Clip placement to prevent delayed bleeding after colonic endoscopic mucosal resection (CLIPPER): study protocol for a randomized controlled trial

A.S. Turan*, L.M.G. Moons, R.M. Schreuder, E.J. Schoon, J.S.T.S. Droste, R.W.M. Schrauwen, J.W. Straathof, B.A.J. Bastiaansen, M.P. Schwartz, W.L. Hazen, A. Alkhalaf, D. Allajar, M. Hadithi, B.W. van der Spek, D.G.D.N. Heine, A.C.I.T.L. Tan, W. de Graaf, J.J. Boonstra, F.J. Voogd, R. RoomerR.J.J. de Ridder, W. Kievit, P.D. Siersema, P. Didden, E.J.M. van Geenen, Dutch EMR Study Group

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


BackgroundEndoscopic mucosal resection (EMR) for large colorectal polyps is in most cases the preferred treatment to prevent progression to colorectal carcinoma. The most common complication after EMR is delayed bleeding, occurring in 7% overall and in approximately 10% of polyps >= 2cm in the proximal colon. Previous research has suggested that prophylactic clipping of the mucosal defect after EMR may reduce the incidence of delayed bleeding in polyps with a high bleeding risk.MethodsThe CLIPPER trial is a multicenter, parallel-group, single blinded, randomized controlled superiority study. A total of 356 patients undergoing EMR for large (>= 2cm) non-pedunculated polyps in the proximal colon will be included and randomized to the clip group or the control group. Prophylactic clipping will be performed in the intervention group to close the resection defect after the EMR with a distance of <1cm between the clips. Primary outcome is delayed bleeding within 30days after EMR. Secondary outcomes are recurrent or residual polyps and clip artifacts during surveillance colonoscopy after 6months, as well as cost-effectiveness of prophylactic clipping and severity of delayed bleeding.DiscussionThe CLIPPER trial is a pragmatic study performed in the Netherlands and is powered to determine the real-time efficacy and cost-effectiveness of prophylactic clipping after EMR of proximal colon polyps <greater than or equal to>2cm in the Netherlands. This study will also generate new data on the achievability of complete closure and the effects of clip placement on scar surveillance after EMR, in order to further promote the debate on the role of prophylactic clipping in everyday clinical practice.Trial NCT03309683. Registered on 13 October 2017. Start recruitment: 05 March 2018. Planned completion of recruitment: 31 August 2021.
Original languageEnglish
Article number63
Number of pages9
Issue number1
Publication statusPublished - 18 Jan 2021


  • clip artifact
  • colonic polyp
  • delayed bleeding
  • emr
  • prophylactic clipping
  • Prophylactic clipping
  • Delayed bleeding
  • EMR
  • Colonic polyp
  • Clip artifact

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