Evaluation of perithyroidal adhesion after thermal ablation of thyroid nodules: a self-controlled study.

PURPOSE: Patients with recurrent or new thyroid nodules after first ablation occasionally require repeat thermal ablation (re-ablation). However, there has been no research focused on perithyroidal adhesion and complications in re-ablation of thyroid nodules. This study aimed to investigate the incidence of perithyroidal adhesion and complication in re-ablation of thyroid nodules. METHODS: This retrospective self-controlled study enrolled a total of 71 patients who underwent re-ablation of thyroid nodules located in the same lobes as the first ablation. Perithyroidal adhesion at re-ablation was evaluated with hydrodissection in ultrasound images during surgery. Perithyroidal adhesion and complications at re-ablation were compared to those at first ablation. RESULTS: Definite adhesion was not encountered at either re-ablation or first ablation. Partial adhesion occurred in two cases (2.7%, 2/71) at re-ablation and no cases at first ablation. Re-ablation and first ablation did not differ in terms of the occurrence of definite and partial adhesion (p = 0.49). Major complications were encountered in one case (1.4%, 1/71) during re-ablation and three cases (4.2%, 3/71) during first ablation. Minor complications were encountered in one case (1.4%, 1/71) during re-ablation and two cases (2.8%, 2/71) during first ablation. There were no significant differences between re-ablation and first ablation in rates of total (p = 0.43), major (p = 0.61), and minor (p = 1.00) complications. CONCLUSION: Thermal ablation did not induce definite adhesion in the perithyroidal soft tissue of patients with thyroid nodules. Partial adhesion was rare and had no clinical impact. The incidence of complications during re-ablation was not higher than that at first ablation.