A new understanding of the principles in the management of complex anal fistula

Med Hypotheses. 2019 Nov:132:109329. doi: 10.1016/j.mehy.2019.109329. Epub 2019 Jul 25.


The management of complex anal fistula is confusing and far from satisfactory. Due to this reason, most colorectal surgeons are not comfortable dealing with this disease and tend to avoid it. Despite the innovation of several new procedures in the last few years, the cure rate of complex anal fistula has not improved much. This points out that there is some flaw with our current understanding of the disease pathogenesis as well as its management. All the surgical procedures described to treat anal fistulas in complex anal fistulas were analyzed. The reasons were sought as why most of the procedures don't work well in complex fistulas. Based on that, the pathophysiology of complex anal fistula was understood from a totally new perspective. The new hypothesis has been categorized in three cardinal principles-Intersphincteric tract is like an abscess in a closed space (ISTAC), draining all pus and ensuring continuous drainage (DRAPED) and healing occurs progressively till it is interrupted irreversibly by a collection (HOPTIC). The surgical procedures which take care of all these three principles have a high success rate in complex fistulas. The success rate falls in the procedures which ignore one or more of these principles. These principles are logical and are basics of wound healing process anywhere in the body but were somehow ignored in the management of complex anal fistulas. These principles fill the void in the understanding of complex anal fistula and when integrated in the management, the cure rate improves drastically.

MeSH terms

  • Abscess / pathology
  • Anal Canal / pathology*
  • Humans
  • Rectal Fistula / pathology
  • Rectal Fistula / therapy*
  • Reproducibility of Results
  • Wound Healing*