Effects of strain and age on ear wound healing and regeneration in mice

Round holes in the ears of MRL mice tend to close with characteristics of regeneration believed to be absent in other mouse strains (e.g., C57BL/6). We evaluated the kinetics and the histopathology of ear wound closure in young (8 weeks old) C57BL/6 and BALB/c mice. We also used middle-aged (40 weeks old) C57BL/6 mice to evaluate the influence of aging on this process. A circular through-and-through hole was made in the ear, photographs were taken at different times after injury and wound area was measured with digital analysis software. The percentages of closed area measured on day 100 were: 23.57 ± 8.66 percent for young BALB/c mice, 56.47 ± 7.39 percent for young C57BL/6 mice, and 75.31 ± 23.65 percent for middle-aged C57BL/6 mice. Mice were sacrificed on days 1, 3, 5, 25, 44, and 100 for histological evaluation with hematoxylin and eosin, Gomori’s trichrome, periodic acid-Schiff, or picrosirius red staining. In young mice of both strains, healing included re-epithelialization, chondrogenesis, myogenesis, and collagen deposition. Young C57BL/6 and BALB/c mice differed in the organization of collagen fibers visualized using picrosirius-polarization. Sebaceous glands and hair follicles regenerated and chondrogenesis was greater in young C57BL/6 mice. In middle-aged C57BL/6 mice all aspects of regeneration were depressed. The characteristics of regeneration were present during ear wound healing in both young BALB/c and young C57BL/6 mice although they differed in intensity and pattern. Greater ear wound closure in middle-aged C57BL/6 mice was not correlated with regeneration.

Blefaroplastia em coelhos por meio de cartilagem auricular alógena conservada em solução saturada de NaCl / Rabbits eyelid repair by means of alogen auricular cartilage preserved in NaCl saturated solution

Avaliou-se a reconstrução da pálpebra inferior de coelhos, com cartilagem auricular alógena, conservada em solução saturada de NaCl em 12 coelhos, adultos, de ambos os sexos. Os animais receberam acepromazina (0,5mg/kg/IM) e tiletamina e zolazepam (7,0mg/kg/IM), após o que removeu-se um fragmento de 1,0x0,5cm das pálpebras inferiores, esquerda e direita. A pálpebra esquerda foi reparada pela técnica de blefaroplastia em H (GC) e a direita por um retalho de cartilagem auricular associado a blefaroplastia em H (GE). Aos sete dias de pós-operatório (PO), as feridas cirúrgicas dos animais do GC apresentavam retração cutânea. Aos 15 dias de PO, observou-se que as feridas nos coelhos do GE estavam cicatrizadas, mas 30 por cento das do GC apresentavam deiscência e retração cicatricial. Aos 30 dias de PO, as feridas nos animais do GE e GC apresentavam-se cicatrizadas, mas, 30 por cento nos do GC não apresentavam as bordas das feridas coaptadas. O enxerto de cartilagem auricular diminuiu a retração cicatricial, possibilitando reparo anatômico à pálpebra

The rabbit inferior eyelid repair was evaluated using NaCl satured-stored alogenous auricular cartilage. Twelve adult male and female rabbits had a 1.0x0.5cm fragment removed from the left and right inferior eyelids after pre-medication with acepromazine (0.5mg/kgIM) and tiletamine-zolazepan (7.0mg/kgIM) anesthesia. The "H" plasty technique was used to the left eyelid repair (CG) and the right one was repaired with auricular cartilage associated with the "H" plasty technique (GG). The CG wounds presented cutaneous retraction at day 7th of the post-operative period. The GG wounds were healed on the day 15th, while the CG wounds presented 30 percent of deiscence and cicatricial retraction. The GG and CG wounds were healed at day 30th of the post-operative period, but 30 percent of the CG wounds did not present the edges lined up. It was concluded that the auricular cartilage graft decreases cicatricial retraction and improves anatomical eyelid repair

Miringoplastia com cartilagem inlay: primeiros resultados brasileiros / Inlay Cartilage Tympanoplasty: First Brazilian Results

A técnica de miringoplastia pode ser realizada com a colocação do enxerto de fáscia temporal ou pericôndrio sobre ou abaixo do anel timpânico. Em 1998, Roland Eavey descreveu em crianças técnica de enxerto cartilaginoso em forma de borboleta, colocado através da membrana do tímpano, sem necessidade de criação de retalho timpano-meatal. Vantagens potenciais incluem maior facilidade técnica, menor tempo cirúrgico, menores cuidados pós-operatórios e maior estabilidade do enxerto. Objetiva-se descrever nossos resultados com a utilização da técnica de Eavey, introduzindo pequenas modificações. Material e método: Foram realizadas sete miringoplastias em adultos para fechamento de perfurações menores do que 50% da membrana do tímpano, no período de março a julho de 1998. Foram realizadas algumas modificações da técnica descrita por Roland Eavey: 1.) - utilização em pacientes adultos; 2.) - uso de anestesia local e 3.) - não utilização de enxerto de pele sobre o enxerto cartilaginoso. Avaliaram-se a pega do enxerto e a diminuição da diferença entre os limiares aéreo e ósseo (GAP) pós-operatória. Resultados: O índice de pega do enxerto foi de 100%. O tempo médio de seguimento foi de 22,7 meses, variando de 19 meses a 24 meses. Todos os enxertos estavam intatos na última consulta de seguimento. Todos os pacientes apresentaram melhora auditiva, dois com fechamento completo do GAP e os restantes com fechamento de GAP superior a 50%. Conclusões: A técnica de Eavey é altamente eficaz também para adultos, com menor morbidade. A não utilização do enxerto de pele e a anestesia local diminuem ainda mais o tempo cirúrgico e não comprometem os resultados da técnica original.

Myringoplasty techniques include either an underlay or an onlay approaches using temporalis fascia or perichondrium as grafts. Roland Eavey in 1998 described a transcanal cartilage butterlly inlay tympanoplasty technique in children. This technique was found to be effective to close tympanic membrane perfurations, more comfortable and less morbid (no external canal incisions). The aim of this study was to describe our results with Eavey's technique, with little modifications. Material and method: Cartilage butterfly tympanoplasty was carried out in seven adult patients to close small to medium tympanic membrane perfurations from March to July, 1998. We introduced three modifications into Eavey's technique: 1. we used adult patients, 2. the surgeries were performed under local anesthesia and 3. we use no skin graft over the cartilage. We evaluated the take rate and postoperative hearing results. Results: All patients had postoperative hearing gain and the take rate was 100% at short-term follow-up period (medium 22.7 months). All cartilage grafts were intact and dry at the last follow-up visit. All patients showed improvement in their audiometric postoperative results. Two of them got closure of their air-bone gap and the rest of them diminished it to 50%. Conclusion This technique described by Eavey is effective to close tympanic membrane perfuration in adults. The modifications introduced (no use of skin graft and local anesthesia) reduced even more surgery time and did not alter postoperative results of the original technique.