Otoplastic Surgery for Calcified Auricular Deformity

Auricular hematoma is one of the most common problems among people who have got repetitive blunt trauma to the external ear. Prompt managements are drainage of hematoma and following prevention of re-accumulation (e.g. compression dressing). If the treatment is not successful, many complications can occur, including perichondritis, infection and necrosis. Especially long-lasting loss of blood supply to the ear cartilage and formation of neocartilage from disrupted perichondrium can result in cauliflower ear deformity. There were some studies trying to classify and to treat the cauliflower ear by the degree of deformities. And excision of deformed cartilage with reshaping of the auricle has been reported several times. In this article, we would like to introduce a successful drilling technique of otoplasty as a useful treatment option.

Does periosteum promote chondrogenesis? A comparison of free periosteal and perichondrial grafts in the regeneration of ear cartilage

Background: Elastic ear cartilage is a good source of tissue for support or augmentation in plastic and reconstructive surgery. However, the amount of ear cartilage is limited and excessive use of cartilage can cause deformation of the auricular framework. This animal study investigated the potential of periosteal chondrogenesis in an ear cartilage defect model.Methods: Twelve New Zealand white rabbits were used in the present study. Four ear cartilage defects were created in both ears of each rabbit, between the central artery and marginal veins. The defects were covered with perichondrium (group 1), periosteum taken from the calvarium (group 2), or periosteum taken from the tibia (group 3). No coverage was performed in a control group (group 4). All animals were sacrificed 6 weeks later, and the ratio of neo-cartilage to defect size was measured.Results: Significant chondrogenesis occurred only in group 1 (cartilage regeneration ratio: mean± standard deviation, 0.97± 0.60), whereas the cartilage regeneration ratio was substantially lower in group 2 (0.10± 0.11), group 3 (0.08± 0.09), and group 4 (0.08± 0.14) (p= 0.004). Instead of chondrogenesis, osteogenesis was observed in the periosteal graft groups. No statistically significant differences were found in the amount of osteogenesis or chondrogenesis between groups 2 and 3. Group 4 showed fibrous tissue accumulation in the defect area.Conclusion: Periosteal grafts showed weak chondrogenic potential in an ear cartilage defect model of rabbits; instead, they exhibited osteogenesis, irrespective of their embryological origin.

Ex Vivo and In Vivo Properties of an Injectable Hydrogel Derived From Acellular Ear Cartilage Extracellular Matrix

Extracellular matrix (ECM) hydrogels provide advantages such as injectability, the ability to fill an irregularly shaped space, and the adequate bioactivity of native matrix. In this study, we developed decellularized cartilage ECM (dcECM) hydrogels from porcine ears innovatively via the main method of enzymatic digestion and verified good biocompatible properties of dcECM hydrogels to deliver chondrocytes and form subcutaneous cartilage in vivo. The scanning electron microscopy and turbidimetric gelation kinetics were used to characterize the material properties and gelation kinetics of the dcECM hydrogels. Then we evaluated the biocompatibility of hydrogels via the culture of chondrocytes in vitro. To further explore the dcECM hydrogels in vivo, grafts made from the mixture of dcECM hydrogels and chondrocytes were injected subcutaneously in nude mice for the gross and histological analysis. The structural and gelation kinetics of the dcECM hydrogels altered according to the variation in the ECM concentrations. The 10 mg/ml dcECM hydrogels could support the adhesion and proliferation of chondrocytes in vitro. In vivo, at 4 weeks after transplantation, cartilage-like tissues were detected in all groups with positive staining of toluidine blue, Safranin O, and collagen II, indicating the good gelation of dcECM hydrogels. While with the increasing concentration, the tissue engineering cartilages formed by 10 mg/ml dcECM hydrogel grafts were superior in weights, volumes, collagen, and glycosaminoglycan (GAG) content compared to the dcECM hydrogels of 1 mg/ml and 5 mg/ml. At 8 weeks after grafting, dcECM hydrogel grafts at 10 mg/ml showed very similar qualities to the control, collagen I grafts. After 12 weeks of in vivo culture, the histological analysis indicated that 10 mg/ml dcECM hydrogel grafts were similar to the normal cartilage from pig ears, which was the source tissue. In conclusion, dcECM hydrogel showed the promising potential as a tissue engineering biomaterial to improve the regeneration and heal injuries of ear cartilage.

