P168. Long-term outcome of fistulizing Crohn's disease treated with infliximab – a 12 years follow up study

J. Florholmen1, C. Dahl1, R. Rismo1, R. Goll1

1Institute Clinical Medicine, Gastroenterology, Tromsø, Norway

Background: Fistulizing Crohn's disease is a more aggressive phenotype of Crohn's disease. In 1999 the introduction of infliximab (IFX) was performed for treatment of this disease. The aim of this study was to study the incidence of fistuliziing Crohn's disease in the IFX era and study the long term clinical outcome.

Methods: Registration of Crohn's fistula was done by searching from the data files at the University Hospital of North Norway from 1999 to 2011; the patients were identified and outcomes were extracted from the patient records. IFX was given as induction therapy until remission (closure and/or fistula without inflammation), retreatment was given if relapse, and patients who did not obtain remission were offered a combined IFX and surgical treatment (duo therapy).

Results: 50 patients were diagnosed fistulising Crohn's disease. An annual incidence of 6/year was observed in the period of 1999–2004 and then the incidence was gradually decreased to 1/year during the observation period. Complete data of long term registration was obtained in 32 patients [14 females/18 males, mean age 31 (range 24–41)].

Perianal fistula was observed in 71%. The total observation time was 61 months (46–76 (95% CI), time with active fistula was 13 months (1–24), in remission 49 months (33–64), total time of remission was 82% (67–97), and finally the number of induction therapies was 1.6 (1.3–1.8). IFX induced remission in 23/32 (71%). Among those 16 (50%) had no relapse after the last induction treatment including 9/32 (28%) with only one induction therapy. In 9/32 (28%) there was a need for duo therapy and additional remission without later relapse was registered in 4/32 (13%). The IFX mono therapy and duo therapy induced a total remission without relapse in 20/32 (71%) patients.

Conclusions: Treatment of fistulizing Crohn's disease with IFX is Treatment of fistulizing Crohn's disease with IFX is effective for short and long term. There is an apparent decreasing incidence of newly diagnosed fistulizing Crohn's disease since the start of IFX treatment in 1999.