Rectus sheath block for analgesia in open abdominal surgery: a systematic review, meta-analysis and trial sequential...

We aimed to evaluate the efficacy of rectus sheath block (RSB) for open abdominal surgery.

We searched PubMed/MEDLINE, Scopus, Embase, and Cochrane Library from inception until June 1, 2025, focusing on both cohort studies (CS) and randomized controlled trials (RCTs). Meta-analysis was restricted to midline laparotomy. The primary endpoint was resting pain scores at one, 12, and 24 hours postoperatively. The secondary endpoints included pain scores during movement/cough at the same timepoints and 24-hour opioid consumption. Standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs) were calculated.

Fifteen RCTs and nine CS were included (N.=1638). RSB was associated with lower resting pain scores at one hour in both RCTs (SMD, -0-73, 95% CI, -1.24 to -0.22, P=0.005, I² =69%) and CS (SMD, -1.01, 95% CI, -1.53 to -0.49, P=0.0001, I²=84%). From RCTs, resting pain was lower in the RSB group at 12 h (SMD, -0.85, 95% CI, -1.23 to -0.47, P<0.0001, I²=24%); and at 24 h, but only when the design was placebo-controlled (SMD, -0.67, 95% CI, -1.16 to -0.18, P=0.007, I²=0%). The type of comparator, local anesthetic infusion method, and urgency of surgery were the primary factors contributing to heterogeneity.

RSB provides adequate early postoperative analgesia in midline laparotomy, but its clinical impact is modest and uncertain due to study heterogeneity and effect sizes that fall below a meaningful Minimal Clinically Important Difference.