Risk Stratification for Surgery in Stricturing Ileal Crohn's Disease: The BACARDI Risk Model.

Abstract Transmural inflammation in Crohn's disease [CD] leads to stricturing or penetrating complications. Factors impacting on the need and timing of surgery in ileal stricturing CD [IS-CD] are understudied. Our aim was to identify risk factors in IS-CD associated with the need for surgery over time. All cross-sectional imaging [XSI] performed for CD between 2006 and 2015 in a tertiary referral centre was analysed. The electronic charts of patients with IS-CD were reviewed for demographic, clinical, biochemical, imaging, genetic, and endoscopic factors. An independent cohort was used for validation. A total of 1803 XSI were performed in 957 patients with CD. IS-CD was diagnosed in 235 patients, and 161 of these [69%] needed surgery. Prestenotic dilation (hazard ratio [HR] 2.05, 95% confidence interval [CI] 1.22-3.45, p = 0.007], C-reactive protein at diagnosis of IS-CD > 11 mg/L [HR 1.53, 95% CI 1.05-2.24, p = 0.026], Montreal B3 phenotype [HR 1.58, 95% CI 1.06-2.36, p = 0.023], previous/current anti-tumour necrosis factor [TNF] exposure [HR 1.44, 95% CI 1.00-2.06, p = 0.048], and presence of at least one NOD2 rs2066844 risk allele [HR 1.51, 95% CI 1.02-2.23, p = 0.038] significantly impacted on the need for surgery in multivariate analysis. The risk stratification model [BACARDI] yielded a surgery-free survival after 5 years of 77%, 38%,19%, and 0% for the low, medium, high, and all risk groups, respectively. Based on an independent cohort of 27 patients, the results were validated and demonstrated adequate performance. This risk model can facilitate therapeutic decisions in IS-CD and suggest the correct time for surgery in daily clinical practice.