Vonoprazan versus proton pump inhibitors in treating post-endoscopic submucosal dissection ulcers and preventing bleeding: Protocol for meta-analysis of randomized controlled trials and observational studies.

Background: Vonoprazan is a potassium-competitive acid blocker (P-CAB). It is often used in Japan for Helicobacter pylori (H pylori) eradication, gastroesophageal reflux disease, and endoscopic submucosal dissection (ESD) ulcers and bleeding. This meta-analysis aims to evaluate whether vonoprazan has better therapeutic effect on ESD-induced ulcers and bleeding than proton pump inhibitors (PPIs) at different length of treatment periods (2, 4, and 8 weeks).

Methods: This meta-analysis will include both randomized controlled trials (RCTs) and observational studies discussing the effectiveness of vonoprazan and PPIs on ESD-induced ulcers and bleeding. Information of studies will be collected from PubMed, Cochrane Library, ClinicalTrials.gov, and Google Scholar. Studies will be selected according to the eligibility criteria and data will be extracted by 2 people and compared with each other to keep in consistency. Cochrane risk of bias tool will be used to assess RCTs and the Newcastle-Ottawa Quality Assessment Scale will be used to assess the observational studies. Meta-analysis based on the random-effects model will be conducted to compare the differences of ulcers' shrinkage ratios (%) and the odds ratios (OR) of scars' stages and delayed bleeding. Publication bias will be evaluated using funnel plots and Egger's regression test. Heterogeneity will be assessed with the I statistics. Sensitivity analysis will be conducted on follow-up periods. The evidential quality of the findings will be assessed with the Grading of Recommendations Assessment Development and Evaluation (GRADE) profiler.

Discussion: The findings of the present systematic review will be critical for physicians, patients, and policymakers regarding the use of vonoprazan in ESD-induced ulcers.

Study Registration: PROSPERO registration number: CRD42018116855.