopathy and often remain misdiagnosed for months to years. Some patients' increased disability cannot be reversed through surgery.