Re-resection Rates and Disease Recurrence in Crohn's Disease: A Population-based Study Using Individual-level Patient Data.

Background and aims: Despite advances in the medical treatment of Crohn's disease [CD], many patients will still need bowel resections and face the subsequent risk of recurrence and re-resection. We describe contemporary re-resection rates and identify disease-modifying factors and risk factors for re-resection.

Methods: We conducted a retrospective, population-based, individual patient-level data cohort study covering 47.4% of the Danish population, including all CD patients who underwent a primary resection between 2010 and 2020.

Results: Among 631 primary resected patients, 24.5% underwent a second resection, and 5.3% a third. Re-resection rates after 1, 5, and 10 years were 12.6%, 22.4%, and 32.2%, respectively. Reasons for additional resections were mainly disease activity [57%] and stoma reversal [40%]. Disease activity-driven re-resection rates after 1, 5, and 10 years were 3.6%, 10.1%, and 14.1%, respectively. Most stoma reversals occurred within 1 year [80%]. The median time to recurrence was 11.0 months. Biologics started within 1 year of the first resection revealed protective effect against re-resection for stenotic and penetrating phenotypes. Prophylactic biologic therapy at primary ileocaecal resection reduced disease recurrence and re-resection risk (hazard ratio [HR] 0.58, 95% confidence interval [CI] [0.34-0.99], p = 0.047). Risk factors for re-resection were location of resected bowel segments at the primary resection, disease location, disease behaviour, smoking, and perianal disease.

Conclusion: Re-resection rates, categorised by disease activity, are lower than those reported in other studies and are closely associated with disease phenotype and localisation. Biologic therapy may be disease-modifying for certain subgroups when initiated within 1 year of resection.