The treatment of subglottic stenosis in children is one of the most complex and difficult challenges in the field of pediatric otolaryngology. Therefore, it requires a team approach that includes an anesthesiologist, a pediatrician, and an intensivist. This article introduces the latest concepts in the treatment of subglottic stenosis and glottal stenosis (glottal softening, glottal cysts, etc.) in children, with particular attention to reports obtained over the years abroad. In order to avoid problems around the peritracheal foramen, a single-stage approach that avoids tracheostomy has recently become the mainstream approach. However, the inability to secure the airway is life-threatening for children, and tracheostomy is also an important method of safety management. The accumulation of further airway surgery results in the future is expected to allow for safer and better treatment strategies.

Laryngotracheal stenosis (LTS) is narrowing of the upper airway between the larynx and trachea. Adult LTS is acquired and has various etiologies, including tracheal intubation, tracheostomy, trauma, autoimmune disease, infection and idiopathic. The majority of LTS cases are subglottic stenosis (SGS). Treatment options for SGS include transoral (endoscopic) surgery and open surgery. Transoral surgery is performed on patients with mild SGS, such as grade 1 or 2 SGS with a normal glottis. Balloon dilation laryngoplasty is an efficient and safe technique and is becoming more and more popular. Open surgery is performed on patients with severe SGS, such as grade 3 or 4. This approach includes laryngotracheal reconstruction (LTR), the trough method and cricotracheal resection (CTR). LTR is a surgery to widen the subglottis and trachea by inserting a small piece of cartilage. The trough method is a surgery to reconstruct the anterior wall of the cricoid and trachea with a skin flap and cartilage graft in the second stage. CTR is a surgery to remove the anterior cricoid ring and trachea and to anastmose resection stumps.

Airway stenosis, in particular, laryngotracheal stenosis, occurs due to various causes and pathological conditions, and a number of surgical procedures have been proposed for its treatment. For bilateral vocal fold paralysis, posterior glottic stenosis, and subglottic stenosis, the transoral and/or open approach, including laterofixation of the vocal fold, arytenoidectomy, and laryngotracheoplasty, can be performed according to the condition, extent, and severity of stenosis. Post tracheostomy laryngotracheal stenosis can also be treated surgically. In addition, the airway stenosis associated with COVID-19 infection has recently been recognized as a problem in relation to the treatment of COVID-19 pneumonia and can be possibly attributed to airway inflammation caused by COVID-19, long-term tracheal intubation, and/or inadequate management of tracheostomy. In order to avoid the risk of exposure to COVID-19 during surgery and to maintain tracheostoma without any complications, a specific method may be recommended for tracheostomy in patients with COVID-19. The proper surgical treatment should be adopted depending on the condition of laryngotracheal stenosis in order to maintain the laryngeal and tracheal lumen.

Postoperative recurrent laryngeal nerve palsy in thyroidectomy is a complication that must be avoided because it impairs speech and the swallowing function. The incidence is reported to be 3.0%-14.6% for postoperative recurrent nerve palsy and 0.7%-5.3% for permanent postoperative recurrent nerve palsy, so it is essential to understand the risk before surgery. In this study, we analyzed the incidence of postoperative recurrent laryngeal nerve palsy in our hospital and the associated patient, disease, and surgical factors to obtain a better clinical index for preventing postoperative recurrent laryngeal nerve palsy. There were 164 patients/217 sides (73 benign cases [45%], 91 malignant cases [55%]) who underwent thyroidectomy at our hospital from April 2018 to December 2019. Postoperative recurrent laryngeal nerve palsy was observed in 22 patients (10.1%), of whom 9 (4.1%) had permanent palsy. There were significant differences in the rate of postoperative recurrent laryngeal nerve palsy based on the preoperative fine-needle aspiration (FNA) class (P<0.01), N classification (P<0.01), surgical procedure (unilateral/total thyroidectomy) (P<0.01), presence of dissection (P<0.01), operative time (P=0.01), amount of bleeding (P=0.02), and presence of adhesions (P=0.05). For permanent palsy, there were significant differences in the preoperative FNA class (P<0.01), surgical form (unilateral/total) (P=0.03), and presence of dissection (P=0.01). In the case of benign lesions, a cut-off value of 100 mm for the tumor diameter was associated with postoperative recurrent laryngeal nerve palsy (P=0.01). Continuous intraoperative nerve monitoring should thus be considered for these high-risk cases.

