Correlation Between the Extent of Lateral Neck Lymph Node Dissection and Postoperative Parathyroid Function in Papillary Thyroid Carcinoma.

BACKGROUND

The graded effect of lateral neck dissection on parathyroid function in papillary thyroid carcinoma (PTC) is unclear. We compared outcomes across three progressively extensive dissection schemes.

METHODS

We retrospectively analysed 347 PTC patients who underwent total thyroidectomy with lateral neck dissection (2019-2023). Groups A (selective, levels II-IV) and B (modified comprehensive, levels II-V) had lateral-only dissection, whereas Group C (comprehensive plus ipsilateral central, levels II-V+VI) added central dissection; Group A-vs-B isolated pure lateral effect. Serum parathyroid hormone (PTH) and calcium were measured at five time points. Transient hypoparathyroidism: day-1 PTH<15 pg/mL recovering by 6 months; permanent: <15 pg/mL at 6 months. Analyses used linear mixed models, Kruskal-Wallis, and multivariable logistic regression.

RESULTS

Day-1 PTH decreased stepwise. Transient hypoparathyroidism increased stepwise, while permanent rates did not differ. Adjusted ORs: B vs A=3.07 (95%CI 1.63-5.79), C vs A=6.15 (3.01-12.54); C estimate reflects combined lateral-plus-central. Day-1 PTH <13.4 pg/mL predicted permanent hypoparathyroidism (AUC 0.835, sensitivity 100%, specificity 74%).

CONCLUSIONS

More extensive lateral dissection independently increases transient hypoparathyroidism, seen in purely lateral groups; the added increase with central dissection reflects central surgery. Permanent disease remained uncommon. Early day-1 PTH measurement shows promise as a triage tool for at-risk patients.