Surgery for mediastinal thyroid gland tumors requires different approaches and considerations compared to standard thyroidectomy, with careful attention to potential complications. This study presents a series of cases along with a literature review to evaluate surgical management strategies for mediastinal thyroid gland tumors. The subjects included 22 cases of mediastinal thyroid gland tumors treated surgically at the Department of Otorhinolaryngology/Head and Neck Surgery, Hamamatsu University School of Medicine, between January 2014 and December 2023. During this period, mediastinal thyroid gland tumors accounted for 6.2% (22/354) of all thyroid surgeries. The mediastinal tumor size ranged from 26 to 80 mm (median : 43.5 mm), with the inferior end of the tumor located at the level of the third thoracic vertebra in 10 cases, the fourth thoracic vertebra in six cases, and the fifth thoracic vertebra in six cases. All cases were preoperatively diagnosed as benign tumors. None required a sternotomy or mediastinoscopy; all tumors were successfully removed via a cervical approach. Complications included hypoparathyroidism in two cases, transient recurrent laryngeal nerve palsy in one case, and one case requiring blood transfusion—all of which occurred in total thyroidectomy cases. Resected specimen weights ranged from 30 to 280 g (median : 72.5 g). Cases with a specimen weight of ≥ 100 g or tumors extending below the fourth thoracic vertebra showed significantly increased blood loss and operative time (p < 0.05). Mediastinal thyroid gland tumors should be considered for surgical removal before significant enlargement, as larger tumors and those extending deeper into the mediastinum pose higher risks for intraoperative complications.

Vertical partial laryngectomy has been used for salvage surgery after radiation failure. This approach is considered safe and effective, and results in reasonable preservation of laryngeal function. It is rare for partial laryngectomy to result in laryngeal stenosis. However, laryngeal stenosis caused by arytenoid entering the laryngeal cavity occurred after vertical partial laryngectomy in this case. It was likely due to asthma and chronic obstructive pulmonary disease to some extent. Post-operatively, the patient was treated by laryngomicrosurgery, especially for arytenoid mucosa.

Laryngeal schwannomas are rare. We experienced two cases of laryngeal schwannoma with extralaryngeal lesions, which are even rarer than laryngeal schwannomas. Case 1, a 19-year-old male, had submucosal swelling in the left false vocal cord and the left piriform sinus. Imaging studies revealed a dumbbell-shaped tumor extending into the epiglottis. The tumor was removed with an external cervical incision. No vocal cord paralysis was observed after surgery, and the tumor was thought to have originated from the Galen's anastomosis. Postoperative imaging studies revealed an asymptomatic right auditory schwannoma, left jugular foramen and spinal cord lesion, and the patient is under observation. Case 2 was a 20-year-old female with a history of forehead schwannoma, left auditory schwannoma and right parietal meningioma. She came to our hospital for oral surgery for a schwannoma of the left aryepiglottic fold. The patient underwent transoral resection to preserve laryngeal function. The schwannoma was thought to have originated from the superior laryngeal nerve. There was no evidence of recurrence two years after the operation. Neither of the two cases met the diagnostic criteria for neurofibromatosis type 2. A laryngeal schwannoma with extralaryngeal lesions has no specific clinical features. However, in the case of extralaryngeal extension and multinodular lesions, there is a possibility of multiple schwannomas outside the larynx. Therefore, we should consider a systemic search and follow-up. If a tumor is benign, a minimally invasive and function-preserving transoral resection is preferable to an external cervical incision.

Neck trauma can occur due to various factors, but injuries caused by a thrust during kendo result in localized trauma with strong force. When the larynx is affected, not only airway stenosis due to submucosal hematoma or swelling of the vocal cords, but also voice disorders caused by thyroid cartilage fractures or laryngeal mucosal damage, become significant concerns. We report a case of thyroid cartilage fracture caused by a bamboo sword thrust during kendo, which was treated with surgical reduction for the resulting voice disorder. The patient was a man in his 40s. He sustained an anterior neck injury from a bamboo sword thrust during kendo. On the day of the injury, there was bleeding on the skin surface, but it stopped immediately. He experienced hoarseness immediately after the injury but had no respiratory distress. Two days after the injury, he visited a local otolaryngologist, where laryngeal endoscopy revealed a submucosal hematoma extending from the right arytenoid to the right vocal cord, but no obvious vocal cord paralysis or upper airway stenosis was observed. CT imaging showed a vertical fracture of the thyroid cartilage with displacement. As his hoarseness persisted, he was referred to our department on the ninth day post-injury for planned open reduction and fixation. On the 11th day post-injury, under general anesthesia we performed an open reduction of the thyroid cartilage fracture. The cartilage surface was carefully dissected to identify the fracture line, and bioabsorbable fixation material was used to stabilize and reduce the thyroid cartilage. Even in cases of thyroid cartilage fractures due to laryngeal trauma without respiratory distress such as airway stenosis, surgical reduction should be promptly performed if hoarseness persists.

