Evidence map of oesophageal surgery: protocol for a living systematic review and meta-analysis

Surgery represents the cornerstone for the treatment of several benign and malignant oesophageal disorders. Yet synthesising the growing body of evidence from clinical research is becoming increasingly challenging. Evidence mapping with living systematic reviews (SRs) and living meta-analyses offers a structured, continuously updated approach to navigating emerging data. This study aims to provide a real-time, interactive resource to support evidence-based decision-making for oesophageal surgery.

This study follows PRISMA guidelines and uses the EVIglance Studio web application to develop a living evidence map in oesophageal surgery. A systematic literature search will be conducted across the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science and MEDLINE (PubMed) to identify randomised controlled trials (RCTs) and SRs related to oesophageal surgery, without any date or language restrictions. Study selection and data extraction will be performed independently by two reviewers. Key clinical and surgical outcomes, including morbidity, mortality, quality of life and oncological endpoints, will be extracted. Risk of bias in RCTs will be assessed using the Cochrane Risk of Bias 2.0 tool, and the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) system will be applied to evaluate the certainty of evidence. If at least three randomised trials address the same research question, a living meta-analysis will be conducted using random-effects models. The evidence map will be updated at least every 6 months.

This study does not involve individual patient data or any private information. Therefore, ethical approval is not required. As it uses only publicly available data, this study design qualifies as exempt from institutional review. The resulting evidence map is designed to support fast and structured access to high-quality surgical data - an approach not yet available in oesophageal surgery. The tool is expected to aid patients, clinicians and researchers alike by improving access to reliable information, supporting clinical decision-making and highlighting gaps in current evidence. On completion, results will be published in an open-access format and made permanently accessible via www.evidencemap.surgery, with continuous updates.

CRD420251022736 (https://www.crd.york.ac.uk/prospero/).