Literatura académica sobre el tema "Autologous ear reconstruction"

Since the pioneering use of autologous rib cartilage for the reconstruction of microtia, there have been significant advances in surgical technique that have helped to ameliorate the psychological burden of microtia. To date, the use of rib cartilage for auricular reconstruction is one of the most enduring and ubiquitous techniques for microtia reconstruction as it provides excellent aesthetic results with lasting durability. In this review, the authors outline the most common methods of microtia reconstruction with a comparison of each technique and illustrative case examples.

Difficulties are associated with reconstruction of middle ear bony structures in surgery for destructive lesions, including cholesteatoma. Although autologous cartilage appears to be the optimal choice because of its resistance to infection, the harvesting of sufficient volumes may be challenging. Therefore, regenerative medicine techniques to obtain sufficient material for reconstruction are awaited. We herein present a case of middle ear surgery for cholesteatoma with a sufficient volume of stick-shaped tissue-engineered cartilage produced from a piece of autologous auricular cartilage and autologous serum, with sufficient firmness to reconstruct bony structures. During surgery, sections of tissue-engineered cartilage were placed side by side to reconstruct the posterior canal wall. The postoperative course was uneventful. This is the first-in-human report of reconstructing middle ear bony structures with tissue-engineered cartilage. The results suggest a promising future for the satisfactory reconstruction of middle ear structures with minimal morbidity at the donor site.

AbstractTotal ear reconstruction has been approached by several techniques involving autologous graft, prosthetic implant, and alloplastic implant options. Recent studies have shown the superiority of porous polyethylene (Medpor, Porex Surgical) reconstruction over autologous reconstruction based on improved aesthetic results, earlier age of intervention, shorter surgery times, fewer number of required procedures, and a simpler postoperative recovery process. A durable and permanent option for total ear reconstruction, like Medpor, can help alleviate the cosmetic concerns that patients with auricular deformities may be burdened with on a daily basis. In this article, the authors discuss the advantages of Medpor-based ear reconstruction and discuss recent advances in the surgical techniques involved, such as harvesting a temporoparietal fascia flap and full-thickness skin graft to adequately cover the Medpor framework and decrease extrusion rates.

Background: Auricular defects pose one of the most difficult challenges in reconstructive surgery of the head and neck. The reason is the unique three-dimensional anatomical architecture of the auricle, with its multiple concavities and convolutions of the cartilage and the thin, delicate skin cover. Acquired auricular deformities commonly result from traumatic injuries, burn trauma or tumour extirpation. These vary in severity from simple lacerations to complete auricular avulsions. Congenital ear deformity (microtia) occurs in every 1 out of 6000 live births. The goal of reconstruction is the precise duplication of the missing anatomical part with regard to size, orientation and anatomical landmarks.Methods: Range from healing by secondary intention to complete replacement with autologous rib cartilage and/or auricular prosthesis. Total auricular reconstruction was done by two methods: (1) Nagata and (2) Brent’s method. Nagata’s technique is commonly performed in this study. The present study aimed to evaluate the reconstruction of auricular defects using autologous rib cartilage graft with or without temperoparietal fascia flap covered by split-thickness skin graft.Results: Excellent cosmetic result can be obtained with adequate skills and training in carving the cartilage for auricular framework. This improves confidence and gives psychological support to microtia patients.Conclusions: With training and method, results in ear reconstruction using autologous rib cartilage are excellent and reproducible.

AbstractAutologous ear reconstruction is the preferred treatment in case of partial or total absence of the patient external ear. This kind of surgery can be really challenging since precise replication of complex three-dimensional structure of the ear is crucial to provide the patients with aesthetically consistent reconstructed anatomy. Therefore, the results strongly depends on the “artistic skills” of the surgeon who is in charge to carry out a three-dimensional sculpture, which resembles the shape of a normal ear. In this context, the definition of a preoperative planning and simulation process based on the patient's specific anatomy may help the surgeon in speeding up the ear reconstruction process and, at the same time, to obtain better results, thus allowing a superior surgical outcome. In the present work the main required features for performing an effective simulation of the ear reconstruction are identified and a strategy for their interactive design and customization is devised with the perspective of a semi-automatization of the procedure. In detail, the paper provides a framework which start from the acquisition of 3D data from both a healthy ear of the patient (or, if not available e.g. due to bilateral microtia of the ear of one of his parents or from a template) and of costal cartilage. Acquired 3D data are properly processed to define the anatomical elements of the ear and to find, using nesting-based algorithms, the costal cartilage portions to be used for carving the ear itself. Finally, 3D printing is used to create a mockup of the ear elements and a prototype of the ear to be reconstructed is created. Validated on a test case, the devised procedure demonstrate its effectiveness.

