P856 Influential factors on the clinical and radiological closure of resistant perianal fistula treated with stoma

Abstract

Abstract Background Perianal fistula (PaF) is a debilitating and difficult to treat form of Crohn's disease. Although biological (anti-TNF) treatments are almost always used, long term fistula closure rates are far from being satisfactory. Radiological closure, which should be the treatment goal, is even much rarer. Stoma is one of the last steps in the treatment of resistant fistula. In our study, we examined the patients who underwent stoma, in our series, due to resistant PaF and the factors associated with radiological closure. Methods Crohn's disease cohort was retrospectively evaluated for patients with resistant perianal fistula (history of poor response to anti-TNF) who underwent stoma. Demographic, treatment, and clinical characteristics of the patients were evaluated in terms of radiological closure (complete resolution of the fistula tract, disappearance of T2 hyperintensity and absence of contrast enhancement on MRI) of the PaF. Results There were 47 patients (11%) who underwent stoma due to perianal fistula among 423 Crohn's disease patients with PaF. The median age in the patient group (at the time of stoma) was 34 years and 47% of the patients were male. Radiological fistula closure was achieved in 42% of the patients and clinical remission (>3 months) was achieved in 66%. Table -1 summarizes the comparison of demographic, clinical and treatment parameters of the study group and patients with and without radiological closure. Radiologic closure and non-closure groups were similar regarding pre-stoma- and during stoma treatment status. Being a never smoker was associated with poor radiological closure and could be an indicator of treatment resistance while ex-smoker status had a favorable outcome. Both recurrent antibiotic treatment (>2/year) need for clinical fistula closure and history of seton replacement were associated with radiological unresponsiveness. During stoma, the early partial radiological response - achieved in the 3rd month of perianal MRI fistulography -was strongly associated with later radiological closure in the follow up. In Kaplan-Meir analysis; anatomically branching fistula had the poorest response, but the number of fistula did not have any influence, mucosal remission was associated with earlier and better radiological response, pre-stoma reccurent antibiotic need was associated with worse outcome Figure 1. Conclusion Radiological closure of PaF can be achieved with stoma in nearly half of the patients under already combined conventional treatment. History of seton replacement, recurrent antibiotic need and being never smoker are the indicators of resistance to radiological closure. Third month radiological response – is an important and early sign of radiological complete fistula closure.