Mioko Fukahori

Origin of Vocal Fold Stellate Cells in the Human Macula Flava

Objectives: There is growing evidence that vocal fold stellate cells (VFSCs) in the human maculae flavae are tissue stem cells of the human vocal fold and that the maculae flavae are a stem cell niche. The origin of the cells in the human maculae flavae (CHMF) and the relationship with bone marrow–derived cells were investigated. Methods: Five human adult vocal fold mucosae were investigated. The CHMF were subcultured and morphological features were assessed. Immunoreactivity to antibodies directed to cytokeratin, desmin, GFAP, vimentin, CD34, CD45, and collagen type I was investigated. Results: Cultured CHMF formed a colony-forming unit, indicating they are mesenchymal stem cells or stromal stem cells in the bone marrow. The CHMF expressed hematopoietic markers (CD34, CD45) and collagen type I, which are the major makers for bone marrow–derived circulating fibrocytes. The cultured CHMF expressed epithelium-associated, muscle-associated, neural-associated, and mesenchymal cell–associated proteins, indicating the CHMF are undifferentiated and express proteins of all 3 germ layers. Conclusions: The CHMF are undifferentiated cells derived from the differentiation of bone marrow cells. The results of this study are consistent with the hypothesis that the VFSCs are tissue stem cells or progenitor cells of the human vocal fold mucosa.

Regeneration of Vocal Fold Mucosa Using Tissue-Engineered Structures with Oral Mucosal Cells.

Objectives Scarred vocal folds result in irregular vibrations during phonation due to stiffness of the vocal fold mucosa. To date, a completely satisfactory corrective procedure has yet to be achieved. We hypothesize that a potential treatment option for this disease is to replace scarred vocal folds with organotypic mucosa. The purpose of this study is to regenerate vocal fold mucosa using a tissue-engineered structure with autologous oral mucosal cells. Study Design Animal experiment using eight beagles (including three controls). Methods A 3 mm by 3 mm specimen of canine oral mucosa was surgically excised and divided into epithelial and subepithelial tissues. Epithelial cells and fibroblasts were isolated and cultured separately. The proliferated epithelial cells were co-cultured on oriented collagen gels containing the proliferated fibroblasts for an additional two weeks. The organotypic cultured tissues were transplanted to the mucosa-deficient vocal folds. Two months after transplantation, vocal fold vibrations and morphological characteristics were observed. Results A tissue-engineered vocal fold mucosa, consisting of stratified epithelium and lamina propria, was successfully fabricated to closely resemble the normal layered vocal fold mucosa. Laryngeal stroboscopy revealed regular but slightly small mucosal waves at the transplanted site. Immunohistochemically, stratified epithelium expressed cytokeratin, and the distributed cells in the lamina propria expressed vimentin. Elastic Van Gieson staining revealed a decreased number of elastic fibers in the lamina propria of the transplanted site. Conclusion The fabricated mucosa with autologous oral mucosal cells successfully restored the vocal fold mucosa. This reconstruction technique could offer substantial clinical advantages for treating intractable diseases such as scarring of the vocal folds.

Surgical management for isolated cricoid fracture causing arytenoid immobility

Cricoid cartilage fractures usually occur concurrently with disorders of laryngeal function. In, particular, displaced cricoid lamina fractures can affect arytenoid movement. However, functional, recovery may require proper repositioning of the cricoid lamina, which is associated with a high rate of, complications. Here we present a case in which an isolated cricoid cartilage fracture with arytenoid, immobility due to displacement of the fracture in the cricoarytenoid joint space was successfully, treated. Our findings suggest that a combination of external approaches with temporary, cricothyrotomy and wide suturing of the entire cricoid framework has the potential to improve, arytenoid movement and prevent associated complications.

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

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.

