Laparoscopic-guided transversus abdominis plane block combined with port-site infiltration for postoperative analgesia after gastric bypass: a randomized, double-blind, controlled trial.

Background: Patients undergoing laparoscopic gastric bypass (LGBP) commonly experience moderate to severe postoperative pain. We conducted a randomized, prospective double-blind placebo-controlled study to evaluate the analgesic effect of laparoscopic-guided TAP (LG-TAP) block after LGBP in a high-volume bariatric center, applying an enhanced recovery after metabolic and bariatric surgery protocol.

Materials And Methods: 84 patients were randomly allocated to receive LG-TAP block with local anesthetic (LA) or saline solution (placebo), both combined with port-site infiltration with LA (LA-PSI). Primary outcome was pain score measured in post-anesthesia care unit (PACU), and at 6, 12, and 24 h after surgery. Secondary outcomes included postoperative nausea and/or vomiting, analgesic requirement, time to walking, time to flatus, length of hospital stay, and surgical complications.

Results: Differences were observed in intra-group comparisons (LG-TAP vs. placebo) for the primary outcome-NRS in postoperative analgesia-with a median (IQR) NRS of 4 (2-5) vs. 2 (2-5) in PACU, 4.5 (2-6) vs. 2.5 (1-6) at 6 h and 3 (0-5) vs. 2 (0-4) at 12 h, although no statistically differences were demonstrated (PACU: p-value = 0.26; 6 h: p-value = 0.3; 12 h: p-value = 0.24). No statistically and clinically differences were observed for NRS at 24 h postoperatively with a median (IQR) of 1 (0-3) vs. 1 (0-4) at 24 h; p = 0.89. No differences were observed as regards secondary outcomes.

Conclusion: While a potential analgesic effect of saline solution through fascial hydrodissection cannot be excluded, our results more convincingly support that LG-TAP block provides no significant analgesic effect when LA-PSI is adequately implemented.