The effect of hybrid ultrasound/fluoroscopy guidance vs only fluoroscopy guidance on procedure time and radiation exposure in caudal epidural steroid injections.

Background: Ultrasonography guidance have had a rapid increase in its popularity for caudal epidural steroid injections. However, unlike fluoroscopy, ultrasound cannot reliably detect intravascular or intradural distribution of the medication. Therefore, the practitioners cannot be entirely certain about the accuracy of the procedure. A hybrid technique may eliminate these drawbacks. The primary objective of this study is to evaluate the effect of hybrid ultrasound/fluoroscopy guidance on procedure time, fluoroscopy duration, and radiation exposure during caudal epidural injections, compared to the conventional method of fluoroscopy-only guidance. Methods: In this prospective randomized controlled trial, 65 patients who were undergoing caudal epidural steroid injection randomized into two groups: the hybrid ultrasound/fluoroscopy group [Group 1 (n = 32)] and the fluoroscopy-only group [Group 2 (n = 33)]. Kerma area product (KAP), elapsed time of the needle insertion into sacral hiatus, elapsed time of the entire procedure and fluoroscopy time were measured. Numeric Rating Scale (NRS) for pain level and Oswestry Disability Index (ODI) were also assessed before the procedure and two weeks later. Results: Radiation exposure measured using fluoroscopy time (group 1 = 0.06 ± 0.01 min; group 2 = 0.09 ± 0.03 min) and KAP (group 1 = 43.73 ± 16.90 cGy cm Conclusions: The hybrid guidance may offer a potentially safer method minimizing radiation risk compared to fluoroscopy-only guidance for caudal epidural steroid injections.