Effects of appendicectomy on the course of ulcerative colitis

Abstract

Background: Appendicectomy reduces the risk of having ulcerative colitis. However, its effect on the natural history of ulcerative colitis remains uncertain. Aim: To determine whether appendicectomy reduces the overall severity of ulcerative colitis. Patients and methods: Appendicectomy status and smoking habits were specified by direct interview in 638 patients seen consecutively between 1997 and 2000. Severity of ulcerative colitis was assessed by reviewing therapeutic needs from the onset of colitis. Additionally, the annual incidence of flare up was assessed prospectively between 1997 and 2000 in patients who had not been colectomised. Results: The 10 year risk of colectomy was 16 (7)% in previously appendicectomised patients (n=49) compared with 33 (2)% in non-appendicectomised patients (n=589, p=0.05). Cox regression showed that previous appendicectomy and current smoking were independent factors protecting against colectomy (adjusted hazard ratio and 95% confidence intervals: 0.40 (0.20-0.78) and 0.60 (0.40-0.95), respectively). The respective proportions of appendicectomised and non-appendicectomised patients who required oral steroids and immunosuppressive therapy were not significantly different (67% v 70% and 27% v 19%, respectively). Between 1997 and 2000, ulcerative colitis was active for 48% of the time in appendicectomised patients (47 of 98 patient years) and for 62% of the time in non-appendicectomised patients (631 of 1024 patient years; p<0.01). Conclusion: Previous appendicectomy is associated with a less severe course of ulcerative colitis. The beneficial effect of appendicectomy on the risk of colectomy is additive to that of current smoking.

Diagnostic evaluation of appendiceal orifice inflammation in ulcerative colitis

“…Although the pathogenesis of UC remains unclear, clinical evidence suggests that appendectomy may protect against the onset and severity of UC (21,22), suggesting that the appendix may be a priming site for UC (4). Hence, the role of the appendix in the pathogenesis of UC should be clarified, as reported by Matsushita et al (23).…”

Prior appendectomy and the phenotype and course of Crohn’s disease

“…Patients who have been appendectomized have a lesser risk of developing UC. Moreover, in the few appendectomized patients who develop UC, disease course is less severe, with a decreased need of colectomy compared to non-appendectomized patients [3,4] . Of note, the effects of smoking and appendectomy are additive [4] .…”

Appendiceal Orifice Inflammation in Ulcerative Colitis

“…The human appendix has long been recognized as a vestigial remnant. Although the pathogenesis of UC has not been fully clarified, clinical evidence has revealed the protective role of appendicectomy on onset and severity of UC [2,3], indicating the appendix as a priming site for UC [4]. Experimental studies of murine models have also shown that the appendix may serve a central role in antigen sampling and immunological signaling [5].…”