Factors associated with surgery in patients with intra-abdominal fistulizing Crohn's disease

Table 1 Demographic, clinical and radiographic characteristics of study cohort n (%)

Number of patients	132
Male	79 (60)
Age at diagnosis	24 (11.6)
Age at time of imaging	31.3 (12.2)
Time from diagnosis to imaging, month, mean ± SD	87 (84)
Penetrating disease at presentation	28 (21)
Previous surgery1	15 (11)
Imaging before 2010	66 (50)
Treatment during fistula presentation2
No IM or anti-TNF	70 (53)
Only IM	33 (26)
Only anti-TNF	11 (8)
Anti TNF + IM	12 (9)
Radiological features
Total no. of fistulae	193
Anatomy of fistulae
Entero-enteric fistula	103 (52)
Entero-colonic fistula	35 (18)
Entero-cutaneous fistula	28 (14)
Entero-vesical fistula	15 (8)
Entero-soft tissue fistula	12 (6)
No. of fistulae per patient
One fistula	72 (55)
Two fistulae	49 (37)
Three or more fistulae	11 (8)
Additional radiological features, n± SD (%)
Diameter of inflammatory conglomerate (cm)	10 ± 2.6
Length of diseased bowel segment (cm)	14.8 ± 17.5
Stricture	31 (23)
Abscess	45 (34)
Prominent lymphadenopathy	40 (30)
Treatment after fistula presentation
No IM or anti-TNF	54 (47)
Only IM	28 (25)
Only anti-TNF	19 (17)
Anti TNF + IM	12 (11)

¹Patients who had surgery within 6-mo prior to index imaging were excluded. All previous surgeries included resection of bowel;

²Detailed treatment characteristics available for 126 patients. IM: Immunomodulators; TNF: Tumor necrosis factor.

Table 2 Association of different parameters with surgery within one year following imaging study n (%)

Clinical/laboratory/radiologic parameter	Surgery	No surgery	P value
Total no. of patients	59 (47)	67 (53)
Age at diagnosis > 18	43 (46)	50 (54)
Age at diagnosis < 18	16 (48)	17 (52)	0.49
No fistulous disease at presentation	47 (49)	48 (51)
Fistulous disease at presentation	12 (39)	21 (61)	0.20
No perianal disease	53 (46)	61 (54)
With perianal disease	6 (50)	6 (50)	0.52
Lab parameters
CRP < 5 mg/L	31 (45)	38 (55)
CRP > 5 mg/L	28 (49)	29 (51)	0.39
Albumin > 35 mg/L	39 (44)	49 (56)
Albumin < 35 mg/L	20 (53)	18 (47)	0.25
Fistula
One fistula	25 (37)	42 (63)	REF
Two fistulae	24 (50)	24 (50)	0.17
Three or more fistulae	10 (91)	1 (9)	0.009
Fistula type (anatomic)
Entero-enteric	47 (46)	56 (54)	REF
Entero-vesical	12 (80)	3 (20)	0.01
Entero-colonic	17 (49)	18 (51)	0.45
Entero-cutaneic	17 (63)	10 (37)	0.08
No lymphadenopathy	40 (44)	50 (56)
Lymphadenopathy	19 (53)	17 (47)	0.26
No stricture	40 (41)	57 (59)
Stricture	19 (66)	10 (34)	0.02
No abscess	35 (43)	47 (57)
Abscess	24 (55)	20 (45)	0.14
Bowel enhancement of 1	18 (43)	24 (57)
Bowel enhancement of ≥ 2	41 (49)	43 (51)	0.33
Treatment before imaging
No treatment with IM or anti-TNF	31 (44)	39 (56)	REF
Immunomodulators (IM)	13 (39)	20 (61)	0.98
Anti-TNF	6 (55)	5 (45)	0.46
Anti-TNF + IM	9 (75)	3 (25)	0.04
Treatment after imaging
No treatment with IM or anti-TNF	35 (65)	19 (35)	REF
IM	13 (46)	15 (54)	0.18
Anti-TNF	5 (26)	14 (74)	0.01
Anti-TNF + IM	0 (0)	12 (100)	0.01

Table 3 Multivariate analysis of patients who underwent surgery up to one year following imaging study

Parameter	RR (95%CI)	P value
Two fistulas	1.52 (0.65-3.5)	0.330
Three or more fistulas	9.23 (0.99-85.8)	0.051
Stricture	2.70 (1.02-7.1)	0.045
Entero-vesical fistula	3.61 (0.81-16.0)	0.090
Entero-cutaneous fistula	2.18 (0.82-5.8)	0.120
Anti-TNF before imaging	2.63 (0.71-9.8)	0.150
Anti-TNF + IM before imaging	3.86 (0.90-16.6)	0.070

IM: Immunomodulators; TNF: Tumor necrosis factor.