Zusanli (ST36) acupoint injection for preventing postoperative ileus: A systematic review and meta-analysis of randomized clinical trials

Objective: To evaluate the preventive effect of Zusanli (ST36) acupoint injections with various agents, for postoperative ileus (POI). Methods: We searched electronic databases for randomized controlled trials from inception to 1st February 2015 evaluating ST36 acupoint injection for preventing POI. Revman 5.2.0 was used for data analysis with effect estimates presented as mean difference (MD) with 95% confidence interval (Cl). Statistical heterogeneity was tested using I-2 (defined as significant if I-2 > 75%). We used a random effects model (REM) for pooling data with significant heterogeneity. Results: Thirty trials involving 2967 participants were included. All trials were assessed as high risk of bias (poor methodological quality). For time to first flatus, meta-analysis favored ST36 acupoint injection of neostigmine (MD -20.70h, 95% CI -25.53 to -15.87, 15 trials, I-2 = 98%, REM), vitamin B1 (MD -11.22h, -5% Cl -17.01 to -5.43, 5 trials, I-2 = 98%, REM), and metoclopramide (MD -15.65h, 95% Cl -24.77 to -6.53, 3 trials, I-2 = 94%, REM) compared to usual care alone. Meta-analysis of vitamin B1 favored ST36 acupoint injection compared to intramuscular injection (MD -17.21 h, 95% CI -21.05 to -13.36, 4 trials, I-2 =89%, REM). Similarly, for time to bowel sounds recovery and first defecation, 5136 acupoint injection also showed positive effects. Conclusions: ST36 acupoint injections with various agents may have a preventive effect for POI. Safety is inconclusive as few of included trials reported adverse events. Due to the poor methodological quality and likely publication bias further robust clinical trials are required to arrive at a definitive conclusion. (C) 2015 Elsevier Ltd. All rights reserved.