Adults with recurrent sore throats may benefit from having a tonsillectomy in the short term, but the overall longer term benefit is still unclear, and any benefits have to be balanced against the side effects of the operation, according to this week's BMJ.

A small study of adults from Finland, published on bmj.com last month, showed that tonsillectomy significantly reduced the likelihood of further infection after 90 days, compared with watchful waiting.

But despite these promising results, an editorial in this week's journal warns that, until we have more evidence about the longer term benefits of surgery, it is difficult for doctors to provide firm advice to patients.

The main problem with the trial is that the follow-up period was relatively short, and people in the watchful waiting group reported improvement during the trial period, says Paul Little, Professor of Primary Care Research at the University of Southampton. This begs the question of whether the benefit of immediate tonsillectomy would be reduced if the follow-up was longer.

Other factors are the small size of the trial and insufficient data on the severity of infections.

Any benefits of the operation must be balanced against potential disadvantages, he writes. The major disadvantage documented in the trial is the 13 days of sore throat after tonsillectomy, which can be severe in many patients. Other disadvantages include the risks associated with an anaesthetic, earache, dehydration, and dental injures, and a risk of life threatening complications, such as major haemorrhage or sepsis.

Until the longer term outcomes in people who do not have surgery are available, and we have more precise estimates of the benefit in terms of the severity of the episodes prevented by surgery, it is difficult to provide firm evidence to patients, he says.

Until such evidence is available, he would advise patients who have had four episodes of tonsillitis in one year or three in six months that they are likely to have on average two and a half days of sore throat in the next six months if they decide not to have the operation; if they decide to have the operation they are likely to have about 13 days of severe pain immediately after surgery, and then on average half a day of sore throat in the next six months.

He would also make them aware that they might have minor postoperative complications and very rarely life threatening complications.

Source: BMJ.