The efficacy and safety of microwave ablation versus conventional open surgery for the treatment of papillary thyroid microcarcinoma: a systematic review and meta-analysis.

Background: Microwave ablation (MWA) technology has been applied to the treatment of papillary thyroid microcarcinoma (PTMC); however, its use as an alternative to conventional open surgery (OS) remains controversial, because it belongs to non-tumor radical treatment. Our article sought to compare the efficacy and safety of MWA and OS in the treatment of PTMC. Methods: We searched seven databases for studies evaluating the treatment of patients with PTMC using MWA as intervention group and OS as control group, the main outcome contained intra-operative, post-operative and follow-up outcomes. Review Manager 5.4 was used to estimate the effects of the results of the included articles and Cochrane Risk of Bias 2.0 was used to assess the risk of bias. The data were pooled to calculate the mean differences (MD) with 95% confidence intervals (CIs) for the continuous data and the odds ratio (OR) with 95% CIs for the dichotomous data. Results: A total of 13 studies, comprising 1,088 and 1,081 patients in the MWA and OS groups, respectively, were identified that compared the results of MWA to OS in the treatment of PTMC. All of the articles were at low risk of bias. There were no differences in terms of the recurrence rate (OR =0.80, 95% CI: 0.37 to 1.77; P=0.59) or lymph node metastasis (OR =0.71, 95% CI: 0.26 to 1.95; P=0.51) between the 2 groups. However, compared to the OS group, the MWA group had a shorter operation time (MD =-44.85, 95% CI: 5.73 to 20.68; P<0.00001), less intra-operative blood loss (MD =-23.37, 95% CI: -29.57 to -17.17; P<0.00001), a smaller surgical incision (MD =-47.04, 95% CI: -81.93 to -12.14; P=0.008), a shorter postoperative hospital stay (MD =-4.19, 95% CI: -5.46 to -2.92; P<0.00001), lower hospitalization expenses (MD =-85.65, 95% CI: -133.86 to -37.45; P<0.00001), and fewer complications (OR =0.23, 95% CI: 0.16 to 0.33; P<0.00001). Conclusions: This meta-analysis suggests that MWA is better than OS at treating PTMC in terms of both intra-operative and post-operative outcomes. Due to the quality and number of the included studies, the long-term effects and suitability of MWA in the treatment of PTMC need to be further studied.