Cartilage Curvature Reshaping: A Quantitative Assessment

Background Horizontal mattress suture is frequently performed procedure during Rhinoplasty and Otoplasty to control the curvature of the cartilages. Despite the popularity of mattress technique, there are no quantitative methods to determine the suture effects in cartilage reshaping. Objectives The aim of the present experimental study was to quantify the straightening effect of mattress suture on convexity of ear cartilage in rabbit models. Methods Eleven young adult male New Zealand white rabbits were used in this study. Horizontal mattress suture with spacing 3×6 mm was used in rectangle demarcated on left ear in area with maximum convexity. Preoperative and postoperative photographers were done before and immediately after surgery respectively. The Radius of curvature (ROC), first order deviation (FOD) and second order deviation (SOD) were calculated to quantify net cartilage reshaping, each point changes and homogeneity of new shaped cartilage respectively. Results The means for ROC were 1.112 and 2.169 before and after surgery respectively. ROC as indicator of net overall changing increased statistically significant. The means of FOD as each point slope index was statistically lower after surgery. (0.269 before surgery, 0.135 after surgery) The means for SOD also significantly decreased after surgery. (0.007 before surgery, 0.003 after surgery) The values of SOD remained positive after surgery that indicate changes in curve were homogenous. Conclusions A quantitative measurement method was introduced to directly quantify the controlling effect of suture. This quantifying method seems to be mandatory to compare the effect of horizontal mattress suture with other techniques in cartilage reshaping.

Conformal Fabrication of an Electrospun Nanofiber Mat on a 3D Ear Cartilage-Shaped Hydrogel Collector Based on Hydrogel-Assisted Electrospinning

Electrospinning is a common and versatile process to produce nanofibers and deposit them on a collector as a two-dimensional nanofiber mat or a three-dimensional (3D) macroscopic arrangement. However, 3D electroconductive collectors with complex geometries, including protruded, curved, and recessed regions, generally caused hampering of a conformal deposition and incomplete covering of electrospun nanofibers. In this study, we suggested a conformal fabrication of an electrospun nanofiber mat on a 3D ear cartilage-shaped hydrogel collector based on hydrogel-assisted electrospinning. To relieve the influence of the complex geometries, we flattened the protruded parts of the 3D ear cartilage-shaped hydrogel collector by exploiting the flexibility of the hydrogel. We found that the suggested fabrication technique could significantly decrease an unevenly focused electric field, caused by the complex geometries of the 3D collector, by alleviating the standard deviation by more than 70% through numerical simulation. Furthermore, it was experimentally confirmed that an electrospun nanofiber mat conformally covered the flattened hydrogel collector with a uniform thickness, which was not achieved with the original hydrogel collector. Given that this study established the conformal electrospinning technique on 3D electroconductive collectors, it will contribute to various studies related to electrospinning, including tissue engineering, drug/cell delivery, environmental filter, and clothing.

Vibrational and Acoustical Characteristics of Ear Pinna Simulators That Differ in Hardness

Because cartilage conduction—the transmission of sound via the aural cartilage—has different auditory pathways from well-known air and bone conduction, how the output volume in the external auditory canal is stimulated remains unknown. To develop a simulator approximating the conduction of sound in ear cartilage, the vibrations of the pinna and sound in the external auditory canal were measured using pinna simulators made of silicon rubbers of different hardness (A40, A20, A10, A5, A0) as measured by a durometer. The same procedure, as well as a current calibration method for air conduction devices, was applied to an existing pinna simulator, the Head and Torso Simulator (hardness A5). The levels for vibration acceleration and sound pressure from these pinna simulators show spectral peaks at dominant frequencies (below 1.5 kHz) for the conduction of sound in cartilage. These peaks were likely to move to lower frequencies as hardness decreases. On approaching the hardness of actual aural cartilage (A10 to A20), the simulated levels for vibration acceleration and sound pressure approximated the measurements of human ears. The adjustment of the hardness used in pinna simulators is an important factor in simulating accurately the conduction of sound in cartilage.

Effect of Expanded Polytetrafluoroethylene Combined with Autologous Ear Cartilage in Nasal Plastic Surgery

Objective: To explore the effect of combined application of expanded polytetrafluoroethylene and autologous ear cartilage in nasal plastic surgery. Methods: 76 cases of nasal plastic surgery patients in our hospital from September 2019 to September 2020 were selected as the research objects and divided into experimental group (38 cases, treated with expanded polytetrafluoroethylene + autologous ear cartilage surgery) and control group (38 cases, treated with autologous ear cartilage surgery). The treatment effect, appearance score and complications were compared. Results: The total effective rate of the experimental group (97.37%, 37 / 38) was higher than that of the control group (78.95%, 30 / 38), P< 0.05; After treatment, the appearance score of the experimental group was (8.97 ± 0.37), which was significantly higher than that of the control group (P< 0.05); The total incidence of complications in the experimental group (5.26%, 2 / 38) was significantly lower than that in the control group (21.05%, 8 / 38), P< 0.05. Conclusion: In the process of nasal plastic surgery, the combined application of autologous ear cartilage surgery and expanded polytetrafluoroethylene has obvious effect, improves the appearance of patients, and has less postoperative complications, which is worthy of promotion.

