Fibrosis in tubularized skin flaps in rats, using silicon catheters with two different degrees of flexibility: experimental model

Abstract

Purpose: Microscopically evaluate the intensity of fibrosis in tubularized skin flaps on the back of Wistar rats, using silicon molds with different degrees of flexibility. Methods: Twenty rats were submitted to three tubularized skin flaps on their backs. In two tubular flaps, we placed, as a mold, silicon catheters with different degrees of flexibility and removed them on the seventh day after the surgery. They were divided into two groups and euthanized, on the seventh and twenty-first days respectively after the surgery for the collection of the pieces, coloration with Masson tricromic, quantification of the area of each sample and comparison among the groups. Results: Fibrosis was less intense on the tubular flaps where a catheter was not used as a mold. No significant difference was verified among the pieces with the silicon catheters, but there was a tendency of less fibrosis on the tubules with the most flexible catheter. Conclusion: There was no significant difference among the two catheter types. Fibrosis was less intense in the flaps where the mold was not used. Key words: Hypospadias. Surgical Flaps. Silicon. Fibrosis. Rats. RESUMOObjetivo: Avaliar microscopicamente a intensidade da fibrose em retalhos tubulares de pele do dorso de ratos Wistar em uso de moldes de silicone de diferentes flexibilidades. Métodos: Vinte animais foram submetidos à confecção de três retalhos tubulizados de pele na região dorsal. Em dois túbulos foram colocados, como molde, cateteres de silicone com flexibilidades diferentes e retirados no sétimo dia após a cirurgia. Foram divididos em dois grupos e sacrificados, respectivamente, no sétimo e vigésimo primeiro dia após a cirurgia para a coleta das peças, coloração pelo tricrômico de Masson, quantificação da área de cada amostra e comparação entre os grupos. Resultados: A fibrose foi menos intensa nos retalhos tubulares em que não se usou cateter como molde. Não se verificou diferença significativa entre os retalhos com os cateteres de silicone, mas sim, tendência de menos fibrose nos túbulos com cateter mais flexível. Conclusão: Não houve diferença significativa entre os dois tipos de cateter. A fibrose foi menos intensa nos retalhos onde não se utilizou molde.

Evaluation of the Biocompatibility of Silicone Gel Implants - Histomorphometric Study

“…This capsule, whose cause is still unclear, could be hypothetically explained by the poor adhesion of the implant surface to the tissues, eventually contracting and avoiding the implant function (7, 15). …”