Although three-dimensional (3D) bioprinting technology has gained much attention in the field of tissue engineering, there are still several significant engineering challenges to overcome, including ...lack of bioink with biocompatibility and printability. Here, we show a bioink created from silk fibroin (SF) for digital light processing (DLP) 3D bioprinting in tissue engineering applications. The SF-based bioink (Sil-MA) was produced by a methacrylation process using glycidyl methacrylate (GMA) during the fabrication of SF solution. The mechanical and rheological properties of Sil-MA hydrogel proved to be outstanding in experimental testing and can be modulated by varying the Sil-MA contents. This Sil-MA bioink allowed us to build highly complex organ structures, including the heart, vessel, brain, trachea and ear with excellent structural stability and reliable biocompatibility. Sil-MA bioink is well-suited for use in DLP printing process and could be applied to tissue and organ engineering depending on the specific biological requirements.
Objectives
To reduce the mastoid cavity‐associated problems secondary to canal wall down mastoidectomy, we designed a new surgical procedure that includes canal wall reconstruction using ...free‐floating cartilages and double musculoperiosteal flaps.
Study Design
Retrospective study.
Materials and methods
Thirty‐three patients were enrolled in this study. Preoperative and postoperative pure tone audiometry/speech discrimination score and postoperative status (complications and EAC status) were analyzed.
Results
Air conduction thresholds were statistically improved (P = 0.008). The air–bone gap was significantly reduced following surgery (P = 0.001). There were no other major complications in any of the patients. Long‐term follow‐up demonstrated gradual widening of the neo‐EAC in 18 patients (54.5%) but normal contour of the neo‐EAC in the other 13 patients (39.4%). In just one case did the neo‐EAC become extremely widened.
Conclusion
Mastoid obliteration and canal wall reconstruction using free‐floating cartilages and double musculoperiosteal flaps is very useful to achieve optimal surgical view, eliminate the middle ear pathology, and prevent recurrence of cholesteatoma and cavity problem.
Level of Evidence
4. Laryngoscope, 127:1153–1160, 2017
For a minimally invasive approach to access the facial nerve, we designed an extended epitympanotomy via a transmastoid approach that has proven useful in cases of traumatic facial nerve palsy and ...pre-cholesteatoma. To evaluate the surgical exposure through an extended epitympanotomy, six patients with traumatic facial nerve palsy were enrolled in this study. The same surgical technique was used in all patients. Patients were assessed and the degree of facial nerve paralysis was determined prior to surgery, 1-week post-operatively, and 6-months post-operatively using the House-Brackmann grading system. In all cases, surgical exposure was adequate. All patients with traumatic facial nerve palsy were male and the age range was 13 to 83 years. In all cases, the location of the facial nerve damage was limited to the area between the first and second genu. Symptoms of all the patients improved by 6 months post-operation (p=0.024). There were no complications in any of the patients. Extended epitympanotomy is useful for safe, rapid surgical exposure of the attic area, sparing the patient post-operative dimpling, skin incision complications, and lengthy exposure to anesthesia. We suggest that surgery for patients with facial nerve palsy secondary to trauma be performed using this described technique.
This case report describes the use a new flexible robotic system in otolaryngology, the FlexRobot
®
for cricopharyngeal myotomy in cadaver dissections, and for the treatment of a patient with ...esophageal stenosis and secondary dysphagia and dysphonia. The Flexrobot
®
facilitates access to the hypopharynx with increased proximity to the surgical field and improved optics, allowing more exact dilatation and injection in our patient. It also would allow surgeons to reach deep inside the cavity of the hypopharynx into anatomical regions that are typically inaccessible without an open approach, as shown in our cadaveric procedure, where full exposure of the posterior aspect of the cricopharyngeus and isolation of the muscle belly were achieved. While esophageal dysmotility can be treated through botulinum toxin injection and esophageal dilation as demonstrated in our patient, for longer term results, operative cricopharyngeal myotomy is superior. Surgical complications include infection, hematoma, mucosal damage, fistula, and recurrent laryngeal nerve paralysis. While endoscopic procedures avoid the risk of recurrent laryngeal nerve or great vessel injury and lower the risk of perforation and fistula, they create the potential for mediastinitis as a consequence of opening the pharyngoesophageal muscosa and violating the buccopharyngeal fascia. Based on the cadaveric procedure, we believe that the robotic approach would reduce the risk of mediastinitis as a result of better visualization of the buccopharyngeal fascia and the robot’s precise instrument control.
