Zoe Garoufalia interviews David Zimmerman, colorectal surgeon at Elisabeth-TweeSteden Ziekenhuis, in Tilburg, the Netherlands, and an international expert in anal fistulae treatment. David shared his insights on advancement flap repair with ESCP, debunking common myths about advancement flaps.



As David highlights, advancement flap repair is not an easy operation. Only 15% of surgeons perform more than 10 procedures per year [1]. Dr Zimmerman notes, "It demands preparation, good knowledge of the anatomy and good technical skills". Furthermore, this kind of operation does not always work, since an experienced surgeon should expect 20% failure of the technique with recurrence of fistula. Regarding the poor functional outcomes that are attributed to this technique, Dr Zimmerman underlines the importance of the selected retractor. The lone star retractor seems to offer better functional results with reviews showing continence impairment reaching 10-20%.

The best position for advancement flap repair operation is not always the prone one. "Flap repair can be done in any position you like" as Dr Zimmerman notes. It has been shown that when other techniques are added to the flap repair, results obtained are poorer than 80% healing rate. Finally, seton drainage is not necessary to precede advancement flap repair. Several authors have shown that there is no difference in outcomes between patients who did and those who did not undergo previous seton drainage. These ‘myths’ are the commonest wrong impressions about this demanding technique which certainly needs expertise and experience.

David Zimmerman (@ZimNL) wishes ESCP community a wonderful fistula month.


  1. Ratto C, Grossi U, Litta F, Di Tanna GL, Parello A, De Simone V, Tozer P, DE Zimmerman D, Maeda Y. Contemporary surgical practice in the management of anal fistula: results from an international survey. Tech Coloproctol. 2019 Aug;23(8):729-741. doi: 10.1007/s10151-019-02051-5. Epub 2019 Jul 31. PMID: 31368010; PMCID: PMC6736896.