Epidural navigation in type 1 spontaneous intracranial hypotension: technique and anatomy

BACKGROUND AND PURPOSE: Spontaneous intracranial hypotension (SIH) with ventral dural tears is associated with spinal longitudinal extradural collections (SLECs). Direct fluoroscopic characterization of the anterior epidural compartment and SLEC morphology in vivo remains limited. We describe wire-catheter epidural navigation and imaging in patients with SIH and SLECs. METHODS: Between June 2023 and December 2025, 20 consecutive patients with type 1 SIH and MRI-confirmed SLECs underwent attempted wire-catheter epidural navigation from a lumbar interlaminar approach. Using a hydrophilic guidewire and 4 French catheter, a controlled dorsoventral transition was performed to access the anterior epidural space. Feasibility of anterior epidural and SLEC cannulation was assessed. Therapeutic outcomes were not evaluated. RESULTS: Anterior epidural and/or SLEC opacification was successfully obtained in 15/20 cases (75%, 95% CI 51% to 91%). Anterior epidural injections demonstrated a segmental pattern with radiolucent septations and periradicular extensions, whereas SLEC injections produced homogeneous ventral opacification without segmental organization. Navigation failed in 5 cases due to dense epidural scarring (n=2) or early procedural discontinuation related to concern for dural violation (n=3). Venous entry occurred in approximately 15-25% of procedures. One early case of subarachnoid opacification resulted in transient symptoms that resolved with conservative management. CONCLUSIONS: Epidural navigation enables fluoroscopic access to the anterior epidural space and SLECs in patients with SIH. Imaging patterns, metameric septations in the anterior epidural space, and homogeneous opacification in SLECs correspond to anatomical structures and distinguish between different compartments. These technical and anatomical observations provide a foundation for therapeutic applications.