Conformal Fabrication of an Electrospun Nanofiber Mat on a 3d Ear Cartilage-shaped Hydrogel Collector Based on Hydrogel-Assisted Electrospinning

Electrospinning is a common and versatile process to produce nanofibers and deposit them on a collector as a two-dimensional nanofiber mat or a three-dimensional (3D) macroscopic arrangement. However, 3D electroconductive collectors with complex geometries, including protruded, curved, and recessed regions, generally caused hampering of a conformal deposition and incomplete covering of electrospun nanofibers. In this study, we suggested a conformal fabrication of an electrospun nanofiber mat on a 3D ear cartilage-shaped hydrogel collector based on hydrogel-assisted electrospinning. To relieve the influence of the complex geometries, we flattened the protruded parts of the 3D ear cartilage-shaped hydrogel collector by exploiting the flexibility of the hydrogel. We found that the suggested fabrication technique could significantly decrease an unevenly focused electric field, caused by the complex geometries of the 3D collector, by alleviating the standard deviation by more than 70% through numerical simulation. Furthermore, it was experimentally confirmed that an electrospun nanofiber mat conformally covered the flattened hydrogel collector with a uniform thickness, which was not achieved with the original hydrogel collector. Given that this study established the conformal electrospinning technique on 3D electroconductive collectors, it will contribute to various studies related to electrospinning, including tissue engineering, drug/cell delivery, environmental filter, and clothing.

Treating Otohematomas in Dogs with Intra-Lesional Corticotherapy

Background: Otohematoma is common in dogs and is characterized by blood accumulation between the skin and cartilage of the outer ear. While the etiology is related to trauma, most cases have a predisposing condition. Treatment must drain the hematoma and maintain appropriate skin apposition to the ear cartilage. Treatment can be surgical, but there are also conservative options such as puncture drainage, followed by intralesional injection of glucocorticoids. This alternative method is less invasive than surgery, with an equivalent success rate. This study aimed to describe intralesional injection of corticosteroids for the treatment of dogs with otohematoma at a veterinary clinic.Materials, Methods & Results: Otohematoma was diagnosed and treated in 23 dogs (14 males and 9 females, weighing 9.6 ± 2.7 kg) at a reference private veterinary clinic. The dogs were chemically restrained, and their ears were cleaned with chlorhexidine. The lower face of each ear with otohematoma was then punctured with a needle coupled to a syringe to drain the liquid. Following drainage, the equipment was removed and the collected liquid volume was measured. A 0.5 mg/kg dose of methylprednisolone acetate was prepared and diluted in saline (0.9% NaCl) to a volume equivalent to 1/10 of the previously drained content volume from the otohematoma. The prepared solution was then injected into the drained ear. Additionally, each patient was treated for the original cause of the otohematoma, according to conventional protocols. Eight animals (34.78%) had bilateral otohematoma and 15 (65.22%) presented with unilateral lesions. Leukocytosis was observed in most patients. Other laboratory alterations present in the studied dogs were thrombocytopenia, leukopenia, and anemia. Twenty (86.96%) patients presented with otitis externa. All patients were reassessed one week after the initial treatment, and 19 (82.60%) fully recovered. The remaining 4 (17.40%) required a new procedure to drain a small accumulation of liquid. Patients were then reassessed on the 15th day when full recovery was observed in 2 (8.7%). The remaining two (8.7%) underwent new drainage on the 15th day, accompanied by a new infusion of corticosteroids, returning recovered on the 21st day.Discussion: Consistent with the previous reports, unilateral otohematomas were more frequently observed in the present study. In most animals, the cause of otohematoma was otitis externa. This disease causes intense itching that leads to autotrauma, resulting in the rupture of vessels and accumulation of fluid between the skin and cartilage of the ear. Leukocytosis detected in the majority of patients was related to external otitis. The other hematological changes observed are common in the disease. The objectives of otohematoma therapy in dogs are to identify and eliminate the source of auricular pruritus, provide adequate drainage of the hematoma content, and maintain the appropriate apposition between the skin and cartilage in the ear. In all 23 patients in this study, these aims were met, culminating in favorable outcomes. The described method led to recovery for most patients (82.60%) in the first week and a success rate of 100% by the end of 21 days. These results observed in animal patients are similar to those seen in humans, where drainage leads to total regression of the disease. Glucocorticoids were chosen for treatment of otohematoma because of their anti-inflammatory effects. Additionally, methylprednisolone acetate, an ester whose absorption was very slow, was used to allow for a longer anti-inflammatory effect.