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 preve nt looping. This feature might allow faster cecal intubation. Patients and Methods Consecutive patients without previous colonic or recta l resection, inflammatory bowel disease, or anticipated need for either a p ediatric or standard insertion tube were evaluated. Four Olympus colonoscop es, including a standard "adult" insertion-tube diameter variable-stiffness colonoscope (VSA), a pediatric variable-stiffness colonoscope (VSP), a sta ndard "adult" colonoscope (CP-140) (SA), and a standard "pediatric" colonos cope (PCF-140) (SP)were used in rotation. Results: Among 358 consecutive patients, 99.2 % of exams were complete to t he cecum. The stiffening device was activated in 61% and 80 % of the adult and pediatric variable-stiffness examinations, respectively. The examiner j udged 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). Th e 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 signifi cant difference between the colonoscopes. Conclusions: Variable-stiffness colonoscopes were frequently judged useful by an experienced examiner but did not impact cecal intubation times in sed ated patients. Additional studies by other experienced and inexperienced ex aminers, as well as evaluation of additional technical improvements and eva luation in unsedated patients, are needed.