Teruhisa Suzuki

Clinical application of in situ tissue engineering using a scaffolding technique for reconstruction of the larynx and trachea.

Objectives: The objective of the present study was to demonstrate the efficacy of the clinical application of in situ tissue engineering using a scaffolding technique for laryngeal and tracheal tissue. Methods: We have developed a tissue scaffold made from a Marlex mesh tube covered by collagen sponge. Based on successful animal experimental studies, in situ tissue engineering with a scaffold implant was applied to repair the larynx and trachea in 4 patients. Results: In 1 patient with subglottic stenosis, the thyroid cartilage, cricoid cartilage, and cervical trachea with scarring and granulation were resected and reconstructed by use of the scaffold. In 3 patients with thyroid cancer, the trachea and cricoid cartilage with tumor invasion were resected and the scaffold was implanted into the defect. Postoperative endoscopy during the observation period of 8 to 34 months showed a well-epithelialized airway lumen without any obstruction. Conclusions: Our current technique of in situ tissue engineering using a scaffold shows great potential for use in the regeneration of airway defects.

A tissue-engineered trachea derived from a framed collagen scaffold, gingival fibroblasts and adipose-derived stem cells.

In some types of tracheal disease, tracheal resection is required. For patients with tracheal resection, artificial grafts, made from collagen sponge with a spiral polypropylene stent and mesh, have been clinically used by our group. However, epithelial regeneration was confirmed to be slow. In the present study, we investigated the potential of gingival fibroblasts (GFBs) and adipose-derived stem cells (ASCs) as autologous transplanted cells in combination with artificial graft for tracheal epithelial regeneration. In in vitro co-culturing with tracheal epithelial cells, GFBs stimulated epithelial cell differentiation and reconstruction of a pseudostratified epithelium. ASCs stimulated epithelial cell proliferation and reconstruction of a multi-layered epithelium. Subsequently, we prepared three kinds of bioengineered scaffolds from GFBs and/or ASCs and implanted them into rat tracheal defects. The bioengineered scaffolds containing GFBs were covered with tracheal epithelial cells after 1 week, and highly ciliated epithelium was formed after 2 weeks of transplantation. The bioengineered scaffold containing ASCs induced thick epithelium, and then pseudostratified epithelium containing goblet cells was formed. Furthermore, the application of both GFBs and ASCs had synergistic effects on tracheal epithelial regeneration, suggesting that bioengineered scaffolds containing GFBs and ASCs are useful for hastening tracheal epithelial regeneration.

Regeneration of the Trachea Using a Bioengineered Scaffold with Adipose-Derived Stem Cells

Objectives: Our group has developed and clinically applied an artificial graft made from a collagen sponge scaffold for the regeneration of tracheal tissue. However, the artificial graft requires about 2 months for epithelial regeneration. The purpose of the present study was to accelerate the regeneration process of the trachea through the effective use of a bioengineered scaffold. Adipose-derived stem cells (ASCs) with multilineage differentiation capability were used. In our study, we implanted a bioengineered scaffold that included autologous ASCs into tracheal defects in rats. Methods: Collagen gel, including ASCs labeled with monomeric yellow fluorescent protein, was layered onto the surface of the collagen sponge to form a bioengineered scaffold. This scaffold was implanted into the tracheal defects in rats. A control scaffold without ASCs was also implanted. Results: On day 14 after implantation, a pseudostratified columnar epithelium with well-differentiated ciliated and goblet cells and neovascularization was observed in rats that received the implant with the bioengineered scaffold that included ASCs. Conclusions: These results suggested that implanted ASCs accelerated neovascularization and epithelialization on the regenerated trachea. Thus, our newly developed bioengineered scaffold contributes to tracheal regeneration.

Tissue Engineering for Regeneration of the Tracheal Epithelium

Objectives: The slowness of epithelialization on the artificial trachea that has been successfully used in humans is a problem. The purpose of this study was to develop a way to regenerate the epithelium on the surface of this artificial trachea. Methods: In an in vitro study, isolated rat tracheal epithelial cells were seeded on a collagenous gel that was stratified on a collagenous sponge. Histologic and immunohistochemical examinations were made. In an in vivo study, we transplanted grafts with green fluorescent protein–positive tracheal epithelial cells onto the tracheal defects of normal rats. At 3, 7, 14, and 30 days after the operation, histologic and immunohistochemical examinations were made. Results: In the in vitro study, the 3 layers — the epithelium, gel, and sponge — could be observed. The epithelium expressed cytokeratin 14, cytokeratin 18, and occludin. In the in vivo study, the artificial trachea was covered with epithelium at 3 days after operation, and then the epithelium differentiated from single- or double-stratified squamous epithelium into columnar ciliated epithelium. Green fluorescent protein–positive cells were found 3 days after operation. Conclusions: We believe that the method used in our experiment is an effective way to regenerate the epithelium on the surface of an artificial trachea. With further experimentation, this method should be suitable for clinical application.

