Transplantation of autologous oral mucosal epithelial cell sheets inhibits the development of acquired external auditory canal atresia in a rabbit model.

Acquired external auditory canal atresia is characterized by fibrous tissue formation in the ear canal, hearing loss and chronic otorrhea. Although the disease can be treated surgically, the recurrence rate is high. This study explored whether autologous oral mucosal epithelial cell sheets could be used as a novel therapy for ear canal atresia. We succeeded in generating a rabbit model of acquired external auditory canal atresia by dissecting the skin of the ear canal. Endoscopic and histological findings in this model indicated that atresia developed over a 4-week period and was not inhibited by the placement of polyglycolic acid sheets immediately after skin dissection. By contrast, transplantation of autologous oral mucosal epithelial cell sheets, which had been fabricated by culture on temperature-responsive inserts without a feeder layer, prevented the development of atresia during the 4-week period after skin dissection. Transplantation of autologous epithelial cell sheets after surgical treatment of acquired external auditory canal atresia could be a promising new method to reduce the risk of disease recurrence. STATEMENT OF SIGNIFICANCE: Acquired external auditory canal atresia is characterized by fibrous tissue formation in the ear canal, which leads to hearing loss and chronic otorrhea. Although surgical treatments are available, the recurrence rate is high. In this study, we successfully generated a rabbit model of acquired external auditory canal atresia by dissecting the skin of the ear canal. Furthermore, we utilized this new animal model to investigate whether the transplantation of autologous oral mucosal epithelial cell sheets could be used as a novel therapy for ear canal atresia. Our results raise the possibility that the transplantation of autologous epithelial cell sheets after surgical treatment of ear canal atresia could be a promising new method to reduce the risk of disease recurrence.

The relationships among mastoid air cell development, tympanic sinus depth, and residual disease after surgery in children with congenital cholesteatoma.

Background: Mastoid development, tympanic sinus depth, and residual disease after surgery for congenital cholesteatoma are probably related, but these relationships have not been examined in detail.Aims/objectives: This study aimed to clarify the relationships between the abovementioned factors. Materials and Methods: The subjects were 31 patients with congenital cholesteatoma (stage III or IV in Potsic's staging system) that underwent mastoidectomy. The cross-sectional area of the mastoid air cells was measured as described previously. Tympanic sinus depth was classified into A-C using Marchioni et al.'s system.Results: Patients with deep tympanic sinuses or residual disease exhibited significantly greater mastoid air cell development. However, little residual disease was found in the mastoid air cells. Conversely, residual disease was observed more frequently in the patients with deep tympanic sinuses.Conclusions and significance: After surgery for congenital cholesteatoma, residual disease is more likely to occur in patients with marked mastoid growth, possibly because they have deep tympanic sinuses. Cases in which congenital cholesteatoma spreads to the mastoid air cells are classified as stage IV in Potsic's system, but our findings indicate that invasion into a deep tympanic sinus is more important than invasion into the mastoid air cells.

Anatomical variation of the pneumatized superior turbinate and its impact on endoscopic sinus surgery in chronic rhinosinusitis.

PURPOSE: The posterior ethmoid sinus is adjacent to important structures, such as the orbit, optic nerve, skull base, and ostium of the sphenoid sinus. The purpose of this study was to examine the effect of pneumatization of the superior turbinate (ST) and its basal lamella, and of the position of the anterior wall of the sphenoid sinus, on opening of the posterior ethmoid and sphenoid sinuses. METHODS: On axial, coronal, and sagittal computed tomography images, 394 sinuses of 197 patients who underwent endoscopic sinus surgery at Toho University Omori Medical Center in Tokyo, Japan, were classified according to the presence or absence of pneumatization of the ST and its basal lamella. The basal lamella of the ST was classified separately into the vertical and horizontal portions. We examined whether the classification of the anterior wall of the sphenoid sinus was associated with the structure of the ST. RESULTS: Pneumatization was observed in the ST in 28 sinuses (7.1%), in the vertical portion of the basal lamella in 127 (32.2%), and in the horizontal portion of the basal lamella in 90 (22.8%). Pneumatization in the horizontal portion of the basal lamella was significantly more common in the anterior sphenoidal wall classified as optic-canal type. CONCLUSION: Consideration should be given to the pneumatization of the ST and its basal lamella and optic-canal-type anterior sphenoidal wall, because these reduce the volume of the posterior-most ethmoid cell and may increase the risk of damaging the skull base and optic nerve.

