Injection laryngoplasty is an option for the surgical treatment for vocal cord paralysis. Paraffin, Teflon, silicon, autologous fat, collagen, hyaluronic acid, calcium phosphate paste, and basic fibroblast growth factor (bFGF) have been used as injectable materials in clinical settings. Some injectable materials are no longer in clinical use because of potential complications, such as granulation formation, inflammation, and migration. This paper describes the characteristics and therapeutic effects of each injection material. The feature of autologous fat is that it is safe because it is an autologous transplant, and its therapeutic effect is long-lasting to some extent. Collagen and hyaluronic acid are easy to prepare because they are commercially available; however, their therapeutic effect is poorly sustained. Since calcium phosphate paste is barely absorbed in the larynx after injection, its effect can be expected to last for an extended period, and bFGF is a regenerative medicine material, so its absorption does not matter.

Vocal fold paralysis impairs breathing, swallowing, and the vocal function. Since it was first described by Isshiki in the 1970s, type I thyroplasty has become an increasingly common procedure for the surgical treatment of glottic incompetence in patients with unilateral vocal fold paralysis. The early days when the medialization laryngoplasty was started, a patient’s own tissue, such as cartilage, was used for the fixation of a medialization. Over the years, to reduce invasion and increase the efficacy of surgery, ready-made implants have been developed. In addition, an instrument designed exclusively for performing these operations smoothly has also been developed. The characteristics and problems associated with various types of thyroplasty implants are herein reported.

Unilateral vocal fold paralysis (UVFP) is a common problem in the otolaryngology field. The most frequent cause is recurrent laryngeal nerve (RLN) injury due to an extra-laryngeal malignancy, such as a thyroid tumor or iatrogenic or idiopathic etiology. Regardless of the cause of nerve injury, The optimal management of UVFP to obtain a “normal” voice post-operatively is becoming an increasingly relevant issue. We herein review the history of the development of laryngeal reinnervation techniques, such as primary RLN anastomosis, Ansa-cervicalis-to-RLN neurorrhaphy and Ansa-cervicalis nerve-muscle pedicle implantation, verified with various experimental animal models. In addition, the treatment algorithm for UVFP is discussed.

Bilateral vocal fold immobility influences not only vocal function but also the airway tract, possibly resulting in dyspnea. Pathophysiological diagnosis using electromyography of laryngeal muscles is also critical for patients with bilateral vocal fold immobility to optimize the surgical procedures. Vocal fold lateralization, transverse cordotomy, and arytenoidectomy can be utilized for bilateral vocal fold paralysis and posterior glottic stenosis depending on the severity of stenosis and mobility of cricoarytenoid joints. A unilateral approach should be recommended for the initial surgery to reduce the risks of aspiration and hoarseness. Laryngofissure with cartilage grafting and T-tube stenting may be performed for severe posterior glottic stenosis, often coinciding with subglottic stenosis. Laryngeal stenosis due to the bilateral vocal fold immobility should be carefully evaluated and treated with appropriate surgical technique, thereby keeping adequate airway space with preventing severe postoperative swallowing and phonatory dysfunction.

Multiple system atrophy (MSA) is a neurodegenerative disease that is associated with cerebellar symptoms, autonomic symptoms and parkinsonism as three significant signs. The prevalence of MSA is 7-10 per 100,000 population, thus, among neurodegenerative diseases, it is not a rare condition.

MSA is known to be associated with vocal cord paralysis, and its onset often occurs during the progression of the disease and rare in the early stage of the disease. We herein report two cases of MSA in which the initial symptoms was bilateral vocal cord abductor paralysis.

Case 1: A 67-year-old woman presented to our hospital with a chief complaint of stridor and respiratory distress. Laryngeal fiberscopy revealed bilateral vocal cord abductor paralysis. She had no symptoms other than stridor and respiratory distress. Considering the possibility of central bilateral vocal cord abductor paralysis, we consulted with the neurology department. Examinations at the neurology department revealed autonomic neuropathy, followed by a diagnosis of MSA. Four months later, she received tracheotomy because of an exacerbation of respiratory distress.

