Abstract
OBJECTIVE: First-generation and second-generation endometrial ablation (EA) techniques, along with medical treatment and invasive surgery, are considered successful lines of management for abnormal uterine bleeding (AUB). We set out to determine the efficacy of first and second-generation ablation techniques compared with medical treatment, invasive surgery and different modalities of the EA techniques themselves. DESIGN: Systematic review and network meta-analysis using a frequentist network. DATA SOURCES: We searched Medline (Ovid), PubMed, ClinicalTrials.gov, Cochrane CENTRAL, Web of Science, EBSCO and Scopus for all published studies up to 1 March 2021 using relevant keywords. ELIGIBILITY CRITERIA: We included all randomised controlled trials (RCTs) that compared premenopausal women with AUB receiving the intervention of second-generation EA techniques. DATA EXTRACTION AND SYNTHESIS: 49 high-quality RCTs with 8038 women were included. We extracted and pooled the data and then analysed to estimate the network meta-analysis models within a frequentist framework. We used the random-effects model of the netmeta package in R (V.3.6.1) and the 'Meta-Insight' website. RESULTS: Our network meta-analysis showed many varying results according to specific outcomes. The uterine balloon ablation had significantly higher amenorrhoea rates than other techniques in both short (hydrothermal ablation (risk ratio (RR)=0.51, 95% CI 0.37; 0.72), microwave ablation (RR=0.43, 95% CI 0.31; 0.59), first-generation techniques (RR=0.44, 95% CI 0.33; 0.59), endometrial laser intrauterine therapy (RR=0.18, 95% CI 0.10; 0.32) and bipolar radio frequency treatments (RR=0.22, 95% CI 0.15; 0.31)) and long-term follow-up (microwave ablation (RR=0.11, 95% CI 0.01; 0.86), bipolar radio frequency ablation (RR=0.12, 95% CI 0.02; 0.90), first generation (RR=0.12, 95% CI 0.02; 0.90) and endometrial laser intrauterine thermal therapy (RR=0.04, 95% CI 0.01; 0.36)). When calculating efficacy based only on calculated bleeding scores, the highest scores were achieved by cryoablation systems (p-score=0.98). CONCLUSION: Most second-generation EA systems were superior to first-generation systems, and statistical superiority between devices depended on which characteristic was measured (secondary amenorrhoea rate, treatment of AUB, patient satisfaction or treatment of dysmenorrhoea). Although our study was limited by a paucity of data comparing large numbers of devices, we conclude that there is no evidence at this time that any one of the examined second-generation systems is clearly superior to all others.