A filum terminale arteriovenous fistula fed by the left L1 artery of adamkiewicz: a case report and updated systematic review of 71 cases

Background Filum terminale arteriovenous fistulas (FTAVFs) are rare spinal vascular malformations, typically arising from the pia mater of the filum terminale and classified as Type IV intradural perimedullary AVFs. Due to their rarity and overlapping imaging features with other spinal lesions, FTAVFs are frequently underdiagnosed, often leading to delayed treatment. Methods We present a case of FTAVF supplied by the artery of Adamkiewicz and successfully treated with surgical ligation. A systematic review of the literature was conducted in accordance with PRISMA 2020 guidelines, analyzing cases reporting clinical presentation, imaging characteristics, arterial supply, treatment modalities, and outcomes of FTAVFs. Databases searched included PubMed, MEDLINE, Cochrane, and EMBASE from inception to the present. Results A total of 34 studies, encompassing 71 patients with FTAVFs, were included. The majority of patients were male (79 %), with a median age of 58 years (IQR, 48–65). Common symptoms included progressive paraparesis (82 %), back or radicular pain (53 %), and bowel/bladder dysfunction (52 %). Symptom duration varied, with 50 % experiencing symptoms for 6 months to 2 years. MRI findings typically showed spinal cord edema, flow voids, and venous congestion at the conus or lower spinal cord. FTAVFs were primarily supplied by the artery of the filum terminale, often a continuation of the anterior spinal artery via the artery of Adamkiewicz. The L4–L5 level was most frequently involved. Surgical treatment was the most effective, with 43 cases managed surgically, including failures of prior embolization. Endovascular embolization alone had a higher failure rate (31 %). Postoperative outcomes were generally favorable, though persistent neurological deficits and rare complications were reported. Conclusions FTAVFs are uncommon yet treatable spinal vascular lesions. Early recognition, aided by high-quality imaging and understanding of their unique vascular anatomy, is critical for diagnosis. Surgical disconnection remains the mainstay of treatment, especially in cases where embolization fails or is not feasible. © 2025 Elsevier Ltd.