Total thyroidectomy is safer with identification of recurrent laryngeal nerve

Objective:To investigate the effect of recurrent laryngeal nerve(RLN)identification on the complications after total thyroidectomy and lobectomy.Methods:Total 134 consecutive patients undergoing total thyroidectomy or thyroid lobectomy from January 2003 to November 2004 were investigated retrospectively.Patients were divided into two groups:RLN identified (Group A)or not(Group B).The two groups were compared for RLN injury and hypocalcaemia.Results:The numbers of patients and nerves at risk were 71 and 129 in Group A,and 63 and 121 in Group B,respectively.RLN injury in Group A(0)was sig- nificantly lower than that in Group B(57.9%)patients,75.8%nerves)for the numbers of patients(P=0.016)and nerves at risk (P=0.006).Temporary hypocalcaemia was significantly higher in Group A than in Group B(1424.1%vs 610.3%,P=0.049). Permanent complications in Group B were significantly higher than those in Group A(1320.6%vs 45.6%,P=0.009).Con- clusion:RLN injury was prevented and permanent complications were decreased by identifying the whole course and branches of the recurrent laryngeal nerve during total thyroidectomy.

Adipose-derived mesenchymal stem cells accelerate nerve regeneration and functional recovery in a rat model of recurrent laryngeal nerve injury

Medialization thyroplasty or injection laryngoplasty for unilateral vocal fold paralysis cannot restore mobility of the vocal fold. Recent studies have shown that transplantation of mesenchymal stem cells is effective in the repair of nerve injuries. This study investigated wheth- er adipose-derived stem celt transplantation could repair recurrent laryngeal nerve injury. Rat models of recurrent laryngeal nerve injury were established by crushing with micro forceps. Adipose-derived mesenchymal stem cells （ADSCs; 8 ×105） or differentiated Schwann-like adipose-derived mesenchymal stem cells （dADSCs; 8×105） or extracellular matrix were injected at the site of injury. At 2, 4 and 6 weeks post-surgery, a higher density of myelinated nerve fiber, thicker myelin sheath, improved vocal fold movement, better recovery of nerve conduction capacity and reduced thyroarytenoid muscle atrophy were found in ADSCs and dADSCs groups compared with the extracellu- lar matrix group. The effects were more pronounced in the ADSCs group than in the dADSCs group. These experimental results indicated that ADSCs transplantation could be an early interventional strategy to promote regeneration after recurrent laryngeal nerve injury.

Experience of Cervical Plexus Reinnervation for Patients with Unilateral Recurrent Laryngeal Nerve Invasion or Injury

OBJECTIVE To explore the clinical and therapeutic effects of cervical plexus reinnervation for infiltrated or injured unilateral recurrent laryngeal nerve （URLN）. METHODS Functional neck dissection for removal of differentiated thyroid carcinoma （DTC） in patients was performed, in which cervical plexus reinnervation was adopted for patients with stage I disease and URLN with injury or with tumor invasion. Outcomes of surgery were evaluated by examination under fibrolaryngoscope, and the patients＇ voices were evaluated before and after surgery. RESULTS All cases were followed up for 3 mon-2 years （average 8 mon）. Abductory motion of the vocal cords of 15 patients was completely or partly restored, but 3 patients＇ vocal cords were immovable. The recovery rate of abductory motion of the paralyzed vocal cords was 83.33% （15/18）. The function of phonation in the 16 patients was restored to normal or near normal limits, and their hoarseness was improved significantly. CONCLUSION Cervical plexus-URLN reinnervation should be considered when treating patients with unilateral vocal cord paralysis. Removing the tumor simultaneously with cervical plexus reinnervation during surgery for repair of unilateral recurrent laryngeal nerve injury was convenient and easy to perform with less functional damage compared with other methods of reinnervation. The abductory motion of vocal cord could be satisfactorily restored by this reinnervation. Surgical performance skills and application of neurotrophic drugs were important for the success of the surgery.

