P561 Risk of stoma formation in patients with Crohn’s perianal fistulas over a two decades period. A cohort study from a tertiary referral center.

Bislenghi, G.(1)*;Baldi, C.(1);Ferrante, M.(2);Sabino, J.(2);Verstockt, B.(2);Wolthuis, A.(1);Vermeire, S.(2);D'Hoore, A.(1);

(1)UZ Leuven, Abdominal Surgery, Leuven, Belgium;(2)UZ Leuven, Gastroenterology and Hepatology, Leuven, Belgium;


Optimal management of perianal Crohn’s disease (pCD) consists of combined medical (preferentially anti-TNF) and surgical treatment.  However, it is still unclear if this has improved outcomes. This study aimed to described outcome and prognosis of pCD patients at a referral center over almost two decades.


All pCD patients referred for active perianal fistulas between 2000-2018 at our center were considered eligible for this retrospective study. Patients were divided into two groups according to the date of pCD diagnosis: period A (2000-2006) and period B (2006-2018). The complement of Kaplan-Meier estimates were used to visualize the time since pCD diagnosis until temporary and definitive fecal diversion. Clinically important outcomes such as need for temporary or permanent fecal diversion, and factors associated to these outcomes were evaluated by Cox regressions models.


A total of 336 patients with active pCD were identified. The mean interval between the diagnosis of CD and the perineal fistulizing disease was 4.9 years (+-7.64). Mean follow up was 10.83 years (SD ± 4.5). The two groups were similar for demographic and clinical characteristics, except for the cumulative exposure to biologicals prior to pCD diagnosis [27.8% vs 46.9% in period A and B, respectively (p<0.001)]. (Table 1) The risk for temporary and definitive fecal diversion was higher for group B, at 5- [temporary stoma: 10.8 CI (6.7%-17.3%) vs 27.3% CI (21.1%-34.9%), p<0.001; definitive stoma: 0.7% CI (0.1%-4.8%) vs 13.1% CI (8.7%-19.5%), p=0.002] and 10-years follow-up [temporary stoma: 23.3% CI (17%-31.5%) vs 39.0% CI (31.1%-48.1%), p<0.001; definitive stoma: 11.7% CI (7.2%-18.7%) vs 19.9% CI (13.9-28.0%), p=0.002], respectively. (Figure 1 and Figure 2). At multivariate analysis, the presence of extraintestinal manifestations [HR 2.55 CI (1.40-4.62)], B2 stricturing disease [HR 4.43 CI (1.46-13.4)],  B3 penetrating disease  [HR 7.10 CI (2.37-21.27)], and diagnosis of pCD diagnosis after 2006 (period B) [HR 2.20 CI (1.16-4.17)], were independent risk factors for need for permanent ileostomy. (Table 2)


This retrospective analysis spanning almost twenty years shows that prognosis of CD patients affected by anal fistulas remains poor and has not much changed over time, despite the introduction of biologicals and new surgical techniques. The observed increase in definitive fecal diversion in more recent years can be partially explained by referral bias and/or a more aggressive clinical management of the most severe cases. Extraintestinal manifestations and synchronous complicated luminal disease increased the risk of definitive stoma in the long-term.