Epidemiology, treatment patterns, and associated risk factors in perianal fistulizing Crohn’s disease: A systematic literature review

Table 1 Definitions of complex Crohn’s perianal fistulas from included studies

Included in definitions for complex CPF	Number of studies
Multiple fistula tracts/external openings1	18
Presence of rectovaginal fistula1	17
High position1	16
High transsphincteric1	16
Signs of perianal abscess (including pain or fluctuation)1	16
High intersphincteric1	15
Anorectal stricture1	14
Suprasphincteric1	13
Extrasphincteric1	12
Endoscopic activity1	6
Supralevator extension	3
Proctitis	2
Horseshoe fistula	2
Procedure as surrogate for complex CPF (ostomies, seton drainage)	2
Perianal disease activity index (not further defined)	1
Translevator extension	1

¹Included in the definition of complex Crohn’s perianal fistulas by the American Gastroenterological Association.

CPF: Crohn’s perianal fistulas.