P0408 Classification of non-fistulising perianal Crohn’s disease: A systematic review
Authors: Pelly T , Anand E , Geldof J , Joshi S , Eathar S , Hanna L , Tozer P , Hart A 
Published: January 2025

Abstract

Background
Perianal Crohn’s disease includes fistulae, abscesses, anorectal structures, ulcers and skin tags, amongst other pathologies (1). Although fistulae are the most common manifestation, non-fistulising manifestations of perianal Crohn’s disease (pCD) can be responsible for significant morbidity and mortality, and severe forms can require major interventions such as defunctioning stoma formation and proctectomy (2). There is a paucity of evidence to guide clinicians in the management of patients with non-fistulising pCD (3). There is a need to categorise and assess available classification methods for non-fistulising pCD for both clinical use and to improve involvement of this cohort in studies.

Methods
The aim of this systematic review was to appraise the literature for existing classification systems for non-fistulising pCD. The systematic review was performed in accordance with PRISMA reporting guidelines. The review was registered prospectively on PROSPERO (533597). Inclusion criteria were all articles with a formal or informal classification relating to pCD, defined as fissures and ulcers, abscesses, skin tags, anorectal strictures, haemorrhoids, and cutaneous or metastatic Crohn’s disease affecting the perianal region. Exclusion criteria were non-english language publications, classification systems for solely fistulising disease, complications relating to pouch surgery, and anal or rectal cancer classifications. Medline, EMBASE and CENTRAL databases were searched on 19/4/2024. A minimum of two reviewers voted on abstracts, full texts, and extracted data using a standardised data extraction tool. Included articles were assessed for bias and validation of their classification systems.

Results
4244 titles and abstracts were screened. 169 full text articles were assessed for eligibility and of these, a total of 22 classification systems were included (Image 1). 18/22 of these classification systems categorised predominantly on an anatomical, morphological or pathological basis. There was no clear consensus regarding which disease features constitute non-fistulising perianal Crohn’s disease. The majority of classification systems were based on non-systematic reviews or limited case series.

Conclusion
The majority of existing classification systems categorise non-fistulising pCD based on anatomical, morphological or pathological factors. There is a need to define which features should be included in classification systems for non-fistulising perianal Crohn’s disease. There is a need for a novel classification system for clinical use and to optimise involvement of this cohort in clinical trials.

References
1.Singh B, McC Mortensen NJ, Jewell DP, George B. Perianal Crohn’s disease. Journal of British Surgery. 2004 Jul;91(7):801-14.
2.Brochard C, Siproudhis L, Wallenhorst T, Cuen D, d’Halluin PN, Garros A, Bretagne JF, Bouguen G. Anorectal stricture in 102 patients with Crohn’s disease: natural history in the era of biologics. Alimentary pharmacology & therapeutics. 2014 Oct;40(7):796-803.
3.Lightner AL, Click B, Yamamoto T, Spinelli A, Kotze P. Management of isolated anal strictures in Crohn’s disease. Diseases of the Colon & Rectum. 2020 Dec 1;63(12):1639-47.