Predictors of depth of maximal insertion at double-balloon enteroscopy

The aim of this study was to determine the factors predictive of the depth of maximal insertion (DMI) at double-balloon enteroscopy (DBE). Eligible patients from the DBE database at our institution were stratified based on their anterograde or retrograde approach. The factors predictive of the DMI were calculated using ANOVA, Spearman, univariate, and multivariate regression analysis. A total of 79 patients had 98 procedures, 67 anterograde and 31 retrograde. Fifty-eight (73%) had previous abdominal surgeries. The average anterograde DMI was 187.5 cm, retrograde 116.5 cm. In univariate regression analysis, a history of abdominal surgery and surgery excluding appendectomy were negative predictors of the DMI for both the anterograde and retrograde approaches (P<0.05). A history of bowel surgery and number of surgeries were negative predictive factors only for the anterograde approach (P<0.005). In multivariate analysis, the number of abdominal surgeries (anterograde) and any abdominal surgery (retrograde) were predictors of the DMI (P = 0.02 and P = 0.003, respectively). Patients with three or more surgeries had a significantly lower DMI than those with ≤1 (137 vs. 214 cm, P<0.001 for anterograde and 114 vs. 148 cm, P<0.001 for retrograde). There was no correlation between the DMI and age, BMI, date of the study, or procedure duration for either approach. Previous abdominal surgeries can significantly impact the DMI at DBE.