Objective To investigate the causes and treatment of recurrent laryngeal nerve （RLN） injury during the operation of thyroidectomy. Methods Clinical data of 48 patients that RLN were injured during thyroidectomy in and out of our hospital from Jun. 2003 to Mar. 2007 were reviewed. Results No patient died while operation and staying in hospital. There were 47 cases of unilateral RLN injury, 1 case of bilateral RLN injury; 21 cases （43.7%） were injured because of suture or scar adhesion, 13 cases （27.1%） were partly broken with formed scar, 14 cases （29.2%） were completely cut off; The locations of RLN injuries were closely adjacent to the crossing of the inferior thyroid artery and RLN in 13 cases （27.1%） and 35 cases （72.9%） were within 2 cm below the point of RLN entering into throat. The injured RLN were repaired surgically in 43 cases, among which 39 cases’ phonation and vocal cord movement were restored completely or had their vocal cord movement recovered partly; There were only 4 cases that the phonation and vocal cord movement were not recovered. Another 5 cases that did not take any repair did not recovered naturally. Conclusion The location of most RLN injuries caused by mechanical injury during thyroid surgery is closely adjacent to the entrance of RLN into throat. Early nerve exploratory operation should be performed once the RLN is injured, and the method of repair should be decided according to concrete conditions of injury．
Objective To investigate the number and location of parathyroid glands in relation to thyroid gland, to increase the knowledge about anatomical variation of parathyroid glands, and to reduce injury of the parathyroid and recurrent laryngeal nerve. Methods A total of 50 cadavers were sectioned. The number and distribution of parathyroid glands and their relations with adjacent structures were observed. Results Mean number of parathyroid glands in one individual was 3.52±0.48, mainly located at the retro-medialis of thyroid, which was called “tri-domain and one area”. Superior parathyroid glands were mainly located in the area of cornu inferior thyroidal cartilage; the inferior parathyroid glands except ectopic parathyroid glands were located in radix nasi of thyroid glands; while the area around inferior thyroid artery contains both the superior and inferior parathyroid glands. These three areas constitute the region of retro-medialis of thyroid that parathyroid glands were inclined to get injured. Most superior parathyroid glands were located beside the lateral of recurrent laryngeal nerve （67.8%） and the inferior parathyroid gland mainly located next to recurrent laryngeal nerve （71.9%）, both showed statistical significance (P＜0.005). About 85.0% of superior parathyroid located in the area around posterior suspensory ligament of thyroid, and most common place for ectopic parathyroid gland was around lingual lobe of thymus (28.6%). Conclusion With extreme caution, familiarity with anatomy and skillful technique, the injury to parathyroid glands and recurrent laryngeal nerve can be prevented, which may not be a restrain of putting standard thyroid operation into practice.