Analgesic effectiveness of serratus anterior plane block in patients undergoing video-assisted thoracoscopic surgery: a systematic review and updated meta-analysis of randomized controlled trials

BACKGROUND: Serratus anterior plane block (SAPB) is a promising regional technique for analgesia in thoracic surgery. Till now, several randomized controlled trials (RCTs) have explored the effectiveness of SAPB for postoperative pain control in patients undergoing video-assisted thoracoscopic surgery (VATS), but the sample sizes were small and conclusions remained in controversy. Therefore, we conducted the present systematic review and meta-analysis. METHODS: RCTs evaluating the analgesic performance of SAPB, comparing to control methods (no block, placebo or local infiltration anesthesia), in patients undergoing VATS were searched in PubMed, EMBASE, Web of Science and Cochrane Library from inception to December 31, 2022. Mean difference (MD) and corresponding 95% confidence interval (95%CI) were calculated for postoperative pain scores at various time points, postoperative opioid consumption and length of hospital stay. Pooled relative risk (RR) with 95%CI were calculated for the risk of postoperative nausea and vomiting (PONV) and dizziness. A random-effect model was applied. RESULTS: A total of 12 RCTs (837 participants) were finally included. Compared to control group, SAPB had significant reductions of postoperative pain scores at 2 h (MD = -1.58, 95%CI: -1.86 to -1.31, P < 0.001), 6 h (MD = -2.06, 95%CI: -2.74 to -1.38, P < 0.001), 12 h (MD = -1.72, 95%CI: -2.30 to -1.14, P < 0.001) and 24 h (MD = -1.03, 95%CI: -1.55 to -0.52, P < 0.001), respectively. Moreover, SAPB conferred a fewer postoperative opioid consumption (MD = -7.3 mg of intravenous morphine equivalent, 95%CI: -10.16 to -4.44, P < 0.001) and lower incidence of PONV (RR = 0.56, 95%CI: 0.41 to 0.77, P < 0.001). There was no difference between both groups regarding length of hospital stay and risk of dizziness. CONCLUSION: SAPB shows an excellent performance in postoperative pain management in patients undergoing VATS by reducing pains scores, postoperative opioid consumption and incidence of PONV. However, due to huge heterogeneity, more well-designed, large-scale RCTs are needed to verify these findings in the future. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12871-023-02197-8.