Long-Term Effects of Fat Injection Laryngoplasty in Relation to the Injected Fat Volume in Patients With Unilateral Vocal Fold Paralysis.

OBJECTIVE: To evaluate the improvements in vocal function and glottal form before and after autologous fat injection laryngoplasty in relation to the injected total fat volume in patients with unilateral vocal fold paralysis. DESIGN: Clinical study. METHODS: Seventy-three patients with unilateral vocal fold paralysis received fat injection laryngoplasty and were divided into low-volume injection (<3 mL; average, 2.0 mL) and high-volume injection (≥3 mL; average, 4.3 mL) groups. Voice function before and after fat injection laryngoplasty were examined by aerodynamics evaluations, pitch and intensity measurements, and acoustic analyses. The glottal form before and after fat injection laryngoplasty was determined by measuring the ratio of vocal fold bowing (bowing ratio) and the ratio of lengths between bilateral vocal process (width ratio) at an easy phonation under laryngeal endoscopic examination. The postoperative parameters were evaluated for a median period of four years after fat injection laryngoplasty. The differences between pre- and postoperative parameters were examined separately for each group by the paired t-test. For each variable, a comparison of the effects of surgery was conducted using an analysis of covariance model with the change between the pre- and postoperative values as a dependent variable and the preoperative value as a covariate. RESULTS: In both groups, all parameters of voice function and glottal form after surgery significantly improved in comparison to those before surgery. Maximum phonation time, amplitude perturbation quotient, and normalized noise energy for 0 to 4 kHz in the high-volume group improved more significantly in comparison to those in the low-volume group. CONCLUSIONS: As a rough guide for males, injection of more than 3 mL of autologous fat to the vocal muscle layer is recommended for reliable improvement of voice function in patients with unilateral vocal fold paralysis.

Endoscopic Sealing With a Polyglycolic Acid Sheet for Restoration of Vocal Fold Mucosa in Dogs.

OBJECTIVES/HYPOTHESIS: Voice outcomes of cordectomy for early glottic cancer are often poor due to vocal fold scarring and tissue defects. Improvements in this aspect could make cordectomy a more acceptable treatment option than radiotherapy. We hypothesized that a polyglycolic acid (PGA) sheet could be used to cover vocal fold defects. The present study aimed to prevent vocal fold scarring after cordectomy using the PGA sheet. STUDY DESIGN: Animal experiment. METHODS: Nine male beagles were divided into three groups including a control group (n = 3). Following cordectomy, the vocal fold defect was covered with the PGA sheet plus fibrin glue (PGA group; n = 3) or with the PGA sheet plus fibrin glue containing basic fibroblast growth factor (bFGF; the PGA-bFGF group, n = 3). Vocal folds were chronologically observed, and larynges were removed 6 months after surgery. Mucosal amplitude was measured using a high-speed camera, and histological analysis was performed. RESULTS: The re-epithelialization process was delayed in the PGA and PGA-bFGF groups compared with the control group. The mucosal amplitude was significantly more normalized and the thickness ratio significantly higher in the PGA and PGA-bFGF groups compared with the control group. The PGA-bFGF group had the highest elastic fiber density, followed by the PGA group and then the control group, with a significant difference between the PGA-bFGF and control groups. CONCLUSIONS: The PGA sheet plus fibrin glue could serve as an effective regenerative scaffold for reconstructing vocal fold morphology and function after cordectomy, with the potential benefit of establishing an endoscopic sealing method for vocal fold defects. LEVEL OF EVIDENCE: NA Laryngoscope, 130:E436-E443, 2020.

The Prevalence and Clinical Characteristics of TECTA-Associated Autosomal Dominant Hearing Loss.

