Reparação tecidual e perfil hematológico de leporinos submetidos à prevenção de aderência abdominal após enterotomia colônica : modelo para equinos
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Data
2018-03-16
Autores
Teixeira, Luisa Gouvêa
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Universidade Estadual Paulista (Unesp)
Resumo
As aderências intra-abdominais acometem até 20% dos equinos submetidos à cirurgia do trato gastrointestinal. Os leporinos também são amplamente acometidos, sendo utilizados como modelo para estudo de aderência abdominal e uso de biomateriais. O objetivo desta pesquisa foi validar três métodos de profilaxia da formação de aderências intestinais, a partir da observação do comportamento das variáveis hematológicas e anatomopatológicas, utilizando o modelo leporino, para futura aplicação em equinos. Foram desenvolvidos e aplicados dois modelos de filmes poliméricos, sendo o primeiro composto por carboximetilcelulose sódica (NaCMC) e poli(álcool vinílico) (PVA), e o segundo com estreptoquinase (STP) adicionada à formulação. O terceiro método constou na administração intraperitoneal de STP. Análise da morfologia dos filmes foi realizada por meio de microscopia eletrônica de varredura, além da avaliação do grau de intumescimento destes. Foram utilizadas 24 coelhas da raça Nova Zelândia Branco, distribuídas em quatro grupos de seis animais (G1, G2, G3 e G4), submetidas à enterotomia e enterorrafia do cólon descendente. No G1 a enterorrafia foi recoberta com o filme de NaCMC + PVA, no G2 a enterorrafia foi recoberta com o filme de NaCMC + PVA + STP, no G3 foi infundida STP na cavidade abdominal após a enterorrafia e no G4 a ausência destes tratamentos. Todos os animais foram submetidos à avaliação hematológica antes da celiotomia (T0), aos três (T1) e sete dias (T2) pós-operatórios, quando foi realizada avaliação macroscópica da cavidade abdominal e histopatológica do cólon descendente. Os dados hematológicos foram submetidos à análise de variância e ao Teste de Tukey, e os escores dos parâmetros histológicos ao Teste de Kruskal-Wallis (p<0,05). Observou-se que o filme de NaCMC + PVA apresentou maior grau de intumescimento e menor porosidade, o oposto do resultado obtido para o filme de NaCMC + PVA + STP. À avaliação hematológica observou-se redução na contagem de hemácias, concentração de hemoglobina e volume globular nos quatro grupos, aumento da contagem de basófilos e monócitos no G2 e aumento de eosinófilos, monócitos e do tempo de tromboplastina parcial ativada no G4. O tempo de protrombina reduziu no G2, G3 e G4. O G1 apresentou o menor percentual de aderência abdominal, seguido do G2 e G3, enquanto o G4 apresentou mais animais com esta alteração à avaliação da cavidade abdominal. Não houve diferença significativa para as variáveis histopatológicas, entre os quatro grupos. Considerou-se este estudo pioneiro na confecção de tais filmes poliméricos e utilização destes in vivo para evitar aderências intestinais. A partir dos resultados deste estudo, pode-se concluir que os três métodos de profilaxia diminuíram a incidência de aderência abdominal. No entanto, o filme composto apenas de NaCMC + PVA apresentou a melhor eficácia como antiaderente, tornando-o promissor para a utilização em cirurgia veterinária, incluindo a gastroenterologia equina.
