Standard or ultrathin device for colonoscopy?

We read with great interest the article by Töx et al. [1]. The authors compared the use of an ultrathin colonoscope (UTC) and a standard colonoscope with regard to demand for propofol during colonoscopy. They found that use of a new type of UTC was associated with less propofol consumption, lower patient sedation levels, and less pain compared with the standard colonoscope. But the time to intubation of the ileum was longer. These findings have relevance for the clinical practice of colonoscopy but are limited in some respects.

First, we agree with the standpoint that using a UTC can reduce the propofol demand, but also decrease patient pain. Garborg et al. [2], and Luo et al. [3] have reported randomized studies whose conclusions support this proposition. Based on our clinical practice, colonoscopy requires stability and variable stiffness of the colonoscope. Therefore the standard colonoscope, with a 13.2 mm diameter and variable stiffness has distinct advantages in colonoscopy and in endoscopic therapy such as polypectomy. The UTC whose diameter is only 9.5 mm is quite light weight for handling; nevertheless this may lead to difficulty in insertion into the cecum because the colonoscope is too pliable. This may be associated with loop formation, which could extend the time to insertion into the terminal ileum or even the time to cecal intubation, while the loop forms an acute angle that will elevate the risk of perforation. Indeed Töx et al. mention that the time to intubation of the terminal ileum was prolonged.

Secondly, their investigation enrolled only 201 patients, still only a small sample, and so the finding may deviate from the actual situation. A more valuable result, which could guide clinical practice, will entail a much larger sample for completion of a prospective randomized blinded controlled study.

• References

• 1 Töx U et al. Effect of ultrathin colonoscope on propofol use during colonoscopy. Endoscopy 2013; 45: 439-444
• 2 Garborg KK, Løberg M, Matre J et al. Reduced pain during screening colonoscopy with an ultrathin colonoscope: a randomized controlled trial. Endoscopy 2012; 44: 740-746
• 3 Luo DJ, Hui AJ, Yan KK et al. A randomized comparison of ultrathin and standard colonoscope in cecal intubation rate and patient tolerance. Gastrointest Endosc 2012; 75: 484-490