Capsule Endoscopy in the Assessment of Obscure Gastrointestinal Bleeding: An Evidence-Based Analysis.

backgroundObscure gastrointestinal bleeding (OGIB) is defined as persistent or recurrent bleeding associated with negative findings on upper and lower gastrointestinal (GI) endoscopic evaluations. The diagnosis and management of patients with OGIB is particularly challenging because of the length and complex loops of the small intestine. Capsule endoscopy (CE) is 1 diagnostic modality that is used to determine the etiology of bleeding.

objectivesThe objective of this analysis was to review the diagnostic accuracy, safety, and impact on health outcomes of CE in patients with OGIB in comparison with other diagnostic modalities. DATA SOURCES: A literature search was performed using Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid Embase, the Wiley Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published between 2007 and 2013. REVIEW

methodsData on diagnostic accuracy, safety, and impact on health outcomes were abstracted from included studies. Quality of evidence was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE).

resultsThe search yielded 1,189 citations, and 24 studies were included. Eight studies reported diagnostic accuracy comparing CE with other diagnostic modalities. Capsule endoscopy has a higher sensitivity and lower specificity than magnetic resonance enteroclysis, computed tomography, and push enteroscopy. Capsule endoscopy has a good safety profile with few adverse events, although comparative safety data with other diagnostic modalities are limited. Capsule endoscopy is associated with no difference in patient health-related outcomes such as rebleeding or follow-up treatment compared with push enteroscopy, small-bowel follow-through, and angiography. LIMITATIONS: There was significant heterogeneity in estimates of diagnostic accuracy, which prohibited a statistical summary of findings. The analysis was also limited by the fact that there is no established reference standard to which the diagnostic accuracy of CE can be compared.

conclusionsThere is very-low-quality evidence that CE has a higher sensitivity but a lower specificity than other diagnostic modalities. Capsule endoscopy has few adverse events, with capsule retention being the most serious complication. Capsule endoscopy is perceived by patients as less painful and less burdensome compared with other modalities. There is low-quality evidence that patients who undergo CE have similar rates of rebleeding, further therapeutic interventions, and hospitalization compared with other diagnostic modalities.