Diagnostic Yield of Small Bowel Videocapsule Endoscopy in Patients with Iron Deficiency Anemia. A Systematic Review and meta-analysis

Background and aim: Gastrointestinal (GI) bleeding or malabsorption represents the most frequent aetiologies of iron deficiency anemia (IDA). The cause of IDA remains undetermined in ~10% to 20% of patients undergoing upper and lower GI endoscopies. In this scenario, a small bowel examination with videocapsule endoscopy (VCE) is recommended. We performed a systematic review with meta-analysis to evaluate the diagnostic yield of VCE in patients with IDA without overt bleeding, assessing the prevalence of either any lesion or lesions at high potential of bleeding. Materials and methods: A computerized literature search was performed using relevant keywords to identify all the pertinent articles published until March 2023. Results: Twelve studies with a total of 1703 IDA patients (Males: 47%; age range: 19-92 y) were included in this systematic review. The diagnostic yield of VCE for overall lesions in the small bowel was 61% (95% CI=44-77; 95 CI=97.2-98.1; I2=97.7%). When analyzing only small bowel lesions likely responsible of IDA, the diagnostic yield was 40% (95% CI=27-53; 95% CI=95.3-97; I2=96.3%). Conclusion: VCE plays a relevant role in the diagnostic work-up of patients with IDA without overt bleeding with a satisfactory diagnostic yield.