P126 The predictive value of the modified Rutgeerts score at index endoscopy after primary ileocolic resection in patients with Crohn’s disease for the risk of re-resection and severe endoscopic inflammation after long-term follow-up

Abstract

Abstract Background The modified Rutgeerts score (mRS) differentiates i2 into lesions confined to the anastomosis (i2a) vs. ileal lesions (i2b), and is considered appropriate to assess postoperative recurrence in Crohn’s disease (CD) patients. This study aimed to assess the predictive value of mRS at index endoscopy after primary ileocolic resection for the risk of re-resection and severe endoscopic inflammation after long-term follow-up. In addition, we aimed to predict the association of i2a and i2b for both outcomes. Methods Data of CD patients who underwent a ICR, between 2000 – 2019, were retrospectively collected from a national, multicenter database. Patients were eligible for inclusion if ≥1 postoperative endoscopy assessed with the mRS was available. Primary outcome was re-resection per mRS (i0-i4) at index (i.e. first postoperative) endoscopy. Secondary outcome was severe endoscopic inflammation (defined as i3-i4) for a subset of patients (mRS i0-i2b). Rates for both outcomes were compared in subgroups (i0-i1, i2a-i2b, i3-i4) by Kaplan-Meier analyses. Multivariable analysis was conducted to identify risk factors for both outcomes. Results In total, 638 patients were included. Index endoscopy was performed at median 8.5 months (IQR: 5.9 – 22.8) after ICR(Table 1), with a mRS of i0(30.4%), i1(17.7%), i2a(15.8%), i2b(19.6%), i3(9.6%) and i4(6.9%). After a mean follow up of 6.5 years (SD: 4.7), re-resection rate (Figure 1) was 7.2% for patients with a mRS of i0, 6.2%(i1), 14.9%(i2a), 18.4%(i2b), 22.9%(i3) and 47.7%(i4). Re-resection rates in the subgroups were significantly higher in the group with a mRS i2a-i2b (16.8%) vs. i0-i1 (6.8%) (log-rank test, p<0.001) and in i3-i4 (33.3%) vs. i2a-i2b (16.8%)(log-rank test, p=0.006). Follow-up endoscopy was performed in 54.0% of the patients with mRS i0-i2b at median interval of 20.4 months (IQR: 10.9 – 37.7). Progression to severe endoscopic recurrence was observed in 19.8% of patients with i0, 33.9%(i1), 25.4%(i2a) and 33.8%(i2b) (Figure 2), but no significant difference was observed between subgroups i0-i1 vs. i2a-i2b (respectively 24.7% vs. 30.2%)(log-rank test, p=0.134). In multivariable analysis, anastomotic lesions (i2a) are not statistically significant associated with re-resection and progression to i3-i4 (Table 2). Conclusion After primary ICR, the ascending order of the mRS corresponds with an increasing long-term risk of re-resection. In multivariable analysis, anastomotic lesions (i2a) are not significantly associated with the risk of re-resection and progression to severe endoscopic inflammation, in contrast to i2b lesions. The influence of therapeutic decisions on these associations requires further investigation.