To investigate time of delayed reinnervated laryngeal muscle, 15 dogs were divided into two groups. The right recurrent laryngeal nerves of 10 dogs in experimental group were cut, and repaired at 4, 6, 8, 10 and 12 months intervals by transposition of the phrenic nerve to the recurrent laryngeal nerve after cutting and suturing the adductor branch to the main branch of ansa cervicalis. The right recurrent laryngeal nerves of 5 dogs in control group were cut, but did not repair. Laryngoscope, electromyography, contractile tension of laryngeal muscle and histologic studies were performed at six months postoperatively. The results showed that fair recovery of adduction and abduction was noted within ten months interval, and the effect of adduction was better than that of abduction. The effect decreased gradually with the denervated time increased. The conclusion demonstrated that delayed reinnervation of laryngeal muscle should be performed within ten months.
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.
Objective To explore the clinical significance of exposure the recurrent laryngeal nerve（RLN） for preventing the RLN injury in thyroidectomy. Methods The data of 1 723 patients with thyroid diseases undergoing total or subtotal thyroidectomy from September 2006 to August 2011 were retrospectively reviewed. RLN were exposed in 914 cases, 1 203 RLNs were exposed（exposed group）. RLN were unexposed in 809 cases, 1 013 sides were cut（unexposed group）. To compare RLN injury rate after operation and recovery of vocal cord in 6 months after operation between the two groups. Results In exposed group, 11 cases had RLN injury, the rate of RLN lesion was 0.91%. In unexposed group, 21 cases had RLN injury, the rate of RLN lesion was 2.07%. The differences between the two groups had statistical significance（P＜0.05）. When six months after operation, 0 case and 13 cases in exposed group and unexposed group respectively occurred permanent RLN injury, the differences between the two groups had statistical significance（P＜0.01）. Conclusion Exposure of RLN in total and subtotal thyroidectomy can significant avoid RLN injury, especially RLN permanent injury.
Objective To investigate the indications and prevention of complications of total thyroidectomy in the management of thyroid diseases. Methods Eighty five patients who received total thyroidectomy between Jan. 2009 and Dec. 2011 were retrospectively analyzed with regard to the surgical procedures and postoperative complications. There were 46 thyroid cancers， 38 nodular goiters， and 1 Hashimoto thyroiditis. Results The postoperative pathological exam-inations revealed that 9 （19.6%） of 46 thyroid cancers were bilateral， and all of nodular goiters were also bilateral multiple nodule. Bilateral recurrent laryngeal nerves were exposed in all of the patients in which 4 recurrent laryngeal nerves were invaded by cancer and 1 was sacrificed. There were 5 patients whose parathyroids were not identified and protected during the operation. Two patients developed postoperative bleeding and needed reoperation， 6 patients developed hoarseness of whom 5 patients recovered except for the one whose nerve was sacrificed. And in terms of hypoparathyroidism， 33 （38.8%） patients developed transient hypocalcemia related symptoms. The permanent hypoparathyroidism occurred only in 2 patients. Conclusions Total thyroidectomy is a safe procedure in the management of thyroid cancer and bilateral nodular goiter. Exposing the recurrent laryngeal nerve and parathyroid is an effective method to prevent major complica-tions. Invasion of recurrent laryngeal nerve by thyroid cancer might not lead to hoarseness.
Objective To assess the value and usage of real-time monitoring of the recurrent laryngeal nerve (RLN) during thyroid reoperation by RLN monitor. Methods One hundred and one patients were under general anesthesia and thyroidectomy. NIM-Response electromyographic (EMG) monitor system was used for assistant of dissection, exposure and protection of the RLN during the surgical procedures.Results There were 192 RLN were exposed during the surgeries in all 101 patients. The unilateral RLN injured in 10 patients was not specially explored the same side nerve. Among them 190 nerves were confirmed intact, the rest 2 nerves were resected because of tumor involving. Conclusions NIM-Response electromyographic monitor system is sensitive and accurate for preserving the integrity of RLN during the thyroid reoperations. It is valuable for protecting RLN against iatrogenic injury. This system deserves general utilization for thyroid surgery, especially reoperation.
ObjectiveThe aim of this study was to evaluate the repair effect of spontaneous reinnervation in rats underwent recurrent laryngeal nerve (RLN) transection. MethodsThirty male Wistar rats (340-360 g) were divided into experiment group (n=15) and blank control group (n=15), and then 15 rats of these 2 groups were divided into 3 time point groups equally:4 weeks group, 8 weeks group, and 12 weeks group. Fifteen rats of experiment group underwent right RLN transection with excision of a 5 mm segment, and other 15 rats of blank control group exposed RLN only, without transection. Grade of vocalization, maximum angle of arytenoid cartilage, axon number of distal part of RLN, and expression of the brain-derived neurotrophic factor (BDNF) in right thyroarytenoid muscle were evaluated at different time points, including 4, 8, and 12 weeks after operation. ResultsGrade of vocalization, maximum angle of arytenoid cartilage, axon numbers of distal part of RLN, and the expression of BDNF in the right thyroarytenoid muscle of experiment group were all lower than those corresponding index of blank control group (P < 0.05), and these indexes of experiment group were restored gradually with time, but failed to reach normal level during the observed time. ConclusionsEven though spontaneous reinnervation is presented after RLN injury, but the effect is unsatisfactory.
