Varied Recurrent Laryngeal Nerve Course Is Associated with Increased Risk of Nerve Dysfunction During Thyroidectomy: Results of the Surgical Anatomy of the Recurrent Laryngeal Nerve in Thyroid Surgery Study, an International Multicenter Prospective Anatomic and Electrophysiologic Study of 1000 Monitored Nerves at Risk from the International Neural Monitoring Study Group.

Background: The recurrent laryngeal nerve (RLN) can be injured during thyroid surgery, which can negatively affect a patient's quality of life. The impact of intraoperative anatomic variations of the RLN on nerve injury remains unclear. Objectives of this study were to (1) better understand the detailed surgical anatomic variability of the RLN with a worldwide perspective; (2) establish potential correlates between intraoperative RLN anatomy and electrophysiologic responses; and (3) use the information to minimize complications and assure accurate and safe intraoperative neuromonitoring (IONM). Methods: A large international registry database study with prospectively collected data was conducted through the International Neural Monitoring Study Group (INMSG) evaluating 1000 RLNs at risk during thyroid surgery using a specially designed online data repository. Monitored thyroid surgeries following standardized IONM guidelines were included. Cases with bulky lymphadenopathy, IONM failure, and failed RLN visualization were excluded. Systematic evaluation of the surgical anatomy of the RLN was performed using the International RLN Anatomic Classification System. In cases of loss of signal (LOS), the mechanism of neural injury was identified, and functional evaluation of the vocal cord was performed. Results: A total of 1000 nerves at risk (NARs) were evaluated from 574 patients undergoing thyroid surgery at 17 centers from 12 countries and 5 continents. A higher than expected percentage of nerves followed an abnormal intraoperative trajectory (23%). LOS was identified in 3.5% of NARs, with 34% of LOS nerves following an abnormal intraoperative trajectory. LOS was more likely in cases of abnormal nerve trajectory, fixed splayed or entrapped nerves (including at the ligament of Berry), extensive neural dissection, cases of cancer invasion, or when lateral lymph node dissection was needed. Traction injury was found to be the most common form of RLN injury and to be less recoverable than previous reports. Conclusions: Multicenter international studies enrolling diverse patient populations can help reshape our understanding of surgical anatomy during thyroid surgery. There can be significant variability in the anatomic and intraoperative characteristics of the RLN, which can impact the risk of neural injury.

Russian thyroid surgery from the 19th to the early 20th century.

INTRODUCTION: The aim of our study was to investigate the contributions made to thyroid surgery by outstanding Russian surgeons;' (Pirogov N.I., Bujalskiy I.V., Velyaminov N.A., Bobrov A.A., Lezhnev N.F., Fyodorov S.P., Opel V.A. and others) MATERIALS AND METHODS: Research was done on thyroid surgery in Russia in the period from the early 19th century to the early 20th century and the achievements of Russian surgeons were assessed in relation to progress in the field worldwide, including the difficulties that prevented Russian surgeons from gaining extensive attention at an international level and the steps taken by Russia in the 21st century to share expertise in thyroid surgery with other countries. Data was gathered from 178 documents. Books, manuals, and other scientific publications, as well as doctors reports and patient records were analyzed. Research was done on 15 surgical instruments and 10 photographs. RESULTS: The first description of thyroid surgery in Russia dates back to 1804. In 1831 Nikolaiy Ivanovich Pirogov described the anatomy, topography, syntopy and the main principals of thyroid surgery. In 1847 he performed the first "strumectomy" in the world under general anesthesia. For bleeding control he used 30 - 40 ligatures and vascular forceps with locks. The next operation on the thyroid under anesthesia was carried out 13 years later by Eugene S. Cooper (USA). Ilya V. Bujalskiy (Russia), consultant at St.-Petersburg Mariinsky hospital, used an ether narcosis in May, 1847 and chloroform in August 1848 when operating on the thyroid. One other description of the use of chloroform narcosis , by Paul von Sick (Germany) in 1867. In 1886 Nicolay A. Velyaminov performed thyroid resection in the Mariinsky hospital. In 1904 Russian surgeon Nikolai F. Lezhnev reported on 106 thyroid operations performed with visual control of the recurrent laryngeal nerves in Bobrov's clinic in Moscow, where those techniques had been introduced in 1893. He also dealt with the problem of ectopic goiter, and at sessions of the Pirogov Surgical Society gave case presentations of patients with lingual goiter (1908, 1926). Sergey P. Fedorov was well-known in Europe. That is why William Mayo came to observe his operations. He called Fedorov a "master surgeon". CONCLUSION: The contribution of famous Russian surgeons to the field of thyroid surgery is important and should be appreciated at its true value. KEY WORDS: History, Thyroid surgery.