Ultrasound-Guided Needle Aspiration of Peritonsillar Abscesses: Utility of Transoral Pharyngeal Ultrasonography.

A peritonsillar abscess is a common deep infection that is usually related to acute tonsillitis. Needle aspiration is often performed for diagnosis and treatment, but several complications, including puncture of the carotid artery, may occur, even when performed by properly trained physicians. The utility of transoral pharyngeal ultrasonography (TOPU) equipped with a biopsy adaptor for safe and full aspiration is presented. A 19-year-old man was admitted to our hospital because of a peritonsillar abscess. TOPU showed the abscess and a branch of the carotid artery, and an otolaryngologist performed puncture through the biopsy adaptor with the aid of the ultrasound image. Needle aspiration was accomplished by avoiding arterial puncture and monitoring the shrinkage of the abscess. TOPU-guided needle aspiration is useful in the safe drainage of peritonsillar abscesses.

Analysis of human nasal mucosal cell sheets fabricated using transported tissue and blood specimens.

Previously, we succeeded in transplanting autologous nasal mucosal cell sheets in the middle ears of 5 patients, who underwent cholesteatoma resection, which prevents recurrence of cholesteatoma in clinical settings. Current good manufacturing practice (GMP) standards for human cell cultivation requires the establishment of cell processing centers (CPC) which act as germ-free facilities. However, due to practical difficulties involved in establishing and maintaining such facilities at each individual hospital, a functional transport system is felt to be needed for the continuation of effective regenerative therapy. In the current study, nasal mucosal tissue and autologous blood obtained from 3 human volunteers were transported for over 3 h. Disinfected nasal tissues were cultured using keratinocyte culture medium, which included autologous serum prepared from blood. After 24 d, cultured nasal mucosal cells were transported for over 3 h and subsequently assessed for cell number, viability and purity. Moreover, CK4, CK8, and CK18 were analyzed the suitability of these nasal mucosal cell sheets for middle ear regenerative therapy. Overall, we confirmed that nasal mucosal cell sheets can be fabricated using transported nasal mucosal tissue and blood. This study would be contribute to establish a new regenerative therapy for clinical application, accompanied with transportation between companies and hospitals.

Clinical Characteristics of Pars Tensa Cholesteatoma: A Comparative Study of Area-Based Classification Systems Proposed by the Japanese Otological Society and the European Academy of Otology - Neuro-Otology.

OBJECTIVES: To assess the clinical characteristics of extent patterns in pars tensa cholesteatoma. MATERIALS AND METHODS: This was a retrospective chart review. Forty-four patients with pars tensa cholesteatoma who underwent primary surgery at a tertiary academic medical center were included. The main outcomes measured were sex, age, clinical background, and stage classification of pars tensa cholesteatoma (including the extent of cholesteatoma and involvement of the sinus tympani) according to two staging classifications: criteria advocated by the Japanese Otological Society (JOS) and those advocated by the European Academy of Otology and Neuro-Otology (EAONO)/JOS joint consensus statements. RESULTS: The mean patient age ± standard deviation was 38.4±19.6 years. The patients comprised 19 men and 25 women. According to the JOS classification, 18 ears (40.9%) were classified as stage I, 22 (50.0%) as stage II, and 4 (9.1%) as stage III. According to the EAONO/JOS joint consensus statements, 14 ears (31.8%) were classified as stage I, 26 (59.1%) as stage II, and 4 (9.1%) as stage III. Fourteen ears (31.8%) demonstrated involvement of the sinus tympani. Four ears (9.1%) that were originally categorized as stage I cholesteatoma by the JOS criteria showed sinus tympani invasion and were subsequently categorized as stage II according to the EAONO/JOS criteria. CONCLUSION: We determined the clinical characteristics of pars tensa cholesteatoma based on the novel and well-defined classification criteria. Further studies including long-term outcomes are necessary to demonstrate the clinical relevance of the discrepancy between the two criteria with respect to involvement of the sinus tympani.

A quantitative study of the suppression of the development of the mastoid air cells by the presence of congenital cholesteatoma.

