Summary of the characteristics of the included studies and the surgical and PVB techniques
| Study | PVB technique | Complications | Type of surgery | Adjuvant therapy | Other CPSP factors |
| Iohom et al25 | Anatomical, continuous, single level | One ipsilateral Horner’s syndrome | Lumpectomy, simple mastectomy, AND | Chemotherapy, radiotherapy | None |
| Kairaluoma et al5 | Anatomical, single shot, single level | Not reported | Simple mastectomy, LNB, LND | Chemotherapy, radiotherapy | Repeated surgery |
| Ibarra et al28 | Neurostimulation, single shot, unknown | One Horner’s syndrome | MRM | Chemotherapy, radiotherapy | None |
| Xu34 | Ultrasound, single shot, single level | Not reported | RM | Not reported | None |
| Elkaradawy et al33 | Ultrasound, continuous, single level | Not reported | Lumpectomy, AND | Chemotherapy, radiotherapy | None |
| Lee32 | Anatomical, continuous, single level | Four failures Four dislodged catheters | Lumpectomy, SM, AND | Chemotherapy | Repeated surgery Postoperative allodynia days 1, 2, and 3 and month 3 |
| Karmakar et al30 | Anatomical, single shot vs continuous single level | No major complication | MRM | Chemotherapy, radiotherapy | None |
| Lam31 | Ultrasound, single shot, single level | Not reported | Total mastectomy | Not reported | None |
| Ilfeld et al29 | Ultrasound, continuous, single level | Not reported | Simple mastectomy, LND | Not reported | None |
| Abdallah et al26 | Ultrasound, single shot, multiple level | None | Segmental mastectomy with SLNB or ALND, total mastectomy with or without SLNB, MRM, and SM with implant insertion | Chemotherapy, radiotherapy | Breast reconstructive surgery |
| Gacio et al27 | Anatomical, single shot, single level | Hypotension (9 vs 3) Bradycardia (12.5% vs 7.5%) Pleural puncture without PNO | SM, MRM, LND | Chemotherapy, radiotherapy | None |
| Sessler et al19 | Ultrasound, single shot, multiple level | No major complication observed | Simple mastectomy, MRM, LND | Chemotherapy, radiotherapy | None |
ALND, axillary lymph node dissection; AND, axillary node dissection; CPSP, chronic postsurgical pain; LNB, lymph node biopsy; LND, lymph node dissection; MRM, modified radical mastectomy; PNO, pneumothorax; PVB, paravertebral block; RM, radical mastectomy; SLNB, sentinel lymph node biopsy; SM, simple mastectomy.