Ethanol ablation of cystic thyroid nodules: institutional experience with one year follow-up

Background: We aimed to identify the main factors influencing the achievement of high efficacy or negative outcomes for ethanol ablation (EA) of cystic thyroid nodules. Methods: We conducted a retrospective cohort study on consecutive patients treated with EA for cytologically benign and symptomatic CTNs at the Vanvitelli University Hospital in Naples (Italy) over a period of four years. Data was analyzed using multivariable logistic regression and Fisher's exact test. All tests were performed at the significant level of 0.05. Results: We included 118 nodules undergoing EA with one year follow-up [median volume 16.2 (7.0–32.8) mL], with important cervical symptomatology [overall visual analogue scale (VAS) score 26.0 (22.0–30.0) and cosmetic score (CS) 4.0 (3.0–4.0)]. At 12 months follow-up (T12), median VRR was 88.9 (77.2–97.6) %, overall VAS score and CS were 0 (0.0–1.5) and 1.0 (1.0–1.0), respectively. The classical EA was the only predictor of VRR > 75% (OR = 3.27; 95% CI 1.01–10.57; p = 0.048). Monolocular aspect was the only predictor (OR = 5.719; 95% CI 1.664–19.652; p = 0.006) of VAS = 0 and CS = 1. Conclusions: EA for CTNs is usually associated with high efficacy and rarely (one out of ten patients) with negative outcomes at one-year follow-up. The classical EA procedure (when the cystic content can be initially aspirated) and the monolocular aspect thyroid nodules seem to be factors that positively influence the high efficacy of EA, regardless of baseline nodule volume, ultrasound composition, number of EA sessions, and total ethanol amount.