Crohn's disease after surgery: Changes in post-operative management strategies over time and their impact on long-term re-operation rate-A retrospective multicentre real-world study

Background: Few data are available addressing the impact of post-operative management of Crohn's disease (CD) on long-term clinical course. Aim: To assess the evolution of post-operative management strategies over the last 40 years and their impact on the re-operation rate of CD. Methods: We included 657 patients with CD who had undergone their first radical ileo-caecal resection between 1980 and 2020. Three cohorts were defined according to year of surgery: cohort 1 (1980-1998; n = 198), cohort 2 (1999-2009; n = 218) and cohort 3 (2010-2020; n = 241). We estimated exposure to immunomodulators and anti-TNF alpha agents after surgery and rates of re-operation using Kaplan-Meier survival analyses. We used Cox proportional hazards regression to assess the association of clinical variables with time to re-operation. Results: Immunosuppressants, (IMMs) and anti-TNF alpha exposure within 5 years after surgery increased significantly from cohort 1 to cohort 2 and cohort 3 (IMMs: 1.6%, 38.2% and 28.0%, respectively, p < 0.001; anti-TNF alpha: 0.0%, 20.7% and 52.0%, respectively, p < 0.001). There was no significant difference across cohorts regarding the cumulative probability of re-operation within 5 and 10 years. Multivariate analysis identified IMMs/anti-TNF alpha exposure before the first surgery (HR 9.15; 95% CI 2.77-30.21) and post-operatively (HR: 0.24; 95% CI 0.07-0.74) as variables associated with the risk of re-operation. However, these associations had a time-varying effect and become non-significant after 5 and 2 years after surgery, respectively. Conclusion: Despite increased post-operative use of IMMs and anti-TNF alpha agents in the last two decades, the impact of these strategies on the risk of long-term re-operation rate has been modest.