Transversus abdominis plane block versus port site anesthetic in adult laparoscopic appendectomy: a systematic review and meta-analysis.

BACKGROUND

Despite advances in minimally invasive surgery, pain after appendectomy remains common. The transversus abdominis plane (TAP) block has been proposed as an alternative to port site local anesthetic. We aimed to synthesize randomized controlled trials (RCTs) comparing the efficacy and safety of 1) TAP block versus port site local anesthetic, and 2) ultrasound to laparoscope-guided TAP blocks following adult minimally invasive appendectomy.

METHODS

Relevant databases were searched for RCTs until December 2024. Two authors independently identified trials, extracted data, assessed risk of bias (ROB 2), and evaluated evidence certainty (GRADE).

RESULTS

Four RCTs (233 patients) were included comparing TAP block to port site anesthetic in laparoscopic appendectomy. No studies examined robotic surgery, and none compared ultrasound to laparoscope-guided technique. TAP block led to decreased total opioid consumption (mean difference: - 4.50 mg morphine equivalents, 95%CI - 6.51, - 2.50, 3 RCTs, 153 patients, low certainty), and reduced pain scores at 4, 6 and 12 h postoperatively, but not at 1 and 2 h, or when pooled across the first 24 h postoperatively (very low certainty). There was no difference in hospital length of stay (mean difference: - 0.03 days, 95%CI: - 0.40, 0.33, 3 RCTs, 177 patients, very low certainty) or postoperative nausea and vomiting (risk ratio: 1.15, 95%CI: 0.77, 1.71, 3 RCTs, 153 patients, low certainty). Patient satisfaction was measured in one study, which favored TAP block. No adverse reactions were reported.

CONCLUSIONS

Compared to port site injection, TAP block may result in a small improvement in opioid consumption, postoperative pain scores, and patient satisfaction following laparoscopic appendectomy. There appears to be no difference in postoperative nausea and vomiting. The impact on length of stay is unclear and may have limited clinical significance. Evidence certainty was low to very low and based on a small number of RCTs, indicating a need for further research.