Polidocanol – a safer and equally effective alternative to ethanol for the treatment of thyroid cysts?
Reviewed by Christopher Burgess

Percutaneous needle aspiration is a minimally invasive treatment option for thyroid cysts but suffers from a high recurrence rate (86% in 1 case series). This recurrence rate can be reduced substantially with the instillation of ethanol following aspiration. Ethanol instillation is, however, rarely associated with significant complications including recurrent laryngeal nerve palsy and Horner’s syndrome. Polidocanol is a sclerosing agent used to treat spider, reticular and varicose veins. This agent has also previously shown efficacy in treating thyroid cysts. The reported efficacy is similar to ethanol but with a lower incidence of adverse events (11% vs. 26%) according to a previous prospective study. This paper reports the outcomes of a modified polidocanol instillation technique to treat thyroid cysts, whereby the cyst was irrigated with saline after aspiration prior to polidocanol administration. This irrigation process was added to help with the removal of viscous and other cyst contents in the hope of creating a more favourable environment for the sclerosant. Outcomes were recorded 12 months post intervention for 126 nodules treated from 2021 to 2023. The overall effectiveness rate was reported to be 91.3%, with an 11.2% rate of adverse events. These adverse events were minor, with no voice alteration encountered in any treated patient. Considering that the previously reported success rate of polidocanol instillation for thyroid cysts was 93.4% following aspiration without saline irrigation, with a 10.5% adverse event recorded, it is unclear what the benefits of the modified instillation technique are. Nevertheless, the data from this paper support the suggestion that polidocanol represents an equally effective alternative to ethanol for the treatment of thyroid cysts. It is also possible that polidocanol has a lower side-effect profile than ethanol based on historic data, albeit at a higher cost for the sclerosant material relative to ethanol.

Modified ultrasound-guided polidocanol sclerotherapy is an effective treatment for thyroid cystic-solid nodules: A single-center retrospective study.
Shuihua X, Ying C, Lanjing W, Zhengming H.
AM J OTOLARYNGOL
2026;47(2):104797.