title: Anatomic classification of the endoscopic appearance of the normal appendiceal orifice: a novel tool for recognition and documentation of cecal intubation.
abstract: Complete colonoscopy for cancer screening requires cecal intubation. Failure to reach and examine the cecum may result in missed right colon pathology. We developed and validated a novel classification scheme for the endoscopic appearance of the normal appendiceal orifice (AO). We analyzed 1,456 AO images and grouped them into four categories based on distinguishing features: "diverticuloid," "umbilicoid," "crescent," and "linear." An expert panel classified the images and modified these categories, combining crescent and linear categories into "curvilinear." A 100-image subset was classified twice by a validation cohort consisting of gastroenterology faculty and fellows. Inter-observer agreement among the expert panel, and intra- and inter-observer agreement among the validation cohort were analyzed using Fleiss' kappa statistic. The distribution of AO images was 67% curvilinear, 19% umbilicoid, and 10% diverticuloid; 85 images (4%) were not classifiable. There was substantial inter-observer agreement among the expert panel (κ, 0.72). Inter-observer agreement among the validation cohort was moderate (κ, 0.53 and 0.55 for the first and second viewing, respectively). Intra-observer κ values among the validation cohort were 0.69 for the overall classification, 0.65 for diverticuloid, 0.70 for umbilicoid, and 0.70 for curvilinear, indicating substantial agreement. This simple, validated classification scheme for the endoscopic appearance of the normal AO can be used both as a research and clinical tool to measure endoscopic quality, improve cecal examination, and document successful cecal intubation.
authors.affiliation: Division of Gastroenterology and Hepatology, Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
authors.forename: Florence M
authors.initials: FM
authors.lastname: Aslinia
authors.forename: Preet
authors.initials: P
authors.lastname: Bagi
authors.forename: John D
authors.initials: JD
authors.lastname: Sorkin
authors.forename: Richard B
authors.initials: RB
authors.lastname: Williams
authors.forename: Robert G
authors.initials: RG
authors.lastname: Knodell
authors.forename: Lawrence F
authors.initials: LF
authors.lastname: Sorkin
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Greenwald
authors.forename: Allison
authors.initials: A
authors.lastname: Steele
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Raufman
mesh_terms: D001065:Appendix; D003113:Colonoscopy / Q000592:standards*; D006801:Humans; D007441:Intubation, Gastrointestinal / Q000592:standards*