Understanding New Ideas in Cryptoglandular Fistula-in-Ano

Abstract

Outcomes of surgical treatment for anorectal abscesses and chronic fistulas varies widely, as there is lack of unified classification and systematic surgical approach to address a wide range of disease pattern. Acute anorectal abscess and chronic fistula-in-ano should be considered the same disease at both end of a spectrum. This article describes in detail the pathogenesis and relevant anorectal anatomy to aid understanding of a new concept of classifying anorectal abscess and fistula based on natural patterns. A better understanding of patterns allows more accurate surgical treatment. Recent evidence shows that definitive surgical treatment for anal fistula during acute abscess stage is safe and feasible. An optimum surgical treatment should focus on eradication of intersphincteric infection, removal of secondary branches or abscesses, allow healing by secondary intention and preserve continence as best as possible. Common challenges faced by clinicians include confusion in classification, inaccurate delineation of fistula, challenging acute abscesses, unable to locate internal opening and facing complex features such as high fistula or multiple branches. Suggested solutions are discussed and a structured treatment strategy according to types and patterns is proposed. Surgical treatment should follow the principles above and combination of surgical techniques is beneficial compared to individual modality.