Regional anaesthesia and chronic postsurgical pain: a systematic review and network meta-analysis

Pain arising after surgery and persisting beyond 3 months is termed 'chronic postsurgical pain' (CPSP). Prevention of CPSP is a research priority. Our objectives were to assess whether regional anaesthesia can reduce the incidence of CPSP and long-term opioid use and to determine which factors influence its effectiveness.

We conducted a Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA)-compliant systematic review and network meta-analysis of randomised controlled trials assessing the effectiveness of regional anaesthesia for reduction of CPSP. We searched various databases up to October 2025. We performed pairwise meta-analysis and network meta-analysis to determine whether type, timing and method (catheter or single injection) of regional anaesthesia influenced the incidence of CPSP. We investigated the effect of surgery type, baseline risk, and sex via meta-regression. We used Grading of Recommendations Assessment, Development and Evaluation (GRADE)/ Confidence In Network Meta-Analysis (CINeMA) to assess certainty of evidence.

We included 158 randomised controlled trials involving 18 794 subjects. Overall, regional anaesthesia reduced the incidence of CPSP compared with no block (risk ratio [RR]: 0.73, 95% confidence interval [CI]: 0.67-0.80), with effects observed up to 12 months after surgery. Reductions in CPSP were also observed within specific surgery types, including mastectomy (RR: 0.69, 95% CI: 0.59-0.79), thoracotomy (RR: 0.72, 95% CI: 0.55-0.96), video-assisted thoracoscopic surgery (RR: 0.73, 95% CI: 0.56-0.96), and knee arthroplasty (RR: 0.71, 95% CI: 0.52-0.97). Opioid use was not statistically significantly different between groups (RR: 0.88, 95% CI: 0.61-1.28). CPSP evidence was low certainty; opioid use was very low certainty. Network meta-analysis suggested that neuraxial techniques reduced the incidence of CPSP more effectively than peripheral techniques after thoracotomy (neuraxial RR: 0.64 95% CI: 0.49-0.83; peripheral RR: 0.84, 95% CI 0.73-0.96) and video-assisted thoracoscopic surgery (neuraxial RR: 0.60, 95% CI: 0.45-0.80; peripheral RR: 0.77, 95% CI: 0.63-0.94), compared with no block. Differences in effectiveness based on administration time point and method of administration varied by surgery type. Network meta-analysis evidence was low to very low certainty. Meta-regression showed no significant effect of surgery type, sex or baseline risk.

Our findings indicate that regional anaesthesia reduces the incidence of CPSP for up to 12 months after surgery. The effectiveness of regional anaesthesia was influenced by the type of regional technique used, whereas the type of surgery, sex, or baseline risk did not have a significant impact.