Wataru Okano

Bioengineered Trachea with Fibroblasts in a Rabbit Model

Objectives: Although our group has had mostly successful results with clinical application of a tracheal prosthesis, delayed epithelial regeneration remains a problem. In our previous studies using rats, it was demonstrated that tracheal fibroblasts accelerated proliferation and differentiation of the tracheal epithelium in vitro and in vivo. The purpose of this study was to evaluate the effects of fibroblasts on epithelial regeneration in larger tracheal defects in rabbits. Methods: We developed a bioengineered scaffold, the luminal surface of which was coated with fibroblasts. This scaffold was implanted into tracheal defects in 12 rabbits (bioengineered group), and scaffolds without fibroblasts were implanted in 12 rabbits (control group). The regenerated epithelium was histologically examined by light microscopy, scanning electron microscopy, and immunohistochemical studies. Results: In the bioengineered group, a stratified squamous epithelium was observed on the surface 7 days after transplantation. However, in the control group, the scaffolds were exposed. Fourteen days after implantation, a columnar ciliated epithelium was observed in the bioengineered group. The average thickness of the regenerated epithelium in the bioengineered group was significantly greater than that in the control group. Conclusions: This study indicated that fibroblasts had a stimulatory effect that hastened regeneration of the epithelium in large tracheal defects.

Bioengineered prosthesis with allogenic heterotopic fibroblasts for cricoid regeneration

This study aimed to determine the effectiveness of a bioengineered prosthesis with allogenic heterotopic fibroblasts for cricoid regeneration.

Surgical Treatment of Laryngeal Papillomatosis Using Narrow Band Imaging

Laryngeal papillomatosis has a high rate of recurrence after surgery. Narrow band 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. The patients were a 34-year-old man and a 30-year-old man. Both patients underwent surgery in another hospital. However, due to recurrence, they were subsequently referred to the authors’ department for further evaluation. 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. Further treatment on the lesions has been carried out several times to date using NBI. The lesions have now been eradicated without further recurrence.

Restricted infection of murine cytomegalovirus (MCMV) in neonatal mice with MCMV-induced sensorineural hearing loss

BACKGROUND Congenital infection with human Cytomegalovirus (HCMV) is known to be a causative agent of sensorineural hearing loss (SNHL). OBJECTIVES To clarify the nongenetic etiology of SNHL by identifying the Cytomegalovirus (CMV)-infected region in the cochleae. STUDY DESIGN We established an animal model of SNHL by injecting neonatal Balb/c mice with intracerebral murine Cytomegalovirus (MCMV) within 24h after delivery. RESULTS At 3 weeks of age, unilateral and bilateral SNHL were observed in 24% (5/21) and 29% (6/21) of the mice, respectively. SNHL thereafter progressed, with 79% of mice developing bilateral SNHL by 6 weeks of age. MCMV antigens and DNA were detected in the spiral ganglion, and cells surrounding the meninges and scala tympani at 1 week of age. However, both MCMV antigens and DNA had completely disappeared by 2 weeks of age. It is possible that the MCMV reached the spiral ganglion via cerebrospinal fluid as the result of meningitis, as the stria vascularis was found to be MCMV antigen negative. Myosin VI expression in the outer hair cells was lost at 3 weeks of age. MCMV and myosin VI expression disappeared before and during SNHL progression, respectively. CONCLUSIONS There was a definite lag time between the period in which MCMV antigens/DNA-positive cells were observed and that in which SNHL developed and myosin VI-negative hair cells were observed. Further study is needed to explore the role of MCMV in the loss of myosin VI expression in the outer hair cells.

Swallowing disorder following salvage total pharyngo-laryngo-esophagectomy with free jejunum reconstruction

For recurrent cases or residual cases following concomitant chemo-radiation therapy (CCRT), salvage surgery is a frequently used treatment options. A swallowing disorder is one of the major complications of CCRT. The purpose of the present study was to evaluate the effect of CCRT on swallowing function in patients who underwent salvage total pharyngo-laryngo-esophagectomy (TPLE), and to evaluate the importance of pharyngeal constriction in patients who underwent TPLE. Between 2008 January and 2014 May, 54 patients were treated with salvage TPLE following CCRT or TPLE at the National Cancer Center Hospital East, Chiba, Japan and were included in the present study. A total of 14 patients underwent salvage TPLE following CCRT for recurrence or residual tumor (the salvage TPLE group), and 40 patients underwent TPLE as initial treatment (the TPLE group). The pharyngeal constriction score and the post-swallowing oropharyngeal residue rate were evaluated, and inadequate velopharyngeal closure was assessed by videofluorography. The pharyngeal constriction score of the salvage TPLE group was poorer than that of the TPLE group (P<0.05). The bolus residue in the oropharynx was significantly larger in the salvage TPLE group than in the TPLE group (P<0.05). With regards to inadequate velopharyngeal closure, there was no significant difference between the TPLE group and the salvage TPLE group (P>0.99). The results of the present study indicate that the swallowing function of patients who undergo salvage TPLE may be affected by CCRT.

The selection of treatment strategy for stage III, IV laryngeal and hypopharyngeal squamous cell carcinoma: —an evaluation of predictable parameters for concurrent chemoradiotherapy—@@@―化学放射線同時併用療法の選択基準についての考察―

In the treatment strategy for advanced laryngeal or hypopharyngeal cancer, it is not so easy to decide whether patient should be performed concurrent chemoradiotherapy (CCRT) or wide resection with total laryngectomy. One hundred-fifty three patients were divided into two groups according to the modality for primary site ; CCRT group and the other wide resection group, and we retrospectively examined whether we could predict the case of having high sensitivity and curative possibility to CCRT. Clinical parameters ; T stage, subsite of tumor, tumor volume, existence of laryngeal paresis and tumor growth pattern, all of them were not predictable. The response to induction chemotherapy was not also predictable. Relapse free survival rate, regional free survival rate and disease specific survival rate were 58.2%, 55.2% and 30.1% in CCRT group and 91.6%, 76.4% and 61.1% in wide resection group and there were significant differences between them.

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.