O17 Geography of peridural space: a map for navigators

<h3>Introduction</h3> Anesthesiologists navigate the epidural space up to the upper dorsal location in a blind and uncontrolled fashion, to deliver drugs. The combination of anesthesiologist and angiographic technologies allows selectively reaching any location, from sacral to cervical, anterior to posterior, left to right. This may be useful for diagnostic and therapeutic purposes. <h3>Aim of Study</h3> To show how epidural navigation works; to depict difficulties, tips and tricks, and materials used, with some examples of diagnostic and therapeutic possibilities. <h3>Methods</h3> Based on the Interventional Neuroradiology group experience in Turin, Italy, during the last two years, 32 epidural catheterisms. <h3>Results</h3> Epidural structures are not visible; contrast injection gives little information. Navigation is mainly based on the analysis of the behavior of the materials, and on the feedback of the patient. Main obstacles for navigation were the venous Batson plexus, prone to rupture, and nerve roots, causing physical obstacles and pain; further difficulties were frequently encountered in the cervico-dorsal junction. Moreover, for unknown reasons, large inter-individual differences were found. <h3>Conclusion</h3> Epidural navigation was feasible in the vast majority of patients. Some embolics were deliverable (blood, coils, acrylic, and sometimes fibrin glue), with variable efficiency, but without a single clinical complication. Understanding was the key.