Differential risk of disease progression between isolated anastomotic ulcers and mild ileal recurrence after ileocolonic resection in patients with Crohn's disease

Background and Aims: It is standard of care to perform ileocolonoscopy within a year of ileocolonic resection for Crohn's disease (CD) and to guide management decisions based on the Rutgeert score (RS). The modified RS subdivides i2 into lesions confined to the anastomosis (i2a) or >5 aphthous lesions in the neoterminal ileum (i2b). There is uncertainty, however, if i2a lesions incur an increased risk of disease recurrence. The primary aim of this study was to compare the rates of endoscopic progression between i2a and i2b when compared with i0-i1. Methods: This was a retrospective, single-center study including patients with CD who had an ileocolonoscopy <= 12 months after ileocolonic resection with primary anastomosis and who had >1 year of documented clinical follow-up after the index endoscopic evaluation. All consecutive eligible patients between 2004 and 2014 were included in the study. Demographic, disease, and treatment data were collected. Patients with i3 or i4 at index colonoscopy were excluded from further analyses. Outcomes included endoscopic progression and recurrent surgery. For patients with RS of i0 to i2, endoscopic progression was predefined as progression of the RS in subsequent colonoscopies to i3 or i4. Recurrent surgical interventions were defined as re-resection or stricturoplasty of the previous ileocolonic anastomosis. Results: Two hundred seven CD patients (median age, 36 years [interquartile range, 26-48]) had an ileocolonoscopy <= 12 months after ileocolonic resection. At index colonoscopy, 95 patients (45.9%) had an RS of i0, 31 (14.9%) i1, 40 (19.3%) i2a, 25 (12.1%) i2b, 10 (4.8%) i3, and 6 (2.9%) i4. One hundred ninety-one patients had an RS of i0 to i2 and were included in the analyses for recurrent surgery. One hundred forty-nine patients had a second endoscopic evaluation and were included in the analysis for the primary outcome of endoscopic disease progression. Kaplan-Meier analyses were performed and found the hazard ratio (HR) of endoscopic progression to be significantly higher with i2b lesions when compared with i0 or i1 (HR, 6.22; 95% confidence interval [CI], 2.38-16.2; P = .0008). Patients with i2a did not have significantly higher rates of endoscopic progression when compared with i0 or i1 (HR, 2.30; 95% CI, .80-6.66; P = .12). Likewise, patients with i2b lesions had higher risk of needing recurrent surgery when compared with i0 or i1 (HR, 3.64; 95% CI, 1.10-12.1; P = .034), whereas patients with i2a lesions were not found to have a significantly elevated risk of recurrent surgery (HR, 1.43; 95% CI, .35-5.77; P = .62). Conclusion: Endoscopic lesions limited to the ileocolonic anastomosis (RS i2a) in patients with CD undergoing colonoscopy within 1 year of their resection were not associated with a significantly higher rate of progression to more severe disease, whereas those in the neoileum (RS i2b) were. Prospective studies are needed to confirm these findings.