Suprascapular nerve block is a clinically attractive alternative to interscalene nerve block during arthroscopic shoulder surgery: a meta-analysis of randomized controlled trials

BACKGROUND: The interscalene brachial plexus block (ISB) is a commonly used nerve block technique for postoperative analgesia in patients undergoing shoulder arthroscopy surgery; however, it is associated with potentially serious complications. The use of suprascapular nerve block (SSNB) has been described as an alternative strategy with fewer reported side effects for shoulder arthroscopy. This review aimed to compare the impact of SSNB and ISB during shoulder arthroscopy surgery. METHODS: A meta-analysis was conducted to identify relevant randomized controlled trials involving SSNB and ISB during shoulder arthroscopy surgery. Web of Science, PubMed, Embase, Cochrane Controlled Trials Register, Cochrane Library, Highwire, CNKI, and Wanfang database were searched from 2010 through March 2021. RESULTS: We identified 1255 patients assessed in 17 randomized controlled trials. Compared with the ISB group, the SSNB group had higher VAS at rest in PACU (P = 0.003), 1 h after operation (P = 0.005), similar pain score 2 h (P = 0.39), 3-4 h (P = 0.32), 6-8 h after operation (P = 0.05), then lower VAS 12 h after operation (P = 0.00006), and again similar VAS 1 day (P = 0.62) and 2 days after operation (P = 0.70). As for the VAS with movement, the SSNB group had higher pain score in PACU (P = 0.03), similar VAS 4-6 h after operation (P = 0.25), then lower pain score 8-12 h after operation (P = 0.01) and again similar VAS 1 day after operation (P = 0.3) compared with the ISB group. No significant difference was found for oral morphine equivalents use at 24 h (P = 0.35), duration of PACU stay (P = 0.65), the rate of patient satisfaction (P = 0.14) as well as the rate of vomiting (P = 0.56), and local tenderness (P = 0.87). However, the SSNB group had lower rate of block-related complications such as Horner syndrome (P < 0.0001), numb (P = 0.002), dyspnea (P = 0.04), and hoarseness (P = 0.04). CONCLUSION: Our high-level evidence established SSNB as an effective and safe analgesic technique and a clinically attractive alternative to interscalene block with the SSNB’S advantage of similar pain control, morphine use, and less nerve block-related complications during arthroscopic shoulder surgery, especially for severe chronic obstructive pulmonary disease, obstructive sleep apnea, and morbid obesity. Given our meta-analysis’s relevant possible biases, we required more adequately powered and better-designed RCT studies with long-term follow-up to reach a firmer conclusion.