Colonic Gallstone Ileus, Diagnostic-therapeutic Algorithm

Gallstone ileus is a rare complication of gallstone disease. There is no systematic review on CGI. We analyze published literature on the subject and plan to propose a diagnostic-therapeutic algorithm for CGI. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) and AMSTAR (Assessing the methodological quality of systematic reviews) guidelines, we will performe a systematic review of English-, German-, Spanish-, Japanese-, and Italian-language articles using PubMed (1946-2021), PubMed Central (1900-2021), and Google Scholar. The search items include 'gallstone ileus', 'colonic gallstone ileus', 'gallstone coleus', 'cholecystocolonic fistula', 'ileo biliar', 'iléus biliaire', 'ileo di calcoli biliary', 'galsteen ileus', 'fístula colecistocolônica', 'fistule cholécystocolique'. Additional studies will be identified by reviewing reference lists of retrieved studies. We will include all cases and case series with a complete description of CGI. Exclusion criteria: (1) small bowel gallstone ileus; (2) gastric outlet gallstone ileus; (3) non-gallstone intraluminal obstruction; and (4) cholecystocolonic fistula without CGI. The primary outcome: a relationship of demographic data, gallstone size, symptoms, obstruction level, risk factors, and comorbidities (biliary history, diverticular disease, cardiovascular disease, radiation of pelvis), diagnostics (palpable mass in the abdomen and rectal exam, laboratory tests, sigmoidoscopy/colonoscopy, x-ray, computed tomography (CT), colonic Rigler's triad) with the correct diagnosis. The secondary outcome: the identification of therapeutic options and related survival. The third outcome: to develop a comprehensive diagnostic-therapeutic algorithm for CGI. The study is exempt from ethics approval because we synthesized data from published studies.