Evidence outside the box: Minimally invasive treatment for anal fistula

Abstract

Management of the complex anal fistula represents a perennial challenge to surgeons. Conventional approaches often upset the balance between recurrence prevention and continence preservation with their high failure rates and significant associated morbidity. The emergence of minimally invasive treatment in recent years, however, offers a promising paradigm shift. Regenerative solutions like autologous stem cell therapy or fistula plugs with extracellular and synthetic matrices represent new frontiers in anal fistula treatment, harnessing physiological regenerative capacities and avoiding the traditional postoperative burden of open wounds, drains, or setons in situ. Together with novel techniques like fistula laser closure, video-assisted fistula treatment, or over-the-scope clip burgeoning over the last decade, these state-of-the-art approaches have been touted for their total sphincter-sparing nature, preserving functional outcomes and quality of life. Despite gaining much scientific and clinical momentum, do these newer modalities live up to their promise? This review aims to critically appraise the latest evidence surrounding minimally invasive approaches, providing up-to-date insights into the constantly evolving landscape of anal fistula management. Further long-term and comparative studies will nevertheless be needed to supplement the significantly heterogenous, retrospective analyses consolidated.

Keywords: Anal fistula management; Minimally invasive; Regenerative methods; Stem cells; Fistula plug; Matrix; Ligation of intersphincteric fistula tract; Fistula laser closure; Video-assisted anal fistula treatment; Over-the-scope clip

Core Tip: We present a review summarising the most up-to-date insights into minimally invasive treatment for anal fistulae. Representing new frontiers in fistula treatment, these “sphincter-preserving” modalities seek to balance both recurrence prevention and continence preservation. The newest regenerative solutions, including autologous stem cell therapy and fistula plugs derived from extracellular and synthetic matrices, will be covered, as well as pertinent non-regenerative solutions like fistula laser closure, video-assisted anal fistula treatment, and over-the-scope clips. We consolidated and examined pertinent literature while weighing the pros and cons of each procedure.