TNF inhibitors in Crohn’s disease and the effect on surgery rates

Surgery is an important therapeutic option for Crohn's disease. The need for first bowel surgery seems to have decreased with the introduction of TNF-inhibitors (TNFi; adalimumab or infliximab). However, the impact of TNFi on the need for intestinal surgery in Crohn's disease patients irrespective of prior bowel resection is not known. Our aim is to compare the incidence of bowel surgery in Crohn's disease patients who remain on versus those who discontinue TNFi treatment.We performed a nationwide register-based observational cohort study in Sweden 2006-2017 of all incident and prevalent cases of Crohn's disease who started first line TNFi treatment. Patients were categorized according to TNFi treatment retention less than or beyond one year. The study cohort was evaluated with regards to incidence of bowel surgery from 12 months after first ever TNFi dispensation.We identified 5003 TNFi exposed Crohn's disease patients, 3748 surgery-naïve and 1255 with bowel surgery prior to TNFi initiation. Of all these patients, 7% (n=353) were subjected to abdominal surgery during the first 12 months after start of TNFi and subsequently excluded from the main analysis. A majority (62%) continued TNFi ≥12 months. TNFi drug survival <12 months was associated with a significantly higher surgery rate compared to patients who continued TNFi ≥12 months (HR 1.26, 95% CI, 1.09-1.46; p=.002).Treatment with TNFi <12 months was associated with a higher risk of bowel surgery in Crohn's disease patients compared to continuing TNFi ≥12 months.