Efficacy of erector spinae plane block for analgesia in breast surgery: a systematic review and meta-analysis

The erector spinae plane block is a new regional anaesthesia technique that provides truncal anaesthesia for breast surgery. This systematic review and meta-analysis was undertaken to determine if the erector spinae plane block is effective at reducing pain scores and opioid consumption after breast surgery. This study also evaluated the outcomes of erector spinae plane blocks compared with other regional blocks. PubMed, Embase, Scopus, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov were searched. We included randomised controlled trials reporting the use of the erector spinae plane block in adult breast surgery. Risk of bias was assessed with the revised Cochrane risk-of-bias tool. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework was used to assess trial quality. Thirteen randomised controlled trials (861 patients; 418 erector spinae plane block, 215 no blocks, 228 other blocks) were included. Erector spinae plane block reduced postoperative pain compared with no block: at 0-2 hours (mean difference (95% CI) -1.63 (-2.97 to -0.29), 6 studies, 329 patients, high-quality evidence, I-2 = 98%, p = 0.02); at 6 hours (mean difference (95% CI) -0.90 (-1.49 to -0.30), 5 studies, 250 patients, high-quality evidence, I-2 = 91%, p = 0.003); at 12 hours (mean difference (95% CI) -0.46 (-0.67 to -0.25), 5 studies, 250 patients, high-quality evidence, I-2 = 58%, p < 0.0001); and at 24 hours (mean difference (95% CI) -0.50 (-0.70 to -0.30), 6 studies, 329 patients, high-quality evidence, I-2 = 76%, p < 0.00001). Compared with no block, erector spinae plane block also showed significantly lower postoperative oral morphine equivalent requirements (mean difference (95% CI) -21.55mg (-32.57 to -10.52), 7 studies, 429 patients, high-quality evidence, I-2 = 99%, p = 0.0001). Separate analysis of studies comparing erector spinae plane block with pectoralis nerve block and paravertebral block showed that its analgesic efficacy was inferior to pectoralis nerve block and similar to paravertebral block. The incidence of pneumothorax was 2.6% in the paravertebral block group; there were no reports of complications of the other blocks. This review has shown that the erector spinae plane block is more effective at reducing postoperative opioid consumption and pain scores up to 24 hours compared with general anaesthesia alone. However, it was inferior to the pectoralis nerve block and its efficacy was similar to paravertebral block. Further evidence, preferably from properly blinded trials, is required to confirm these findings.