Forward-viewing endoscope for ERCP in patients with Billroth II gastrectomy: a systematic review and meta-analysis

The forward-viewing endoscope has been increasingly used to perform endoscopic retrograde cholangiopancreatography (ERCP) in patients who underwent Billroth II gastrectomy. This study intended to assess efficacy and safety of the forward-viewing endoscope for ERCP in Billroth II gastrectomy patients compared with conventional side-viewing endoscope using a systematic review and meta-analysis. A systematic review was conducted for studies that evaluated the outcomes of ERCP for patients with Billroth II gastrectomy. Random-effect model meta-analyses with subgroup analyses were conducted. The methodological quality of the included publications was evaluated using the risk of bias assessment tool for non-randomized studies. The publication bias was assessed. In total, 25 studies (1 randomized, 18 retrospective, 1 prospective, and 5 case series studies) with 2446 patients (499 forward-viewing and 1947 side-viewing endoscopes) were analyzed. The pooled afferent loop intubation rate was higher with the forward-viewing endoscope (90.3%, 95% confidence interval (CI) 85.6–93.6 vs. 86.8%, 95% CI 82.8–89.9%). The pooled selective cannulation rate was higher with the side-viewing endoscope (92.3%, 95% CI 88.0–95.2 vs. 91.1%, 95% CI 87.2–93.9%). The pooled bowel perforation rate was higher with the side-viewing endoscope (3.6%, 95% CI 2.3–5.7 vs. 3.0%, 95% CI 1.7–5.3%). The pooled pancreatitis rate was higher with the forward-viewing endoscope (5.4%, 95% CI 3.6–8.0 vs. 2.5%, 95% CI 2.3–5.7%). The pooled bleeding rate was higher with the forward-viewing endoscope (3.0%, 95% CI 1.6–5.5 vs. 2.0%, 95% CI 1.4–3.0%). The heterogeneity among the studies was not significant. The publication bias was minimal. This meta-analysis indicates that the forward-viewing endoscope is as safe and effective as conventional side-viewing endoscope for ERCP in patients with Billroth II gastrectomy.