A total of 716 records were obtained from the initial literature search. Following the screening of titles and abstracts, 57 articles were identified as potentially meeting the criteria. Upon full-text examination, 49 records were excluded for various reasons: one article was withdrawn, one article by Zhao X et al. [28] contained duplicate data found in a subsequent publication by the same author. To prevent redundancy in data analysis, only the later publication [10] was considered. Two studies were not RCTs, 27 studies did not report results, nine studies had a follow-up time of less than 2 months and nine studies involved only one of the following interventions: control group (without regional anesthesia techniques), PVB, ICNB, SAPB, ESPB and TEA or employed two or more regional anesthesia techniques concurrently on the same patient. Ultimately, eight articles [10, 28,29,30,31,32,33,34] met the eligibility criteria and were included in our final NMA. Figure 1 illustrates the literature selection process. These trials, conducted between 2017 and 2023, were from five different countries and involved 785 individuals. Detailed information on participants and intervention measures from the eight studies is provided in Table 1.

Flow diagram of the study selection process

Figure 2 illustrates the risk of bias for eight eligible RCTs. Risk levels are denoted by colors: green indicates low risk, yellow indicates unclear risk, and red indicates high risk. Six studies demonstrated low risk regarding random sequence generation by detailing methods such as computer-generated list of random numbers, block randomization, or Research Randomizer. Three studies achieved low risk in allocation concealment by employing consecutively numbered, sealed, opaque envelopes for participant assignment. Four RCTs were deemed to have low risk in blinding of participants and personnel, as participants were blinded to group assignments by receiving the regional anesthesia technique under midazolam-induced sedation or after induction of general anesthesia. Seven studies maintained low risk in blinding of outcome assessment, ensuring outcome assessors remained unaware of group assignments. In terms of incomplete outcome data, six RCTs showed low risk, with balanced dropout rates and reasons across groups. One study was deemed high risk due to a notable loss of participants during follow-up. Regarding selective reporting, one article reporting all predefined outcomes was rated low risk, while four articles were rated high risk due to unreported predefined primary outcomes and non-predefined reported outcomes. Three articles were categorized as unclear risk due to lack of registration information and unreported predefined secondary outcomes. All articles were considered to have low risk in terms of other bias, with no significant additional bias identified.

Risk of bias assessment using Cochrane criteria

Visual network geometries (Fig. 3A, B) were utilized to illustrate each arm of the analysis. Each treatment was represented by a unique node, with the size of the node proportional to the number of patients receiving that treatment.

Network plots of Control, PVB, ICNB, SAPB, ESPB and TEA. A CPSP at 2–3 months; B CPSP at 6 months. Control control group, PVB paravertebral nerve block, TEA thoracic epidural analgesia, SAPB serrate anterior plane block, ICNB intercostal nerve block, ESPB erector spinae plane block

Our NMA for CPSP at 2–3 months included six analgesic methods (Fig. 3A). PVB was the most frequently studied intervention, with five studies (n = 230) included. Control group followed closely, with four studies (n = 193) included. ESPB was evaluated in two studies (n = 83), while ICNB and SAPB were each studied in one trial (n = 50 for ICNB and n = 46 for SAPB). TEA was also evaluated in one study (n = 50).

In the heterogeneity tests for CPSP incidence at 2–3 months, no heterogeneity was observed among the included studies (I2 = 0%, P = 0.2603). Therefore, a fixed-effect model was employed for the analysis. A closed loop was formed by control group, PVB and ESPB and the inconsistency test was conducted using the “node-splitting” method with P > 0.05, indicating no inconsistency.

