Humans ; Recurrent Laryngeal Nerve ; pathology

Injury to the recurrent laryngeal nerve is the most common and serious complication after thyroid surgery. Many different techniques have been described in the literature and interest in intraoperative neuromonitoring (IONM) has increased in an effort to prevent adverse events. IONM implicated for identification of the nerve and evaluation of its function during the operation. Continuous IONM was recently introduced and looks promising for early recognition and safe operation in the end. This paper describes the role of IONM, and its current and future issues.
Recurrent Laryngeal Nerve ; Thyroid Gland* ; Thyroidectomy

Adult ; Humans ; Male ; Recurrent Laryngeal Nerve ; abnormalities

Various energy devices had been used in thyroid surgery. Aim of study is to develop canine model for recurrent laryngeal nerve injury by harmonic scalpel and to evaluate feasibility of using this model for evaluating the safety use of harmonic scalpel during thyroid surgery. Nine dogs were divided into 3 groups according to distance between harmonic scalpel application and recurrent laryngeal nerve; group 1 (1 mm), 2 (2 mm), and 3 (3 mm). Vocal cord function was assessed pre- and postoperatively using video laryngoscopy. Harmonic scalpel was applied adjacent to left recurrent laryngeal nerve and, two weeks later, right recurrent laryngeal nerve at assigned distances. Recurrent laryngeal nerves were evaluated for subacute and acute morphologic changes. Laryngoscopy demonstrated 3 abnormal vocal cords in group 1, 1 in group 2, and no in group 3 (P=0.020). Subacute histologic changes were observed in nerves with abnormal function. Acute histologic changes were observed 5/8 (62.5%) in group 1, 1/7 (14.3%) in group 2, and not in group 3. We developed canine model for recurrent laryngeal injury. The functional outcomes matched with the histologic changes. These warrant further study to determine the safety margin for energy device in vicinity of recurrent laryngeal nerve.
Animals ; Dogs ; Laryngoscopy ; Recurrent Laryngeal Nerve ; Recurrent Laryngeal Nerve Injuries ; Thyroid Gland ; Vocal Cords

Humans ; Iatrogenic Disease ; prevention & control ; Monitoring, Intraoperative ; Recurrent Laryngeal Nerve ; physiology ; Recurrent Laryngeal Nerve Injuries

Objective: To determine the prevalence of vocal cord paralysis among post thyroidectomy patients based on severity and laterality, and explore possible associations with age, sex, diagnosis and type of thyroid lesion and surgical procedure. Methods: Design: Cross-sectional study. Setting: Tertiary Government Training Hospital. Participants: Records of patients who underwent thyroidectomy under the Department of Otorhinolaryngology – Head and Neck Surgery of the Ospital ng Maynila Medical Center from January 1, 2014 to June 30, 2021. Results: There were strong associations between the type of lesion and the presence of recurrent laryngeal nerve injury (V=.211, p=.001) and the diagnosis and the presence of RLNI (V=.245, p=.006). There were no significant associations between patient’s sex, age, diagnosis, type of thyroid lesion, surgical procedure with laterality and severity of RLNI. It was notable that all cases of bilateral recurrent laryngeal nerve injury were due to carcinoma only. Patients with malignant tumors were 2.8x (95% CI: 1.48-5.29) as likely to develop post surgical RLNI than those with benign tumors (p=.0015). Conclusion The factors that had a strong association with the presence of vocal cord paralysis among post-thyroidectomy patients were the diagnosis and type of thyroid lesion. Malignant thyroid lesions (specifically thyroid carcinoma) had a higher incidence of recurrent laryngeal nerve injury compared to benign thyroid lesions. More data from different institutions and including other predisposing factors may confirm our findings.
Paralysis ; Vocal Cords ; Thyroidectomy ; Recurrent Laryngeal Nerve ; Recurrent Laryngeal Nerve Injuries

