A prospective trial of variable stiffness pediatric vs. standard instrument colonoscopy

The pediatric variable stiffness colonoscope is believed to have theoretical advantages over the standard colonoscope, however a systematic evaluation of this instrument in routine clinical practice involving adult patients is lacking.

Consecutive patients (blinded) undergoing colonoscopy in an outpatient endoscopy center by one of 4 experienced colonoscopists had the procedure performed with a standard colonoscope (n=384) or pediatric variable stiffness colonoscope (n=413). Failure to negotiate the sigmoid colon within 10 minutes was regarded as a failure and, if suitable, the patient was crossed over to colonoscopy with the alternative instrument.

Median (95% CI) time to the cecum was significantly faster in the pediatric variable stiffness colonoscope group (odds ratio 5.0: 95% CI[4.7,5.3] minutes) compared with the standard colonoscope group (odds ratio 5.5: 95% CI[5.2,5.8] minutes, p=0.01). There were 22 failures overall (2.8%), 14 in the standard colonoscope group (3.6%) and 8 in the pediatric variable stiffness colonoscope group (1.9%; p=0.1). With regard to the 14 failures in the standard colonoscope group, colonoscopy was attempted with the pediatric variable stiffness colonoscope in 13 and completed successfully in 12 (92%). The pediatric variable stiffness colonoscope was superior in cases of severe stenosing diverticular disease; two of 27 examinations with the pediatric variable stiffness colonoscope were rated as failed vs. 12 of 18 with the standard colonoscope (p<0.001).

Intubation time was faster with the pediatric variable stiffness colonoscope, but use of this instrument was not associated with a superior cecal intubation rate compared with the standard colonoscope. However, in patients with severe stenosing diverticular disease, the intubation rate with the pediatric variable stiffness colonoscope was superior.