Enquanto o papel dos enxertos cartilaginosos na reconstrução da lamela interna palpebral está bem estabelecido, o crescimento da conjuntiva sobre ele, proveniente de áreas adjacentes, necessita de comprovação mais aprofundada. Este estudo tem como objetivos analisar comparativamente, após a reconstrução palpebral inferior com enxertos de cartilagem auricular conchal com e sem pericôndrio, em ambas as pálpebras inferiores de coelhos, a presença de crescimento conjuntival sobre os enxertos, a área de epitelização conjuntival sobre eles, a integridade da estrutura corneana dos globos oculares em contato com os enxertos cartilaginosos e a presença de alterações das áreas dos enxertos de cartilagem com e sem pericôndrio, após sua implantação. Foram utilizados, para o experimento, 50 coelhos albinos adultos da raça New Zealand (Oryctolagus cuniculus), entre 3 e 4 meses de vida, com pesos médios variando de 2,5 a 3,0 quilogramas no início do experimento, provenientes do biotério da Faculdade de Medicina da Universidade de São Paulo. Cem pálpebras inferiores foram reconstruídas em sua lamela interna, com enxertos autógenos de cartilagem auricular conchal, e cobertos com retalho miocutâneo. As pálpebras do lado direito receberam enxerto de cartilagem com pericôndrio posicionado em contato direto com o globo ocular, enquanto as do lado esquerdo foram reconstruídas da mesma forma, porém com enxertos cartilaginosos sem pericôndrio. A cada semana, em um total de 5 semanas, eram sacrificados 10 animais após a reconstrução palpebral, e suas pálpebras inferiores foram analisadas macroscópica e histologicamente. A planimetria digital demonstrou que, com 5 semanas, a área média das cartilagens com pericôndrio apresentava redução de 8,33%, e a área média das cartilagens sem pericôndrio encontravase reduzida em 18,52%. Detectou-se, em cada semana de avaliação, que as áreas das cartilagens com pericôndrio se apresentaram significativamente maiores do que aquelas sem pericôndrio nas semanas 4 e 5 (p=0,0003 e p=0,0001, respectivamente), e uma tendência para significância na semana 2 (0,0706). Na primeira e terceira semanas, a diferença entre as áreas se manteve igual (p=0,8583 e p=0,2092). Em relação ao crescimento conjuntival, observouse que a diferença porcentual do crescimento sobre as cartilagens com e sem pericôndrio foi de 11,41% na primeira semana do experimento, de 13,64% na segunda semana, de 18,69% na terceira, de 10,38% na quarta, e de 6,17% na quinta. Observou-se, em cada semana do experimento, que a porcentagem média de crescimento da conjuntiva nas pálpebras reconstruídas com enxerto condro-pericondral apresentou-se significativamente maior do que aquelas apenas com enxerto cartilaginoso nas 5 semanas do experimento (p<0,0001). Observou-se que houve crescimento conjuntival sobre os enxertos de cartilagem em contato direto com o globo ocular, ocorrendo tanto nas cartilagens com pericôndrio, como naquelas que não o possuíam. A área de cobertura conjuntival com 5 semanas nas cartilagens com pericôndrio, foi maior do que a observada nas cartilagens sem pericôndrio. Não houve ceratite ou úlceras de córnea na maioria da amostra estudada e houve diminuição das áreas dos enxertos cartilaginosos em graus variados, com maior intensidade nos enxertos sem pericôndrio.
Although the role of cartilage grafts in reconstruction of the posterior eyelid lamella is well established, conjunctival epithelialization on such grafts has yet to be fully proven. The aim of this study is to perform a comparative analysis, after inferior eyelid reconstruction in rabbits with cartilage grafts with and without perichondrium, the presence of conjunctival epithelialization over conchal cartilage grafts, the area of conjunctival epithelialization over those grafts, the integrity of the corneal structure in contact with the cartilage grafts and the variation of the areas of the cartilage grafts with and without perichondrium. Fifty adult albino New Zealand rabbits (Oryctolagus cuniculus) between 3 and 4 months of age with average weights from 2.5 to 3.0 kilograms from the University of São Paulo Medical School animal colony were used for the experiment. The posterior lamellae of 100 lower eyelids from were reconstructed with autogenous grafts of conchal ear cartilage and covered with a myocutaneous flap. In the right eyelids, cartilage was grafted with the perichondrium in direct contact with the eyeball, while the left eyelids were reconstructed in a similar manner but using cartilage grafts without perichondrium. The animals were sacrificed after 1, 2, 3, 4 and 5 weeks after eyelid reconstruction, and their lower eyelids were analyzed macroscopically and histologically. The digital planimetry has demonstrated that in the first week of the experiment there was a reduction of 8,33%, in the average area of the cartilages with perichondrium and a reduction of 18,52% in the average area of the cartilages with perichondrium. The average areas of the cartilages with perichondrium were significantly larger than those on cartilages without perichondrium in weeks 4 and 5 (p=0,0003 and p=0,0001, respectively) and tended to vary over the week 2 (0,0706). No difference was noted between the areas in weeks 1 and 3 (p=0,8583 and p=0,2092). When the conjunctival growth was assessed, it was found that the percentage difference in conjunctival epithelialization on the cartilage with perichondrium and that without perichondrium was 11.41% in the first week of the experiment, 13.64% in the second week, 18.69% in the third, 10.38% in the fourth and 6.17% in the fifth. The average percentage conjunctival epithelialization in the eyelids reconstructed with a cartilage graft with perichondrium was significantly higher for the five weeks of the experiment than that in the eyelids reconstructed with cartilage without perichondrium (p<0.0001). It was found that there was conjunctival growth on the cartilage grafts with and without perichondrium when they were placed in direct contact with the eye. The area of the epithelialization on cartilages with perichondrium was larger than that on cartilages without perichondrium in week 5. Neither keratitis nor corneal ulcers were observed during the 5 weeks of the experiment in the majority of the animals operated on and there was reduction in the areas of the grafts in various degrees, with larger intensity in the grafts without perichondrium.

