P488 Perianal Crohn's disease in the biological era. (25th January 2019) - Pires, F
Abstract: Background: The purpose of this study was to characterise perianal disease (PD) in a cohort of patients with Crohn's disease (CD) followed prospectively for 10 years. Methods: We performed a prospective cohort study to analyse data from 298 patients, 96 of whom with PD, over the period of 10 years (2007–2017). The characteristics of patients with PD were compared with controls with CD without PD. Perianal lesions were described in abscess, fistula, abscess and/or fistula, fissure, ulcer, fissure and/or ulcer, and stenosis. The Montreal classification was used to characterise CD. Results: The analysis of patients with and without PD showed no difference in sex, behaviour (B1, B2, B3) and involvement of the upper gastrointestinal tract (L4). However, the group of patients with PD had a significantly lower age at onset of symptoms (median=25.5 years, IQR 20.5–34.0) vs. patients without PD (median=30.5 years, IQR 22.0–41.0) ( p = 0.018), higher colon involvement (L2 + L3 vs. L1) (OR = 2.64, p = 0.001), higher rectal involvement (OR = 5.60, p < 0.001), higher rate of abdominal resection surgery (OR = 1.70, p = 0.046), and higher rate of biological therapy (OR = 2.86, p < 0.001). In patients with PD, 42 (43.8%) had abscess, 62 (64.6%) had fistula, 69 (71.9%) had abscess and/or fistula, 29 (30.2%) had fissure, 4 (4.2%) had ulcer, 33 (34.4%) had fissure and/or ulcer, 8 (8.3%) had anal stenosis; 37 (38.5%) had L1 involvement, 23 (24%) had L2, 36 (37.5%) had L3; 9 (9.4%) had L4 involvement; 38 (39.6%) had rectal involvement; 49 (51%) had B1 behaviour, 29 (30.2%) had B2; 18 (18.8%) had B3; 70 (72.9%) were under biological therapy; 35 (36.5%) had abdominal surgery and 60 (62.5%) had perianal surgery. In this group of patients, patients with abscesses and/or fistula had a higher rate of abdominal (OR = 3.38, p = 0.022) and perianal surgery (OR = 24.77, p < 0.001); patients with fissure and/or ulcer had a lower rate of abdominal (OR = 0.34, p = 0.025) and perianal surgery (OR = 0.11, p < 0.001); patients with anal stenosis had a higher rectal involvement (OR = 12.87; p = 0.006); and patients with fistula had a higher rate of biological therapy (OR = 3.66, p = 0.005). Conclusions: One third of patients with CD had PD, which is more prevalent in patients with colic involvement. The severity of the perianal location can be inferred by the higher rate of abdominal surgery in this group of patients. Of the perianal lesions, abscess and/or fistula were associated with a worse overall prognosis. These data are in agreement with what is previously described in the literature. Patients with PD had higher rates of biological therapy, with a higher rate in patients with fistula compared with other lesions.