Efeito da mitomicina C tópica na cicatrização de prega vocal em modelo suíno

Abstract

several adjuvant therapies to surgery have been used to modulate the healing process of vocal folds, including topic mitomycin (MTC). Aim: to evaluate the effect of topical MTC in the healing process of vocal folds 30 days after the exeresis of a mucosal fragment with CO 2 laser in a swine model (control group without mitomycin and study group with topical MTC), with collagen deposition measurement. Study type: prospective experimental in swine. Methods: two groups of 6 swine each were subjected to exeresis of a mucosal fragment of the vocal fold with CO 2 laser. Immediately after the procedure MTC was applied topically for three minutes on the study group. Thirty days later the animals were slaughtered and samples of the vocal folds were collected for histological analysis, with the purpose of quantifying collagen deposition by Picrosirius Red stain. Results: the average area of total collagen in the vocal folds in the control group was 2.648,03 µm2, whereas in the study group it was 2.200,30 µm2 (p = 0.0043). Conclusion: topical application of MTC after the exeresis of a mucous fragment of vocal fold with CO 2 laser in swine significantly decreased total collagen deposition.

Efeito da mitomicina-C tópica sobre os depósitos de colágeno total na submucosa das pregas vocais íntegras de suínos

“…Under experimental conditions quite similar to those of the present study, it was possible to demonstrate a significant decrease in the area of total collagen deposited on vocal folds with partial resection of the free border and treated with topical mitomycin-C at the concentration of 0.4 mg/mL, when compared with vocal folds submitted to an identical operation, yet without topical application of the chemotherapeutic agent 4 . In the current study, when mitomycin-C was applied to the intact surface of anatomically healthy vocal folds, even at higher concentrations (4mg/mL and 8mg/ mL), no difference was found in the estimated areas of total collagen deposition compared with the controls (Table 1).…”

“…In a past study 4 using the same model as the present study, in which an investigation was undertaken concerning the effect of topical mitomycin-C applied on a raw area of vocal fold fragment resection with CO 2 laser, it was found virtually impossible to ensure the absolutely selective use of mitomycin-C in such a small cavity as the larynx. Regardless of the greatest surgical care, the contact of the chemotherapeutic agent with the contralateral vocal fold would eventually occur.…”

“…Topical mitomycin-C has been increasingly used for situations in which the aim is to effectively control the scarring process that takes place following the surgical manipulation of vocal folds 2,[10][11][12][13] . However, in spite of experimental evidence showing significantly lower amounts of total collagen on operated vocal folds treated with mitomycin-C 1,4,[14][15][16][17] , no clinical or experimental reports can be found in the literature of similar effects or otherwise of mitomycin-C on intact vocal cords.…”

“…Studies have shown the effectiveness of mitomycin-C in reducing cicatrix formation and describe its mechanism of action as the inhibition and blockage of DNA synthesis, thus preventing fibroblast proliferation in the surgical area, allowing for less scar tissue formation where the substance is applied [2][3][4] . The action of mitomycin is directly related to its concentration and the length of time it remains in contact with the wound 5 .…”

Impacto da mitomicina-C tópica na deposição de colágeno em torno de enxerto de gordura na prega vogal de coelhos: estudo histológico e morfométrico

“…Na Otorrinolaringologia, a mitomicina-C tem sido utilizada como droga coadjuvante no tratamento de estenoses laríngeas (Ingrams et al, 1998;Ward et al, 1998;Correa et al, 1999;Rahbar et al, 2000a,b;Sennes et al, 2003;Eliashar et al, 2004;Perepelitsyn et al, 2004;Unal, 2004;Türkylmaz et al, 2005), nas dacriocistorrinostomias e em cirurgias nasosinusais (Ingrams et al, 1998). Ainda, alguns raros trabalhos na área otorrinolaringológica foram feitos apenas experimentalmente em animais para observar cicatrizações de traumas laríngeos induzidos (Spector et al, 1999;Ribeiro et al, 2004;Pereira, 2006;Camargo et al, 2006), assim como para retardar a cicatrização de paracenteses da membrana timpânica, o que poderia ser usado como alternativa para a cirurgia de colocação de tubos de ventilação (Estrem et al, 1999; Finalmente, Camargo et al (2006) realizaram estudo experimental para avaliar os efeitos da mitomicina-C no processo de cicatrização de pregas vocais suínas. Os animais foram divididos em dois grupos de 6 suínos cada, sendo avaliados após exérese de fragmento de mucosa de prega vocal a laser de CO 2 (um grupo com uso de mitomicina-C tópica e o outro grupo considerado controle).…”