Inclusion Criteria:  Patient with complex anal fistula treated by the FiLaC™ between 05/01/17 and 05/01/18  Exclusion Criteria:  Patient scheduled for treatment by FiLaC™ and collected as such but finally treated by fistulotomy given a fistula pathway considered intraoperatively less complex than expected Patient with recto vaginal or vaginal skin fistula Patient under guardianship or curators Patient deprived of liberty Patient objecting to the use of their data for this research