RESUMEN
OBJECTIVES: Mitomycin C, a widely used chemotherapeutic drug, has been proposed as a potential adjuvant for the control of scar tissue in surgical wounds because of its capacity to inhibit fibroblast proliferation. The current study used a combination of topical and injected mitomycin C to slow the healing process of surgical wounds in rats. METHODS: An experimental model of surgical wounding at the dorsum of rats was used. A total of 43 animals were subdivided into 3 groups: control, topical mitomycin C, and a combination of topical treatment and intradermal injections of the drug at 30 and 60 days after the initial topical treatment. After 3 months, the animals were painlessly sacrificed and the surgical scars were removed for microscopic analysis. RESULTS: The group that received only topical mitomycin C presented milder inflammatory signs and consequently had a less intense healing process than the control group. The group treated with a combination of both topical and injected mitomycin C presented results comparable to those of the control group. CONCLUSIONS: The toxic characteristics of mitomycin C were most likely responsible for the greater tissue damage that occurred when it was used in the injected form, causing increased scar tissue formation. Mitomycin C slows the healing process of surgical wounds when used topically, but causes enhanced scar tissue formation when injected.
Asunto(s)
Antibióticos Antineoplásicos/administración & dosificación , Mitomicina/administración & dosificación , Cicatrización de Heridas/efectos de los fármacos , Heridas y Lesiones/tratamiento farmacológico , Administración Tópica , Animales , Antibióticos Antineoplásicos/uso terapéutico , Proliferación Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Fibroblastos/efectos de los fármacos , Fibroblastos/patología , Estudios de Seguimiento , Inyecciones Intradérmicas , Masculino , Mitomicina/uso terapéutico , Ratas , Ratas Wistar , Resultado del Tratamiento , Heridas y Lesiones/patologíaRESUMEN
UNLABELLED: Experimental study in animals. INTRODUCTION: Mitomycin C has been used as a fibroblasts inhibitor, thus reducing the scaring process in surgical wounds. AIM: This paper aims at assessing the use of Mitomycin C to reduce the scaring process through its topical use and later injected reinforcements. MATERIALS AND METHODS: We used a model of a creating a wound in the dorsum of rats, removing a circular piece of skin and letting it heal by itself. We used 18 rats, divided in three groups. The first group - Control, the second with topical use, and a third group with injected mitomycin C reinforcement, monthly for 2 months. After 3 months the animals were slaughtered and the scars were surgically removed and sent for histology study. RESULTS: We noticed, under different criteria, that healing with topical mitomycin is less intense; however, when it was injected, the parameters were again comparable to those from the control group. DISCUSSION: We believe that injected mitomycin C in the scar, since it is highly toxic, it destroys tissue and brings about scar neoformation. CONCLUSIONS: Mitomycin C reduces the scaring process when used topically; however, it increases scar tissue formation when injected in these wounds.
Asunto(s)
Alquilantes/administración & dosificación , Fibroblastos/efectos de los fármacos , Mitomicina/administración & dosificación , Cicatrización de Heridas/efectos de los fármacos , Administración Tópica , Animales , Fibrosis/prevención & control , Masculino , Ratas , Ratas Wistar , Factores de TiempoRESUMEN
Estudo experimental em animais. A mitomicina C vem sendo usada como inibidor de fibroblastos, acarretando, com isso, diminuição do processo cicatricial em feridas cirúrgicas. OBJETIVO: Este trabalho visa avaliar o uso de Mitomicina C para diminuir o processo cicatricial, através de seu uso tópico com reforços posteriores injetáveis. MATERIAL E MÉTODOS: Foi usado um modelo de feridas em dorso de ratos, com retirada circular da pele e cicatrização por segunda intenção. Foram usados 18 ratos, divididos em três grupos: controle; com uso tópico; e com reforço de mitomicina C injetável, mensalmente e por 2 meses. Após 3 meses os animais foram sacrificados e as cicatrizes retiradas cirurgicamente e submetidas a estudo histológico. RESULTADOS: Notou-se sob vários critérios que a cicatrização com o uso tópico é menos intensa, mas ao se usar o reforço injetável os parâmetros voltam a ser comparados ao do grupo controle. DISCUSSÃO: Acreditamos que a administração injetável de mitomicina C nas cicatrizes, pela sua elevada característica tóxica, acarreta destruição tecidual e neoformação cicatricial. CONCLUSÕES: A mitomicina C diminui o processo cicatricial quando usada topicamente, mas acarreta aumento da cicatrização quando nestas feridas são feitos reforços injetáveis.
Experimental study in animals. Introduction: Mitomycin C has been used as a fibroblasts inhibitor, thus reducing the scaring process in surgical wounds. AIM: This paper aims at assessing the use of Mitomycin C to reduce the scaring process through its topical use and later injected reinforcements. MATERIALS AND METHODS: We used a model of a creating a wound in the dorsum of rats, removing a circular piece of skin and letting it heal by itself. We used 18 rats, divided in three groups. The first group - Control, the second with topical use, and a third group with injected mitomycin C reinforcement, monthly for 2 months. After 3 months the animals were slaughtered and the scars were surgically removed and sent for histology study. RESULTS: We noticed, under different criteria, that healing with topical mitomycin is less intense; however, when it was injected, the parameters were again comparable to those from the control group. DISCUSSION: We believe that injected mitomycin C in the scar, since it is highly toxic, it destroys tissue and brings about scar neoformation. CONCLUSIONS: Mitomycin C reduces the scaring process when used topically; however, it increases scar tissue formation when injected in these wounds.
