Clinical results and development of variable-stiffness video colonoscopes

Background and Study Aims: This study was designed to assess the usefulness of variable-stiffness video colonoscopes, compared with conventional videoscopes. Patients and Methods: The first prototype XCF-QAY1 and the latter prototype XCF-Q240AI used in this study can be varied to 4 levels of stiffness of tube insertion during examination. In 352 consecutive colonoscopic examinations performed using these and two conventional scopes, the following data were recorded: time for intubation to the cecum, frequency of changes in the patients' posture, frequency of abdominal pressure attempts, and pain score. The degree of stiffness of the insertion tube and the examiners' impressions score were recorded only in procedures where the variable-stiffness scopes were used. Results: There was no significant difference between colonoscopes in the pain score. Total colonoscopy rate was 97.4 %. The frequency of usage of the varying stiffness control in the colon according to site was as follows: descending colon, 57.3 %; transverse colon, 32.8 %, sigmoid colon, 7.6 %; and ascending colon, 2.3 %. A significant difference in the mean time for intubation to the cecum between the XCF-Q240AI and conventional scopes was observed. Moreover, there were significant differences in the frequency of abdominal pressure attempts and changes in the patient's posture between conventional scopes and the new scopes. Conclusions: These results suggest that only one scope, the XCF-Q240AI, is needed for any colonic examination by any examiner.