Diagnostic Yield of Capsule Endoscopy in Obscure Gastrointestinal Bleeding

Abstract

Objectives:Chronic occult blood loss from the gastrointestinal tract is a recognized major cause of iron-deficiency anemia. After conventional investigation of the upper and lower parts of the gastrointestinal tract, the source of bleeding remains unidentified in ~10% of these patients. We evaluated the diagnostic yield of capsule endoscopy from patients enrolled in clinical studies due to persistent or recurrent iron-deficiency anemia. Methods: In this large cohort study, patients with obscure gastrointestinal bleeding were identified in a company-sponsored clinical study (Given Imaging, Ltd.) database which contains data from >50 clinical studies. Information on suitable patients was derived from 31 of them. Each subject swallowed an M2A^® Given Capsule containing a miniature video camera, batteries, a transmitter and an antenna. Recording time was ~8 h. The capsule was excreted naturally in the patient’s bowel movement, and the data it transmitted were retrieved and interpreted the next day. Results: 293 patients were studied (135 males, 46.1%, mean age 59.4 ± 16.8 years) whose mean number of bleeding episodes was 4.3 ± 5.5 and mean hemoglobin level was 9.8 ± 2.4 g/dl. The average number of diagnostic procedures per patient prior to the capsule endoscopy study was 5.59. Capsule endoscopy detected definitive findings in 213/293 patients (72%) and findings missed by other diagnostic procedures in 22/293 patients (8%). Neither capsule endoscopy nor the other diagnostic procedures yielded diagnoses in 58/293 patients (20%). Conclusions: Capsule endoscopy has a high diagnostic yield in evaluating patients with obscure gastrointestinal bleeding.