title: Mechanisms of hyoscine butylbromide to improve adenoma detection: A case-control study of surface visualization at simulated colonoscope withdrawal.
abstract: OBJECTIVE
  Antispasmodics may improve mucosal visualization during colonoscope withdrawal, potentially improving polyp and adenoma detection. Meta-analysis and case-control studies suggest a 9 % to 13 % relative increase in adenoma and polyp detection. We aimed to assess the impact of hyoscine butylbromide on the expected visualization during colonoscope withdrawal using a CT colonography (CTC) simulation.
  
  
  METHODS
  Datasets from a previous CTC study examining the effect of antispasmodic were re-analyzed with customised CTC software, adjusted to simulate a standard colonoscopic view. Eighty-six patients received intravenous (IV) hyoscine butylbromide 20 mg, 40 mg or no antispasmodic. Main outcome measurements at unidirectional flythrough, simulating colonoscope withdrawal, were percentage colonic surface visualization, numbers and sizes of unseen areas, and colonic length.
  
  
  RESULTS
  Use of antispasmodic was associated with a significant relative increase in percentage surface visualization of 2.6 % to 3.9 %, compared with no antispasmodic, P < 0.006. Total numbers of missed areas and intermediate sized (300 - 1000 mm(2)) missed areas were significantly decreased, by approximately 20 %. There were no differences between the 20-mg and 40-mg doses. Mean colonic length (161 - 169 cm) was unchanged by antispasmodic.
  
  
  CONCLUSIONS
  IV hyoscine butylbromide at simulated colonoscope withdrawal was associated with significant increases in surface visualization, which might explain up to half the improvement in adenoma detection seen in clinical studies.
authors.affiliation: Translational Gastroenterology Unit, University of Oxford, John Radcliffe Hospital, Oxford, United Kingdom ; Wolfson Unit for Endoscopy, St. Mark's Hospital, Watford Road, Harrow, Middlesex, HA1 3UJ, United Kingdom.
authors.forename: James E
authors.initials: JE
authors.lastname: East
authors.affiliation: Wolfson Unit for Endoscopy, St. Mark's Hospital, Watford Road, Harrow, Middlesex, HA1 3UJ, United Kingdom.
authors.forename: Brian P
authors.initials: BP
authors.lastname: Saunders
authors.affiliation: Intestinal Imaging Centre, St. Mark's Hospital, Watford Road, Harrow, Middlesex, HA1 3UJ, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Burling
authors.affiliation: Department of Specialist Radiology, University College Hospital, 235 Euston Road, London, NW1 2BU, United Kingdom ; Department of Radiology, Frimley Health NHS Foundation Trust, Wexham Park Hospital, Wexham Street, Slough, Berkshire, SL2 4HL.
authors.forename: Emily
authors.initials: E
authors.lastname: Tam
authors.affiliation: Department of Specialist Radiology, University College Hospital, 235 Euston Road, London, NW1 2BU, United Kingdom.
authors.forename: Darren
authors.initials: D
authors.lastname: Boone
authors.affiliation: Department of Specialist Radiology, University College Hospital, 235 Euston Road, London, NW1 2BU, United Kingdom.
authors.forename: Steve
authors.initials: S
authors.lastname: Halligan
authors.affiliation: Department of Specialist Radiology, University College Hospital, 235 Euston Road, London, NW1 2BU, United Kingdom.
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Taylor