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Published on: October 20, 2017
Navigating the epidural plexus: a venographic classification system to predict technical feasibility in cerebrospinal
Federico Cagnazzo1, Anne Ducros2, Nicolas Lonjon3
1Neuroradiology, Montpellier University Hospital, Gui-de-Chauliac, Montpellier, France f-cagnazzo@chu-montpellier.com.
Background:
Navigating the epidural plexus (EP) is a key step in transvenous embolization of cerebrospinal fluid-venous fistulas (CSFVFs) in spontaneous intracranial hypotension (SIH). However, no standard venographic classification currently exists to predict procedural complexity. This study proposes a venographic classification of the EP and evaluates its correlation with technical outcomes.
Methods:
From November 2022 to May 2025, 85 patients underwent transvenous embolization for CSFVF. In 75 cases, detailed EP venography was available and categorized as: Type I (55%), homogeneous EP, Type II (34.5%), septated channels, and Type III (10.5%), complex, narrow pathways. Of the 75 cases with available EP venography, EP microcatheter navigation was performed in 65 cases: technical endpoints were extracted from these cases.
Results:
Overall, embolization was technically successful in all cases. EP navigation was performed in 65/75 cases (87%), with a 91% success rate overall: highest in Type I (97.5%)-Type II (90%), and lowest in Type III (50%). Type III EPs were associated with longer fluoroscopy times per level (510 vs 60-70 s, p=0.0008) and a higher rate of EP perforation (66% vs 10% Type I and 0% Type II; p<0.001). EP navigation time per segment decreased over time, from 130 s (first year) to 60 s (after 24 months), reflecting a learning curve.
Conclusions:
The proposed EP classification correlates with procedural complexity and outcomes. It may aid in preprocedural planning and improve the safety and efficiency of transvenous CSFVF embolization.
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