Clinical and anatomical characteristics of craniocervical junction arteriovenous fistulas fed from the vertebral artery dural ring: patient series.

BACKGROUND: Manifestations of craniocervical junction (CCJ) arteriovenous fistulas (AVFs) include bleeding and congestive myelopathy. CCJ AVFs are classified as epidural, dural, radicular, and perimedullary. On diagnostic imaging, differentiation between dural and radicular AVFs is difficult because of the shortness of the feeding artery from the vertebral artery dural ring. Herein, the authors investigated the feeding artery of these AVFs. OBSERVATIONS: Angiographic findings were described for 11 cases of CCJ AVFs (perimedullary, n = 1; radicular, n = 4; dural, n = 4; epidural 2), and direct surgery was performed in 8 patients (perimedullary, n = 1; radicular, n = 3, dural; n = 4). It is important to determine whether the posterior spinal artery branches have an epidural or intradural origin, and 2 cases (25%) of postoperative complications (brainstem ischemia, subarachnoid bleeding) were observed. In direct surgery, perimedullary AVFs must be treated just before the shunt point, and it is important to treat only the refluxing bridging veins in dural AVFs. LESSONS: CCJ AVF requires classification of shunt points and understanding of vascular anatomy, including variations of posterior spinal artery. https://thejns.org/doi/10.3171/CASE26142.