Difficulties and countermeasures in reoperation of postoperative recurrence of thyroid cancer        ZHU Yi-ming, LIU Shao-yan. Department of Head and Neck Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College，Beijing 100021, China
Corresponding author: LIU Shao-yan, E-mail: shaoyanliu.bj@263.net
Abstract    Differentiated thyroid cancer has a good prognosis. Recurrence of thyroid cancer requires comprehensive treatment based on reoperation. Compared with the initial surgery, the risk of reoperation is significantly increased, and the incidence and severity of complications are elevated. Therefore, adequate evaluation and well-informed consent should be carried out before the reoperation. The difficulty of reoperation in the central compartment lies in grasping the surgical indications, intraoperative localization of the recurrent lymph nodes, intraoperative protection of the recurrent laryngeal nerve and parathyroid glands, and the treatment of invasion of surrounding organ structures. Preoperative ultrasound-guided nanocarbon injection can be reliably helpful in intraoperative localization. Intraoperative nerve monitoring techniques can be helpful in the identification of the recurrent laryngeal nerve. If the recurrent laryngeal nerve needs to be removed, repair it at the same time as possible. During the operation, reducing the disturbance of the superior parathyroid area, carefully identifying the parathyroid glands in the specimen, and if necessary, parathyroid autotransoplantation can protect the parathyroid gland as much as possible. When the trachea, larynx, and esophagus involved, techniques such as partial laryngectomy, trachelectomy, and reconstruction are required. The difficulty of reoperation in the lateral cervical region lies in the re-excision of easily missed sites in initical neck dissection, the treatment of some rare recurrent sites such as parapharyngeal, and the treatment of nerve and large vessel invasions. Standardized zone dissection is still the main treatment for recurrent metastatic lymph nodes in the lateral cervical region. For the recurrence of rare sites, we should be familiar with local anatomy to reduce secondary injury. Functional nerves should be preserved whenever possible. The internal jugular vein can be removed if necessary. Recurrence in the superior mediastinal region is mainly accomplished by superior mediastinal dissection. The open access with sternal splitting provides better exposure, which makes a wide resection possible, and is relatively safe but larger traumatic. The endoscopic superior mediastinum dissection is less invasive and requires relative trainings. The prognosis of recurrent thyroid cancer is quite good with active treatment. Reoperation is recommended to be performed by experienced specialists. Postoperative adjuvant multidisciplinary treatment can improve the efficacy of reoperation.