Evaluating the Impact of Transcutaneous Electrical Nerve Stimulation on Patients Undergoing Inguinal Hernia Surgery: A Meta-Analysis of Randomized Controlled Trials

Objective: A comprehensive meta-analysis based on the latest randomized controlled trials (RCTs) was conducted to investigate the effects of transcutaneous electrical nerve stimulation (TENS) on patients undergoing treatment after inguinal hernia surgery. Methods: A detailed search of Embase, PubMed, Web of Science, and the Cochrane Library was performed for RCTs investigating the use of TENS during inguinal hernia surgery up to September 28, 2021. The Cochrane tool was applied to assess the risk of bias in the included studies. Results: Seven eligible RCTs with a total of 379 cases were included. The meta-analysis showed a mean difference (MD) in VAS of -1.61 [95% CI: -2.20 – -1.02, P < 0.00001] at 2 hours post-operation, VAS MD = -1.33 at 4 hours post-operation [95% CI: -2.84 – -0.18, P = 0.09], VAS MD = -2.36 at 8 hours post-operation [95% CI: -4.04 – -0.69, P = 0.006], and VAS MD = -1.75 at 24 hours post-operation [95% CI: -2.64 – -0.85, P = 0.0001]. The cortisol level MD at 24 hours post-operation was -52.56 [95% CI: -168.8 – -63.76, P = 0.38]. Conclusion: TENS significantly reduces postoperative pain following inguinal hernia surgery and promotes patient recovery. TENS is recommended for patients undergoing inguinal hernia surgery. However, further high-quality studies are needed to confirm additional effects.