Background: The mastoid air cells are considered to develop better in children with congenital cholesteatoma but only a few quantitative studies have examined. Aims/objectives: The present study was undertaken in order to clarify the relationships between the development of the mastoid air cells in children with congenital cholesteatoma and clinical factors. Materials and methods: Mastoid air cell development was evaluated in 53 children with congenital cholesteatoma. The sizes of the mastoid air cells were measured on computed tomography scans of the temporal bone, and clinical factors, including age, the extent of invasion, and whether it was located close to the eustachian tube were evaluated. Results: The cross-sectional area of the mastoid air cells was significantly smaller on the affected side than on the unaffected side, especially in the older patients. The cases involving invasion into the mastoid portion also had smaller mastoid cells. Whether the cholesteatoma was located close to the eustachian tube had no effect. Conclusions and significance: The mastoid air cells on the affected side were less well developed. Our findings indicate that a high age and the presence of cholesteatoma in the mastoid region might be associated with suppressed mastoid pneumatization.

Practical analysis of pars flaccida cholesteatoma with classification and staging system proposed by Japan Otological Society: a comparative study.

BACKGROUND: The Japan Otology Society (JOS) proposed the classification and staging system for middle ear cholesteatoma. However, there was little analysis of the pathology of cholesteatoma using this staging system. AIMS/OBJECTIVES: To analyze the pathology of pars flaccida cholesteatoma using the staging system by JOS. MATERIAL AND METHODS: A total of 183 cases of fresh pars flaccida cholesteatoma treated between January 2009 and December 2015 were included. We used the staging system recommended by JOS (2015). The association of the following variables in each stage of pars flaccida cholesteatoma was examined: age, gender, preoperative hearing level, staging, statuses of mastoid cell growth and stapes, tympanic sinus invasion. RESULTS: Stage II disease showed the highest degree of progression, and peak incidence was observed in the third and fourth decades of life. Stage III significantly increased after the age of 40 years. The progression of the disease stage was significantly associated with deterioration of hearing level. Cholesteatoma invasion to tympanic sinus was recognized in 14.2% of cases. The state of the stapes is increasingly likely be to fracture as stage progresses. CONCLUSIONS: The JOS Staging System appropriately reflects the disease state, and it was found to be clinically meaningful in this study.

Middle ear mucosal regeneration by tissue-engineered cell sheet transplantation.

The recurrence of cholesteatoma after surgical treatment often occurs as a result of poor mucosal regeneration in the middle ear cavity and mastoid cavity and changes, such as granulation tissue formation, which impair gas exchange in the middle ear cavity. Conventional tympanoplasty often results in a lack of mucosal regeneration in the resected area of the mastoid cavity. In particular, mucosal regeneration in a poorly pneumatized mastoid cavity is extremely difficult. If the middle ear mucosa can be preserved or rapid postoperative regeneration of mucosa on the exposed bone surface can be achieved after middle ear surgery, the results of surgical treatment for otitis media, including cholesteatoma, can potentially be improved and the physiological function of the middle ear can be recovered. To overcome these limitations, we developed a novel treatment method combining tympanoplasty and autologous nasal mucosal epithelial cell sheet transplantation for postoperative regeneration of the middle ear mucosa. In clinical research, we endoscopically removed an approximately 10 × 10 mm2 piece of nasal mucosal tissue. Tissue-engineered autologous nasal mucosal epithelial cell sheets were fabricated by culturing the harvested cells in an aseptic environment in a good manufacturing practice-compliant cell processing facility. The cultivated cell sheets were transplanted, during tympanoplasty, onto the exposed bony surface of the attic of the tympanic and mastoid cavities where the mucosa had been lost. We performed this procedure on four patients with middle ear cholesteatoma and one patient with adhesive otitis media. All patients showed favorable postoperative course with no adverse events or complications and the patients' hearing ability post-transplantation remained good.

Autologous human nasal epithelial cell sheet using temperature-responsive culture insert for transplantation after middle ear surgery.

