Perithyroidal hemorrhage caused by hydrodissection during radiofrequency ablation for benign thyroid nodules: Two case reports

BACKGROUND: Hydrodissection is a widely used technique during radiofrequency ablation (RFA) for benign thyroid nodules. Although it could effectively avoid thermal injury to the surrounding critical structures and achieve complete treatment, routine operation of the remaining needle could cause perithyroidal hemorrhage. In this report, we present 2 cases of perithyroidal hemorrhage during RFA caused by a hydrodissection needle, which have not been reported before. CASE SUMMARY: A 21-year-old female and a 45-year-old male were admitted for RFA for benign thyroid nodules. Considering that their nodules were adjacent to the recurrent laryngeal nerve, the needle used for hydrodissection was placed and remained between the dorsal capsule of the lateral lobe and the recurrent laryngeal nerve. During the procedure, active bleeding near the needle appeared on ultrasonography (US). Although moderate pressure was quickly applied to the neck for several minutes, contrast-enhanced US (CEUS) still showed an active hemorrhage. A radiofrequency electrode was placed at the bleeding point under the guidance of CEUS to stop the bleeding, and the procedure was finally confirmed to be successful by CEUS, without other complications. CONCLUSION: Hydrodissection during RFA of benign thyroid nodules was associated with a risk of perithyroidal hemorrhage. The timely recognition of this acute hemorrhage could help in the timely control of the bleeding, and CEUS-guided ablation of the bleeding point could be useful.