ObjectiveTo investigate the predictive value of pretracheal lymph node (Ⅵc) subdivision for contralateral central lymph node (CLN) metastasis in clinical lymph node negative (cN0) unilateral papillary thyroid carcinoma (PTC). MethodsThe data of patients with cN0 unilateral PTC who initially underwent total thyroidectomy and bilateral CLN dissection in the Department of Thyroid Surgery of West China Hospital, Sichuan University from July 2017 to June 2021 were collected retrospectively. The Ⅵc subdivision was divided into right anterior trachea (Ⅵc1) and left anterior trachea (Ⅵc2); If the lymph nodes crossed the middle line of trachea, which would be included in the side of cancer focus. ResultsA total of 175 patients were included in this study, and the incidences of lymph nodes metastasis in the prelaryngeal (Ⅵd), Ⅵc, ipsilateral Ⅵc, contralateral Ⅵc, ipsilateral central, and contralateral central regions were 54 cases (30.9%), 118 cases (67.4%), 85 cases (48.6%), 72 cases (41.1%), 108 cases (61.7%), and 43 cases (24.6%), respectively. The results of the univariate analysis found that the contralateral CLN metastasis was associated with the lymph node metastases of Ⅵd, Ⅵc, contralateral Ⅵc, and ipsilateral central regions; The results of the multivariate analysis found that the lymph node metastases of Ⅵd and contralateral Ⅵc regions increased the probability of contralateral CLN metastasis (OR=4.444, P<0.001; OR=6.655, P=0.001). ConclusionsFrom the results of the study,Ⅵc subdivision is reasonable and effective, and has a certain predictive value for the metastasis of contralateral CLN in cN0 unilateral papillary thyroid carcinoma. And bilateral CLN dissection should be recommended in patients with a positive intraoperative frozen section result of contralateral pretracheal lymph node metastasis.