Accuracy of polyp localization at colonoscopy

O'Connor, Sam A., Hewett, David G., Watson, Marcus O., Kendall, Bradley J., Hourigan, Luke F. and Holtmann, Gerald (2016) Accuracy of polyp localization at colonoscopy. Endoscopy International Open, 4 6: E642-E646. doi:10.1055/s-0042-105864

Author O'Connor, Sam A.
Hewett, David G.
Watson, Marcus O.
Kendall, Bradley J.
Hourigan, Luke F.
Holtmann, Gerald
Title Accuracy of polyp localization at colonoscopy
Journal name Endoscopy International Open   Check publisher's open access policy
ISSN 2196-9736
Publication date 2016-06
Year available 2016
Sub-type Article (original research)
DOI 10.1055/s-0042-105864
Open Access Status DOI
Volume 4
Issue 6
Start page E642
End page E646
Total pages 5
Place of publication Stuttgart, Germany
Publisher Georg Thieme Verlag
Collection year 2017
Language eng
Formatted abstract
Background and study aims: Accurate documentation of lesion localization at the time of colonoscopic polypectomy is important for future surveillance, management of complications such as delayed bleeding, and for guiding surgical resection. We aimed to assess the accuracy of endoscopic localization of polyps during colonoscopy and examine variables that may influence this accuracy.

Patients and methods: We conducted a prospective observational study in consecutive patients presenting for elective, outpatient colonoscopy. All procedures were performed by Australian certified colonoscopists. The endoscopic location of each polyp was reported by the colonoscopist at the time of resection and prospectively recorded. Magnetic endoscope imaging was used to determine polyp location, and colonoscopists were blinded to this image. Three experienced colonoscopists, blinded to the endoscopist’s assessment of polyp location, independently scored the magnetic endoscope images to obtain a reference standard for polyp location (Cronbach alpha 0.98). The accuracy of colonoscopist polyp localization using this reference standard was assessed, and colonoscopist, procedural and patient variables affecting accuracy were evaluated.

Results: A total of 155 patients were enrolled and 282 polyps were resected in 95 patients by 14 colonoscopists. The overall accuracy of polyp localization was 85 % (95 % confidence interval, CI; 60 – 96 %). Accuracy varied significantly (P < 0.001) by colonic segment: caecum 100 %, ascending 77 % (CI;65 – 90), transverse 84 % (CI;75 – 92), descending 56 % (CI;32 – 81), sigmoid 88 % (CI;79 – 97), rectum 96 % (CI;90 – 101). There were significant differences in accuracy between colonoscopists (P < 0.001), and colonoscopist experience was a significant independent predictor of accuracy (OR 3.5, P = 0.028) after adjustment for patient and procedural variables.

Conclusions: Accuracy of localization of polyps is imprecise and affected by position within the colon and colonoscopist, including their level of experience. Magnetic endoscope imaging may improve the localization of lesions during colonoscopy.

Keyword Polyp localization
Colorectal cancer
Magnetic endoscope imaging
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

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Created: Mon, 25 Jul 2016, 19:57:51 EST by Marcus Watson on behalf of School of Psychology