Abstract: Objective To investigate the deep lymph node metastasis of right recurrent laryngeal nerve(RLN) in patients with papillary thyroid carcinoma(PTC) after total thyroidectomy.
Methods 80 patients with papillary thyroid cancer in our hospital from November 2017 to November 2019 were selected.All patients were treated with total thyroidectomy combined with bilateral central lymph node dissection or right central lymph node dissection according to their condition.The right central lymph nodes were divided into superficial(Ⅵ a) and deep(Ⅵ b) according to the boundary of recurrent laryngeal nerve,The pathological samples of all lymph nodes were detected in time,and the lymph node metastasis of all patients was recorded according to the detection results.The related factors were analyzed by univariate and multivariate logistic regression analysis.
Results In this study,47 cases of PTC patients had cervical lymph node metastasis,the positive rate of lymph node metastasis was 58.8%,the average number of lymph node dissection was 13.65±2.15,the average number of positive lymph nodes was 5.61±1.17.Among them,the positive rate of deep lymph nodes of right recurrent laryngeal nerve was 15.0%,the positive rate of superficial lymph nodes was 55.0%,the positive rate of deep lymph nodes of right recurrent laryngeal nerve combined with superficial lymph nodes was 12.5%,and the positive rate of cervical lymph nodes was 6.3%.After univariate and multivariate logistic regression analysis,multiple tumors,tumor diameter > 10mm,positive lymph nodes in superficial layer of right recurrent laryngeal nerve and positive lymph nodes in lateral cervical region were independent risk factors of deep lymph node metastasis of right recurrent laryngeal nerve in PTC patients,and the difference was statistically significant(P<0.05).
Conclusion The number of tumors,tumor size,the positive superficial lymph nodes of the right recurrent laryngeal nerve and the cervical lymph nodes are the risk factors affecting the deep lymph node metastasis of the right recurrent laryngeal nerve in PTC patients.For these patients,the range of central lymph node dissection should include the deep lymph node of the right recurrent laryngeal nerve,in order to ensure the thoroughness of lymph node dissection and reduce the risk of postoperative recurrence.

Key words: papillary thyroid carcinoma, central regional lymph nodes, deep lymph node of the right recurrent laryngeal nerve, risk factors