We have had a case of unilateral vocal cord paralysis following endotracheal anesthesia for abdominal surgery. Electromyographic examination of the intrinsic laryngeal muscle to study the nerve injury was not done but we have considered that the recurrent laryngeal nerve was injured following endotracheal anesthesia according to the post-operative laryngeal view and recovery progress. Som factors of nerve injury such as overrotation of the neck during the operation, pressure on the nerve by an overexpanded cuff, vulnerability and the anatomy of the nerve were all deemed to do possible causes, and we considered the interaction of this combination responsible for the nerve injury. The recovery were relatively good and healed within 80 dyas after operation.
Anesthesia* ; Laryngeal Muscles ; Neck ; Recurrent Laryngeal Nerve ; Vocal Cord Paralysis*

Recovery from the laryngeal dysfunction caused by the recurrent laryngeal nerve (RLN) injury is not common. Recently, we have found that PEMS treatment improved the functional recovery rate and shortened the recovery time after RLN transection and reanastomosis in rat. In this study, we compared the morphology of RLN stumps according to their laryngeal functional status to investigate 1) the nerve morphology associated with functional recovery and 2) the possible underlying mechanism of persistent laryngeal dysfunction after RLN injury. We transected left RLN and then performed primary neurorrhaphy in Sprague-Dawley rats (n = 36). They were randomly divided into PEMS and control groups. 19 animals (10 PEMS group, 7 control group and 2 normal control animals) survived until the end of the experiment were included in the morphological analysis. Both the proximal and distal segments of reanastomosed RLN were obtained and the ultrastructural study was done using transmission electron microscope. There is no prominent morphological difference between the PEMS and control groups. In the functional recovery group, the findings suggestive of nerve regeneration were prominent both in the proximal and distal segments. Many regenerating axons were also observed in the proximal segments of RLNs in non-recovery group. But findings such as degenerating axons, infiltration of macrophage and inflammatory cells, increased collagen fibrils were frequently observed in this group. Even in the distal segments of functional non-recovery group, prominent regenerative findings were observed in 9 out of 10 (4 out of 5 PEMS and all control group animals) samples. We could not find any regenerating findings in one case of the PEMS group. Through the above results, failure of the nerve regeneration is unlikely the main cause of functional non-recovery after RLN injury in rat. Possible other causes such as synkinesis or definite but inadequate nerve regeneration should be considered and needs further investigation.
Animals ; Axons ; Collagen ; Macrophages ; Nerve Regeneration* ; Rats ; Rats, Sprague-Dawley ; Recurrent Laryngeal Nerve Injuries* ; Recurrent Laryngeal Nerve* ; Synkinesis

No abstract available.
Humans ; Recurrent Laryngeal Nerve* ; Thyroid Gland* ; Vocal Cord Paralysis*

PURPOSE: Among the various energy-based devices, ultrasonic shears are popular in thyroid surgeries. In this study, we tested the safety of Harmonic ACE and Harmonic ACE+ around the recurrent laryngeal nerve (RLN) in experimental swine models. METHODS: Harmonic ACE and Harmonic ACE+ were each tested in 4 piglets. Harmonic ACE and Harmonic ACE+ were activated at a 0- to 5-mm distance from the RLN. The function of the RLN was assessed using continuous electrophysiological monitoring. RESULTS: For Harmonic ACE, there was no adverse EMG event found when activated at 4- and 5-mm distances from the RLN. At a 2- to 3-mm distance, there were 4 adverse EMG events observed. In these 4 cases, adjacent tissue shrinkage occurred after 6 to 15 seconds of activation, and the RLN touched the Harmonic ACE. At a 1-mm distance, there were 2 adverse EMG events found after 25 seconds of activation. For Harmonic ACE+, there was no adverse EMG event observed when activated at 1- and 3-mm distances from the RLN. At a 0-mm distance, 2 adverse EMG events occurred after 6 to 10 seconds of activation. CONCLUSION: The safe distance of Harmonic ACE and ACE+ was 4 and 1 mm, respectively, in the swine models. Harmonic ACE+ is safer than Harmonic ACE because it did not cause any tissue shrinkage. Surgeons need to understand the characteristics of devices for safe operation.
Recurrent Laryngeal Nerve* ; Surgeons ; Swine* ; Thyroid Gland ; Ultrasonics