Shape Optimization of Costal Cartilage Framework Fabrication Based on Finite Element Analysis for Reducing Incidence of Auricular Reconstruction Complications

Skin necrosis is the most common complication in total auricular reconstruction, which is mainly induced by vascular compromise and local stress concentration of the overlying skin. Previous studies generally emphasized the increase in the skin flap blood supply, while few reports considered the mechanical factors. However, skin injury is inevitable due to uneasily altered loads generated by the intraoperative continuous negative suction and uneven cartilage framework structure. Herein, this study aims to attain the stable design protocol of the ear cartilage framework to decrease mechanical damage and the incidence of skin necrosis. Finite element analysis was initially utilized to simulate the reconstructive process while the shape optimization technique was then adopted to optimize the three-pretested shape of the hollows inside the scapha and fossa triangularis under negative suction pressure. Finally, the optimal results would be output automatically to meet clinical requirement. Guided by the results of FE-based shape optimization, the optimum framework with the smallest holes inside the scapha and fossa triangularis was derived. Subsequent finite element analysis results also demonstrated the displacement and stress of the post-optimized model were declined 64.9 and 40.1%, respectively. The following clinical study was performed to reveal that this new design reported lower rates of skin necrosis decrease to 5.08%, as well as the cartilage disclosure decreased sharply from 14.2 to 3.39% compared to the conventional method. Both the biomechanical analysis and the clinical study confirmed that the novel design framework could effectively reduce the rates of skin necrosis, which shows important clinical significance for protecting against skin necrosis.

Reconstruction of congenital microtia after ear canaloplasty using V-Y advancement of a temporal triangular flap

Background Reconstruction of congenital microtia remains challenging, particularly in patients with a history of ear canaloplasty due to insufficient regional soft tissue. The insertion of a tissue expander prior to implantation of the cartilage framework has traditionally been employed. However, this procedure could induce additional morbidity. Herein, we present a method using V-Y advancement of a temporal triangular flap to gain additional soft tissue in these challenging cases.Methods Congenital microtia patients with a history of ear canaloplasty who underwent auricular reconstruction using the Nagata technique between 2016 and 2020 were reviewed. To obtain additional soft tissue, V-Y advancement of a temporal triangular flap was performed concurrently with implantation of the costal cartilage framework, without prior insertion of a tissue expander. The outcomes of these patients with respect to postoperative complications and esthetics were evaluated.Results Eight patients with bilateral lesions were included. No specific complications developed after the first-stage surgery. However, one patient experienced complications after the second stage (auricular elevation). An analysis of the esthetic results showed most patients had excellent outcomes, achieving a satisfactory convolution. The median number of operations needed to complete reconstruction was 2, which was fewer than required using the conventional method with prior insertion of a tissue expander.Conclusions In patients with a history of previous canaloplasty, V-Y advancement of a temporal triangular flap could serve as an alternative to tissue expansion for microtia reconstruction. This technique provided reliable and satisfactory results with a reduced number of surgical stages.

107 The Role of Tissue Engineering in Auricular Reconstruction: A Critical Review

Aim Despite several decades of research in tissue engineering, reconstructing a 3D human-sized ear that can stand the test of time has remained a challenge. Autologous cartilage reconstruction remains the main treatment choice despite the associated morbidity. Progress in the field has been made and several studies have used tissue-engineered implants in immunocompetent animals with promising results. Method This study critically reviews and assesses the characteristics that make auricular reconstruction so challenging and how far research has come in addressing the following: mechanical properties; vascularisation; immune response; cell sourcing; surgical attachments; allografts; and cost. Results The question is whether tissue engineering will realistically replace autologous cartilage reconstruction in the short-term, or will advances in other areas, outlined in this article, manage to provide suitable and aesthetically accurate scaffolds. Conclusions Advances in tissue engineering are slowly progressing and utilise advances in both biomaterial design and 3D bioprinting to try and address the challenges of auricular reconstruction. Tissue engineering is still a promising solution to auricular reconstruction but still requires further research before becoming a reality.

