Mucosa-Associated Lymphoid Tissue Surgeries as a Possible Risk for Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

Background: Inflammatory bowel disease (IBD) is a group of chronic inflammatory gastrointestinal disorders that are caused by genetic susceptibility and environmental factors and affects a significant portion of the global population. The gut-associated lymphoid tissue (GALT) is known to play a crucial role in immune modulation and maintaining gut microbiota balance. Dysbiosis in the latter has a known link to IBD. Therefore, the increasing prevalence of adenoidectomy in children should be explored for its potential association with IBD. The objective of this paper was to assess the association between adenoid tissue removal and the risk of developing Crohn's disease (CD) and ulcerative colitis (UC).

Methods: We conducted a pooled meta-analysis to evaluate the extended clinical outcomes in patients who underwent appendicectomy and tonsillectomy compared to those who did not. Our approach involved systematically searching the PubMed database for relevant observational studies written in English. We followed the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines to collect data from various time periods, and to address the diversity in study results; we employed a random-effects analysis that considered heterogeneity. For outcomes, odds ratios (ORs) were pooled using a random-effects model.

Results: Seven studies, out of a total of 114,537, met our inclusion criteria. Our meta-analysis revealed a significant association between appendicectomy and CD (OR: 1.57; 95% confidence interval (CI): 1.01 - 2.43; heterogeneity I² = 93%). Similarly, we found a significant association between tonsillectomy and CD (OR: 1.93; 95% CI: 0.96 - 3.89; I² = 62%). However, no significant association was observed between appendicectomy and UC (OR: 0.60; 95% CI: 0.24 - 1.47; I² = 96%), while a modest association was found between tonsillectomy and UC (OR: 1.24; 95% CI: 1.18 - 1.30; I² = 0%).

Conclusions: In summary, we found that the trend of appendicectomy is linked to higher odds of CD, and tonsillectomy is more likely associated with increased odds for both CD and UC, with a risk of bias present.