Ultrasonography-guided catheter-over-needle insertion for caudal epidural catheter placement in adults: technical considerations.

Abstract

Background: Caudal epidural analgesia significantly reduces acute pain after anorectal surgery; however, caudal epidural catheter placement (CECP) remains challenging, and the safety of real-time ultrasonography-guided CECP is uncertain. This study aimed to evaluate the success rate and related complications of real-time ultrasonography-guided CECP and describe the technical considerations.

Methods: This prospective, single-center observational study included 233 patients catheterized in the left lateral decubitus position. The sacral hiatus was palpated and then confirmed using ultrasonography. A catheter-over-needle was inserted through the sacrococcygeal ligament under real-time ultrasonographic guidance, the metallic needle was withdrawn through the outer sleeve, and the epidural catheter was placed through the outer sleeve into the sacral canal epidural space. The primary outcome was the success rate of CECP; several surgical variables, the incidence of related complications, and improvement measures were also assessed.

Results: CECP through the sacral hiatus was successful in 231 patients. The sacral canal depth at the hiatus apex, the mean distance between the sacral cornua, and the distance from the skin to the inferior margin of the sacrococcygeal ligament were 5.07 ± 1.38, 8.00 ± 1.94, and 14.24 ± 4.18 mm, respectively. The sacral canal depth was > 3 mm in 94.4% of patients. No complications, such as epidural hematoma, dura puncture, and intraspinal infection during postoperative epidural catheter utilization, occurred.

Conclusion: Ultrasonography-guided CECP through the sacral hiatus is a simple, feasible, safe, and effective technique for postoperative anorectal analgesia. Additionally, caudal epidural analgesia manages severe pain after anorectal surgery. Therefore, this technology merits comprehensive clinical application.

Trial registration number: No. ChiCTR 2,000,038,918.