Open Access Highly Accessed Study protocol

The Anal Fistula Plug versus the mucosal advancement flap for the treatment of Anorectal Fistula (PLUG trial)

Paul J van Koperen1, Willem A Bemelman1, Patrick MM Bossuyt2, Michael F Gerhards3, Quirijn AJ Eijsbouts4, Willem F van Tets5, Lucas WM Janssen6, F Robert Dijkstra6, Annette D van Dalsen7 and J Frederik M Slors1*

Author affiliations

1 Department of Surgery, Academic Medical Centre, Amsterdam, The Netherlands

2 Department of Clinical Epidemiology and Bio-statistics, Academic Medical Centre, Amsterdam, The Netherlands

3 Department of Surgery, Onze Lieve Vrouwe Gasthuis, Amsterdam, The Netherlands

4 Department of Surgery, Spaarne Hospital, Heemstede, The Netherlands

5 Department of Surgery, Sint Lucas Andreas Hospital Amsterdam, The Netherlands

6 Department of Surgery, Zuwe Hofpoort Hospital, Woerden, The Netherlands

7 Department of Surgery, Isala Clinics, Zwolle, The Netherlands

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Citation and License

BMC Surgery 2008, 8:11  doi:10.1186/1471-2482-8-11

Published: 23 June 2008



Low transsphincteric fistulas less than 1/3 of the sphincter complex are easy to treat by fistulotomy with a high success rate. High transsphincteric fistulas remain a surgical challenge. Various surgical procedures are available, but recurrence rates of these techniques are disappointingly high. The mucosal flap advancement is considered the gold standard for the treatment of high perianal fistula of cryptoglandular origin by most colorectal surgeons. In the literature a recurrence rate between 0 and 63% is reported for the mucosal flap advancement. Recently Armstrong and colleagues reported on a new biologic anal fistula plug, a bioabsorbable xenograft made of lyophilized porcine intestinal submucosa. Their prospective series of 15 patients with high perianal fistula treated with the anal fistula plug showed promising results.

The anal fistula plug trial is designed to compare the anal fistula plug with the mucosal flap advancement in the treatment of high perianal fistula in terms of success rate, continence, postoperative pain, and quality of life.


The PLUG trial is a randomized controlled multicenter trial. Sixty patients with high perianal fistulas of cryptoglandular origin will be randomized to either the fistula plug or the mucosal advancement flap. Study parameters will be anorectal fistula closure-rate, continence, post-operative pain, and quality of life. Patients will be followed-up at two weeks, four weeks, and 16 weeks. At the final follow-up closure rate is determined by clinical examination by a surgeon blinded for the intervention.


Before broadly implementing the anal fistula plug results of randomized trials using the plug should be awaited. This randomized controlled trial comparing the anal fistula plug and the mucosal advancement flap should provide evidence regarding the effectiveness of the anal fistula plug in the treatment of high perianal fistulas.

Trial registration

ISRCTN: 97376902