Experience of prophylactic lymphodissections for papillary thyroid carcinoma according to hospital registry data

Abstract. Prophylactic central lymph node dissection (PCLND) of the neck for papillary thyroid carcinomas (PTC) is one of the widely discussed issues, on which there is still no consensus. Most researchers discuss the range of indications for PCLND, recognizing that along with increased oncologic radicality, it increases the risk of postoperative hypoparathyroidism and phonation disorders. The aim. To evaluate the outcomes of PCLND performance in PTC according to hospital registry data. Material and methods. To assess the effectiveness of PCLND, all surgeries performed between 2015 and 2023 in patients with PTC were analyzed. All cases of cN0 and thyroidectomy (TE) only and TE+PCLND (1781 and 801 cases, respectively) were selected. Reoperations for disease progression were analyzed by comparing groups using Pearson’s χ² (mean follow-up 1.9 years). To analyze postoperative changes in phonation, a patient questionnaire was used. All cases of TE and TE+PCLND (1785 questions) were analyzed, and the comparison was also performed using Pearson’s χ² method. To assess the level of ionized calcium the day after surgery, the means were compared by t-test method and Fisher’s F-test (550 patients in total). Results. When analyzing reoperations in the entire group with a mean follow-up period of 1.9 years, no statistically significant difference was found between TE and TE+PCLND (p>0.05). Limiting the group to a follow-up period from 1 to 5 years (mean follow-up period 2.6 years) does not change the situation: 2.1% of reoperations for TE and 3% for TE+PCLND (p>0.05). According to the questionnaire data on phonation changes (total 1785 questions), it was revealed that after only TE, 55.2% of patients had complaints, whereas after TE+PCLND they were 60.2% (p<0.05). If we do not take into account the minimal complaint of minor voice hoarseness, the statistical significance of the differences becomes even more confident: p<0.001 (13.7% vs. 20.4%). Postoperative ionized calcium levels also had statistically significant differences between groups (for TE mean 1.15; for TE+PCLND mean 1.13). Comparison of means by the t-test method yielded p<0.001, and by Fisher’s test p<0.05. Conclusions. According to our hospital registry, performing PCLND for PTC does not result in a reduction in the percentage of reoperation but is associated with a higher percentage of phonation complaints and statistically significantly lower ionized calcium levels in the first day after surgery.