Intraabdominal adhesions affects up to 20% of horses undergoing gastrointestinal surgery. Rabbits are also widely affected being used as role model for abdominal adhesions and biomaterials studies. The aim of this study was to validate three methods for intestinal adhesions formation prophylaxis by observing the hematological and anatomopathological variables of rabbits as a study model for further use in horses. Two models of polymer films were developed and applied. The first one being composed of sodium carboxymethylcellulose (NaCMC) and polyvinyl alcohol (PVA), and the second with streptokinase (STP) added to the formulation. The third method involved intraperitoneal administration of STP. Analysis of the film morphology was done by scanning electron microscopy, as well as the evaluation of the degree of swelling. Twenty four New Zealand White female rabbits were divided into four experimental groups of six animals (G1, G2, G3 e G4). The subjects were submited to enterotomy and enterorrhaphy of the descending colon. For G1 and G2 groups, the enterorrhaphy site was covered with thin layer of NaCMC + PVA and NaCMC + PVA + STP, respectively. On G3 group, abdominal infusion of STP was done after enterorrhaphy and G4 was the control group without any treatment. All animals were submitted to hematological evaluation before celiotomy (T0), three (T1) and seven days (T2) following surgery when macroscopic assessment of the abdominal cavity and descending colon histology was done. Hematological data was submitted to analyses of variance and Tukey’s test to compare different moments within each group and moments in-between the four groups. Kruskal-Wallis test was used to compare histological parameters scores among the four groups (p<0.05.). It was observed that the NaCMC + PVA thin layer presented higher degree of swelling and lower porosity. The exactly opposite results were obtained with the thin layer of NaCMC + PVA + STP. There was a reduction on red blood cell count, hemoglobin concentration and globular volume in the four groups. In G2 group there was an increase in basophils and monocytes and in G4 group showed increase in eosinophils, monocytes and in activated partial thromboplastin time. The prothrombin time decrease in G2, G3 and G4 groups. The G1 group presented lower percentage of abdominal adhesion followed by groups G2 and G3, while G4 showed more animals with abdominal adhesions. There was no significant difference for the histological variables among all four groups. It was considered that this was a pioneer study in making those polymer thin layers and its use in vivo to avoid intestinal adhesions. From the analysis of the results of this study it is possible to conclude that all three treatments decreased the incidence of abdominal adhesion. However the thin layer of NaCMC + PVA presented greater effectiveness as anti-adhesion, making it promising for use in veterinary surgery including equine gastroenterology.
Intraabdominal adhesions affects up to 20% of horses undergoing gastrointestinal surgery. Rabbits are also widely affected being used as role model for abdominal adhesions and biomaterials studies. The aim of this study was to validate three methods for intestinal adhesions formation prophylaxis by observing the hematological and anatomopathological variables of rabbits as a study model for further use in horses. Two models of polymer films were developed and applied. The first one being composed of sodium carboxymethylcellulose (NaCMC) and polyvinyl alcohol (PVA), and the second with streptokinase (STP) added to the formulation. The third method involved intraperitoneal administration of STP. Analysis of the film morphology was done by scanning electron microscopy, as well as the evaluation of the degree of swelling. Twenty four New Zealand White female rabbits were divided into four experimental groups of six animals (G1, G2, G3 e G4). The subjects were submited to enterotomy and enterorrhaphy of the descending colon. For G1 and G2 groups, the enterorrhaphy site was covered with thin layer of NaCMC + PVA and NaCMC + PVA + STP, respectively. On G3 group, abdominal infusion of STP was done after enterorrhaphy and G4 was the control group without any treatment. All animals were submitted to hematological evaluation before celiotomy (T0), three (T1) and seven days (T2) following surgery when macroscopic assessment of the abdominal cavity and descending colon histology was done. Hematological data was submitted to analyses of variance and Tukey’s test to compare different moments within each group and moments in-between the four groups. Kruskal-Wallis test was used to compare histological parameters scores among the four groups (p<0.05.). It was observed that the NaCMC + PVA thin layer presented higher degree of swelling and lower porosity. The exactly opposite results were obtained with the thin layer of NaCMC + PVA + STP. There was a reduction on red blood cell count, hemoglobin concentration and globular volume in the four groups. In G2 group there was an increase in basophils and monocytes and in G4 group showed increase in eosinophils, monocytes and in activated partial thromboplastin time. The prothrombin time decrease in G2, G3 and G4 groups. The G1 group presented lower percentage of abdominal adhesion followed by groups G2 and G3, while G4 showed more animals with abdominal adhesions. There was no significant difference for the histological variables among all four groups. It was considered that this was a pioneer study in making those polymer thin layers and its use in vivo to avoid intestinal adhesions. From the analysis of the results of this study it is possible to conclude that all three treatments decreased the incidence of abdominal adhesion. However the thin layer of NaCMC + PVA presented greater effectiveness as anti-adhesion, making it promising for use in veterinary surgery including equine gastroenterology.
Descrição
Palavras-chave
biomaterial, carboximetilcelulose, coelhas, cólon descendente, estreptoquinase, poli(álcool vinílico), carboxymethylcellulose, descending colon, streptokinase, poly(vinyl alcohol)