Clinical Outcomes of Negative Balloon-Assisted Enteroscopy for Obscure Gastrointestinal Bleeding: A Systematic Review and Meta-Analysis

BACKGROUND: For patients with obscure gastrointestinal bleeding (OGIB), finding the bleeding site is challenging. Balloon-assisted enteroscopy (BAE) has become the preferred diagnostic modality for OGIB. The long-term outcome of patients with negative BAE remains undefined. The present study aimed to evaluate the long-term outcomes of patients with negative BAE results for OGIB and to clarify the effect of further investigations at the time of rebleeding with a systematic review and meta-analysis of the available cohort studies. METHODS: Studies were searched through the PubMed, EMBASE, and Cochrane library databases. The following indexes were analyzed: rebleeding rate after negative BAE, rebleeding rate after different follow-up periods, the proportion of patients who underwent further evaluation after rebleeding, the percentage of patients with identified rebleeding sources, and the percentage of patients with rebleeding sources in the small intestine. Heterogeneity was assessed using the I(2) test. RESULTS: Twelve studies that involved a total of 407 patients were included in the analysis. The pooled rebleeding rate after negative BAE for OGIB was 29.1% (95% CI: 17.2–42.6%). Heterogeneity was significant among the studies (I(2) = 88%; p < 0.0001). The Chi-squared test did not show a difference in rebleeding rates between the short and long follow-up period groups (p = 0.142). The pooled proportion of patients who underwent further evaluation after rebleeding was 86.1%. Among the patients who underwent further evaluation, rebleeding sources were identified in 73.6% of patients, and 68.8% of the identified rebleeding lesions were in the small intestine. CONCLUSION: A negative result of BAE in patients with OGIB indicates a subsequently low risk of rebleeding. Further evaluation should be considered after rebleeding.