ObjectiveTo research the relevancy between the amplitudes of EMG signal of recurrent laryngeal nerve (RLN) during thyroidectemy with the movement of vocal cords after operation by applying the intraoperative neuromonitoring (IONM) and verify the proper warning criterion. MethodsFrom April 2013 to October 2013, 130 patients (214 nerves at risk) underwent complex thyroidectomy with the application of IONM. According to the degree of amplitude changing on different sites of RLN (proximal site and distal site) before closing incision, all the patients were divided into 10 groups. Every patient's vocal cords movement after operation by laryngoscopy and simulated the neural function in real time were compared. ResultsSeven patients got abnormal movement of vocal cords, the corresponding amplitudes of the EMG signal of RLN were in the range between 0 to 50%, 1 case from Group 6 (40%≤Rp/Rd<50%), 1 case from Group 8 (20%≤Rp/Rd<30%), 1 case from Group 9 (10%≤Rp/Rd<20%), 4 cases from Group 10 (0≤Rp/Rd<10%), and there's no permanent RLN palsy. ConclusionThe final amplitude of RLN decrease below 50%R1 would probably lead to vocal cords' abnormal movement, and when it decrease below 30%R1, the possibility of abnormal movement would increase; 50% decrease of EMG amplitude can be used as a warning criterion to prevent nerve function damage.
OBJECTIVE In order to investigate the opportunity of repair and prognosis of recurrent laryngeal nerve injuries after thyroidectomy. METHODS Twelve cases with recurrent laryngeal nerve injuries after thyroidectomy were immediately and delayed operated on nerve repair and reinnervation. In immediate operation, 5 cases were repaired by direct recurrent laryngeal nerve suture, and 1 case was treated by transposition of the phrenic nerve to the recurrent laryngeal nerve and sutured the adductor branch to the branch of ansa cervicalis. In delayed operation, 3 cases were treated by anastomosis the main trunk of ansa cervicalis to the adductor branch of recurrent laryngeal nerve, and 3 cases were operated on neuromuscular pedicle to reinnervate posterior cricoarytenoid muscle. RESULTS Followed up 6 months, the effect was excellent in 1 case who was immediately operated by selective reinnervation of the abductor and adductor muscles of the larynx, better in 9 cases, and poor in 2 cases who were delayed operated over 12 months. CONCLUSION It can be concluded that the earlier reinnervation is performed, the better prognosis is.
ObjectiveTo investigate effect of recurrent laryngeal nerve monitoring in video-assisted thyroidectomy for huge thyroid nodules. MethodsThe clinical data of 158 patients with huge thyroid nodules underwent videoassisted thyroidectomy from January 2013 to June 2015 were analyzed retrospectively, the recurrent laryngeal nerves were monitored in 79 cases (monitoring of recurrent laryngeal nerve group) while the recurrent laryngeal nerves were not monitored in the other patients (non-monitoring of recurrent laryngeal nerve group). The operative time, blood loss, postoperative drainage, postoperative hospital stay, and the incidences of transient and permanent recurrent laryngeal nerve injury were observed between these two groups. ResultsThe video-assisted miniincision thyroidectomy was successfully completed in these 158 cases. Compared with the non-monitoring of recurrent laryngeal nerve group, the operative time (min) was shorter (76.2±23.4 versus 89.2±29.8, P < 0.05), the blood loss and the postoperative drainage were less (16.3±13.6 versus 20.6±10.7, P < 0.05; 20.7±9.6 versus 25.5±9.1, P < 0.05) in the monitoring of recurrent laryngeal nerve group. But the postoperative hospital stay (d) had no significant difference between the monitoring of recurrent laryngeal nerve group and the non-monitoring of recurrent laryngeal nerve group (3.2±1.3 versus 3.3±1.9, P > 0.05). Eight weeks later, the incidence of transient recurrent laryngeal nerve injury in the monitoring of recurrent laryngeal nerve group was significantly lower than that in the non-monitoring of recurrent laryngeal nerve group [5.6% (5/90) versus 21.8% (17/78), P < 0.05], while the incidence of permanent nerve injury had no statistical difference between the monitoring of recurrent laryngeal nerve group and the non-monitoring of recurrent laryngeal nerve group [0(0/90) versus 1.3% (1/78), P > 0.05]. ConclusionRecurrent laryngeal nerve monitoring under video-assisted thyroidectomy for huge thyroid nodules could effectively reduce incidence of nerve injury and shorten operation time.