Augmentation surgery on the cartilaginous portion of the vocal fold in a patient with cricoarytenoid joint ankylosis

Surgical management of cricoarytenoid joint (CAJ) ankylosis is challenging and has the risk of worsening voice quality. In the present case, augmentation surgery was performed on the cartilaginous portion of the vocal fold in a patient with CAJ ankylosis. A 24-year-old man sustained blunt trauma to the anterior neck three years prior to developing severe breathiness. Posterior glottal insufficiency resulting from lateral fixation of the right vocal fold was observed during phonation under laryngoscopy. In addition, electromyography and CT scan revealed severe ankylosis of the right CAJ. Type I thyroplasty performed on the right vocal fold did not improve postoperative vocal function. Therefore, augmentation surgery on the cartilaginous portion of the right vocal fold was performed via endolaryngeal microsurgery under general anesthesia with jet ventilation. A piece of temporalis fascia was autotransplanted into the submucosal space created at the posterior cartilaginous portion of the right vocal fold. This resulted in the narrowing of the posterior glottal gap during phonation, leading to improvement in hoarseness. Microsurgical management with autologous fascia augmentation of the cartilaginous portion of the vocal fold can be effective in patients with lateral vocal fold fixation due to CAJ ankylosis.

Recurrent laryngeal nerve regeneration using an oriented collagen scaffold containing Schwann cells.

Regeneration of the recurrent laryngeal nerve (RLN), which innervates the intrinsic laryngeal muscles such that they can perform complex functions, is particularly difficult to achieve. Synkinesis after RLN neogenesis leads to uncoordinated movement of laryngeal muscles. Recently, some basic research studies have used cultured Schwann cells (SCs) to repair peripheral nerve injuries. This study aimed to regenerate the RLN using an oriented collagen scaffold containing cultured SCs.

Endoscopic surgical technique for benign fibrotic strictures of the upper esophageal sphincter

A 43‐year‐old man with complaints of increased difficulty swallowing and weight loss underwent videofluorographic examination of swallowing, which revealed severely reduced cricopharyngeal opening. Endoscopic cricopharyngeal myotomy was carried out using a modified technique (mECPM). A benign fibrotic stricture of the upper esophageal sphincter (UES) was identified under visualization of a distending operating laryngoscope. A vertical midline incision in the strictured mucosa and submucosal resection of the cricopharyngeal muscle were done using a CO2 laser. The initial vertical mucosal incision was tightly sutured in the horizontal direction with absorbable surgical sutures. Histopathological examination of the cricopharyngeal muscle revealed infiltration of inflammatory cells. The patient started oral intake on postoperative day 7. He has been symptom free for 2 years with an improved body mass index, and postoperative laryngoscopy revealed no salivary retention in the piriform sinuses. The technique presented here provides sufficient opening of the UES by eliminating the problem of restenosis. mECPM will be useful for treating benign fibrotic strictures of the UES.

Vocal Fold Cover Layer with a Tissue-Engineered Structure Containing Epithelium and Fibroblast of Oral Mucosa:

Objectives: A potential treatment option for severe vocal fold scarring is to replace the vocal fold cover layer with a tissue-engineered structure containing autologous cells. The aim of this study is to develop a three-dimensional cell-populated matrix resembling the vocal fold layers of epithelium and lamina propria from autologous oral mucosa. Methods: A 3-by-3-mm specimen of canine buccal mucosa was harvested and divided into epithelium and submucosa. Epithelial cells from the epithelium and fibroblasts from the submucosa were isolated and separately cultured. After the culturing for 2 weeks, the epithelial cells were seeded on mesh type oriented collagen gels containing the fibroblasts throughout a 2-week-culture period. The morphological characteristics of the cultured tissue were observed with immunohistochemical staining and transmission electron microscopy. Normal canine vocal fold and buccal mucosa were used as positive controls. Results: We successfully fabricated a vocal fold cover layer with a tissue-engineered structure closely resembling the normal vocal fold layers of epithelium and lamina propria. The epithelium had three to five cell layers and did not resemble the original oral mucosa. The epithelial cells were immunostained with anti-keratin 3 antibodies, anti-b1 integrin antibodies, and anti-p63 antibodies. The fibroblasts in the collagen gels were immunostained with anti-vimentin antibodies. Electron microscopy revealed developed microvilli on the apical surface of the epithelial cells. Conclusions: The tissue-engineered vocal fold cover layer from autologous oral mucosa has the possibility to reconstruct the vocal fold surface and to restore voice in patients with severe vocal fold scarring.