| [ Summary ] |
Soft-shaft colonoscopy has been used to prevent perforation of the colon during the colonoscopic examination. In order to cover the shortcomings of the soft-shaft colonoscope, that it is too flexible, variable stiffness colonoscopes have been developed. There are two methods for using variable stiffness colonoscopes. The first method is that where, the operator passes through sigmoid colon with the scope in its most flexible condition, then straightens the scope while the tip is at the splenic flexure, and increase the stiffness to prevent loop formation and inserts it further. The second is that where, the scope is inserted with the scope in its least flexible condition. The stiffness of the scope is decreased only when a painful loop is formed. Theoretically the perforation of the colon while converting the flexibility of the scope from its least flexible condition to its most, inside the colon, will not occur, because the force for conversion of flexibility is less than the force necessary to cause perforations. |