Impact of cartilage graft size on success of tympanoplasty / Impacto do tamanho do enxerto de cartilagem no sucesso da timpanoplastia

Abstract Introduction: In the last decade, there has been an increasing use of cartilage grafts in the primary repair of tympanic membrane perforations. The major advantages of cartilage are its stiffness and its very low metabolic requirements, which make it particularly suitable for difficult conditions, such as subtotal perforations, adhesive otitis and reoperation. Objective: To analyze the impact of different perforation sizes requiring different sizes of cartilage on the anatomical and functional outcome after tympanoplasty. Methods: Through this prospective non-controlled, non-randomized study, 50 patients underwent cartilage type 1 tympanoplasty (20 females and 30 males), with a mean age of 19.3 ± 9.8 years. According to size of perforation, patients were subdivided into three groups, Group I had perforation >50% of tympanic membrane area, in Group II patients the perforations were 25-50% of tympanic membrane area, and in Group III the perforations were ≤25% of tympanic membrane. All patients had pre and postoperative Pure Tone Average and Air Bone Gap frequencies (0.5, 1, 2, 4 kHz). All patients were followed up at least 12 months after operation. Results: The anatomical success rate among all patients was 92%, all groups showed statistical significant improvement between pre and postoperative air bone gap, no significant correlation between size of cartilage graft and degree of air bone gap improvement was noticed among the three groups. Conclusion: Size of a cartilage graft has no impact on degree of hearing improvement or anatomical success rate after tympanoplasty.

Resumo Introdução: Na última década, tem havido um interesse crescente no uso de enxertos de cartilagem como opção para o reparo de perfurações primárias de membrana timpânica. As principais vantagens da cartilagem são a sua rigidez e o metabolismo braditrófico, o que a torna particularmente adequada para condições difíceis, tais como perfurações subtotais, otite adesiva e reoperações. Objetivo: Analisar o impacto de diferentes tamanhos de perfuração, portanto diferentes tamanhos de cartilagem, sobre o desfecho anatômico e funcional da timpanoplastia. Método: Através deste estudo prospectivo, não controlado, não randomizado, 50 pacientes foram submetidos a timpanoplastia de cartilagem tipo 1 (20 mulheres e 30 homens), com idade média de 19,3 ± 9,8 anos. De acordo com o tamanho da perfuração, os pacientes foram subdivididos em três grupos, Grupo I com perfuração > 50% da área da membrana timpânica, Grupo II com perfuração de 25%-50% da área da membrana timpânica, Grupo III com perfuração ≤ 25% da membrana timpânica. Todos apresentavam Audiometria tonal pura pré e pós-operatório - gap Aéreo-Ósseo para frequências testadas (0,5, 1, 2, 4 kHz). Todos os pacientes foram acompanhados por pelo menos 12 meses após a cirurgia. Resultados: A taxa de sucesso anatômico entre todos os pacientes foi de 92%, todos os grupos apresentaram melhoria estatisticamente significante entre pré e pós-operatório nos três grupos, não houve correlação significante entre o tamanho do enxerto de cartilagem e observou-se algum grau de melhoria do gap nos 3 grupos. Conclusão: O tamanho do enxerto de cartilagem não tem impacto sobre o grau de melhoria da audição ou na taxa de sucesso anatômico após timpanoplastia.

Fate of implanted autologus cartilage grafts in rabbits: an experimental histological study

Cartilage grafts are commonly used for a variety of purposes in plastic and reconstructive surgery. Despite their extensive use, the fate of cartilage as a graft is frequently disputed; many factors could affect such fate, among which the role of perichondrium and that of surgical trauma. The present study was conducted to evaluate the fate of implanted autologous cartilage grafts in rabbits and to study the effect of the perichondrium and that of the scoring on cartilage survival and resorption. 10 adult male New Zealand white rabbits were operated upon. Four equal sized auricular cartilage grafts were harvested from each rabbit, as well as a pre-implanted control cartilage graft. After accurate measuring and weighing of the grafts, they were implanted in a dorsal subcutaneous pocket in the same rabbit. The role of perichondrium was examined by implanting three types of cartilage grafts; the first with no perichondrium on either side, the second with perichondrium removed from one side, while in the third, the perichondrium was left intact on both sides. The effect of mechanical surgical trauma was examined by implanting a scored cartilage graft. Twelve weeks after their implantation. all cartilage grafts were retrieved, examined macroscopically. measured accurately, weighted and subjected to histological examination. Pre and post-implanted cartilage grafts were stained by: Haematoxylin and Eosin, Orcein and Toluidine blue stains. They were also examined by the scanning electron microscope. The results were compared to the preoperative values. Gross examination revealed ho obvious deviation from the preimplanted auricular cartilage graft regarding color, texture and consistency, although cartilage grafts without perichondrium seemed to be thinner and more pliable. These findings correlate well with the histological [light microscopic and scanning electron microscopic findings in which unscored cartilage grafts retaining their perichondrium were the most viable with active chondrocytes, healthy looking matrix and increased proliferative activity of chondroblasts adjacent to the perichondrium. These grafts have shown a modest increase in their post-implantation weight which could be either due to the observed neochondrogenesis or to a change in the ability of the cartilage grafts to retain water. Cartilage grafts in which perichondrium was removed from both sides has shown an insignificant decrease in their post-implantation weight, yet histologicaly they were viable but no chondrocytic activity was observed They showed definite decrease in the metachromatic reaction which was more evident at the periphery of either side of the cartilage plates which could be due to a change in the chemical composition of the bare mucopolysaccharides. Peripheral decrease in metachromasia along with the lack of chondrocyte activity could represent an early but slow resorption process of the bare cartilage. In scored cartilage grafts, although the perichondrium was preserved on both sides of the grafts, no significant change in the weight was observed; also on histological examination, they did not show any evident chondrocytic proliferation. This could reflect also a slow resorption process in the scored cartilage grafts. Cartilage grafts implanted subcutaneously do survive regardless the presence of perichondrium. Perichondrium enhances cartilage graft survival and seems to act as a protecting shell preventing direct exposure of the graft to the notorious effects of local mediators of wound healing environment that might lead to cartilage resorption. Although scored cartilage grafts implanted subcutaneously do survive and maintain its curvature, yet scoring increases the surface area of the bare cartilage exposed to the local mediators and thus might put them at risk of slow long term resorption

