Background: While paediatric and adolescent onset Crohn's disease (CD) is more severe disease with adverse outcomes, there is no comparative data on outcomes in perianal fistulas in paediatric/adolescent versus adult onset CD. Management paradigms in perianal fistulas in Crohn's disease is not fully defined and approaches from paediatric and adult IBD clinicians and surgeons may be different. We aimed to study any differences in diagnostic and treatment approaches in paediatric/adolescent onset CD with perianal fistula (CD-PAF) and adult onset disease and the outcomes of CD-PAF.
Methods: Data was collected on patients included in 2 retrospective multicentre multinational cohorts (11 adult and 7 pediatric centres)of perianal fistula with paediatric/adolescent onset and adult onset CD PAF. We evaluated fistula characteristics, surgical and medical treatments following onset of CD-PAF and fistula healing. We also compared the need for re-intervention defined as the need for re-insertion of seton or abscess drainage or diverting stoma or proctectomy.
Results: 253 adults and 116 paediatric/adolescent patients were included. Complex fistulas were identified in 53% of adult and 67% of paediatric/adolescent group. MRI was done at presentation in 77% and 73% respectively in adult and paediatric/adolescent group. Proctitis was recorded in 43% of adult onset and in 3% of paediatric/adolescent onset CD-PAF. Examination under anaesthesia (EUA) was done in similar proportion of patients (70% and 69%) but significantly higher proportion of adult CD-PAF patients had seton insertion (15% vs 54%, p<0.001). Anti TNF use was more often is paediatric onset CD-PAF (83% vs 68%) when compared to adult onset CD-PAF with majority of patients maintained on combination therapy. Complete clinical fistula healing was more often noted in paediatric/adolescent onset CD-PAF (71% vs 49%, p=0.015). Reintervention rates were higher in adult onset CD (40.3% vs 16.05%, p= <0.001. Radical surgery (diverting stoma or proctectomy) was required in 3 patients (2.58%) with paediatric/adolescent onset and 26 patients (10.28%) with adult onset CD-PAF (p=0.04).
Conclusions: Paediatric/adolescent onset CD-PAF appears to have better outcomes with less radical surgery or re-interventions when compared to adult onset disease despite less frequent use of seton. The impact of more frequent and prolonged therapy in paediatric/Adolescent onset CD-PAF with combined immunomodulation needs further evaluation.