Background Pectoral (PECs) block was first described by Blanco et al for postoperative analgesia in breast surgery. It was proposed to be an easier and safer alternative to thoracic epidural or paravertebral block (PVB). In this systematic review and meta-analysis, we compare the perioperative analgesic efficacy and adverse events of PECs block and PVB.

Methods We systematically searched PubMed, Central, EMBASE, CINAHL, Google Scholar, Web of Science citation index, US clinical trials register, Wanfang database, as well as recent conference abstracts, for clinical studies comparing the two techniques. Analgesic efficacy was assessed according to the time to first rescue analgesia and 24 hours opioid consumption. Adverse events from the trials were recorded and reported descriptively.

Results The literature search was last updated on 20 February 2020. We identified a total of 10 randomized controlled trials (RCTs) comparing PECs to PVB with 252 and 250 patients, respectively. There was no difference in 24 hours opioid consumption between PECs and PVB. There was no significant difference in the time to rescue analgesia between the two cohorts. The most common adverse event noted was postoperative nausea and vomiting). Trial sequence analysis indicate that further studies are unlikely to alter the conclusion regarding opioid requirement.

Conclusion Our systematic review suggests that PECs and PVB are comparable in postoperative analgesia efficacy for mastectomy, and further studies are unlikely to alter the conclusion. The choice of technique should, therefore, be based on practitioner skill and institutional guidelines.

PROSPERO registration number CRD42020165137.