Gut doi:10.1136/gutjnl-2011-300187
  • Colon
  • Original article

Higher adenoma detection rates with cap-assisted colonoscopy: a randomised controlled trial

  1. Prateek Sharma1,2
  1. 1Gastroenterology and Hepatology, Veterans Affairs Medical Center, Kansas City, Missouri, USA
  2. 2Gastroenterology and Hepatology, University of Kansas School of Medicine, Kansas City, Kansas, USA
  1. Correspondence to Dr Amit Rastogi, University of Kansas School of Medicine, Kansas City Veterans Affairs Medical Center, 4801 East Linwood Boulevard, Kansas City, MO 64128-2295, USA; amitr68{at}
  1. Contributors Amit Rastogi, Ajay Bansal, Sharma Prateek and Sachin B Wani conceptualized and designed the study; Amit Rastogi, Ajay Bansal, Sharma Prateek, Neil Gupta, Deepthi Rao, Tracy Shipe, Srinivas Gaddam and Vikas Singh contributed to the acquisition of data; Amit Rastogi and Neil Gupta analysed and interpreted the data; Amit Rastogi drafted the manuscript and obtained funding; Ajay Bansal, Prateek Sharma, Sachin B Wani and Neil Gupta handled the critical revision of the manuscript for important intellectual content; Amit Rastogi and Neil Gupta performed statistical analysis; and Deepthi Rao, Tracy Shipe, Srinivas Gaddam and Vikas Singh performed administrative and technical tasks and provided technical support.

  • Revised 28 June 2011
  • Accepted 29 June 2011
  • Published Online First 13 October 2011


Objective Cap-assisted colonoscopy (CAC) uses a small plastic transparent cap attached to the tip of the colonoscope that can depress and flatten colonic folds and thus improve visualisation of their proximal aspects. The aim of this study was to compare CAC with standard colonoscopy (SC; high-definition white light) for adenoma detection rates.

Design This is a prospective randomised controlled trial.

Setting The study was performed in a tertiary-care Veterans Affairs Medical Center in the USA.

Patients Subjects undergoing screening or surveillance colonoscopy were enrolled.

Interventions Subjects were randomised to undergo either CAC or SC.

Main outcome measures The outcome measures were the proportion of subjects with at least one adenoma, the number of adenomas detected per subject, insertion time, caecal intubation rates and complications.

Results 420 subjects were enrolled and included in the study (210 in each group). The proportion of subjects with at least one adenoma was higher with CAC compared to SC (69% vs 56%, p=0.009). CAC also detected a higher number of adenomas per subject (2.3 vs 1.4, p<0.001). The caecal intubation time was shorter with CAC (3.29 min vs 3.98 min, p<0.001). The caecal intubation rates were similar in the two groups (99% vs 98%, p=0.37). There were no complications associated with CAC or SC.

Conclusions CAC detected a 13% higher number of subjects with at least one adenoma and 59% higher adenomas per subject. CAC is a safe, effective and practical means to improve adenoma detection rates.

Clinical Trial Registration NCT 01211132.


  • The corresponding author had full access to all of the data and takes full responsibility for the veracity of the data and statistical analysis.

  • Funding AR was supported by the Endoscopic Research Career Development Award from the American Society for Gastrointestinal Endoscopy.

  • Competing interests None.

  • Ethics approval Ethics approval was provided by the institutional review board.

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

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