Colonoscope Withdrawal Times and the Presence or Abscence of Colonic Adenomas at Screening Colonoscopy

Abstract

Purpose: To determine the relationship between colonoscope withdrawal time, adenoma detection, and adenoma size during screening colonoscopy in an ambulatory private practice setting. Methods: 97 consecutive patients undergoing screening colonoscopy included 46 males (47%) and 51 females (53%). No patient had undergone previous colonoscopy or colon resection surgery. Patients with first degree family members suffering from colon cancer were excluded from the study. The examination was performed with Olympus colonoscopes after either phosphosoda or PEG lavage purge. Diprovan was used for sedation and all exams were performed by one endoscopist (apk). Upon entering the cecum and identifying the ileocecal valve withdrawal timing was initiated with a stop watch. Results: The mean age of the study patients was 60.7 years. All exams were successful to the cecum. The average age of patients with no adenomas was 59.1 yrs, with adenomas 64.3 years. Adenoma Incidence: Patients with adenomas: 26 (27%) Patients with adenomas >1 cm: 13 (13%) Patients with adenomas >2 cm: 3 (3%) Colonoscope Withdrawal Times: Mean withdrawal time all patients: 12 min 37 sec Mean withdrawal time in patients with no adenomas: 10 min 59 sec Mean withdrawal time in patients with adenomas: 14 min 9 sec Mean withdrawal time in patients with adenomas >1 cm: 21 min 37sec Mean withdrawal time in patients with adenomas >2 cm: 30 min 50 sec Conclusions: The adenoma incidence rate at screening colonoscopy in this study was 27%. Withdrawal time for patients with no adenomas detected (10:59) was longer than the recently recommended 6 minute minimum time for withdrawal in negative exams. Withdrawal times for more complex adenomas (>1 cm) were substantially longer than withdrawal times for the total adenoma subset. (p < .01) 3% of patients harbored adenomas >2 cm in diameter. Screening colonoscopy in private practice should be successful to the cecum in a very high percentage of patients.