TECTA is well known as a causative gene for autosomal dominant mid-frequency hearing loss observed in various populations. In this study, we performed next-generation sequencing analysis of a large Japanese hearing loss cohort, including eight hundred and twelve (812) subjects from unrelated autosomal dominant hearing loss families, to estimate the prevalence and phenotype-genotype correlations in patients with TECTA mutations. The prevalence of TECTA mutations in Japanese autosomal dominant sensorineural hearing loss families was found to be 3.2%. With regard to the type of hearing loss, the patients with mutations in the nidogen-like domain or ZA domain of TECTA showed varied audiograms. However, most of the patients with mutations in the ZP domain showed mid-frequency hearing loss. The rate of hearing deterioration in TECTA-associated hearing loss patients and in the normal hearing Japanese control population were the same and regression lines for each group were parallel. We carried out haplotype analysis for four families which had one recurring missense variant, c.5597C>T (p.Thr1866Met). Our results revealed four different haplotypes, suggesting that this mutation occurred independently in each family. In conclusion, TECTA variants represent the second largest cause of autosomal dominant sensorineural hearing loss in Japan. The hearing loss progression observed in the patients with TECTA mutations might reflect presbycusis. The c.5597C>T mutation occurred in a mutational hot spot and is observed in many ethnic populations.

Significance of cytodiagnosis in primary carcinoid tumor of the middle ear: A case report.

Primary carcinoid tumors of the middle ear are uncommon. Cytodiagnosis of the middle ear is not usually performed as a preoperative examination because of the anatomical structure of the middle ear. To the best of our knowledge, the present study reports for the first time a case of a carcinoid tumor of the middle ear, which was preoperatively diagnosed using cytodiagnosis, and also review current literature. A 22-year-old woman complained of left-sided otalgia. A subcutaneous tumor in the left middle ear was observed. Magnetic resonance imaging revealed that the tumor was primarily present in the tympanic cavity of the middle ear and extended to the mastoid antrum and mastoid cells of the middle ear and to the external acoustic meatus. Fine needle aspiration cytology was performed from the tumor protruding into the external acoustic meatus. Cytologically, the tumor was composed of small uniform cells with small round nuclei and granular eosinophilic cytoplasm, arranged in a nested pattern. Tumor cells were immunocytochemically positive for synaptophysin and cytokeratin CAM5.2. These results indicated that this was a neuroendocrine tumor. No other tumor lesions were identified on computed tomography scans, and the tumor was considered to be the primary lesion. Tympanoplasty and mastidectomy were then performed and carcinoid tumor was diagnosed in the postoperative pathological diagnosis. To the best of our knowledge, the present study is the first to report on preoperative cytodiagnosis for carcinoid tumors of the middle ear.

Histoanatomical characteristics to increase the success in transoral surgery for hypopharyngeal cancer.

OBJECTIVES/HYPOTHESIS: Transoral laser microsurgery (TLM) for hypopharyngeal cancer results in a lower incidence of complications than conventional open surgery. However, additional knowledge regarding the histoanatomical characteristics of the hypopharynx is necessary to prevent severe complications during TLM. The purpose of this study is to investigate the histoanatomical characteristics of the hypopharynx for TLM. STUDY DESIGN: Histoanatomical study. METHODS: Whole organ serial sections of three hypopharynges and larynges from autopsy cases were subjected to hematoxylin & eosin and Elastica van Gieson staining. Surgical histoanatomy of the hypopharynx was observed with each section, and the histoanatomical characteristics directly related to TLM performance were examined microscopically. RESULTS: The histological structures of muscle layers showed obvious differences between each hypopharyngeal subsite. The posterolateral wall had two kinds of pharyngeal elevator muscles. These fasciae were connected to the perichondrium of the thyroid cartilage. The anterolateral wall between the superior horn and the lamina of the thyroid cartilage had no muscle layer. The superior laryngeal artery and the internal branch of the superior laryngeal nerve run into the larynx and hypopharynx at that site. The inner perichondrium of the thyroid cartilage was present beneath the mucosa. The dihedral angle of the anterior piriform fossa had a deep propria mucosa and paraglottic space. The postcricoid wall consisted of a multilayered structure, including cricoid cartilage covered with laryngeal muscles and mucosa. CONCLUSION: A precise understanding of the histoanatomical characteristics of the hypopharynx increases the success of TLM, decreases complication rates, and improves laryngeal preservation. LEVEL OF EVIDENCE: N/A. Laryngoscope, 126:1783-1789, 2016.