Small Bowel Transit Time Index Demonstrates Good Agreement and Accuracy in Predicting Best Approach for Double Balloon Enteroscopy

Abstract

Introduction: Advances in capsule endoscopy (CE) have brought enhanced visualization in small bowel mucosa; however, it is limited by its inability to localize and intervene on abnormalities. Double balloon enteroscopy (DBE) allows for tissue acquisition, therapeutic intervention, and improved visualization. A negative procedure often requires repeat procedure from an alternate approach. When performed prior to DBE, CE can help decide the appropriate endoscopic route and reduce unnecessary procedures. The objective of our study was to evaluate the agreement and accuracy of using a small bowel transit time (SBTT) index value of 0.6 in determining the best approach for DBE. Methods: We performed a retrospective analysis of 71 patients with positive findings on CE who underwent DBE at our hospital. Incomplete CE studies or patients with prior GI surgery were excluded. CE was analyzed for transit time to duodenum, culprit lesion, and ileocecal valve. SBTT index was calculated as the time from the duodenum to index lesion divided by the total SBTT (time from duodenum to ileocecal valve). SBTT index of less than 0.6 was chosen to suggest anterograde approach and a value of greater than 0.6 was used to suggest retrograde approach. Cohen's kappa, which accounts for the possibility of the agreement occurring by chance, was used to measure agreement between suggested and actual DBE results. For example, if the lesion was detected on anterograde DBE and SBTT index was less than 0.6, agreement was suggested. Accuracy was calculated as a proportion of correct suggestions. Results: 71 patients (mean age 65, 49% male) with positive findings on CE were included (Table 1). Of these, 53 had SBTT index < 0.6, suggesting that the lesion might be best detected on anterograde approach. The lesion was found in 48 of the 53 patients with the method suggested by SBTT. 18 patients had SBTT index >0.6. 13 of these patients underwent retrograde endoscopy with lesions identified. Cohen's Kappa for the level of agreement between suggested DBE based on SBTT index and actual DBE was 0.63 (0.35, 0.82). The level of accuracy for the suggestion of anterograde compared to retrograde approach was 0.86 (95%CI 0.75, 0.93).Table: Table. Summary of the findings on double-balloon enteroscopy (DBE) with suspected findings on capsule endoscopy (CE)Conclusion: There is good agreement between suggested DBE based on SBTT index of 0.6 and actual DBE results as judged by this study. The accuracy of the SBTT index in choosing the correct route for DBE is 0.86. A SBTT index of 0.6 can reliably be used to predict the best insertion route for DBE.