Retroauricular Advancement Flap In Single Stage Auricular Defect Reconstruction

Auricular defects must be treated early and properly because they may interfere with facial symmetry. Retroauricular skin is an ideal flap source for a non-reduction reconstruction procedure of the upper, middle, and lower auricular defects. Auricular reconstruction aims to achieve good anthropometric and aesthetic ear unit. The purpose of this case report is to present a reconstruction of auricular defects using the rectroauricular flap that results in a favorable aesthetic and normal anthropometric dimensions of the auricular. We report a case of auricular defect caused by post-excision of keloid located in the helical and antithetical area of the middle third of the right auricular, using a retroauricular flap. Normal values of the auricular’s anthropometric measurements were achieved, followed by a complete aesthetic ear unit. Retroauricular flaps are suitable for reconstructing partial auricle defects in the helical rim, temporal area, and conchae. Keywords: auricular defect, retroauricular flap, aesthetic ear unit, auricular anthropometry. Jabir Retroaurikular untuk Rekonstruksi Defek Telinga Abstrak Daun telinga berperan penting pada simetri wajah sehingga defek di daun telinga harus ditangani dengan baik sejak dini. Kulit retroaurikular merupakan sumber jabir ideal untuk rekonstruksi tanpa reduksi pada defek daun telinga bagian atas, tengah, dan bawah. Rekonstruksi daun telinga bertujuan untuk mendapatkan hasil yang baik secara antropometri dan estetika unit telinga. Tujuan laporan kasus ini adalah menunjukkan hasil yang baik berdasarkan unit telinga estetik dan dimensi normal antropometri pada rekonstruksi defek daun telinga menggunakan jabir rektroaurikular. Dilaporkan satu kasus defek telinga pasca-eksisi keloid, di area heliks dan antiheliks sepertiga tengah daun telinga kanan, menggunakan jabir retroaurikular. Didapatkan nilai normal pada pengukuran antropometri telinga dan kelengkapan estetika unit telinga. Jabir retroaurikular baik untuk rekonstruksi defek telinga parsial di lengkung heliks, area temporal, dan konka. Kata kunci: defek aurikular, jabir retroaurikular, unit telinga estetik, antropometri daun telinga.

Utilization of Alexandrite Laser for Hair Removal in Pediatric Auricular Reconstruction

Auricular reconstruction with autologous rib cartilage involves using a soft tissue envelope to cover the cartilage framework. In patients with a low hairline, hair-bearing skin may be incorporated on the reconstructed ear, creating a difficult and conspicuous aesthetic problem. A retrospective chart review was conducted to summarize and share the experience of using the Candela GentleMax Pro 755-nm alexandrite laser system (Candela Corp) in children following auricular reconstruction. Nine patients received laser hair removal via the alexandrite laser system with good results. The number of completed sessions ranged from 1 to 5. The procedures were completed without the need for premedication or procedural sedation. Laser hair removal with an alexandrite laser system was safe, fast, and effective. With multistage auricular reconstruction, it was feasible to incorporate laser hair removal between the stages.

New strategies for base frame fabrication in microtia reconstruction

The base frame provides a stable support for the helix, antihelix, and tragus–antitragus complex in microtia reconstruction, and this support is vital to attain a highly defined outline for a reconstructed auricle. The success of base frame sculpting depends on appropriate treatment of the cartilage, mainly the sixth and seventh costal cartilages, which may have different characteristics. The aim of this study was to demonstrate the relevant details for base frame fabrication under various scenarios. Between 2016 and 2019, a total of 352 patients with microtia underwent autologous auricular reconstruction. Concerning the different sizes and characteristics of the costal cartilage used for the base frame reconstruction, we describe the related methods for fabrication and introduce corresponding strategies for proper management. We found that 90% of the patients responded at follow-up, and 76% of them were satisfied with the cosmetically refined auricle with harmonious integrity. The elaborate design and appropriate utilization of costal cartilage for base frame sculpting is one of the most significant and fundamental processes in microtia reconstruction. It contributes to achieving a clearly defined outline of the auricle with harmonious integrity, which is as important as the other projected subunits.