We report on a case of relapsing polychondritis (RP) that was difficult to manage after tracheotomy. The patient was a 67-year-old woman who was being treated for localized granulomatosis with polyangiitis (GPA) by a collagen disease physician. Despite high-dose corticosteroids and immunosuppressive therapy, her dyspnea progressively worsened, and a tracheotomy was performed for subglottic stenosis. During the tracheotomy, the trachea had an esophageal appearance due to destruction of the tracheal cartilage ring, and the trachea collapsed immediately after the tracheotomy, requiring ventilator management. The airway lesions in RP are often steroid-resistant and may be associated with stenosis along the entire length of the trachea. If a tracheotomy is performed in the case of RP where destruction of the tracheal cartilage ring is expected, a ventilator or other support is desirable.

A minitracheostomy kit is primarily used for airway management and postoperative care in emergency and surgical departments. Although cricothyrotomy is a simple procedure, it can lead to severe complications if not performed correctly. This report highlights two cases of tracheal cannula malposition due to improper use of the minitracheostomy kit. In case 1, a pulmonary surgeon used a minitracheostomy kit to avoid postoperative sputum aspiration. However, the tracheal cannula penetrated the posterior tracheal wall and migrated into the right chest cavity. In case 2, the same procedure was performed by a gastroenterology surgeon, but the tracheostomy tube was inserted from the supraglottis to the subglottis. In both cases, the cause of tracheal cannula malposition was inadequate identification of the puncture site and direction and inadequate verification after insertion. We removed the malpositioned tracheostomy tube and performed a tracheotomy. As an otolaryngologist, it is important to understand the characteristics of the minitracheostomy kit and its potential complications. It is also essential to respond promptly and accurately to complications and to educate all healthcare personnel on its proper use to ensure patient safety.

Steroid nebulizer therapy is used routinely in laryngeal diseases as a safe treatment compared to systemic administration because the drug can be administered directly to the mucosa of the upper airway and does not migrate into the bloodstream. In this study, we report a case in which iatrogenic Cushing's syndrome occurred due to the appearance of side effects such as central obesity and lower leg edema during the course of steroid nebulizer therapy. The patient is a female in her late 20s. Her occupation is voice actor and live streamer. She was referred to our department complaining of hoarseness that began after medical treatment at a local otolaryngologist's office five months earlier. She was diagnosed as laryngitis and vocal fold nodules due to voice overuse, and anti-inflammatory drugs, voice therapy, and steroid nebulizer therapy were started. After three months a full moon-like face and edema of the lower leg were observed. Two months later, the diagnosis of iatrogenic Cushing's syndrome due to steroid nebulizer therapy was made. The nebulizer therapy was stopped and the patient was followed up, and by the eighth month after her initial visit her full moon-like facial expression and leg edema improved. Prolonged steroid nebulizer therapy is a risk factor for iatrogenic Cushing's syndrome. It is necessary to avoid aimless administration of steroid nebulization therapy, to closely monitor the larynx during the course, to be aware of side effects, and to establish a drug withdrawal period while conducting appropriate nebulization management.

Hypoglossal nerve stimulation is an innovative treatment for obstructive sleep apnea (OSA) that electrically stimulates the hypoglossal nerve during sleep to maintain airway patency at the base of the tongue. It is particularly beneficial for patients who cannot adhere to continuous positive airway pressure (CPAP), the first-line treatment for OSA. This therapy is becoming increasingly widespread, particularly in the United States. In Japan, hypoglossal nerve stimulation was approved for insurance coverage in June 2021, and the number of procedures performed has been gradually increasing. The implantation of a hypoglossal nerve stimulation device involves placing a nerve stimulation cuff on branches of the hypoglossal nerve that protrude or stiffen the tongue, while avoiding branches that retract the tongue backward. The point of divergence between these branches, known as the “functional breakpoint” (FB), is identified intraoperatively using a nerve integrity monitor (NIM^TM). However, this identification process can be challenging. Here, we report two cases in which hypoglossal nerve stimulation device implantation was performed at our department. Despite using microscope and NIM^TM, determining the optimal placement of the nerve stimulation cuff proved difficult. We discuss key considerations for FB identification and the surgical procedure based on our experience.

Background: The relationship between optimal dosage of intracordal trafermin injection and voice improvement in cases of unilateral vocal fold paralysis is unclear. Method: We retrospectively reviewed the medical records of 18 patients with unilateral vocal fold paralysis who underwent intracordal trafermin injection at our hospital between January and December 2021. The endpoints were changes in maximum phonation time, pitch range, mean flow rate and voice handicap index before and after injection in patients who received normal and high doses of trafermin. Results: There were significant differences in mean flow rate and voice handicap index in the high-dose group. Conclusion: High-dose trafermin injection may improve voice.