The original version of this Article contained errors in Figs. 5 and 6. In Fig. 5b, the second panel on the bottom row was stretched out of proportion. In Fig. 6d, the first panel was also stretched ...out of proportion. In Fig. 6f, the fifth panel inadvertently repeated the fourth. This has been corrected in both the PDF and HTML versions of the Article.
The purpose of the present study was to define the applicability of tissue clearing to the field of otology. We combined tissue clearing with vital staining perfusion via a pumping system to examine ...the vascular anatomy of temporal bones in laboratory animals. We used six different types of species including Korean wild mouse, mouse, Mongolian gerbil, hamsters and Guinea pigs. A mixture of Alcian blue reagent and 4% paraformaldehyde was circulated throughout the entire circulatory system of the animal via a perfusion pump system. Transparency images were obtained from the temporal bones according to the protocol of the SunHyun 3D Imaging Kit. In examining the inner surface of the tympanic membrane, flaccid part (pars flaccida) was positioned along the entire marginal area in Guinea pig. In the Guinea pig, unlike the other species, the cortical bone of the mastoid (bullae) was easily removed using cold instruments, allowing a direct approach to the enclosed structures. The distribution and pattern of cochlea melanocytes were compared among the species. “Mobius strip”‐like accumulated melanocytes in vestibules were shown in both the Korean wild mouse and mouse. The collateral blood supply to the cochlea in six different species was checked in various pattern. Combining dye infusion with tissue‐clearing techniques, we documented the middle ear and transparent inner ear structures in six different species. The information and associated images will help other researchers to develop hypotheses and design experimental investigations.
To examine and identify the changing pattern of published articles in the otology literature over the past several decades. We used a variety of search engines available through PubMed.gov based on ...key words in the following categories: diagnosis, diagnostic tools, and therapeutic tools. The number of searchable key words increased from 1945 to the present. Overall, there has been a major shift in topics cover in the otological literature. Most recently, there has been significant increases in the following categories: age-related hearing loss, speech discrimination, and cochlear implantation. Based on this analysis, we believe these represent the areas of major research in the field of otology today. The present study is a bibliometric analysis of the changing pattern of published articles using a new analytic approach. The results identify the shifting topics of research in otology and might be helpful for future studies in Otorhinolaryngology Head and Neck Surgery.
Silk fibroin has recently become an important biomaterial for tissue engineering application. In this study, silk fibroin nanomatrix was fabricated by electrospinning and evaluated as wound dressing ...material in a burn rat model. The wound size reduction, histological examination, and the quantification of transforming growth factor TGF-β1 and interleukin IL-1α, 6, and 10 were measured to evaluate the healing effects. The silk fibroin nanomatrix treatment exhibited effective performance in decreasing the wound size and epithelialization. Histological finding also revealed that the deposition of collagen in the dermis was organized by covering the wound area in the silk fibroin nanomatrix treated group. The expression level of pro-inflammatory cytokine (IL-1α) was significantly reduced in the injured skin following the silk fibroin nanomatrix treatment compared to the medical gauze (control) at 7 days after burn. Also, the expression level of TGF-β1 in the wound treated with silk fibroin nanomatrix peaked 21-days post-treatment whereas expression level of TGF-β1 was highest at day 7 in the gauze treated group. In conclusion, this data demonstrates that silk fibroin nanomatrix enhances the burn wound healing, suggesting it is a good candidate for burn wound treatment.
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