The Erector Spinae Plane Block Provides Visceral Abdominal Analgesia in Bariatric Surgery: A Report of 3 Cases.

Postoperative pain after bariatric surgery can be significant and yet difficult to manage. These patients frequently have associated obstructive sleep apnea and are at risk of respiratory depression with opioid analgesia. Abdominal wall blocks such as the subcostal transversus abdominis plane block are not of significant benefit, probably in part because they provide only somatic analgesia. The ultrasound-guided erector spinae plane (ESP) block is a recently described regional anesthetic technique for providing thoracic analgesia when performed at the level of the T5 transverse process. Local anesthetic injected into the fascial plane deep to the erector spinae muscle spreads in a craniocaudal fashion over several levels. Local anesthetic also penetrates anteriorly through the intertransverse connective tissue and enters the thoracic paravertebral space where it can potentially block not only the ventral and dorsal rami of spinal nerves but also the rami communicantes that transmit sympathetic fibers. Coupled with the fact that the erector spinae muscle and ESP extend down to the lumbar spine, this suggests that the ESP block could result in both visceral and somatic abdominal analgesia if the injection were performed at a lower thoracic level. We describe a series of 3 cases that illustrate the efficacy of bilateral ESP blocks performed at the level of the T7 transverse process for relieving visceral abdominal pain following bariatric surgery. Further investigation is recommended to establish the potential of the ESP block as an analgesic modality in abdominal surgery.