What is the optimal way to use variable stiffness colonoscopes in difficult colonoscopies? Have you had any adverse events?
Variable stiffness is a wonderful addition to colonoscopes, especially pediatric colonoscopes, which I use for most colonoscopies in the hospital where I have these scopes. At my other hospital we have a different scope brand (Fujifilm), which are also wonderful scopes. Variable stiffness is especially useful in floppy colons, elongated sigmoid colon and long colons that make turns in the pelvis. I advise to use variable stiffness mode in a “dynamic” fashion, meaning that once you feel there is some “floppyness” or you are about to enter the transverse coming from the descending colon, you apply more stiffness. Once you have mastered the area, it’s advisable to remove the stiffness and allow the colon to move into your scope (to “accordion”) into the scope. Do not apply variable stiffness while the scope is torqued or in alpha or reverse alpha loop, as this may increase the chances of laceration, but mainly may impede you advancing as you “lock” your scope in a twisted position. Also, do not start insertion in the rectum with a stiffened scope. The scope should be floppy when it is pushed from rectum to recto-sigmoid and sigmoid colon. I also like to use variable stiffness when located at the hepatic flexure. That “final” stiffening of the scope “straightens” the transverse and splenic flexure, adding the last needed push for the scope tip to conquer the hepatic flexure and reach the cecum. Once in the cecum I take the stiffness off and continue travel to the ileum.