Korean J Anesthesiol.  2025 Apr;78(2):171-176. 10.4097/kja.24832.

Modified approach to external oblique intercostal block: a proof-of-concept pilot case series and anatomical evaluation -a case series-

• Fujino T
• Ichimura K
• Anetai H
• Kawagoe I

• KMID: 2566174
• DOI: http://doi.org/10.4097/kja.24832

Abstract

Background
Regional anesthesia techniques that provide analgesia to the entire lateral abdomen are limited. We present a modified external oblique intercostal block for complete lateral abdominal analgesia with a single injection. Case: We performed a modified version of the external oblique intercostal block unilaterally at the tenth rib along the mid-axillary line in three patients undergoing robot-assisted partial nephrectomy (two single injections, one catheter placement) and tested the technique on a cadaver with 20 ml of dye bilaterally. All patients reported good postoperative pain relief without complications and had consistent sensory coverage of the T8–T12 dermatomes from the anterior-to-posterior axillary line. Anatomical assessment confirmed consistent bilateral staining of the lateral cutaneous branches T8–T12.
Conclusions
The initial clinical success and anatomical findings of the modified approach to the external oblique intercostal block suggest that this technique may be an effective option for lateral abdominal analgesia.

Keyword

Acute pain; External oblique muscle; Intercostal nerves; Nerve block; Postoperative pain; Regional anesthesia; Robotic surgical procedures