Systematic review with meta-analysis: risk of post-operative complications associated with pre-operative exposure to anti-tumour necrosis factor agents for Crohn’s disease

Background: Post-operative complications after anti-tumour necrosis agent treatment for Crohn's disease (CD) have been analysed with conflicting results. Aim: To assess the effects of pre-operative anti-tumour necrosis factor (TNF) therapy on post-operative complications within 30 days post-operatively in patients with CD undergoing abdominal surgery. Methods: Systematic review with meta-analysis was performed on articles found in MEDLINE, Embase, Cochrane Library, Scopus, and the International Clinical Trials Registry Platform until September 2018. Results: Twenty studies (7115 patients) were included. Without confounder adjustment, pre-operative anti-TNF therapy in patients with CD undergoing abdominal surgery was associated with increased rates of infectious complications (unadjusted odds ratio, OR, 1.49; 95% CI, 1.08-2.06). After confounder adjustment, Pre-operative anti-TNF therapy was significantly associated with both increased rates of total and infectious complications (adjusted OR, 1.53 and 2.09; 95% CI, 1.11-2.09 and 1.19-3.65, respectively). After subgroup analyses, the association between anti-TNF agents and total complications was significant in high incidence countries (adjusted OR, 1.86; 95% CI, 1.43-2.42) but not in low incidence countries (adjusted OR, 0.77; 95% CI, 0.48-1.25). Conclusions: Exposure to anti-TNF agents is an independent risk factor for post-operative infectious complications in patients with CD, especially in countries with a high incidence of Crohn's disease. We suggest postponing elective surgery or carefully monitoring these patients post-operatively.