Otoplastia: revisão de uma casuística / Ear correction surgery: revision of cases

Concorre à cirurgia plástica, a remoção cirúrgica da orelha proeminente, restituindo a harmonia da forma e reintegrando o indivíduo ao convívio social. Referenciamos a técnica de Stenstrõn, defendida em 1963, que modificou o conceito do comportamento da cartilagem conchal quando escarificada, conceito este fundamentado em Gibson. Relatamos uma seqüëncia de quarenta e sete (47) casos realizados no Hospital Cristo Redentor, com técnica mista (Stenstrõn associada a rotação conchal), com obtenção de excelentes resultados.

Plastic surgery is credited with the correction of the protruding ear, making beneficial changes on patient’s self – image. We make reference to the Stenstrõn technique that was described in 1963 and brought a new concept on conchal cartilage’s physical and phisiological changes. We also consider the use of this technique associated to conchal rotation procedures. Fourty seven (47) cases have been treated by this method at Hospital Cristo redentor, wich is described herein.

Reconstrucción auricular en microtia / Auricular reconstruction in microtia

Dada la compleja morfología de la oreja, su reconstrucción en una microtia es un verdadero desafío para el cirujano plástico. Se han propuesto muchas alternativas terapéuticas para mejorar su aspecto estético como el uso de prótesis externas, implantes osteo integrados, materiales aloplásticos subdérmicos, colgajos microquirúrgicos, etc., pero sin duda la solución ideal es la reconstrucción auricular con injerto de cartílago costal autólogo a semejanza del pabellón auricular normal. Son varios los factores involucrados en la obtención de un óptimo resultado, como el tipo de microtia, características y posición del remanente, disponibilidad de piel, existencia o no de cirugías previas, así como un buen tallado del injerto y su posición definitiva. En este estudio prospectivo se analiza la reconstrucción auricular realizada a pacientes con microtia, en la Unidad de Cirugía Plástica del Hospital Luis Calvo Mackenna, por un período de 3 años, resolviéndose en 1-2 tiempos quirúrgicos con seguimiento y evaluación de sus características finales. Se analizan 50 casos consecutivos de microtia, 44 con microtia unilateral en distintos grados (I, II y III) según clasificación de Marx y 6 casos bilaterales. La reconstrucción se realizó en un rango de 6 a 19 años (X=9,9). El 48 por ciento de los casos unilaterales sólo han requerido una cirugía, mientras que el 52 por ciento restante 1 o 2 retoques. En el análisis postoperatorio, el 84 por ciento de los casos era del mismo tamaño que la oreja normal; el 96 por ciento se encontraban en buena posición con relación a la comisura y ángulo externo del ojo; la altura fue similar a la normal en el 84 por ciento de los casos, mientras en el 14 por ciento se encontraba más baja, correspondiendo a los casos de microsomía hemifacial severa. Los pacientes expresaron estar satisfechos con su reconstrucción en un 88 por ciento de los casos

O trago como área doadora de enxerto de cartilagem: estudo anatômico / The tragus as a donor area of cartilage grafts: anatomic study

A orelha externa é uma das principais áreas doadoras de cartilagem. Geralmente, a regiao de retirada de enxertos é a concha da orelha. OBJETIVO. Neste trabalho, propoe-se a retirada de cartilagem também a partir da lâmina do trago, especialmente naqueles casos em que nao dispomos da porçao conchal da cartilagem da orelha. CASUISTICA E MÉTODO. Estudaram-se 40 orelhas de 20 cadáveres, quando foram aferidas as dimensoes da lâmina do trago. RESULTADOS. A cartilagem da lâmina do trago demonstrou ser de bom tamanho para retirada de enxertos, podendo se obter fragmentos de 13,8cm de largura, 21,4cm de altura e 1,6cm de espessura, em média. CONCLUSAO. O enxerto cartilaginoso obtido a partir da lâmina do trago é uma alternativa viável, principalmente para rinoplastias de correçao de dorso e ponta nasal.