Applied anatomy of the cervical region of the recurrent laryngeal nerve

BACKGROUND AND OBJECTIVE： To avoid recurrent laryngeal nerve （RLN） injury during thyroid surgery, it is important to identify the nerve and to follow its projection carefully to discriminate it from the inferior thyroid artery. DESIGN, TIME AND SETTING： All studies were performed at the Anatomy Division of Shaoyang Medical College from May 2003 to May 2004 with repeated measurement design. MATERIALS： Fifty embalmed adult corpses, comprising 20 females and 30 males, were obtained by donation. METHODS AND MAIN OUTCOME MEASURES： The projection, branches, and the relationship of the RLN to the inferior thyroid artery were observed. RESULTS： The RLN in all cases ascended through the tracheoesophageal groove at the isthmus superior levels of the thyroid gland. However, the RLN in 14 cases were situated inferior to the isthmus of the thyroid gland; 11 cases were to the right side and 2 cases to the left side, projected in the tracheoesophageal groove, and ascended away from the groove after 4.5-6.5 mm. The RLN typically ramified at the thyroid isthmus plane （44 cases, 44% of all cases）. The RLN branches were variable. Type 2 rami were most common in the RLN, accounting for 55%; the second most common was RLN branches with no rami. RLN braches with type 3 rami, 4 rami, and 5 rami were less common. Approximately 54% of nerves were situated behind the main branch artery. The nerves located adjacent to the arteries, and between the arterial branches, were similar; the former applied to 19 cases, accounting for 19%, whereas the latter applied to 18 cases, accounting for 18%. Left nerves behind the artery, and right nerves before the artery, were more common. There were significant differences between the left and right nerves （P 〈 0.01）. CONCLUSION： There was not a significant difference in the projection of the RLN, while a significant difference in the number of RLN branches existed. In addition, the anatomical relationship of the RLN and the inferior thyroid artery exhibited side differences.

Clinical Significance of Recurrent Laryngeal Nerve Exposure During Esophagogastric Anastomosis of the Neck

OBJECTIVE To investigate the clinical value in a comparison between intraoperative exposure and non-exposure of the recurrent laryngeal nerve （RLN） of the neck during left neck esophagogastric anastomosis following resection of carcinomas of the middle and inferior-segment esophagus. METHODS From January 2003 to April 2009, 237 patients were selected to undergo resection of esophageal squamous carcinoma via posteroexternal incision of the left chest plus gastroesophageal anastomosis at the left neck incision. The 237 cases were divided into 2 groups： 115 of the total cases were in group A （the study group）, cases of resections with neck RLN exposure. Of the patients in this group, 64 were male and 51 female, with a mean age of 49 ranging from 31 to 73 years. Another 122 cases were in group B （the control group）, cases of resections without neck RLN exposure. In this group, 51 of the patients were male and 71 female, with a mean age of 45 ranging from 33 to 75 years. In the 2 groups, there were 9 cases in total with symptoms induced by RLN injury. RESULTS Hoarseness, choking cough when drinking, and difficult expectoration were found in 1 of the cases （1/115） in group A （0.087%）, while there were 8 cases （8/122） presenting with these symptoms in group B （6.5%）. There is statistical signi.cance in the di.erences of RLN injury between the 2 groups （P 〈 0.05）. CONCLUSION Analysis of study cases of esophageal carcinoma resection with left-neck esophagogastric anastomosis in the 2 groups indicated that the exposure of the RLN in group A resulted in an obviously lower rate of neck RLN injury after the surgery, compared to group B, where the RLN was not exposed. Exposure can lead to the avoidance of complications induced by RLN injury, such as dysarthria and choking cough when eating. As a result, satisfactory expectoration, which would diminish the incidence of pulmonary complications, can be reached allowing the patients to recover as early as possible. The results of our study suggest that the exposure of the RLN during the left -neck esophagogastric anastomosis has signi.cant clinical value, and that this approach can be recommended with con.dence.