For CPSP at 2–3 months, PVB (RR = 0.716, 95% CrI = 0.557–0.901), ICNB (RR = 0.589, 95% CrI = 0.407–0.806) or TEA (RR = 0.642, 95% CrI = 0.454–0.862) showed significantly lower incidences compared to control group. Additionally, the incidence of CPSP was significantly lower with PVB (RR = 0.539, 95% CrI = 0.286–0.937), ICNB (RR = 0.442, 95% CrI = 0.211–0.854) or TEA (RR = 0.480, 95% CrI = 0.233–0.926) compared to SAPB. No significant difference in the incidence of CPSP was observed in the comparison of the remaining interventions (Fig. 4A).

Forest plots of network comparisons. A CPSP at 2–3 months; B CPSP at 6 months. Control control group, PVB paravertebral nerve block, TEA thoracic epidural analgesia, SAPB serrate anterior plane block, ICNB intercostal nerve block, ESPB erector spinae plane block

The rank probability results and Surface Under the Cumulative Ranking Curve (SUCRA) are presented in Figs. 5A and 6A, respectively. In Fig. 5A, the probability of ICNB being the most effective technique is 0.595, with a 0.000 probability of being the least effective. For SAPB, the probability of being the most effective is 0.003, while the probability of being the least effective is 0.790. The SUCRA results indicate that ICNB has the highest probability (0.8853) of being the most effective intervention, followed by TEA (0.789), PVB (0.641), ESPB (0.405), control group (0.211) and SAPB (0.068).

Ranking probabilities for Control, PVB, ICNB, SAPB, ESPB and TEA. A CPSP at 2–3 months; B CPSP at 6 months. Control control group, PVB paravertebral nerve block, TEA thoracic epidural analgesia, SAPB serrate anterior plane block, ICNB intercostal nerve block, ESPB erector spinae plane block

Surface under the cumulative ranking (SUCRA) of the reduction of the incidence of chronic post-surgical pain (CPSP) for Control, PVB, ICNB, SAPB, ESPB and TEA. A at 2–3 months; B at 6 months. Control control group, PVB paravertebral nerve block, TEA thoracic epidural analgesia, SAPB serrate anterior plane block, ICNB intercostal nerve block, ESPB erector spinae plane block

For CPSP at 6 months, a total of seven studies were included, incorporating the same six analgesic methods mentioned previously (Fig. 3B).

In the heterogeneity tests for CPSP incidence at 6 months, no heterogeneity was observed among the included studies (I2 = 32.1%, P = 0.1158). Therefore, a fixed-effect model was employed for the analysis. Two closed loops were formed by control group, PVB and ESPB as well as control group, PVB and TEA. The inconsistency tests were conducted using the “node-splitting” method with P > 0.05, indicating no inconsistency.

The NMA results indicated that PVB (RR = 0.695, 95% CrI = 0.525–0.904), ICNB (RR = 0.600, 95% CrI = 0.407–0.832) or TEA (RR = 0.608, 95% CrI = 0.427–0.830) exhibited significantly lower incidences than control group. No significant difference in the incidence of CPSP was observed in the comparison of the remaining interventions (Fig. 4B).

The rank probability results and SUCRA are presented in Figs. 5B and 6B, respectively. In Fig. 5B, the probability of ICNB being the most effective technique is 0.429, with a 0.000 probability of being the least effective. For SAPB, the probability of being the most effective is 0.099, while the probability of being the least effective is 0.491. The SUCRA results suggest that ICNB has the highest probability (0.815) of being the most effective intervention, followed by TEA (0.804), PVB (0.622), ESPB (0.312), SAPB (0.266), and control group (0.1802).

The corrected funnel plots revealed no significant asymmetry in the intergroup comparison of the incidence of CPSP at 2–3 months and 6 months (Fig. 7A, B). Furthermore, the P values of Egger’s test were > 0.05 (P = 0.7875 for 2–3 months CPSP, P = 0.1836 for 6 months CPSP).

Corrected funnel plots of the included studies. A 2–3 months; B 6 months. Control control group, PVB paravertebral nerve block, TEA thoracic epidural analgesia, SAPB serrate anterior plane block, ICNB intercostal nerve block, ESPB erector spinae plane block