A randomized comparison of ultrathin and standard colonoscope in cecal intubation rate and patient tolerance

Complete colonoscopy examination cannot be performed in as many as 10% of cases. The new 9.2-mm ultrathin colonoscope (UTC) with an extra bending section may improve procedure tolerance and allow improvement in colonoscopy completion rate compared with a 12.9-mm standard colonoscope (SC).

To compare the performance of the 9.2-mm UTC with that of the 12.9-mm SC.

Prospective, randomized, controlled trial.

Academic endoscopic unit.

Subjects 18 years and older undergoing their first colonoscopy.

Subjects were randomized to either the UTC or SC group.

First and rescue successful cecal intubation rates, subject satisfaction scores, and sedation requirements were compared.

A total of 1121 patients (56% women, mean age 53.6 years) were randomized to the UTC group (n = 551) or the SC group (n = 570). There was no statistically significant difference in the first successful cecal intubation rate between the UTC and SC groups (98.9% vs 97.4%, P = .057). The mean (standard deviation) dose of midazolam and pethidine used was significantly lower in the UTC group (2.65 [0.65] mg vs 2.82 [0.85] mg, P < .001 and 27.6 [7.4] mg vs 29.7 [9.6] mg, P < .001, respectively). The mean (standard deviation) patient satisfaction score was similar between groups (6.99 [2.89] vs 7.04 [3.06], P = .762). Of the 21 patients (1.9%) with an incomplete initial colonoscopy (6 in the UTC group and 15 in the SC group), all 6 in the UTC group had their procedure completed with an SC. Eleven of 15 patients in the SC group had their procedures completed with a UTC in the same session.

Low failure rate may mask any difference between the 2 colonoscopes as a rescue instrument.

The 9.2-mm UTC has performance characteristics similar to those of an SC in Chinese subjects undergoing their first colonoscopy performed by experienced and trainee endoscopists. (

NCT01142167.).