Postoperative mucosal regeneration of the middle ear cavity and the mastoid cavity is of great importance after middle ear surgery. However, the epithelialization of the mucosa in the middle ear is retarded because chronic inflammation without epithelialization aggravates gas exchange and clinical function. These environmental conditions in the middle ear lead to postoperative retraction and adhesion of the newly-formed tympanic membrane. Therefore, if the mucosa on the exposed middle ear bone surface can be rapidly regenerated after surgery, the surgical treatments for cholesteatoma and adhesive middle ear disease can potentially be improved. In this study, we successfully generated a cell sheet designed for the postoperative treatment of cholesteatoma. We used nasal cells to create an artificial middle ear mucosal cell sheet with a three-dimensional (3D) configuration similar to that of the middle ear mucosa. The sheets consisted of multi-layered mucosal epithelia and lower connective tissue and were similar to normal middle ear mucosa. This result indicates that tissue-engineered mucosal cell sheets would be useful to minimize complications after surgical operations in the middle ear and future clinical applications are expected. Copyright © 2015 John Wiley & Sons, Ltd.

Cochlin-tomoprotein test and hearing outcomes in surgically treated true idiopathic perilymph fistula.

CONCLUSION: Approximately 50% of patients with sPLF based on the clinical diagnosis criteria were definitively diagnosed with CTP-positive sPLF. These results suggest that early surgery within 7 days of the disease onset contributes to improvements in the therapeutic response of hearing loss. OBJECTIVES/HYPOTHESIS: Idiopathic spontaneous perilymph fistula (sPLF) cannot be diagnosed reliably. It is speculated that this condition occurs in patients with vertigo-accompanied acute sensorineural hearing loss that progresses rapidly in spite of steroid therapy. This study herein evaluated cochlin-tomoprotein (CTP) test results in patients with sPLF who underwent exploratory tympanotomy and considered surgical outcomes with true sPLF. STUDY DESIGN: Retrospective study. METHODS: Twenty-three patients diagnosed with sPLF based on the clinical diagnosis criteria who underwent exploratory tympanotomy were included. RESULTS: CTP test results were positive in 11 cases. In CTP-positive cases, the mean hearing level was 66.5 dB pre-operatively and 42.3 dB post-operatively. The hearing level post-operatively completely recovered in four cases, markedly recovered in three cases, slightly recovered in one case and showed no response in three cases. Hearing level improvements were significantly better in CTP-positive patients who underwent surgery within 7 days of the disease onset than in those treated 8 or more days after the disease onset.

Middle ear mucosal regeneration with three-dimensionally tissue-engineered autologous middle ear cell sheets in rabbit model.

The likelihood of recurrent retraction and adhesion of newly formed tympanic membrane is high when middle ear mucosa is extensively lost during cholesteatoma and adhesive otitis media surgery. If rapid postoperative regeneration of the mucosa on the exposed bone surface can be achieved, prevention of recurrent eardrum adhesion and cholesteatoma formation, for which there has been no definitive treatment, can be expected. Suture-less transplantation of tissue-engineered mucosal cell sheets was examined immediately after the operation of otitis media surgery in order to quickly regenerate middle ear mucosa lost during surgery in a rabbit model. Transplantable middle ear mucosal cell sheets with a three-dimensional tissue architecture very similar to native middle ear mucosa were fabricated from middle ear mucosal tissue fragments obtained in an autologous manner from middle ear bulla on temperature-responsive culture surfaces. Immediately after the mucosa was resected from middle ear bone bulla inner cavity, mucosal cell sheets were grafted at the resected site. Both bone hyperplasia and granulation tissue formation were inhibited and early mucosal regeneration was observed in the cell sheet-grafted group, compared with the control group in which only mucosal removal was carried out and the bone surface exposed. This result indicates that tissue engineered mucosal cell sheets would be useful to minimize complications after the surgical operation on otitis media and future clinical application is expected.

The effect of transplantation of nasal mucosal epithelial cell sheets after middle ear surgery in a rabbit model.

Postoperative regeneration of the middle ear mucosa and pneumatization of the middle ear cavity are of great importance after middle ear surgery. This study developed a new method to transplant autologous nasal mucosal epithelial cell sheets into the damaged middle ear cavity. The aim of this study was to evaluate postoperative healing after the transplantation of the cell sheets. Rabbit nasal mucosal epithelial cell sheets were fabricated on a temperature-responsive culture dish, and transplanted into the damaged middle ear of rabbit, which was surgically created. The healing of middle ears was evaluated by histology and X-ray computed tomography after transplantation. Functional evaluation was performed by measuring the maximum middle ear total pressure reflecting a trans-mucosal gas exchange function. Two control groups were used: the normal control group and the mucosa-eliminated control group. Transplantation of cell sheets suppressed the bone hyperplasia and the narrowing of pneumatic space in the middle ear cavity compared with the mucosa-eliminated control group. The mucosal gas exchange function was also better in the cell sheet-transplanted group. Nasal mucosal epithelial cell sheet was confirmed to be useful as an effective graft material after middle ear surgery and hopefully become a novel therapy in the future.

