Terminal ileal photography or biopsy to verify total colonoscopy: does the endoscope agree with the microscope?

Background: Various modalities exist to document the extent of colonoscopy, including a terminal ileum (TI) biopsy, which is considered the criterion standard by some authorities. A TI biopsy adds to procedure costs, is potentially hazardous, and the detection of pathology in routinely acquired biopsy specimens of a macroscopically normal TI is limited. A safer, less costly alternative for documenting total colonoscopy is desirable.

Objective: To evaluate the effectiveness of TI photography as a means of documenting total colonoscopy. We also assessed the diagnostic yield of TI biopsies in patients with a macroscopically normal TI.

Design: Prospective, observational study.

Setting: District general hospital in the United Kingdom.

Patients: A total of 232 unselected patients undergoing colonoscopy, TI intubation, photography, and biopsy.

Main Outcome Measurements: Independent, experienced endoscopists were asked to state whether villi (and, therefore, TI entry) were "definitely," "probably," or "definitely not" depicted in TI photographs. This was compared with TI histology as a means of verifying total colonoscopy. The diagnostic yield of biopsy specimens from a macroscopically normal TI was determined.

Results: Reviewers agreed that villi were "definitely present" in 93.8%, "probably present" in 5.9%, and "definitely not" present in 0.3% of cases, with excellent interobserver agreement (kappa value = 0.778, P < .0001). TI photographs "definitely" depicting villi (93.8%) did not differ significantly from histology confirming TI mucosa (96.1%, P = .285). Microscopic evidence of pathology was only detectable in 2.3% of patients with an endoscopically normal TI.

Conclusions: TI photography is an effective, safe, and cost-effective means of documenting total colonoscopy. Routine biopsy of a "normal" TI has a low diagnostic yield.