Comparative Effectiveness of Transversus Abdominis Plane (TAP) Block and Epidural Analgesia in Abdominal Surgery: A Meta-Analysis of Randomized Controlled Trials.

Transversus abdominis plane (TAP) block and thoracic epidural analgesia (TEA) are commonly used techniques for managing postoperative pain following abdominal surgery. While TEA has traditionally been the gold standard, TAP block has emerged as a simpler, potentially safer alternative. This meta-analysis compares the efficacy and safety of TAP block versus TEA across multiple postoperative outcomes in abdominal surgery. A systematic literature search was conducted in PubMed, Embase, CENTRAL, and Scopus to identify randomized controlled trials (RCTs) that compared TAP block and TEA in adult patients undergoing abdominal surgery. Primary outcomes included pain scores at rest and during coughing at 24 and 48 hours. Secondary outcomes included postoperative opioid consumption, incidence of hypotension, time to pass first flatus, and hospital stay. Data were synthesized using a random-effects model, and heterogeneity was assessed using the ² statistic. Eight RCTs were included. Pain scores at rest at 24 hours showed no significant difference between TAP and TEA (mean difference [MD] = 0.26, 95% confidence interval [CI]: -0.52 to 1.03, = 0.51; ² = 99%), as did pain scores during coughing at 24 hours (MD = 0.39, 95% CI: -0.16 to 0.94, = 0.16; ² = 98%). At 48 hours, pain at rest remained similar (MD = 0.22, 95% CI: -0.40 to 0.85, = = 0.48; ²² = 99%), while TEA showed a modest benefit during coughing (MD = 0.62, 95% CI: 0.02-1.21, = 0.04; ² = 99%). TEA significantly reduced postoperative opioid consumption compared to TAP (MD = 8.79 mg morphine equivalent, 95% CI: 1.82-15.76, = 0.01; ² = 82%). However, the TAP block was associated with a significantly lower risk of hypotension (risk ratio [RR] = 0.08, 95% CI: 0.01-0.40, = 0.002; ² = 0%). No significant difference was found in time passing first flatus (MD = 4.19 hours, 95% CI: -5.22 to 13.60, = 0.39; ² = 96%) or length of hospital stay (MD = -0.32 days, 95% CI: -1.24 to 0.60, = 0.50; ² = 79%). TAP block provides analgesia comparable to TEA for postoperative pain at rest, with fewer hemodynamic side effects. Although TEA offers advantages in reducing opioid requirements and cough-related pain at 48 hours, its higher risk of hypotension limits its suitability in certain patients. TAP block represents an effective and safer alternative in abdominal surgical settings, particularly when TEA is contraindicated or poses a higher risk.