title: Safety, reliability and limitations of the given patency capsule in patients at risk of capsule retention: a 3-year technical review.
abstract: BACKGROUND
  The patency capsule may prevent capsule retention in high-risk patients. However data on its use in routine clinical practice is limited.
  
  
  METHODS
  Patients referred to our institution between Feb-04 and Jan-07 were reviewed. The following data was collected: presenting symptoms; medical/surgical history; medication; radiology; patency/video capsule result; subsequent investigations; clinical outcomes.
  
  
  RESULTS
  373 patients were referred. In 315 (84%) 'low-risk' patients (no patency capsule): delayed transit occurred in three, with no cases of capsule retention. In 58 (16%) 'high risk' patients (patency capsule): asymptomatic retention occurred in eight, all with pathology despite normal prior barium studies in six; in four cases patency location was incorrectly assessed radiologically, leading to video capsule retention and surgery in one.
  
  
  CONCLUSIONS
  Most patients can safely undergo capsule endoscopy without a patency capsule. The patency capsule appears safe and is indicative of pathology when retained. Assessment of patency capsule location post ingestion can be difficult, and if barium radiology is equivocal a limited abdominal computed tomography (CT) scan is suggested.
authors.affiliation: Wolfson Unit for Endoscopy, St Mark's Hospital, Watford Road, London, HA1 3UJ, UK. apostgate@yahoo.com
authors.forename: Aymer Jonathan
authors.initials: AJ
authors.lastname: Postgate
authors.forename: David
authors.initials: D
authors.lastname: Burling
authors.forename: Arun
authors.initials: A
authors.lastname: Gupta
authors.forename: Aine
authors.initials: A
authors.lastname: Fitzpatrick
authors.forename: Chris
authors.initials: C
authors.lastname: Fraser
mesh_terms: D000368:Aged; D001464:Barium; D053705:Capsule Endoscopes / Q000009:adverse effects* / Q000706:statistics & numerical data*; D053704:Capsule Endoscopy / Q000379:methods*; D004869:Equipment Safety; D005260:Female; D005772:Gastrointestinal Transit / Q000502:physiology; D006801:Humans; D007415:Intestinal Obstruction / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed
chemical_list: D001464:Barium