Ablation

Background and Aims
A small but significant proportion of patients with Barrett’s esophagus (BE) have persistent dysplasia or intestinal metaplasia (IM) after treatment with radiofrequency ablation (RFA). Cryotherapy is a cold-based ablative modality that is increasingly being used in this setting. We aimed to better understand the efficacy of second-line cryotherapy in patients with BE who have persistent dysplasia or IM after RFA by conducting a systematic review and meta-analysis. Methods
We performed a systematic literature search of Pubmed, EMBASE, and Web of Science through September 1, 2017. Articles were included for meta-analysis based on the following inclusion criteria: ≥5 patients with BE treated with RFA had persistent dysplasia or IM; they subsequently underwent ≥1 session of cryotherapy with follow-up endoscopy; the proportions of patients achieving complete eradication of dysplasia (CE-D) and/or IM (CE-IM) were reported. The main outcomes were pooled proportions of CE-D and CE-IM by using a random effects model. Results
Eleven studies making up 148 patients with BE treated with cryotherapy for persistent dysplasia or IM after RFA were included. The pooled proportion of CE-D was 76.0% (95% confidence interval [CI] 57.7-88.0), with substantial heterogeneity (I2 = 62%). The pooled proportion of CE-IM was 45.9% (95% CI, 32.0-60.5) with moderate heterogeneity (I2 = 57%). Multiple preplanned subgroup analyses did not sufficiently explain the heterogeneity. Adverse effects were reported in 6.7% of patients. Conclusion
Cryotherapy successfully achieved CE-D in three fourths and CE-IM in half of patients with BE who did not respond to initial RFA. Considering its favorable safety profile, cryotherapy may be a viable second-line option for this therapeutically challenging cohort of patients with BE, but higher-quality studies validating this remain warranted.

Background and Aims
Unresectable malignant biliary strictures are generally managed by palliative stent placement for drainage of biliary tree. Recently, radiofrequency ablation (RFA) has been used to improve the patency of biliary stents in these patients. Several studies have evaluated the effectiveness of biliary stent placement with RFA on stent patency and patient survival with variable results. We performed this meta-analysis to evaluate the efficacy and safety of biliary stent placement with RFA compared with stent placement alone in patients with malignant biliary strictures. Methods
We performed a comprehensive search of electronic databases for all studies comparing RFA with biliary stent placement versus stent placement only. Measured outcomes included patient survival, stent patency, and procedure-related adverse events. An inverse variance method was used to pool data on stent patency into a random-effects model. Cox-regression analysis was used to calculate hazard ratio for survival analysis. We used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework to interpret our findings. Results
Nine studies (including 2 abstracts) with a total of 505 patients were included in the meta-analysis. The pooled weighted mean difference in stent patency was 50.6 days (95% confidence interval [CI], 32.83-68.48), favoring patients receiving RFA. Pooled survival analysis of the reconstructed Kaplan-Meier data showed improved survival in patients treated with RFA (hazard ratio, 1.395; 95% CI, 1.145-1.7; P