ObjectivesTo systematically review the efficacy and safety of ultrasound-guided percutaneous microwave ablation versus traditional open surgical operation in the treatment of benign thyroid nodules.MethodsPubMed, The Cochrane Library, EMbase, CBM, CNKI and VIP databases were electronically searched to collect randomized controlled trials (RCTs) on ultrasound-guided percutaneous microwave ablation versus traditional open surgery for benign thyroid nodules from inception to June 30th, 2018. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was then performed by RevMan 5.3 software.ResultsA total of 38 RCTs involving 4 078 patients were included. The results of meta-analysis showed that: ultrasound-guided percutaneous microwave ablation might be more effective than traditional open surgery for the treatment of benign thyroid nodules (RR=1.09, 95% CI 1.00 to 1.19, P=0.04), and compared with traditional open surgery, ultrasound-guided percutaneous microwave ablation reduced the rate of postoperative complication (RR=0.26, 95%CI 0.21 to 0.31, P<0.000 01), shortened postoperative hospital stay (MD=–3.60, 95%CI –4.04 to –3.15, P<0.000 01) and the time consumed in operation (MD=–48.79, 95%CI –54.16 to –43.41, P<0.000 01), and reduced operative blood loss (MD=–22.02, 95%CI–23.87 to –20.17, P<0.000 01). Meanwhile, microwave ablation reduced the elevated levels of serum IL-6 content (MD=–10.34, 95%CI –10.70 to –9.97, P<0.000 01), serum CRP content (MD=–9.70, 95%CI –10.95 to –8.44, P<0.000 01) and serum TNF-α content (MD=–7.94, 95%CI –9.00 to –6.88, P<0.000 01).ConclusionsCurrent evidence shows that ultrasound-guided percutaneous microwave ablation may improve clinical efficacy and can reduce postoperative complications, bleeding volume, operation time, hospitalization days and postoperative inflammatory reaction. Due to limited quality and quantity of the included studies, more high quality studies are required to verify above conclusions.