Ultrasound-assisted middle thoracic epidural catheter placement utilizing the most dorsal sites of bilateral transverse process roots as anatomical landmarks: A cadaveric observational study and a clinical randomized controlled trial

Tatsuya Kunigo; Yusuke Yoshikawa; Shunichi Niki; Masahiro Ohtani; Mami Muraki; Asako Nitta; Yuki Ohsaki; Kanna Nagaishi; Michiaki Yamakage

doi:10.1016/j.jclinane.2024.111740

Ultrasound-assisted middle thoracic epidural catheter placement utilizing the most dorsal sites of bilateral transverse process roots as anatomical landmarks: A cadaveric observational study and a clinical randomized controlled trial

J Clin Anesth. 2025 Jan 2:101:111740. doi: 10.1016/j.jclinane.2024.111740. Online ahead of print.

Authors

Tatsuya Kunigo¹, Yusuke Yoshikawa², Shunichi Niki³, Masahiro Ohtani³, Mami Muraki³, Asako Nitta³, Yuki Ohsaki⁴, Kanna Nagaishi⁵, Michiaki Yamakage³

Affiliations

¹ Department of Anesthesiology, Sapporo Medical University School of Medicine, 291 South 1 West 16, Chuo-ku, Sapporo-shi, Hokkaido 060-8543, Japan. Electronic address: tatsuya_9250@yahoo.co.jp.
² Department of Anesthesiology, Sapporo Medical University School of Medicine, 291 South 1 West 16, Chuo-ku, Sapporo-shi, Hokkaido 060-8543, Japan. Electronic address: y.yoshikawa@sapmed.ac.jp.
³ Department of Anesthesiology, Sapporo Medical University School of Medicine, 291 South 1 West 16, Chuo-ku, Sapporo-shi, Hokkaido 060-8543, Japan.
⁴ Department of Anatomy (I), Sapporo Medical University School of Medicine, 291 South 1 West 17, Chuo-ku, Sapporo-shi, Hokkaido 060-8556, Japan. Electronic address: yohsaki@sapmed.ac.jp.
⁵ Department of Anatomy (II), Sapporo Medical University School of Medicine, 291 South 1 West 17, Chuo-ku, Sapporo-shi, Hokkaido 060-8556, Japan. Electronic address: kanna@sapmed.ac.jp.

PMID: 39752792
DOI: 10.1016/j.jclinane.2024.111740

Abstract

Study objective: We developed an innovative method for ultrasound-assisted thoracic epidural catheter placement and assessed its potential to reduce procedural duration for trainees.

Design: A cadaveric observational study and a clinical randomized controlled trial.

Setting: Sapporo Medical University Hospital.

Patients: A total of 52 adult patients scheduled for thoracic or abdominal surgery and four cadavers.

Interventions: Patients were randomly assigned to either group receiving conventional palpation (conventional group) or combination of the ultrasound examination and conventional palpation (ultrasound group).

Measurements: The primary outcome was total procedure time (sum of skin marking time and needling time) by trainees. The secondary outcomes were (1) skin marking time, (2) needling time, (3) multiple skin punctures, (4) needle redirection, (5) complications, and (6) failed cases.

Main results: Through dissection of four cadavers, the most dorsal site of the transverse process root was identifiable by ultrasound and the reliable indicator of the interlaminar space. We devised ultrasound-assisted middle thoracic epidural catheter placement utilizing the most dorsal sites of bilateral transverse process roots as anatomical landmarks. Trainees in the ultrasound group had significantly longer skin marking time and significantly shorter needling time than those in the conventional group (107 [87-158] vs 46 s [34-54] s, p < 0.001 and 197 [156-328] vs 341 [303-488] s, p = 0.003). Consequently, there was no significant difference between the two groups in total procedure time (326 [263-467] s vs 391 [354-533] s, p = 0.167). Moreover, the probability of trainee failure in epidural anesthesia was significantly lower in the ultrasound group (2/26 [17.7 %] vs 10/26 [38.5 %], p = 0.019).

Conclusions: Our novel technique for thoracic epidural catheter placement resulted in expedited needling and enhanced success rates among trainees, although there was no significant difference between total procedure time when using ultrasound guidance and that when using conventional palpation.

Keywords: Cadaver; Epidural anesthesia; Epidural catheter; Trainee; Transverse process; Ultrasound.