Value of section plane,MPR,and 3D-CTVR techniques in the fine differential diagnosis of ossicular chain in the case of conductive hearing loss with intact tympanic membrane

Aim: To assess the quality of high-resolution CT section planes(HRCT), multi-planar reformation(MPR) and 3-dimensional volume rendered computer tomography(3D-CTVR) were here used in the fine differential diagnosis of ossicular chain in the case of conductive hearing loss with intact tympanic membrane.Methods: Here, 17 cases of otosclerosis and 22 cases of ossicular chain deformity were selected. All patients had normal external ear canals,intact tympanic membranes, conductive hearing loss, type A tympanograms, and negative Gelle's tests. The respective radiological reports of the status of the ossicles via 3 protocols were compared to surgical findings. The quantitative assessments of the representation of different segments of the ossicular chain were based on a 3-point scoring system.Results: MPR and CTVR imaging both showed the integrity of whole ossicular chain well. MPR and CTVR imaging were found to be superior to section planes with respect to showing the superstructure of the stapes and malformations(P > 0.05).Conclusion: CTVR and MPR imaging were found to be better able to show the whole ossicular chain in the conductive hearing loss with normal tympanic membranes. Furthermore, the use of these techniques can have profound contributive value in the differential diagnosis of otosclerosis and ossicular chain absence or malformation.

Scala tympani drill-out technique for oval window atresia with malformed facial nerve: A report of three cases

Objective: To report a scala tympani drill-out technique for managing malformed facial nerve covering the entire oval window(OW).Methods: Data from three cases with OW atresia, malformed stapes and abnormal facial nerve courses were reported, in which a scala tympani drill-out technique was employed with a TORP between the tympanic membrane and scala tympani fenestration for hearing reconstruction.Results: Air conduction hearing improved in two of the three cases following surgery. In the third case, there was no improvement in air conduction hearing following a canal wall up mastoidectomy and tympanoplasty. There were no vertigo, tinnitus or sensorineural hearing loss in the three cases.Conclusion: The scala tympani drill-out technique, which is basically fenestration at the initial part of the basal turn, provides a choice in hearing reconstruction when the OW is completely covered by abarrently coursed facial nerve.

In vitro permeability of round window membrane to transforming dexamethasone with delivery vehicles——a dosage estimation

Background In recent years the interest of sustained drug delivery into inner ear is promising, at the same time a great deal of novel oral drugs using biodegradable vehicles have been produced to achieve sustained drug release. The aim of this study was to use biodegradable vehicles to release dexamethasone in the round window membrane application. Methods Dexamethasone gels composed of alginate and chitin were prepared and the release-permeating profiles were studied using a reproducible in vitro apparatus. A longer-period time course was simulated using the parameters acquired in this study. The data obtained in this study was compared with those of other studies in intratympanic drug delivery, and an appropriate initial dosage was extrapolated. Results The combination of alginate and chitin could efficiently restrict dexamethasone diffusion and the time course suggested a sustained drug concentration within 24 hours. A higher initial dosage was estimated to achieve a stable therapeutic concentration in vivo. Conclusion The combination of alginate and chitin could be used as vehicle for sustained release of dexamethasone in intratympanic application.

Epithelial defect repair in the auricle and auditory meatus by grafting with cultured adipose-derived mesenchymal stem cell aggregate-extracellular matrix

Background: Several patients experience persistent otorrhea after a flawless surgical procedure because of insufficient epithelial healing. Several efforts, such as autologous tissue allograft and xenograft, have been made to halt otorrhea. However, a stable technology to induce temporal epithelial repair is yet to be established. Therefore, this study aims to investigate whether implantation of seeding adipose-derived mesenchymal stem cell (ADMSC) aggregates on extracellular matrix (ECM;herein, ADMSC aggregate-ECM) into damaged skin wound promotes skin regeneration. Methods: ADMSC aggregate-ECM was prepared using a previously described procedure that isolated ADMSCs from rabbits and applied to the auricle and auditory meatus wound beds of New Zealand white rabbits. Wound healing was assessed by general observation and hematoxylin and eosin (H&E) staining. Secretion of growth factor of the tissue was evaluated by western blotting. Two other groups, namely, ECM and control, were used. Comparisons of three groups were conducted by one-way analysis of variance analysis. Results: ADMSCs adhered tightly to the ECM and quickly formed cell sheets. At 2 weeks, general observation and H&E staining indicated that the wound healing rates in the ADMSC aggregate-ECM (69.02±6.36%) and ECM (59.32 + 4.10%) groups were higher than that in the control group (43.74± 12.15%;P=0.005, P<0.001, respectively) in ear auricle excisional wounds. At 7 weeks, The scar elevation index was evidently reduced in the ADMSC aggregate-ECM (2.08±0.87) and ECM (2.31 ±0.33) groups compared with the control group (4.06 ±0.45;P < 0.001, P < 0.001, respectively). In addition, the scar elevation index of the ADMSC aggregate-ECM group reached the lowest rate 4 weeks in advance. In auditory meatus excisional wounds, the ADMSC aggregate-ECM group had the largest range of normal skin-like structure at 4 weeks. The ADMSC aggregate-ECM and ECM groups secreted increased amounts of growth factors that contributed to skin regeneration at weeks 1 and 2, respectively. Conclusions: ADMSC aggregate-ECM and ECM are effective repair materials for wound healing, especially ADMSC aggregate- ECM. This approach will provide a meaningful experimental basis for mastoid epithelium repair in subsequent clinical trials.