Clinical analysis of secondary acquired cholesteatoma.

OBJECTIVE: This study aimed to analyze the clinical features of patients who underwent surgery for secondary acquired cholesteatoma (SAC). MATERIALS AND METHODS: The subjects were 30 patients who underwent surgery for SAC in 30 ears. We investigated the age distribution, sex, tympanic membrane (TM) findings, temporal bone pneumatization, morphology of TM epidermis invasion, extent of cholesteatoma invasion, ossicular erosion, surgical methods and surgical results. RESULTS: There were 10 males (33.3%) and 20 females (66.6%), with a mean age 54.9 years. The TM perforation was medium-sized or larger in 27 ears (90%). Temporal bone pneumatization was poor or bad in 90% (18/20) of the evaluated ears. The cholesteatoma invaded from the malleus manubrium to the promontory in 23 ears (76.7%). There were no patients in whom the cholesteatoma invaded the antrum or mastoid. The ossicles were affected in 19 ears (63.3%). Ossiculoplasty with a columella on the stapes was the most frequent procedure, performed for 16 ears (53.3%). There were no hearing results with a postoperative air-bone gap of more than 31 dB. CONCLUSIONS: Although SAC is rare, it is important for the clinician to keep this type of cholesteatoma in mind.

Comparison between endoscopic and microscopic stapes surgery.

OBJECTIVES/HYPOTHESIS: To investigate whether endoscopic stapes surgery is safer and less invasive than conventional stapes surgery using an operating microscope. STUDY DESIGN: Retrospective study. METHODS: The subjects were 15 patients (15 ears) who underwent endoscopic stapes surgery for otosclerosis or congenital stapedial fixation. Another 35 patients (41 ears) in whom microscopic stapes surgery was performed by the same surgeon were assigned to the control group. The procedures for endoscopic surgery were fundamentally the same as those for microscopic surgery, unless there was no anterior or posterior auricular skin incision. The two surgical techniques were compared with respect to the operating time, postoperative hearing, complications, postoperative pain, and the extent of drilling at the posterosuperior part of the external auditory canal. RESULTS: There were no differences of operating time or postoperative hearing between the endoscopic and microscopic groups. There was very little postoperative pain in the endoscopic group. Postoperative dizziness was mild in all patients who received endoscopic surgery. Drilling at the posterosuperior part of the external auditory canal was less extensive in the endoscopic group than in the microscopic group. CONCLUSION: Endoscopic surgery is particularly suitable for stapedial disease. Endoscopic stapes surgery can even be done in patients with a curved and narrow external auditory canal. Endoscopic surgery is also suitable for education: The surgical anatomy can be understood easily and both the surgeon and assistants can observe the procedure on the same monitor. However, it should only be performed by experienced surgeons because one-handed manipulation is required and stereoscopic vision is not available.

Cholesteatoma fibroblasts promote epithelial cell proliferation through overexpression of epiregulin.

To investigate whether keratinocytes proliferate in response to epiregulin produced by subepithelial fibroblasts derived from middle ear cholesteatoma. Tissue samples were obtained from patients undergoing tympanoplasty. The quantitative polymerase chain reaction and immunohistochemistry were performed to examine epiregulin expression and localization in cholesteatoma tissues and retroauricular skin tissues. Fibroblasts were cultured from cholesteatoma tissues and from normal retroauricular skin. These fibroblasts were used as feeder cells for culture with a human keratinocyte cell line (PHK16-0b). To investigate the role of epiregulin in colony formation by PHK16-0b cells, epiregulin mRNA expression was knocked down in fibroblasts by using short interfering RNA and epiregulin protein was blocked with a neutralizing antibody. Epiregulin mRNA expression was significantly elevated in cholesteatoma tissues compared with that in normal retroauricular skin. Staining for epiregulin was more intense in the epithelial cells and subepithelial fibroblasts of cholesteatoma tissues than in retroauricular skin. When PHK16-0b cells were cultured with cholesteatoma fibroblasts, their colony-forming efficiency was 50% higher than when these cells were cultured with normal skin fibroblasts. Also, knockdown of epiregulin mRNA in cholesteatoma fibroblasts led to greater suppression of colony formation than knockdown in skin fibroblasts. Furthermore, the colony-forming efficiency of PHK16-0b cells was significantly reduced after treatment with an epiregulin neutralizing antibody in co-culture with cholesteatoma fibroblasts, but not in co-culture with skin fibroblasts. These results suggest that keratinocyte hyperproliferation in cholesteatoma is promoted through overexpression of epiregulin by subepithelial fibroblasts via epithelial-mesenchymal interactions, which may play a crucial role in the pathogenesis of middle ear cholesteatoma.