Asunto(s)
Animales , Masculino , Ratas , Alquilantes/administración & dosificación , Fibroblastos/efectos de los fármacos , Mitomicina/administración & dosificación , Cicatrización de Heridas/efectos de los fármacos , Administración Tópica , Fibrosis/prevención & control , Ratas Wistar , Factores de TiempoRESUMEN
OBJECTIVES/HYPOTHESIS: The proven ability of mitomycin C to inhibit fibroblasts in vitro has stimulated its use in research animals and in humans to control healing. The objective of the study was to follow the healing process of surgical wounds in the dorsum of rats treated topically with mitomycin C. STUDY DESIGN: Prospective experimental study. METHODS: Two distinct surgical wounds were made to the dorsum of 10 adult rats. One of the wounds received topical mitomycin C diluted at 0.5 mg/mL during a 5-minute period, and the other wound was used as a control. The healing process was followed clinically and histologically after the rats were killed at different post-treatment periods. The degree of fibrosis was evaluated histologically by two different pathologists. RESULTS: Surgical wounds treated with mitomycin C presented delayed healing when compared with the untreated wounds, with remission of scabs 7 days after the control wounds. Histological analysis at 1 month after treatment revealed a significant reduction in fibrosis of the wounds treated with mitomycin C when compared with the untreated wounds. After the third month the degree of fibrosis was comparable in both wounds. CONCLUSION: Topical mitomycin C delays the healing of surgical wounds in rats up to the fourth week following treatment, but the degree of fibrosis is comparable in both treated and untreated wounds after 12 weeks. In otolaryngology this characteristic of the drug may be useful in the treatment of external ear canal stenosis, choanal atresias, nasal cicatricial stenosis, laryngeal stenosis, and keloids.
Asunto(s)
Antibióticos Antineoplásicos/uso terapéutico , Mitomicina/uso terapéutico , Cicatrización de Heridas/efectos de los fármacos , Administración Tópica , Animales , Antibióticos Antineoplásicos/administración & dosificación , Procedimientos Quirúrgicos Dermatologicos , Fibrosis , Masculino , Mitomicina/administración & dosificación , Ratas , Ratas WistarRESUMEN
OBJETIVO: A Mitomicina C é um quimioterápico que apresenta a capacidade de inibir fibroblastos in vitro. Esta característica a levou a ser usada experimentalmente em animais de laboratório e no ser humano, principalmente em oftalmologia, para inibir o processo cicatricial. Este trabalho visa acompanhar o processo de cicatrizaçäo de feridas cirúrgicas feitas em dorsos de ratos e tratadas topicamente com Mitomicina C, comparando-as com feridas no mesmo local, näo tratadas. Propöe-se também a avaliar a resposta da pele quando injetada com concentraçöes diferentes do medicamento. FORMA DE ESTUDO: Experimental. MATERIAL E MÉTODO: Foram feitas, em 10 ratos, duas feridas cirúrgicas em seus dorsos. Uma delas foi tratada topicamente com Mitomicina C na diluiçäo de 0,5 mg/ml por 5 minutos e outra näo. O processo de cicatrizaçäo destas feridas foi acompanhado clinicamente. Posteriormente, os ratos foram sacrificados em períodos diferentes, e suas feridas estudadas histologicamente quanto ao grau de fibrose por dois anatomopatologistas. Posteriormente, três ratos foram submetidos a injeçöes intradérmicas com concentraçöes diferentes de Mitomicina C, e o comprometimento local foi avaliado clínica e histologicamente, sendo que apenas na concentraçäo de 0,01mg/ml näo se observou necrose tecidual. RESULTADOS: As feridas tratadas com Mitomicina C tiveram seu processo cicatricial retardado, com o desaparecimento das crostas locais 7 dias após o das feridas näo tratadas. Ao exame histológico, observado separadamente por dois anatomopatologistas, observou-se no primeiro mês uma nítida diminuiçäo do grau de fibrose nas feridas tratadas com Mitomicina C em relaçäo às näo tratadas. Este grau de fibrose se iguala, nas duas feridas, no terceiro mês. Quanto às diluiçöes injetadas, notou-se clínica e histologicamente uma necrose tecidual proporcional ao grau de concentraçäo (0,5; 0,1; e 0,05 mg/ml), que näo foi observada na concentraçäo de 0,01mg/ml. CONCLUSÄO: A Mitomicina C usada topicamente em feridas cirúrgicas em ratos retarda seu processo de cicatrizaçäo até a 4ª semana. Na 12ª semana este processo se equaliza. Quando usada intradermicamente, causa necrose tecidual apenas em concentraçöes elevadas. Estas características da Mitomicina C podem ser usadas, em otorrinolaringologia, como coadjuvante no tratamento de estenoses do meato acústico externo, imperfuraçöes coanais, sinéquias nasais, estenoses laríngeas e quelóides