Comparison Between Eleven-Bar Cushion and Pillow for Contrast Media Spread in Caudal Block

Abstract

Background/Objectives: A caudal epidural steroid injection (CESI) is a widely used technique for managing low back and lower extremity pain due to its relative ease and safety. However, cephalic spread of the injectate may be limited by the long distance from the sacral hiatus and by increased intra-abdominal pressure caused using conventional abdominal pillows during prone positioning. This study aimed to investigate whether an eleven-bar cushion could facilitate higher cephalic spread of contrast medium during CESI compared to a conventional pillow. Methods: This retrospective study was approved by the Institutional Review Board (IRB number: AJOUIRB-DB-2025-103). Data from 76 patients, who underwent CESI between January 2023 and March 2024, were analyzed. Patients were divided into two groups the eleven-bar group (n = 38) using a pelvic eleven-bar cushion and the pillow group (n = 38) using a conventional pillow. Fluoroscopic images were reviewed to identify the highest vertebral level reached by the injectate and the number of nerve roots visualized. Visual analogue scale (VAS) scores before and one month after the procedure were also assessed. Statistical analyses included Mann-Whitney U tests, linear regression, and Poisson regression. Results: Baseline demographic characteristics were similar between groups. The cephalic spread of contrast medium was significantly higher in the eleven-bar group compared with the pillow group (median level L3/4 vs. L4/5, p = 0.0002). No significant differences were observed in the number of nerve roots reached or in the VAS score improvement between groups. Conclusions: The eleven-bar cushion facilitated greater cephalic spread of contrast medium during CESI compared with a conventional pillow. Although this technique did not affect nerve root distribution or pain reduction outcomes, it may represent a useful positioning strategy to enhance drug delivery to higher lumbar levels during caudal epidural injections.