[Petrous cholesteatoma: clinical features and surgical outcome].

In this study we analyzed the clinical features and surgical treatment of petrous cholesteatoma in 9 patients (9 ears) who underwent surgery at the Jikei University Hospital. Most patients initially experienced hearing loss, then facial nerve palsy or otorrhea. Congenital cholesteatoma was diagnosed in four patients, acquired cholesteatoma in one patient, and postoperative recurrence in three patients. The proportion of cases of congenital cholesteatomas was higher than in previous reports. The area of the cholesteatoma was classified according to Dr. Sanna cases and the supralabyrinthine type in two cases. Hearing preservation surgery was performed in four patients via the middle cranial fossa approach or by partial labyrinthectomy, and the results seemed satisfactory. These results suggested that hearing preservation surgery should be adopted in every case.

Endoscope-assisted surgery via the middle cranial fossa approach for a petrous cholesteatoma.

OBJECTIVE: Surgical approaches to petrous cholesteatomas are the translabyrinthine-transcochlear approach, partial labyrinthectomy, and the middle cranial fossa approach. Selection of surgical approach is determined by region of cholesteatoma in the petrous bone as well as preoperative status of hearing and facial nerve function. The middle cranial fossa approach is the best approach for patient having good preoperative hearing and facial nerve function. However, application of this approach is limited for patients having relatively small petrous cholesteatomas, and sometimes difficult for patients in whom inner ear function is preserved but a cholesteatoma surrounds whole cochlea and extends to lower part of the labyrinth. In such case, we performed endoscope-assisted surgery via the middle cranial fossa approach to preserve cochlear and its function. METHODS: 30 degrees and 70 degrees rigid endoscopes were used for the operation via the middle cranial fossa. RESULTS: The inferior surface of the cochlea and the region around the internal carotid artery could be well visualized by use of endoscopy, and we succeeded in removal of petrous cholesteatoma surrounding the cochlea completely with preserving preoperative hearing. CONCLUSION: Endoscope-assisted surgical technique that allowed safe and complete removal of a cholesteatoma extended inferior surface of coclear and around carotid artery in the petrous.

Middle ear hemangiona: a case report.

A middle ear hemangioma was detected in a 51-year-old man who suffered from fullness and hearing loss in the left ear. This case is presented with a review of the relevant literature. The mass was surgically resected for diagnostic and therapeutic reasons, and pathologic examination revealed a benign hemangioma. The CT, MRI, angiography, and light microscopy findings of the tumor are documented and compared with those a glomus tumor. The significance of this diagnosis is also discussed.

Middle ear mucosa regeneration by grafting of artificial mucosa.

CONCLUSION: Artificial middle ear mucosa (AMEM), a sheet of mucosal cells grown on collagen gel populated with fibroblasts, is useful as graft material that is able to promote mucosal regeneration after middle ear surgery. OBJECTIVES: Regeneration of the middle ear mucosa and pneumatization of the mastoid cavity is critical for good prognosis. We examined whether implantation of AMEM into damaged middle ear cavity would promote mucosal regeneration. MATERIALS AND METHODS: AMEM was prepared as described previously using epithelial cells and fibroblasts isolated from the rabbit middle ear. We implanted AMEM into rabbit middle ear from which mucosa had been surgically removed and evaluated its histological and functional recovery 8 weeks later. Three other groups were used for comparison: a normal control group, a mucosa-eliminated group, and a collagen-implanted group. RESULTS: AMEM grew to be morphologically similar to the native middle ear mucosa. Electron microscope studies showed that implanted AMEM has basal lamina and cilia. AMEM implantation suppressed bone hyperplasia and granulation, leading to better mucosal regeneration. Mucosal gas exchange was also significantly improved after implantation.