Tonsillectomy is an effective treatment option for obstructive sleep apnoea in selected adult patients, but there has been a lack of long-term follow-up data.

To analyse the long-term outcomes of extracapsular tonsillectomy in the treatment of obstructive sleep apnoea in adults, with the longest follow-up periods to date.

We recruited adults who had undergone extracapsular tonsillectomy because of obstructive sleep apnoea between 2004 and 2018 in the Hospital District of Southwest Finland. A new home sleep study, questionnaires, and a structured phone interview were conducted on these patients 4–17 years after surgical treatment. The primary outcome was the change in the apnoea-hypopnoea index.

The mean apnoea-hypopnoea index was reduced from 27.1 preoperatively to 14.1 after the long-term follow-up (mean 12 years), and the mean Epworth Sleepiness Scale score decreased from 9.2 to 4.6. The long-term surgical success rate was 38.5%. Four out of five patients would choose the surgery again according to the phone interview.

This study supports the notion that extracapsular tonsillectomy alone can be considered as a surgical treatment option for selected adults with obstructive sleep apnoea and tonsillar hypertrophy. For most of the patients, the obstructive sleep apnoea is alleviated.