P295 Proctitis during Crohn's disease, would it be a factor in the sustainability of anoperineal fistulas ?

Mtir, M.(1);Hassine, H.(1);Kahlaoui, F.(1);Cherif, D.(1);Tlili, R.(1);Kchir, H.(1);Maamouri, N.(1);

(1)La Rabta hospital, department of gastro-enterology B, tunis, Tunisia;

Background

Rectal involvement during Crohn's disease (CD) was identified as a risk factor associated with poor therapeutic response of anoperineal fistulas (APF).

The aim of our study was to evaluate the impact of rectal mucosal healing on the healing of APF during CD treated with anti-Tumour Necrosis Factor Alpha (anti-TNFα).

Methods

We conducted a monocentric retrospective study, including records of all patients followed for CD with APF treated with anti-TNFα over a 10-year period [2010 - 2020]. We collected clinical, biological, endoscopic and radiological data as well as the evolution of the patients on anti-TNFα. The therapeutic response was assessed clinically and radiologically by perineal MRI. Healing of the rectal mucosa was investigated by endoscopy with biopsies, and compared with that of the APF.

Results

A total of 38 patients were included, with a mean age equal to 42 years [26 - 73] and a M/F sex ratio equal to 0,4. Two patients (5,2%) had exclusively perineal involvement. APF was associated with luminal involvement in 94,7% of cases. Twenty-three patients (60,5%) had associated proctitis. APF were complex in 92,1% of cases, associated with a perineal abscess in 44,7% of cases and anorectal stricture in 7,9% of cases. All patients had received anti-TNFα after disappearance of perineal collections if initially present (Infliximab (92,1%), Adalimumab (7,9%)) combined with thiopurines in 97,4% of cases. After a mean follow-up of 40 months, the response of the APF to treatment was associated with healing of the rectal mucosa in 10 patients (43,5%), healing of the APF alone with persistence of proctitis was observed in 6 patients (26,1%), healing of the rectum with persistence of APF was described in only one patient (4,3%). The absence of rectal and anoperineal healing together was observed in 6 patients (26,1%).

In a univariate study and using the chi-square test, there was no statistically significant relationship between rectal mucosal healing and APF healing after treatment with biotherapy with p = 0,069 [95% confidence interval].

Conclusion

Our results suggest that healing of the rectal mucosa does not influence the natural history of anoperineal fistulas in Crohn's disease. Larger scale studies are needed to confirm these results.