ObjectiveTo investigate long-term efficacy of infliximab (IFX) combined with seton placement in treatment of perianal fistulizing Crohn disease (CD) and to analyze factors affecting its clinical healing and recurrence.MethodsThe patients with perianal fistulizing CD underwent the IFX combined with seton placement therapy from July 2010 to January 2017 were collected from the HIS database of the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine. The healing and recurrence of perianal fistulizing CD were counted and their influencing factors were analyzed.ResultsA total of 103 patients with perianal fistulizing CD were included in the study. After a median follow-up of 36 months, 64 patients (62.1%) had a complete fistula healing, 34 patients (33.0%) relapsed. The cumulative recurrence rates of fistula in the 1, 3, and 5 years was 21.8%, 32.6%, and 37.4%, respectively. The multivariate analysis showed that the Montreal classification B1 ［HR=3.987, 95% CI (1.640, 9.694), P=0.023］ and without abscess ［HR=2.724, 95% CI (1.101, 6.740), P=0.030］ were positively associated with the long-term healing of fistula, and the IFX maintenance treatment >3 times ［HR=5.497, 95% CI (1.197, 25.251), P=0.028］ was a risk factor for the recurrence of the fistula.ConclusionsLong-term healing rate of fistula by IFX combined with seton placement therapy is higher. Montreal classification B1, without abscess, and IFX maintenance treatment less than 3 times are expected to have a better long-term efficacy.