Included studies
| Author | Year | Procedure | USG | Number treatment/control | Block/control | Type of anesthesia | Block complications | Modified Jadad Score (1–5) |
| Bashandy et al 16 | 2015 | Modified radical mastectomy | Y | 60/60 | Pecs block II (levobupivacaine)+ GA Pecs block II (NS)+ GA | Fentanyl, propofol, isoflurane and cisatracurium | Not reported | 3 |
| Cros J et al 17 | 2018 | Mastectomy with or without lymph node dissection | Y | 14/15 | Pecs block I (bupivacaine)+ GA Pecs block I (NS)+ GA | Fentanyl/sufentanil, propofol, sevoflurane/desflurane and rocuronium | Pectoral hematoma/ bleeding | 5 |
| Neethu et al 18 | 2017 | Modified radical mastectomy with or without lymph node dissection | Y | 30/30 | Pecs block II (ropivacaine)+ GA | Fentanyl, propofol and vecuronium | None | 5 |
| Ali Hassn et al 19 | 2016 | Modified radical mastectomy | Y | 30/30 | Pecs block II (bupivacaine) and dexmedetomidine)+ GA Pecs block II (NS)+ GA | Propofol, isoflurane and cisatracurium | None | 4 |
| Kamiya et al 20 | 2018 | Modified radical mastectomy with or without lymph node dissection | Y | 29/30 | Pecs block II (levobupivacaine) + GA Pecs block I (NS)+ GA | Propofol, remifentanil and rocuronium | None | 5 |
| O’ Scanaill et al 21 | 2018 | Mastectomy without lymph node biopsy | Y | 15/15/15 | Pecs block II (levobupivacaine) cLA WI +Pecs block II (levobupivacaine) cLA WI | Propofol, sevoflurane | None | 5 |
| Versyck et al 22 | 2017 | Mastectomy with lymph node resection | Y | 45/40 | Pecs block II (bupivacaine)+ GA Pecs block II (NS)+ GA | Sufentanil, propofol, sevoflurane and rocuronium | None | 5 |
.GA, general anesthesia; LA, local anesthetic; PACU, postoperative anesthesia care unit; Pecs, pectoral nerve block; USG, ultrasound guided; WI, wound infiltration; cLA, continuous local anesthetic.