The Clinical Relevance of an Inflamed Appendix in Crohn's Disease

Background and Aims: An appendectomy for appendiceal inflammation has been suggested to ameliorate the clinical course of patients with ulcerative colitis [UC]. In contrast, for Crohn's disease [CD] an inverse association has been suggested with a higher incidence of CD and worse prognosis after appendectomy. The aim of this study was to analyse the clinical relevance of an inflamed appendix in CD patients undergoing ileocaecal resection [ICR]. Methods: All consecutive patients undergoing primary ICR between 2007 and 2018 were considered for inclusion. Microscopic data of available appendiceal resection specimens [n=99] were revised by a dedicated inflammatory bowel disease [IBD] pathologist and scored as inflamed or not inflamed. Eighteen patients had a previous appendectomy. Pathological findings were correlated with disease characteristics and recurrence rates [clinical, endoscopic, and intervention-related]. Results: In total 117 patients were included, 77 [65.8%] females, with a median age of 30 years (interquartile range [IQR] 24-43), and a median follow up of 102 months [IQR 76-114]. Of patients without previous appendectomy [n=99], 39% had an inflamed appendix. No significant differences in disease characteristics [eg, disease location, behaviour, time to surgery] or prognosis could be demonstrated between the two groups. In contrast, previous appendectomy [n=18] was associated with penetrating disease and numerically shorter disease duration at the time of resection. Furthermore, a trend was seen towards a stronger association with postoperative recurrence. Conclusion: The current study could not confirm a different prognosis for CD patients with and without an inflamed appendix. In contrast, in patients with a previous appendectomy, a trend was seen towards increased postoperative recurrence, which might be related to the higher incidence of penetrating disease.