Case 2: A 77-year-old man presented to our hospital with a chief complaint of stridor. Laryngeal fiberscopy revealed bilateral vocal cord abductor paralysis. A detailed examination was performed at the neurology department, but no obvious abnormality was observed. One year later, the patient underwent Ejnell’s operation at another hospital. Three years after surgery, he complained of symptoms, which were suspected to be associated with autonomic dysfunction. He was examined again by the neurology department and diagnosed with MSA.

The acute exacerbation of bilateral vocal cord abductor paralysis can cause sudden death in MSA patients. It is important for otolaryngologist to include MSA in the differential diagnosis of solo bilateral vocal cord abductor paralysis without any other neurological symptoms.

A 41-year-old woman, presented with sore throat and dyspnea of 1 week’s duration. Fiberoptic laryngoscopy showed a swollen edematous epiglottis. Because the patient developed stridor and shortness of breath, tracheostomy was performed to secure the airway. Contrast-enhanced computed tomography (CT) showed high-density areas in the epiglottis, base of the tongue, and aryepiglottic folds. The patient was positive for proteinase 3 (PR3)-antineutrophil cytoplasmic antibody (ANCA, 4.9 U/ml) and negative for myeloperoxidase (MPO)-ANCA. A histo-pathological examination of an epiglottis biopsy specimen showed geographic necrotizing granuloma with a few scattered multinucleated giant cells. Transmural inflammation, luminal occlusion, and vessel disruption were observed on elastic staining. Based on these findings, the patient was diagnosed with granulomatosis with polyangiitis (GPA). Two months after the patient started therapy with high-dose steroids and cyclophosphamide, the epiglottic swelling improved. The level of PR3-ANCA returned to the normal range two months after starting treatment. Subglottic stenosis is reportedly a common clinical feature of GPA. Although the involvement of supraglottic structures, including the epiglottis, is rare in GPA, clinicians should include GPA in the differential diagnosis of a life-threatening airway obstruction.

Fibrous histiocytoma is a tumor mainly that occurs in the limbs and soft tissue, and rarely occurs in the head and neck region. We experienced a case of cellular fibrous histiocytoma of the larynx. The patient was a 36-year-old man who had complained of hoarseness. A hemorrhagic tumor was detected at the left subglottis by laryngoscopy. We initially suspected subglottic inflammatory granulation and treated the patient conservatively; however, this was ineffective. We performed microscopic laryngeal surgery for diagnostic and treatment purposes. A histopathological examination of the resected tumor, revealed spindle cells with a narrow nucleus and acidophilic cytoplasm that proliferated tightly in the tumor tissue. The number of mitotic cells was 6/10 high power field and the tumor was negative for malignancy. On immunostaining, most tumor cells were positive for CD68 and CD163, the histiocytes were positive for S-100, while staining of CD34 and α-smooth muscle actin was negative. Thus, the diagnosis was cellular fibrous histiocytoma. The tumor recurred after ten months, we performed transoral surgery with CO₂ laser, which is useful for coagulation and resection. No recurrence was detected at two years after the second surgery. To our knowledge, there are no previous reports of cellular fibrous histiocytoma of the larynx.

Introduction: Type A botulinum toxin (BT) injection for spasmodic dysphonia (SD) has been covered by insurance since July 2018 in Japan. After insurance adaptation, BT injection was performed for three cases of abductor spasmodic dysphonia (ABSD), and the progress is reported here.

Subjects: We herein report three cases in which ABSD was diagnosed at our hospital and related hospitals and treated with BT injection.

Case 1. A 30-year-old woman had a chief complaint of aphonia and breathlessness for the past 5 years. ABSD was suspected, so BT 5.0 units were injected into the left posterior cricoarytenoid muscle (PCA) using an electromyogram (EMG). At a re-examination three weeks later, the vocal cords has only opened to the middle position. The treatment was deemed effective for PCA but did not improve the symptoms.

