Methodology of percutaneous bi-polar radiofrequency ablation of thyroid adenomas under ultrasound guidance and monitoring

Abstract

Objective To establish a treatment proposal of thyroid adenoma by using percutaneous radiofrequency ablation(RFA) and investigate its techniques and skills, means and steps, and safety and efficacy. Methods Contrast-enhanced ultrasound-guided percutaneous RFA of thyroid adenomas were conducted on 202 patients by using an auto-controlled bi-polar electrode system. The indications of thyroid RFA,the optimal puncture route,the ways of anesthesia administration, protection of vital neck vessels and recurrent laryngeal nerve(RLN) and reduction of bleeding from core biopsy, indicators of ending ablation procedure following a complete ablation were investigated and analyzed. Resalts An adenoma smaller than 20 mm in maximal diameter was the optimal candidate for RFA. Either of two puncture routes could be selected upon the target lesion's location. Areas surrounding to the thyroid capsule needed adequate local anesthesia to kill pain. Liquid-isolating maneuver could effectively protect carotid artery and RLN from core needle cutting and electrode heating injury. Advanced block of supplying arteries with heating markedly reduced bleeding involved in the biopsy. Multipoint and multicenter ablation was essential to a complete coagulation. Filling-defect in the ablated adenoma on CEUS was the key sign to terminate ablation procedure. Conclusions Percutaneous bi-polar RFA was proved feasible, effective, safe and supermicroinvasive for treating thyroid adenoma under the way stated here of puncture and technical points and use of CEUS for monitoring. Key words: Ultrasonography; Microbubbles; Thyroid neoplasms; Catheter ablation