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

Gastrointest Endosc. 2012 Mar;75(3):484-90. doi: 10.1016/j.gie.2011.07.032. Epub 2011 Oct 1.


Background: 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).

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

Design: Prospective, randomized, controlled trial.

Setting: Academic endoscopic unit.

Patients: Subjects 18 years and older undergoing their first colonoscopy.

Intervention: Subjects were randomized to either the UTC or SC group.

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

Results: 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.

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

Conclusions: 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. (

Clinical trial registration number: NCT01142167.).

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cecum*
  • Colonoscopes*
  • Equipment Design
  • Female
  • Humans
  • Intubation / statistics & numerical data*
  • Male
  • Middle Aged
  • Patient Satisfaction*
  • Prospective Studies

Associated data

  • ClinicalTrials.gov/NCT01142167