Case 2. A 27-year-old woman had a chief complaint of voice loss from 2 months earlier. Suspecting ABSD, BT 5.0 units were injected into the left PCA using an EMG. One month after the injection, the vocal cords has only opened to the middle. The treatment was deemed effective for PCA but did not improve the symptoms.

Case 3. A 57-year-old man had a chief complaint of difficuly vocalizing for the past 8 years. No improvement had been observed despite voice therapy at another hospital for the past three years. ABSD was suspected, so BT 5.0 units were injected into the left PCA using an EMG. One month after the injection, the vocal cords has only opened to the middle. The treatment was deemed effective for PCA but did not improve the symptoms.

Discussion: ABSD accounts for about 5% of SD cases. However, the number of injection cases at our hospital was 1.6%, which was less than in previous reports.

The treatment of ABSD by 5.0 units BT injection to the unilateral PCA conforms to Japanese insurance practice. However, it must be confirmed that the vocal cords on the opposite side move sufficiently, as when the vocal cords on the injection side do not move due to the drug, poor movement of the vocal cords on the opposite side can cause wheezing and dyspnea.

However, the domestic phase 2/3 study included only two ABSD cases, and the effectiveness of this strategy was observed in only one case. In international literature, there have been reports that the efficacy of unilateral administration ranges from insufficient to sufficient in 20% of cases, while bilateral administration has reached 89% efficacy. In the future, bilateral administration of BT should be considered as a treatment for ABSD in Japan.

Various factors, including tracheal intubation, trauma, burns, foreign bodies, infections, and tumors, can cause subglottic stenosis. Diagnosing the cause of stenosis is often difficult, and interviewing the patient is useful for achieving an accurate diagnosis; however, dyspnea due to subglottic stenosis can make it difficult for the patient to speak, or the patient may not be aware of the reason for their stenosis. We herein report a nine-year-old girl with subglottic stenosis. She suffered from wheezing, and had been treated for upper respiratory inflammation at a local clinic. As the wheezing was worsening, she was sent to our hospital. Computed tomography showed subglottic stenosis, and emergency tracheostomy was performed. Fiberscope showed swollen subglottic mucosa, but the reason for the stenosis was unclear. Four months later, while the swollen mucosa had improved, she still suffered from sputum and cough. A deep investigation with laryngoscopy was planned under general anesthesia. A foreign body was found under the vocal cords, and removed. After the surgery, the patient’s entire condition improved. As ingestion of foreign bodies does not show specific symptoms, patients might be treated as having respiratory inflammation. We should never forget the possibility of foreign body ingestion in such cases.

Laryngeal papilloma is an intractable disease that can easily to recur. Therefore, it`s treatment is often difficult. We herein report a case of recurrent laryngeal papilloma successfully treated with bevacizumab. The patient was a woman in her 70 s. He was referred to our hospital with a chief complaint of hoarseness for the past six months. Laryngoscopy revealed a tumor behind the left vocal cord. A biopsy was performed under general anesthesia, and a diagnosis of laryngeal papilloma was made. Since the patient was undergoing systemic chemotherapy due to lung cancer, Yokuinin and Hochuekkito were administered, and the patient was followed up for laryngeal papilloma on an outpatient basis. After the laryngeal papilloma shrank, the respiratory physician administered bevacizumab. However, the laryngeal papilloma rapidly increased in size again after the administration of bevacizumab had been completed. Because of dyspnea, the tumor was debulked twice under general anesthesia. However, since recurrence of laryngeal papilloma was observed again, the administration of bevacizumab for lung cancer was started again. The laryngeal papilloma disappeared and her voice quality improved. He has been treated with bevacizumab once a month for more than two years without recurrence of laryngeal papilloma and maintains a good voice.