Surgery After Thermal Ablation of Thyroid Nodules: A Systematic Review of Surgical Risk, Strategy and Pathological Findings

Background: Thermal ablation is increasingly used for selected thyroid nodules, but some patients subsequently require thyroidectomy. The effect of prior ablation on surgical risk, operative strategy, and histopathology remains unclear. Methods: PubMed/MEDLINE, EMBASE, and the Cochrane Library were searched from inception to May 2026 for studies reporting surgical and/or histopathological outcomes of thyroidectomy after radiofrequency, laser, or microwave ablation. Cohort studies and case series with at least two patients were included. Data were synthesized descriptively and stratified by ablation indication: benign/indeterminate nodules versus primary papillary thyroid carcinoma. Results: Nine retrospective studies including 150 patients were included: six on benign/indeterminate nodules (n = 105) and three on primary papillary thyroid carcinoma (n = 45). In benign/indeterminate cases, transient recurrent laryngeal nerve palsy ranged from 0% to 9.7%, transient hypoparathyroidism from 0% to 6.5%, and hematoma requiring reoperation from 0% to 6.5%; no permanent recurrent laryngeal nerve palsy or hypoparathyroidism was reported. Controlled studies showed longer operative times, higher thyroidectomy difficulty scores, and more severe adhesions after ablation, although overall complication rates did not differ significantly. Histopathology showed fibrosis, hyalinization, coagulative necrosis, and treatment-related atypia, potentially complicating assessment of follicular-patterned neoplasms; no carcinoma arising within the ablated zone was identified. In the papillary thyroid carcinoma group, surgical specimens frequently revealed residual tumor and lymph node metastases after ablation used as primary treatment, while oncological follow-up was largely absent. Reporting of surgical strategy and intraoperative adjuncts was inconsistent. Conclusions: Thyroidectomy after thermal ablation appears feasible in experienced endocrine surgery centers, with low reported permanent morbidity, but may be technically more complex than primary surgery. Current evidence is limited to small, heterogeneous retrospective series and cannot define the true incremental surgical risk, optimal operative strategy, or long-term oncological impact of prior ablation. Prospective multicenter comparative studies with standardized reporting are needed.