The risk factors for postoperative temporary vocal cord paralysis after thyroid cancer surgery: an observational retrospective cohort study

Objective: To analyze the potential factors influencing new-onset postoperative transient vocal cord paralysis (VCP) in thyroid cancer patients. Methods: Case information of 8,340 thyroid cancer patients hospitalized at XX from January 2018 to December 2020 was collected retrospectively and analyzed. The possible influencing factors were analyzed using a chi-square test, rank-sum test, and multiple logistic regression analysis. A nomogram was used to construct the clinical prediction model that was validated in the validation set by ROC, calibration curves, and DCA. Results: The STROCSS guideline was followed to conduct a retrospective cohort study. A total of 8,340 patients, including 1,817 (21.8%) men and 6,523 (78.2%) women, were enrolled in this study. The rate of temporary VCP was 3.6% (308/8,340). Based on the results of postoperative laryngoscopy, the patients were divided into VCP group and non-VCP group. Comparative analysis between the groups revealed that potential factors associated with postoperative transient VCP were tumor location on the dorsal side of the gland (P = 0.042), ultrasound showing a maximum nodal diameter > 1 cm (P = 0.002), multifocal carcinoma (P < 0.001), invasion of surrounding tissue (P = 0.005), lymph node metastases in the central compartment (P = 0.034), lateral cervical lymph node metastasis (P < 0.001), and prolonged operation (P < 0.001). A multiple logistic regression analysis showed that the independent risk factors in postoperative transient VCP were T stage (OR = 1.411, P = 0.013, 95% CI: 1.075-1.853), multifocal carcinoma (OR = 1.532, P = 0.013, 95% CI: 1.095-2.144), and duration of surgery (OR = 1.009, P < 0.001, 95% CI: 1.006-1.012). Finally, a clinical prediction model was established via a nomogram and was validated in the validation set, although its diagnostic efficacy needs to be improved further. Conclusion: High T stage, multifocal carcinoma, and prolonged operation time may be independent risk factors for the occurrence of postoperative transient VCP in patients undergoing initial surgery for thyroid cancer.