Effect of variable stiffness colonoscopes on cecal intubation times for routine colonoscopy by an experienced examiner in sedated patients

Background and Study Aims: Variable-stiffness colonoscopes allow passage of the rectosigmoid colon in a flexible mode, followed by stiffening to prevent looping. This feature might allow faster cecal intubation. Patients and Methods Consecutive patients without previous colonic or rectal resection, inflammatory bowel disease, or anticipated need for either a pediatric or standard insertion tube were evaluated. Four Olympus colonoscopes, including a standard "adult" insertion-tube diameter variable-stiffness colonoscope (VSA), a pediatric variable-stiffness colonoscope (VSP), a standard "adult" colonoscope (CP-140) (SA), and a standard "pediatric" colonoscope (PCF-140) (SP)were used in rotation. Results: Among 358 consecutive patients, 99.2 % of exams were complete to the cecum. The stiffening device was activated in 61% and 80 % of the adult and pediatric variable-stiffness examinations, respectively. The examiner judged the device to be very useful, somewhat useful, and of no help in 46 %, 44 %, and 10 % of VSA colonoscope examinations and 55%, 33 %, and 12% of VSP colonoscope examinations. However, the mean cecal insertion time was 4.04 minutes, with no difference between the four colonoscopes (P = 0.98). The percentage of intubations in <2 minutes was 15.4 %, 2-3 minutes 25.9 %, 3-4 minutes 19.1%, 4-5 minutes 16.0 %, and >5 minutes 23.7%, with no significant difference between the colonoscopes. Conclusions: Variable-stiffness colonoscopes were frequently judged useful by an experienced examiner but did not impact cecal intubation times in sedated patients. Additional studies by other experienced and inexperienced examiners, as well as evaluation of additional technical improvements and evaluation in unsedated patients, are needed.