OP19 Classifying perianal fistulising Crohn’s Disease: An expert-consensus to guide decision-making in daily practice and clinical trials

Abstract

Background Perianal fistulising Crohn’s disease (CD) is an aggressive disease phenotype that can have a significant impact on patients’ quality of life. Current biological understanding of perianal fistulising CD remains inadequate and previous classification systems have not provided clear guidance on therapy in clinical practice nor on defining patient cohorts within clinical trials. To counter this unmet need, we propose a new classification system for perianal fistulising CD. Methods The proposed classification system was developed through a modified nominal group technique expert consensus process involving open discussion and formal voting on previously defined statements. Consensus agreement was defined a priori as 80% voting “strongly agree” or “agree with minor reservation”. Participants included gastroenterologists, radiologists, surgeons active in a tertiary IBD centre and a patient representative. Results The classification identifies four groups of patients with perianal fistulising CD. Key elements include stratification according to disease severity as well as disease outcome; synchronisation of patient and clinician goals in decision making, with a proactive, combined medical and surgical approach, on a ‘treat to patient goal’ basis; and identification of indications for curative fistula treatment, diverting ostomy and proctectomy. The new classification retains an element of flexibility, in which patients can cycle through different classes over time. Furthermore, with each specific class comes a paired treatment strategy suggestion and description of clinical trial suitability. Conclusion The proposed classification system is the first of its kind and is an important step towards tailored standardisation of clinical practice and research in patients with perianal fistulising CD.

Development of a core descriptor set for Crohn's anal fistula

“…Use of this in conjunction with an appropriate COS [12] might provide a strong foundation for studies. Future work might include the use of this CDS in CAF registries and adequately powered cohort studies, to evaluate current classification strategies [29] and to identify a range of key phenotypes, allowing more precise treatment strategies and predictors of success and failure of potential treatments [30].…”