Clinical significance and characteristics of recurrent laryngeal nerve lymph node metastasis of thoracic esophageal cancer

Objective To investigate the clinical significance and characteristics of recurrent laryngeal nerve lymph node metastasis of thoracic esophageal cancer. Methods One hundred and twenty-four patients who had undergone thoracic esophageal resection with recurrent laryngealnerve lymph node dissection in our hospital from March 2007 to February 2010. All clinical data were retrospectively analysed. Results Recurrent laryngeal

Intraoperative monitoring of the recurrent laryngeal nerve in surgeries for thyroid cancer: a review

Intraoperative nerve monitoring(IONM)has evolved into an objective tool not only for the identification but also for the preservation and prognostication of function of the recurrent laryngeal nerve in thyroid surgeries.Technical improvements have resulted in the increasing incorporation of IONM into operating rooms around the world.The importance of adherence to recommended standards is also recognized as being vital in optimizing the efficacy of IONM.The advent of continuous IONM has made real-time nerve monitoring possible,thus providing the surgeon with an ally in difficult surgeries.Additionally,as thyroid surgeries are evolving into remote access and minimally invasive procedures,so also is the applicability of IONM.This review focuses on the use of IONM for nerve monitoring in thyroidectomies for neoplastic conditions while discussing the rationale,technique,and interpretation of findings and their implications.

Current landscape in motoneuron regeneration and reconstruction for motor cranial nerve injuries

The intricate anatomy and physiology of cranial nerves have inspired clinicians and scientists to study their roles in the nervous system. Damage to motor cranial nerves may result from a variety of organic or iatrogenic insults and causes devastating functional impairment and disfigurement. Surgical innovations directed towards restoring function to injured motor cranial nerves and their associated organs have evolved to include nerve repair, grafting, substitution, and muscle transposition. In parallel with this progress, research on tissue-engineered constructs, development of bioelectrical interfaces, and modulation of the regenerative milieu through cellular, immunomodulatory, or neurotrophic mechanisms has proliferated to enhance the available repertoire of clinically applicable reconstructive options. Despite these advances, patients continue to suffer from functional limitations relating to inadequate cranial nerve regeneration, aberrant reinnervation, or incomplete recovery of neuromuscular function. These shortfalls have profound quality of life ramifications and provide an impetus to further elucidate mechanisms underlying cranial nerve denervation and to improve repair. In this review, we summarize the literature on reconstruction and regeneration of motor cranial nerves following various injury patterns. We focus on seven cranial nerves with predominantly efferent functions and highlight shared patterns of injuries and clinical manifestations. We also present an overview of the existing reconstructive approaches, from facial reanimation, laryngeal reinnervation, to variations of interposition nerve grafts for reconstruction. We discuss ongoing endeavors to promote nerve regeneration and to suppress aberrant reinnervation and the development of synkinesis. Insights from these studies will shed light on recent progress and new horizons in understanding the biomechanics of peripheral nerve neurobiology, with emphasis on promising strategies for optimizing neural regeneration and identifying future directions in the field of motor cranial neuron research.

A three-dimensional digital visualization model of cervical nerves in a healthy person

Three-dimensional reconstruction nerve models are classically obtained from two-dimensional images of ＂visible human＂ frozen sections. However, because of the flexibility of nerve tissues and small color differences compared with surrounding tissues, the integrity and validity of nerve tissues can be impaired during milling. Thus, in the present study, we obtained two-dimensional data from a healthy volunteer based on continuous CT angiography and magnetic resonance myelography. Semi-automatic segmentation and reconstruction were then conducted at different thresholds in different tissues using Mimics software. Small anatomical structures such as muscles and cervical nerves were reconstructed using the medical computer aided design module. Three-dimensional digital models of the cervical nerves and their surrounding structures were successfully developed, which allowed visualization of the spatial relation of anatomical structures with a strong three-dimensional effect, distinct appearance, clear distribution, and good continuity, precision, and integrality. These results indicate the validity of a three-dimensional digital visualization model of healthy human cervical nerves, which overcomes the disadvantages of milling, avoids data loss, and exhibits a realistic appearance and three-dimensional image.