Regeneration of Tracheal Epithelium Utilizing a Novel Bipotential Collagen Scaffold

Objectives: The purpose of the present study was to evaluate the effectiveness of a novel bipotential collagen scaffold as a bioengineered trachea for the regeneration of the tracheal epithelium. Methods: The bipotential collagen scaffold was developed by conjugating a collagen vitrigel membrane to a collagen sponge in order to promote both epithelial cell growth and mesenchymal cell infiltration. The bipotential collagen scaffold was transplanted into tracheal defects in rats, and a conventional collagen sponge was implanted as a control model. Histologic examinations were undertaken to evaluate the results. Results: The bioengineered trachea was covered with epithelium in the vitrigel model, but not in the control model, at 7 days after implantation. At 14 days after implantation, the bioengineered trachea was covered with epithelium involving the basal cell layer in the vitrigel model. At 28 days after implantation, a columnar ciliated epithelium was observed only in the vitrigel model. Conclusions: Our technique for trachea reconstruction using a novel bipotential collagen scaffold affords a feasible approach for accelerating epithelial regeneration on the intraluminal surface of the host tracheal defect.

Age-dependent degeneration of the stria vascularis in human cochleae.

Objective: Aging is a common cause of acquired hearing impairments. This study investigated age‐related morphologic changes in human cochleae, with a particular focus on degeneration of the stria vascularis (SV) and the spiral ganglion (SG).

Surgical Treatment of Laryngeal Papillomatosis Using NBI

Objective: Multiple laryngeal papillomatosis has a high rate of recurrence after surgery. Narrowband imaging (NBI) is a novel optical enhancement technology used for the diagnosis. This is the first report to date to indicate the availability of the combination of laryngomicro surgery and videoendoscopic surgery for laryngeal papillomatosis using NBI technology. Method: The patients were 34-year-old and 30-year-old men. Both cases underwent surgery in another hospital. However, because of recurrence, they were subsequently referred to our department for further evaluation. Examination in our outpatient clinic revealed papilloma-like mucosal changes, and recurrent multiple laryngeal papillomatosis was diagnosed in both cases. Results: In laryngomicroscopic surgical findings, the presence of papillomas was confirmed by NBI, and the papillomas were removed using an XPS Micro Debrider and a CO2 laser. Using the NBI system, the border between the normal mucosa and the papillomas could be clearly identified, allowing precise resection. Two months later, CO2 laser resection using a laryngeal flexible endoscope under topical anesthesia was undertaken in an outpatient setting for recurring or remaining papilloma lesions. Further treatment on the lesions has been carried out several times to date using NBI. The lesions have now been eradicated without further recurrence. Conclusion: Herein we reported 2 cases of multiple laryngeal papillomatosis that were treated by tumor resection using NBI. Clearer identification of the tumor border was obtained by this technique, thus allowing minimally invasive resection. This paper demonstrates the applicability of the NBI system to the identification and resection of laryngeal papillomatosis.

Angioedema of the Larynx

Tomohiro Miura Fukushima Medical University Email: tako@fmu.ac.jp Phone:+81-24-547-1325 Website:http://www.fmu.ac.jp/home/jibika/fmu orl/index.html Objective: To clarify the clinical manifestations of laryngeal edema in patients with angioedema. Study design: Retrospective study. Setting: University hospital. Methods: Patients with angioedema who visited the otolaryngology clinic in our institution were examined (including the face, lips, tongue, pharynx, larynx and neck) for the presence of oral cavities and upper airway edema. In addition, the etiology of the angioedema in each patient was surveyed. Results: Twenty patients (12 men, 8 women; mean age, 63 years) were diagnosed with angioedema, visiting out clinic on a total of 27 occasions (one patient visited our clinic three times and five patients visited us twice each with each visit regarded as a separate patient). An edema was observed in the pharynx in 22 (81%), the tongue in 20 (74%), the arytenoids in 15 (56%), the lip in 11 (41%) and the epiglottis in 8 patients (30%). Edema of the larynx, including the arytenoids and/or epiglottis, was present in 16 of the 27 patients (59%) receiving treatment. The etiology of the angioedema was identified in 11 patients as follows: C1 inhibitor deficiency (3), of which two showed hereditary angioedema and one acquired; renin-aingiotensin system inhibitors (4), estrogen (1) and diet (3). Two patients underwent tracheotomy and another one underwent tracheal intubation for airway management. Conclusion: More than 50% of patients with angioedema who initially consult at an otolaryngology clinic are found to have a laryngeal edema; therefore, examination of the upper airway is recommended for all patients diagnosed with angioedema. Angioedema of the larynx

Temporal Bone Pathology in Syphilitic Osteitis

This study aimed at demonstrating the typical temporal bone histopathology of a 74-year-old female with syphilitic osteitis. There was osteitic fistulization between lateral semicircular canal and antrum and contact of the dilated saccular wall with the medial surface of the footplate. This case most likely would have had not only a positive fistula sign caused by fistulization, but also Hennebert’s sign caused by the contact of the saccular wall with the footplate.