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Adenoma detection with cap-assisted colonoscopy versus regular colonoscopy: a randomised controlled trial
  1. Thomas R de Wijkerslooth1,
  2. Esther M Stoop2,
  3. Patrick M Bossuyt3,
  4. Elisabeth M H Mathus-Vliegen1,
  5. Jan Dees2,
  6. Kristien M A J Tytgat1,
  7. Monique E van Leerdam2,
  8. Paul Fockens1,
  9. Ernst J Kuipers2,
  10. Evelien Dekker1
  1. 1Department of Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, The Netherlands
  2. 2Department of Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, The Netherlands
  3. 3Department of Clinical Epidemiology and Biostatistics, Academic Medical Center, Amsterdam, The Netherlands
  1. Correspondence to Dr Evelien Dekker, Gastroenterologist, Department of Gastroenterology & Hepatology C2-115, Academic Medical Center, PO Box 22700, 1100 DE Amsterdam, The Netherlands; e.dekker{at}


Objective Conventional colonoscopy (CC) is considered the reference standard for detection of colorectal neoplasia, but it can still miss a substantial number of adenomas. The use of a transparent plastic cap may improve colonic visualisation. Cap-assisted colonoscopy (CAC) was compared with CC for adenoma detection. Secondary outcomes were caecal intubation time, caecal intubation rate and the degree of discomfort of colonoscopy.

Design This is a parallel, randomised, controlled trial at two centres. Asymptomatic participants (aged 50–75 years) in a primary colonoscopy screening programme were consecutively invited. Consenting subjects were 1:1 randomised to either CAC or CC. All colonoscopies were performed by experienced endoscopists (≥1000 colonoscopies) who were trained in CAC. Colonoscopy quality indicators were prospectively recorded.

Results A total of 1380 participants were randomly allocated to CC (N=694) or CAC (N=686). Caecal intubation rate was comparable in the two groups (98% vs 99%; p=0.29). Caecal intubation time was significantly lower in the CAC group: 7.7±5.0 min with CAC vs 8.9±6.2 min with CC (p<0.001) (values mean±SD). Adenoma detection rates of all endoscopists were ≥20%. The proportion of subjects with at least one adenoma was similar in the two groups (28% vs 28%; RR 0.98; 95% CI 0.82 to 1.16), as well as the mean number of adenomas per subject (0.49±1.05 vs 0.50±1.03; p=0.91). Detection of small size, flat and proximally located adenomas was comparable. CAC participants had lower Gloucester Comfort Scores during colonoscopy (2.2±1.0 vs 2.0±1.0; p=0.03).

Conclusion CAC does not improve adenoma detection, but does reduce caecal intubation time by more than 1 min and does lessen the degree of discomfort during colonoscopy.

  • Adenoma
  • cap
  • hood
  • randomised trial
  • screening
  • colonoscopy
  • endoscopy
  • barretts carcinoma
  • barretts oesophagus
  • laser
  • IBD
  • endoscopic sphincterotomy
  • familial adenomatous polyposis
  • pancreato-biliary disorders
  • colorectal carcinoma
  • family cancer
  • gastrointestinal bleeding
  • gastro-oesophageal reflux disease
  • gastrointesinal endoscopy
  • endoscopic ultrasonography
  • endoscopic procedures
  • Helicobacter pylori
  • gastric cancer
  • gastritis
  • endoscopic polypectomy
  • CRC surveillance
  • advanced endoscopic imaging
  • narrow band imaging
  • colorectal cancer

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  • Funding The study was funded by The Netherlands Organisation for Health Research and Development (ZonMW 120720012) and by the Center for Translational Molecular Medicine (CTMM DeCoDe-project).

  • Competing interests None.

  • Ethics approval Dutch Health Council (2009/03WBO, The Hague, The Netherlands).

  • Provenance and peer review Not commissioned; externally peer reviewed.

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