Identifying a Safe Range of Stimulation Current for Intraoperative Neuromonitoring of the Recurrent Laryngeal Nerve： Results from a Canine Model

Background： lntraoperative neuromonitoring （IONM） of the recunent laryngeal nerve （RLN） has been widely applied during thyroid surgery. However, the sale range of stimulation intensity for IONM remains undetermined, Methods： Total thyroidectomies were performed on twenty dogs, and their RLNs were stimulated with a current of 5 20 mA （step-wise in 5 mA increments） for 1 min. The evoked electromyography （EMG） of vocal muscles before and after supramaximal stimulation were recorded and compared. Acute microstructural morphological changes in the RLNs were observed immediately postoperatively under an electron microscope. Results： The average stimulating threshold for RLNs stimulated with 15 mA and 20 mA showed no significant changes compared to the unstimulated RLNs （15 mA group： 0.320 ± 0.123 mA vs. 0.315 ±0.097 mA, P =0.847; 20 mA group： 0.305 ± 0.101 mA vs. 0.300 ＋ 0.103 mA, P = 0.758）. Similar outcomes were shown in average evoked EMG amplitude （15 mA group： 1,026 ± 268 p.V xs. 1,021 ± 273 p.V, P = 0.834; 20 mA group： 1,162 ± 275 μV vs. 1,200 ± 258μV, P = 0.148）. However, obvious acute microstructural morphological changes were observed in the nerves that were stimulated with 20 mA. Conclusions： A stimulation intensity less than 15 mA might be safe for IONM of the RLN.

Ⅰ型神经纤维瘤病累及喉返神经1例

1 临床资料患者,女,16岁,发现颈前肿物2个月。专科查体:颈部正中偏右侧肿大,表面皮肤无红肿破溃,触诊可及一直径约4 cm×2 cm大小肿物,质软,无压痛,边界清楚,活动度良好。彩超检查示:甲状腺右叶后方实性肿物,大小约4.7 cm×2.7 cm×2.5 cm,与甲状腺关系不清(图1A)。CT示:甲状腺后方低密度灶,考虑良性病变,对应部位气管轻度受压变形。

Compare the postoperative complications incidence of benign multi-nodular goiter: A meta-analysis

Objective： The aim of our study was to compare the risk of main postoperative complications of patients un- derwent total thyroidectomy （TT）, near total thyroidectomy （NTT） and subtotal thyroidectomy （ST） for treating BMNG. Methods： Electronic databases including Cochrane Controlled Trials Register, EMbase, Medline, SCI Expanded-ISI, NTIS, SIGLE and CNKI were searched. Eligible studies were randomized controlled trials which compared the incidence of postoperative complications of TT with ST/NTT for treating BMNG. Data extraction was using predefined data fields and assessment of methodological quality with the GRADE approach. A ManteI-Haenszel random-effects model was used and the effect sizes were expressed by using relative risks and 95% confidence intervals. Results： Four studies including 881 participants that met inclusion criteria were analyzed. Compared with ST/NTT, TT was associated with increased risk of transient RLNI （recur- rent laryngeal nerve injuries） （relative risk 2.18, 95% confidence interval 1.08 to 4.42; P 〈 0.05） and transient hypocalcemia （3.79, 1.64 to 8.77; P 〈 0.05）, but there were no statistically significant differences in permanent RLNI （1.36, 0.31 to 6.02; P 〉 0.05） and permanent hypocalcemia （2.37, 0.35 to 15.97; P 〉 0.05）. The quality of evidence for each individual outcome was ultimately rated as moderate （permanent RLNI and permanent hypocalcemia）, low （transient RLNI and transient hypocalce- mia）. Conclusion： For treating BMNG with thyroidectomy, there were no statistically significant differences in postoperative complications between TT and ST/NTT on a long view.