Radiofrequency ablation of benign thyroid nodules: the value of anterolateral hydrodissection.

Purpose: This study aimed to evaluate the technical feasibility, efficacy, and safety of anterolateral hydrodissection (ALHD) in radiofrequency ablation (RFA) for benign thyroid nodules.

Methods: Between November 2019 and April 2020, 39 patients underwent 41 sessions of RFA with the ALHD technique to treat benign thyroid nodules. ALHD was performed with cold (0°C-4°C) 5% dextrose solution during RFA to minimize pain and secure sufficient safety margins from critical neck structures. The initial ablation ratio (IAR) was measured to assess the technique's efficiency. Ultrasound examinations, symptoms, and cosmetic scores were evaluated pre-procedure and at 6 and 12 months post-procedure. Procedure-related pain during RFA and complications were recorded.

Results: The mean index nodule volume was 20.5±21.6 mL. ALHD was technically feasible in all patients. The mean IAR was 90.7%±8.3%, and significant reductions in mean nodule volume were noted at 6- and 12-month follow-ups (P<0.001, 63.9%±19.0%, and 76.3%±18.9%, respectively). Symptom and cosmetic scores showed significant improvements at 6- and 12-month follow-ups (P<0.001). Pain during the procedure was well-controlled with ALHD in all patients. After the initial use of 5-10 mL of lidocaine at the start of the procedure, no further lidocaine injection was given to any patient. Transient voice change was observed in one patient, but the patient recovered spontaneously within 30 minutes.

Conclusion: The ALHD technique was technically feasible and effective in all patients, achieving a mean IAR of 90.7%. The ALHD technique also had a pain-relieving effect, resulting in only low amounts of lidocaine administration being required during the procedure.