Randomized crossover trial comparing through-the-scope balloon enteroscopy via colonoscope with standard colonoscopy...

Retrograde enteroscopy for evaluation of the small bowel can be performed using through-the-scope balloon-assisted enteroscopy (TTSE). TTSE consists of a balloon catheter designed for anchoring in the small bowel, inserted through the instrument channel of a standard colonoscope. We aimed to assess the ability of TTSE to improve the depth of maximal ileal insertion (DMI) compared with the colonoscope alone (C1).

We performed a prospective, randomized, crossover study to compare the DMI between TTSE and enteroscopy using the adult colonoscope alone. After measuring the DMI by the randomized sequence, the endoscopist switched the technique and measured the DMI again. The primary end point of the study was a comparison of DMI (centimeters) between the colonoscope with TTSE (DMI-N) and the colonoscope alone (DMI-C).

A total of 18 subjects were enrolled, with 9 randomized to colonoscope alone first (C1) followed by TTSE (N2) and 9 to TTSE first (N1) followed by colonoscope alone (C2). The mean (standard deviation) of DMI was DMI-C1: 69.4 (40.3), DMI-N2: 107.2 (62.4), DMI-N1: 92.2 (31.3), and DMI-C2: 102.8 (29.1). Overall, TTSE showed a trend toward an increased DMI compared with the colonoscope alone (difference = 13.61; 95% confidence interval, -3.12 to 30.34; P = .06). In the stratified analyses by the randomization sequence (ie, C1N2), TTSE produced a significant increase in DMI (difference = 37.8; 95% confidence interval, 14.08-61.48; P = .006) compared with the colonoscope alone.

As per design-based analysis, the TTSE technique produced an increased DMI ranging between 13.6 and 37.8 cm more than with the standard colonoscope, which trended toward significance. Retrograde enteroscopy using TTSE may help improve DMI compared with colonoscope alone.