Efficacy and safety of suprascapular nerve block combined with axillary nerve block for arthroscopic shoulder surgery: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

A variety of peripheral nerve block methods are used in the clinic to enhance the effect of postoperative analgesia. In recent years, an increasing number of surgeons have considered the efficacy and safety of suprascapular nerve block (SSNB) combined with axillary nerve block (ANB) for controlling perioperative pain in shoulder arthroscopy. The purpose of this study was to compare the efficacy and safety of SSNB + ANB and interscalene block (ISB) versus SSNB alone for shoulder arthroscopic surgery.

STUDY DESIGN

Systematic review; Level of evidence, 1.

METHODS

The protocol for this meta-analysis is registered with PROSPERO (CRD42021254008). PubMed, Cochrane Library, Embase and CNKI were searched for RCTs from inception to April 30, 2021. A meta-analysis was performed with Review Manager 5.3 to calculate the RR or WMD of related outcome indicators.

RESULTS

Nine RCTs involving 543 cases from 5 countries were included. Compared with SSNB alone, SSNB + ANB was more effective at pain relief at 6, 12, 24, 36 and 48 h postoperatively. In terms of patient satisfaction score, scores for SSNB + ANB at 12 (WMD = 2.01, 95% CI = 0.25 to 3.78) and 24 (WMD = 1.68, 95% CI = 0.11 to 3.24) hours after the operation were higher than those of SSNB alone, but there was no significant difference at 36 and 48 h postsurgery. There was no significant difference in pain score between SSNB + ANB and ISB at 6 and 12 h after surgery or in patient satisfaction at 24 h (WMD = 0.13, 95% CI = -0.36 to 0.63) postsurgery between SSNB + ANB and ISB. In terms of safety, compared with ISB, SSNB + ANB reduced the incidence of dyspnea (RR = 0.25, 95% CI = 0.09 to 0.68).

CONCLUSIONS

Compared with SSNB alone, SSNB + ANB has better advantages regarding pain relief and patient satisfaction within 24 h after surgery. Compared with ISB, SSNB + ANB shows no difference in postoperative pain relief or patient satisfaction, but SSNB + ANB can reduce the incidence of dyspnea more than ISB.

Analgesic benefits and clinical role of the posterior suprascapular nerve block in shoulder surgery: a systematic review, meta-analysis and trial sequential analysis

The posterior suprascapular nerve block has been proposed as an analgesic alternative for shoulder surgery based on the publication of several comparisons with interscalene block that failed to detect differences in analgesic outcomes. However, quantification of the absolute treatment effect of suprascapular nerve block on its own, in comparison with no block (control), to corroborate the aforementioned conclusions has been lacking. This study examines the absolute analgesic efficacy of suprascapular nerve block compared with control for shoulder surgery. We systematically sought electronic databases for studies comparing suprascapular nerve block with control. The primary outcomes included postoperative 24-h cumulative oral morphine consumption and the difference in area under the curve for 24-h pooled pain scores. Secondary outcomes included the incidence of opioid-related side-effects (postoperative nausea and vomiting) and patient satisfaction. Data were pooled using random-effects modelling. Ten studies (700 patients) were analysed; all studies examined landmark-guided posterior suprascapular nerve block performed in the suprascapular fossa. Suprascapular nerve block was statistically but not clinically superior to control for postoperative 24-h cumulative oral morphine consumption, with a weighted mean difference (99%CI) of 11.41 mg (-21.28 to -1.54; p = 0.003). Suprascapular nerve block was also statistically but not clinically superior to control for area under the curve of pain scores, with a mean difference of 1.01 cm.h. Nonetheless, suprascapular nerve block reduced the odds of postoperative nausea and vomiting and improved patient satisfaction. This review suggests that the landmark-guided posterior suprascapular nerve block does not provide clinically important analgesic benefits for shoulder surgery. Investigation of other interscalene block alternatives is warranted.