Use of a Transparent Cap Increases the Diagnostic Yield in Antegrade Single-Balloon Enteroscopy for Obscure GI Bleed

Background and Aims: Single-balloon enteroscopy (SBE) is utilized in the evaluation of obscure gastrointestinal bleeding, but 40–50% of these patients experience continued GI blood loss, in part due to missed lesions. The utilization of a transparent cap attached to the end of the endoscope can improve mucosal visualization in other endoscopic applications, but has not yet been evaluated in SBE. The aim of this study was to evaluate the impact of a cap on the diagnostic yield of SBE. Methods: Consecutive adult patients scheduled for anterograde SBE for the evaluation of obscure GI bleeding were screened for inclusion from 2014 to 2017. Patients were randomized to SBE with or without a transparent cap. The primary outcome was the proportion of enteroscopies in which a P2 lesion (high potential for bleeding) was identified. Results: A total of 90 patients (65.7 ± 12.7 years old, 47.7% female) were analyzed. There were significantly more P2 arteriovenous malformations identified in the cap group (14.8% vs. 0%, p = 0.02). Additionally, the use of a cap was associated with a significantly greater depth of small bowel insertion (191.9 cm vs. 156.2 cm, p = 0.01). There was one perforation in the group without a cap, successfully treated with clip placement, and no adverse events in the cap group. Conclusions: The use of a transparent cap during SBE performed for the evaluation of obscure gastrointestinal bleeding may be an important, safe augmentation to standard SBE techniques.