title: The utility of flexible sigmoidoscopy after a computerized tomographic colonography revealing only rectosigmoid lesions.
abstract: BACKGROUND
  Identifying polyps by computerized tomographic colonography typically prompts colonoscopy, increasing its cost, risk and inconvenience. Many polyps are confined to the rectosigmoid and theoretically amenable to resection via flexible sigmoidoscopy.
  
  
  OBJECTIVE
  To determine the prevalence of advanced proximal colonic neoplasia when computerized tomographic colonography reveals only rectosigmoid polyps, and characterize the yield of polypectomy via flexible sigmoidoscopy in such patients.
  
  
  METHODS
  Subjects underwent computerized tomographic colonography and colonoscopy with segmental unblinding. Patients with only rectosigmoid findings by computerized tomographic colonography were identified retrospectively. Flexible sigmoidoscopy findings were estimated by including lesions distal to the descending/sigmoid colon junction during colonoscopy. Proximal lesions were also reviewed. Advanced lesions were defined as: adenocarcinoma, tubular adenoma >1 cm, > or =3 tubular adenomas, tubulovillous histology or high-grade dysplasia.
  
  
  RESULTS
  By computerized tomographic colonography, 15% (203 of 1372) had only rectosigmoid polyps. Concomitant lesions in the proximal colon were seen in 32% (64 of 203) during colonoscopy. Advanced proximal neoplasia occurred in 2% (three of 203) with only rectosigmoid polyps on computerized tomographic colonography.
  
  
  CONCLUSIONS
  Using flexible sigmoidoscopy to follow-up computerized tomographic colonography demonstrating only rectosigmoid polyps would eliminate 15% of subsequent colonoscopies. This strategy carries a small risk of missed proximal advanced neoplasia. This miss rate appears comparable to that of colonoscopy alone. Further study on the cost-effectiveness of this approach is warranted.
authors.affiliation: Division of Gastroenterology, National Naval Medical Center, Uniformed Services University of Health Sciences, Bethesda, MD, USA. peyoungmd@hotmail.com
authors.forename: P E
authors.initials: PE
authors.lastname: Young
authors.forename: A B
authors.initials: AB
authors.lastname: Gentry
authors.forename: B D
authors.initials: BD
authors.lastname: Cash
mesh_terms: D000368:Aged; D003111:Colonic Polyps / Q000175:diagnosis*; D023881:Colonography, Computed Tomographic / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012004:Rectal Neoplasms / Q000175:diagnosis*; D012811:Sigmoid Neoplasms / Q000175:diagnosis*; D012812:Sigmoidoscopy / Q000379:methods*