Adenoid, tonsil removal in childhood may raise long-term respiratory risk
Children who undergo adenoidectomy, tonsillectomy, or both (adenotonsillectomy) within the first 9 years of life may have an elevated long-term risk of respiratory, allergic, or infectious diseases, results from a Denmark-based study show.
“[These findings highlight] the importance of adenoids and tonsils for normal immune system development and [suggest] that their early-life removal may slightly but significantly perturb many processes important for later-life health,” said the researchers led by Professor Jacobus Boomsma from the University of Copenhagen in Copenhagen, Denmark and Dr Sean Byars from the University of Melbourne, Victoria, Australia.
“[O]ur observed results that show increased risks for long-term diseases after surgery support delaying tonsil and adenoid removal if possible, which could aid normal immune system development in childhood and reduce these possible later-life disease risks,” said Byars.
Using data of 1,189,061 children born between 1979 and 1999 in Denmark (48 percent female), researchers compared the long-term outcomes (up to 30 years) of 17,460 children who underwent adenoidectomy, 11,830 who underwent tonsillectomy, and 31,377 who underwent adenotonsillectomy before age 9 years with 1,157,684 children who did not undergo these surgeries (control group).
The risk of upper respiratory tract conditions was almost three times higher among individuals who underwent a tonsillectomy in childhood compared with those who did not (relative risk [RR], 2.72, 95 percent confidence interval [CI], 1.54–4.80), with an 18.61 percent increased absolute risk of these conditions. [JAMA Otolaryngol Head Neck Surg 2018;doi:10.1001/jamaoto.2018.0614]
Individuals who underwent an adenoidectomy in childhood had almost twice the risk of developing upper respiratory tract conditions than those who did not (RR, 1.99, 95 percent CI, 1.51–2.63) with an increase in absolute risk of 10.7 percent. While the risks of chronic obstructive pulmonary disease (COPD; RR, 2.11, 95 percent CI, 1.53–2.92) and conjunctivitis (RR, 1.75, 95 percent CI, 1.35–2.26) were also elevated among patients who underwent an adenoidectomy in childhood, the absolute risks of these two conditions was lower than that of upper respiratory tract conditions (absolute risk difference, 0.29 and 0.16 percent, respectively).
This higher absolute risk of upper respiratory tract conditions compared with COPD and conjunctivitis could be attributed to the higher prevalence of respiratory conditions in the general population, said the researchers.
Individuals who underwent an adenotonsillectomy experienced an increase in the risk of infectious diseases (RR, 1.17, 95 percent CI, 1.10–1.25), with an absolute risk increase of 2.14 percent.
The impact of surgery on the conditions that the surgeries were meant to treat varied, with adenoidectomy significantly reducing the risk of sleep disorders (RR, 0.30) and all surgeries reducing the risk of tonsillitis and chronic tonsillitis (RR, 0.09–0.54), while no impact was demonstrated for abnormal breathing with any surgery or for sinusitis following adenoidectomy or tonsillectomy. Conversely, the risk of sinusitis increased after adenotonsillectomy (RR, 1.68) as did otitis media after any surgery (RR, 2.06–4.84).
“[S]hort-term health benefits of these surgeries for some conditions may not continue up to age 30 years,” said the authors, pointing out that except for the consistent reduced risk of tonsillitis post-surgery and sleep disorders post-adenoidectomy, the long-term risks for sinusitis, chronic sinusitis, otitis media, and abnormal breathing either increased or were similar with that of individuals who did not undergo surgery.
“Our results raise the important issue of when the benefits of operating outweigh overall short- and long-term morbidity risks. [The long-term risk associations] suggest that revived discussion may be timely, because these surgical procedures remain among the most common medical interventions in childhood,” said the researchers.
They cautioned that the results may not extend to other populations and called for further research to help establish these findings. They were unable to account for childhood exposure to parental smoking which may have influenced the risk of respiratory conditions, and did not rule out that, despite their attempts at minimizing reverse causation and confounding, these may still have occurred.
“As we uncover more about the function of immune tissues and the lifelong consequences of their removal, especially during sensitive ages when the body is developing, this will hopefully help guide treatment decisions for parents and doctors,” said Byars.