Long-term risks of adenoidectomy and tonsillectomy examined

By Nicole MacKee
Children who have their tonsils or adenoids removed may be at long-term increased risk of respiratory, infectious and allergic diseases in adulthood, say researchers in JAMA Otolaryngology – Head and Neck Surgery.

Their study of Danish public health data included almost 1.2 million children – 60,000 of whom had undergone adenoidectomy, tonsillectomy or adenotonsillectomy by age 9 years – who were followed up to the age of 30 years. Adenoidectomy and tonsillectomy were found to be associated with a two- and threefold increased risk, respectively, of upper respiratory tract diseases compared with controls (relative risks, 1.99 and 2.72). Smaller increased risks were also found for infectious and allergic diseases.

The researchers said that increases in long-term absolute disease risks were ‘considerably larger’ than changes in the risk for the disorders these surgeries aimed to treat.

Associate Professor Melville da Cruz, Ear, Nose and Throat Surgeon and Associate Professor of Otolaryngology, The University of Sydney, said such large, long-term studies were rare, and this one had been well conducted. But, he added, it was difficult to be confident in the findings when there were many other factors, including important confounders like smoke exposure, that could influence the results. The author of an accompanying editorial said confounding, reverse causation, selection bias and measurement bias could all be playing a role in the findings.

Associate Professor da Cruz said the indication for tonsillectomy, adenoidectomy and adenotonsillectomy had changed in the past 15 to 20 years, and the surgeries were now more often indicated for sleep apnoea than for repeated infectious disease.

‘The benefits of tonsillectomy and adenoidectomy for airway obstruction are phenomenal,’ Associate Professor da Cruz said. ‘A child with mild-to-moderate sleep apnoea can have their sleep patterns and educational and growth trajectories normalised very rapidly and completely with surgery.’

He said it would be premature to raise with parents the possibility of a long-term increased risk of infectious or allergic disease after removal of tonsils and/or adenoids.

‘I don’t think there is enough strength in just one paper to bring this into the discussion,’ he said. ‘It’s something that will have to be looked at in greater depth before our practices are likely to change.’
JAMA Otolaryngol Head Neck Surg 2018; doi: 10.1001/jamaoto.2018.0614.