Percutaneous ethanol injection (PEI) - procedure aimed to reduce the size of the thyroid nodule.
Benign cysts and predominantly cystic thyroid nodules have an estimated risk of malignancy smaller than 1% and 3%, respectively. They can be qualified for PEI by an endocrinologist based on their ultrasonographic (US) features and / or results of a fine needle biopsy (FNA).
In these particular types of nodules PEI is effective and safe. Therefore it is dedicated to patients who would like to avoid thyroid surgery and do accept an extremely small (below 3%) risk of residual malignancy.
For PEI the patient does not have to be admitted to hospital. The whole Procedure takes several minutes and is similar to FNA: after the skin of the neck is sterilized a thin needle is inserted into the selected nodule with US guidance, some fluid is aspirated, and then a small volume of 95-99% ethyl alcohol solution is injected. Alcohol causes coagulative necrosis of the tissue within the nodule. The succes rate after PEI i.e. nodular size regression is 75-85%. Sometimes a single ethanol injection in insufficient and it has to be repeated after several months.
There are few possible complications of the Procedure including: mild to moderate burning pain, flushing, dizziness, and dysphonia. These side effects may last several days.
As the influence of the injected ethanol on concentration is uncertain patients should refrain from driving a car or similar activities for 24 hours.