The advent and the consolidation of Reverse Engineering (RE) and Additive Manufacturing (AM) techniques in the medical field changed significantly the common therapeutic and surgical approach, pushing towards a new perspective of treatment in which each patient is considered unique. The integration of RE e AM techniques enables the modeling and realization of customized medical devices: RE techniques allow to acquire and reconstruct the patient-specific anatomy, AM processes make possible to create any geometric shape, that could not be realized with traditional production techniques. In the field of plastic surgery, is observed a wide use of such techniques for the production of patient-specific implants and patient-specific surgical guides. Reconstructive surgery is, in fact, a challenge even for the most experienced surgeons due to the complex anatomy involved and the uniqueness of defects and malformations; the use of medical devices which accurately fit the anatomy of the defect, has demonstrated to improve surgical outcomes in terms of aesthetic results, of surgical time and safety for the patients. In this context, the present thesis focuses on the development and design of tools able to support the surgeon in the reconstruction of the external ear. Such reconstructive intervention is performed in patients affected by deformation or absence of the external ear due to congenital reasons (microtia), as a result of trauma, burns or tumor resections. The intervention is considered among the surgeons particularly complex and the surgical outcomes are highly dependent on the experience of clinicians. For such reasons, my research thesis initially focused on the study of methods and tools for the simulation, planning and execution of the intervention with the aim to improve the performance of experienced surgeons and to make this intervention accessible to a wider range of physicians. From a close collaboration with the plastic surgeons of the Meyer Children's Hospital (Florence, Italy), arose the idea of new surgical guides for preoperative simulation and surgery. Technical and clinical requirements of surgical guides were identified by physicians and through a trial phase, that foresaw CAD modeling by engineers and testing by surgeons, the final design of the devices was defined. Secondly, with the idea of making physicians independent of experienced CAD modelers in the manufacturing process of such instruments, a systematic procedure was defined that starts from the patient's anatomy data and leads to 3D modeling of the devices. The procedure was semi-automated and made easily accessible to surgeons through an intuitive graphical user interface that allows them to be independent in the creation of each new device. The aim is to introduce a new tool in the common clinical practice, suitable for use in a hospital environment, which pushes towards a new concept of personalized assistance.

AbstractMicrotia is a congenital deformity of the external ear, with a prevalence rate of approximately 1 in 10,000 live births worldwide. The auricle is a distinguishing feature of the face. Its deformity may have severe psycho-social implications on the affected children, affecting their self-confidence. Current reconstructive techniques for microtia mainly include the auricular prosthesis, implantation of alloplastic or an autologous rib cartilage framework. Alloplastic implant reproduces an excellent shape of the ear with no donor site morbidity, however its bio-integration is questionable and may make them prone for extrusion and infection. Sub-cutaneous implantation of autologous rib cartilage still remains the gold-stand treatment for microtia. However this technique has its surgical morbidities and skill demands, which makes it difficult to master. Translational research in the fields of tissue engineering for generation of bone and cartilage for ear reconstruction are emerging trends.

Abstract Autologous ear reconstruction, i.e. the reconstruction of the outer ear from autologous cartilage tissue, is a very important surgery considering the psychosocial repercussions of an individual affected by microtia (i.e. the total or partial absence of the outer ear). The execution of this surgery can be very complex due to the unique characteristics of this anatomical region. In order to help the surgeon in the process of cutting and suturing, innovative surgical guides were designed that can transmit information about the shape and size of the anatomy to be reconstructed. This work lays the foundation for the creation of a semi-automatic and easy-to-use tool for the modeling of surgical guides. The goal is to make the hospital staff autonomous in the creation of instruments that can be used in pre-surgical simulation and during surgery.