A large-scale study of patients with preoperative vocal cord paralysis associated with thyroid disease and related clinicopathological features.

BackgroundThe performance of thyroidectomies has been increasing over the last decade due to the growing prevalence of thyroid diseases. The purpose of this study was to investigate the clinical significance of preoperative vocal cord paralysis (VCP) associated with thyroid disease and other incidences of malignant or benign lesions, as well as different thyroid pathological features. Additionally, the epidemiological changes of thyroid diseases with preoperative VCP were investigated.MethodsNinety-nine out of 12,530 patients with preoperative VCP who had undergone thyroid surgery for various diseases in the Zhejiang Cancer Hospital from January 2007 to December 2015 were identified. Their clinicopathological data was recorded and case distributions from different years and intraoperative recurrent laryngeal nerve statuses were retrospectively analyzed.ResultsThe incidence of preoperative VCP in 2007 was reported to be 1.53% (9/590) and had decreased to 0.53% (12/2,247) by 2015 ( < 0.05). Among the 99 patients with preoperative VCP, 81 had malignancies (81.82%), while 18 (18.18%) had benign thyroid diseases. The incidences of preoperative VCP in malignant and benign diseases were 1.13% (81/7,159) and 0.35% (18/5,371), respectively ( < 0.05). There were only 5 (0.04%, 5/12,530) cases of papillary thyroid microcarcinoma with preoperative VCP. There was no statistical difference between the incidence of preoperative hoarseness in malignant 69.14% (56/81) and benign diseases 61.11% (11/18) with preoperative VCP.ConclusionsThe preoperative VCP incidence rate had gradually decreased with an increased proportion of papillary thyroid cancer. Preoperative voice symptoms do not necessarily suggest a malignancy. Selective rather than routine preoperative laryngoscopic examinations should be performed on papillary thyroid microcarcinomas. The probability of preoperative VCP in malignancy was significantly higher than in benign lesions.