Endocrine Abstracts

Introduction: Percutaneous ethanol injection (PEI) or thyroid enolisation is a minimally invasive technique applicable to benign cystic thyroid nodules, not adhered to neighbouring structures, due to local compressive symptoms or aesthetic discomfort. Classically, the treatment of choice for these nodules has been simple aspiration, followed by surgery in refractory cases. Currently, PEI has emerged as an alternative to surgery due to its high efficacy, speed, safety, low rate of serious side effects, outpatient nature and low cost. Although it is a procedure with limited experience, it is safe when performed by experienced professionals.

Method: Prospective observational study including 14 patients undergoing PEI in our Endocrinology Clinical Management Unit between January 2020 and December 2022. Demographic, clinical and ultrasound data were collected prior to the procedure. All patients underwent prior ultrasound-guided fine needle aspiration puncture (FNA) with a cytological diagnosis of benignity, and all had a history of simple evacuation with subsequent recurrence of the nodule. Technique: a single ultrasound-guided puncture was performed, without anaesthesia, following a transisthmic approach; using a double guidewire, the cystic content was emptied almost entirely, immediately followed by the administration of 10cc of 99% ethanol; a 30-minute observation was then maintained for the possible appearance of symptoms and/or immediate complications. Evacuated content was quantified and an ultrasonographically follow-up at 3 and 6 months was performed.

Results: The highest percentage of reduction was observed in men vs women (68.0±23.71 vs 23.10±31.6); in patients over 70 y.o. vs under 50 y.o. and between 50-70 y.o. (35.30±27.54 vs 20.0±39.77 and 29.90±25. 22, respectively); in single nodule vs multinodular goitre (34.4±21.57 vs 20.0±25.60); in TIRADS-2 vs TIRADS-1 and TIRADS-3 (32.6±38.37 vs 25.7±24.84 and 21.4±15.91, respectively) and in older nodules vs those with a shorter time of evolution (37.3±28.05 vs 23.4±33.23).

Conclusions: PEI is an effective treatment for symptomatic cystic thyroid nodules, with a mean reduction in nodule size of 29.7% at 6 months. After a second PEI, performed in 3 patients, the performance of the technique improved with a mean reduction of 35.7% at 12 months follow-up. No serious side effects were reported (transient pain in 53.8% of cases). The highest percentage of reduction is observed in men, older than 70 y.o., with single nodule, TIRADS-2 and >5 years of evolution. These results are not statistically significant, probably due to the small sample size.