Postoperative recurrent nerve paralysis can cause severe complications such as aspiration pneumonia after lung surgery or aortic surgery. After thoracic surgery, we examine the larynx with a laryngoscope immediately after tracheal extubation in the operation room or intensive care unit. When we find unilateral recurrent nerve paralysis, we tell the surgeon, anesthetist, and nurse to prevent aspiration pneumonia. Then we continue to follow laryngeal examination post-discharge. When recurrent nerve paralysis does not improve, we perform surgery, such as thyroplasty type 1 and laryngeal nerve reinnervation.

We analyzed the examination of the larynx, vocal cord paralysis, the results of tracking, and voice before and after phonosurgery. Between 2012 and 2017, 214 patients who received lung surgery and 231 patients who received aortic surgery were analyzed.

Larynx examinations were performed for 192 patients who received lung surgery, we found 21 vocal cord paralysis cases and performed phonosurgery in 6 cases. Meanwhile larynx examinations were performed for 120 patients who received aortic surgery, we found 30 vocal cord paralysis cases and performed phonosurgery in 2 cases. After phonosurgery, the MPT of 8 cases was longer in comparison to before the operation.

We examine larynx immediately after extubation, rather than after hoarsness occurs, in order to clarify risk of aspiration pneumonia and maintain safe from the early stage.

Extramedullary plasmacytoma is a rare malignant tumor that most commonly occurs in the head and neck region. A 76-year-old woman presented to a local hospital with complaints of mild respiratory symptoms that failed to resolve. A laryngoscopic examination revealed the presence of a mass at the left subglottis extending into the intratracheal regions. This finding was further confirmed by computed tomography (CT). Tracheostomy and microscopic laryngeal surgery were subsequently performed to obtain a sample for a histopathological examination. The results of this examination were inconclusive, but inflammation was detected. The patient was thus asked to come in for regular follow-up examinations over the course of which the mass was observed to be increasing in size. She was subsequently introduced to our hospital for a further diagnosis and treatment. We first performed a biopsy via microscopic laryngeal surgery, but once again, the histopathology results were inconclusive. However, the mass continued to increase in size, so surgery was performed to excise the mass via a neck incision. The histopathology results revealed that the mass was an extramedullary plasmacytoma. Immunostaining further revealed that the tumor cells were positive for IgG, CD38 and CD79a. The plasmacytoma was detected again and was increasing in size. Positron emission tomography (PET)-CT further revealed marrow infiltration throughout the body, which was diagnosed as multiple myeloma. The patient subsequently underwent chemotherapy (Bortezomib, Dexamethasone) and the original plasmacytoma was no longer detected via laryngoscopy at four months after the chemotherapy. Additional PET-CT revealed that multiple myeloma tumors were also no longer detected.

Subglottic stenosis is a well-known complication after prolonged endotracheal intubation or tracheostomy. There is a risk of suffocation due to severe subglottic stenosis, which requires immediate surgical intervention．Coronavirus disease (COVID-19) may cause severe pneumonia and require respiratory management via endotracheal intubation or tracheostomy. Case 1 was a 48-year-old man who had been intubated for 6 days due to respiratory failure caused by COVID-19 pneumonia. He recovered from the pneumonia, but his dyspnea recurred after discharge. Upon laryngeal endoscopy, granulation was detected under the glottis. His dyspnea improved with steroid treatment and conservative treatment was given without surgery. Case 2 was a 67-year-old man who had been intubated for 30 days and had a tracheostomy due to COVID-19 pneumonia. His dyspnea improved with steroids, and conservative treatment was administered without surgery. Case 2 was a 67-year-old man who had been intubated for 30 days and received tracheostomy due to COVID-19 pneumonia. His tracheostomy tube was removed 69 days later, but after another 2 months, he had difficulty breathing due to subglottic granulation. His subglottic mass took up almost the whole subglottic space, and he was considered to need surgical treatment. We performed a staged operation and totally removed the mass using a laryngofissure. Under the COVID-19 pandemic, there is a possibility that the number of patients with subglottic stenosis will increase, so an immediate diagnosis and prompt treatment are important. In addition, the numbers of patients who require laryngofissure are expected to increase, so otolaryngologists will need to be familiar with this operation.