Comparison of the risk of Crohn's disease postoperative recurrence between modified Rutgeerts score i2a and i2b categories: an individual patient data meta-analysis

Background The modified Rutgeerts’ score [RS] differentiates i2a—lesions confined to the anastomosis—and i2b—more than five aphthous ulcers in the neoterminal ileum with normal intervening mucosa, with or without anastomotic lesions—categories. Its relevance for the therapeutic management of Crohn’s disease [CD] patients after ileocolic resection is still debated. Our objective was to compare the postoperative recurrence risk in patients with an i2a or i2b score, using an individual patient data meta-analysis. Methods We conducted a systematic literature search until July 2020, to identify all relevant studies reporting the i2a/i2b status in the year following ileocolic resection and clinical and/or surgical postoperative CD recurrence in their follow-up. Individual patient-level data were obtained from the corresponding authors. The association between the modified RS and time-to-event was evaluated using a mixed Cox model with the centre as the random effect. Results Seven studies published between 2008 and 2019 were included, corresponding to 400 patients: 189 [47%] i2a and 211 [53%] i2b. Median [interquartile range, IQR] time from ileocolic resection to ileocolonoscopy was 6.2 [5.5, 7.9] months and median [IQR] follow-up time after ileocolonoscopy was 4.5 [2.9, 7.3] years. The risk of clinical postoperative recurrence at 1 and 3 years was 11% [6–15%], and 25% [18–32%] in the i2a group versus 9% [5–13%] and 33% [26–41%] in the i2b group [p = 0.63 and p = 0.12, respectively]. No significant difference was observed in terms of time to clinical postoperative recurrence [p = 0.16] or surgical postoperative recurrence [p = 0.87]. Results did not change after excluding patients having initiated an immunosuppressant or a biologic in the 3 months after endoscopy [remaining cohort, n = 361]. Conclusions In this individual patient data meta-analysis, no difference was observed between i2a and i2b subcategories with regards to clinical or surgical postoperative recurrence. As we wait for prospective trials, the same treatment strategy could be applied to all patients classified as i2 on the Rutgeerts score.