Tracheal repair with acellular human amniotic membrane in a rabbit model.

Surgical correction of tracheal stenosis is still a complex and challenging procedure. Acellular human amniotic membranes (AHAM) represent a promising biomaterial source for tissue regeneration. The aim of this study was to evaluate whether AHAM grafts improve tissue regeneration of the trachea in a rabbit model of tracheostomy. Twenty rabbits were randomized into 2 groups. Animals in the control group underwent surgical tracheostomy only, and animals in the AHAM group underwent surgical tracheostomy and received an AHAM graft that covered the defect site. We examined tissues at the site of tracheostomy 60 days after surgery by histological analysis with haematoxylin and eosin, Movat's pentachrome stain and immunohistochemistry by analysis with antiaggrecan antibodies. The average perimeter and area of the defect 60 days after surgery were smaller in animals in the control group than in the AHAM group (p = .011 and p = .011, respectively). Histological analysis of AHAM group revealed neovascularization, islands of immature cartilage, pseudostratified ciliated epithelium. and connective tissue at the site of AHAM engraftment, whereas only pseudostratified ciliated epithelium and connective tissue were observed at the defect site in tissues of animals in the control group. Regeneration of islands of immature cartilage tissue with hyaline pattern and pseudostratified ciliated epithelium were confirmed by immunohistochemistry analysis. These results indicate that AHAM engraftment could facilitate neovascularization and regeneration of immature cartilage in a model of tracheal injury. Its use may lower the risk of post-operative complications including stenosis of trachea.

Regeneration of Tracheal Tissue in Partial Defects Using Porcine Small Intestinal Submucosa.

BACKGROUND: Surgical correction of tracheal defects is a complex procedure when the gold standard treatment with primary end-to-end anastomosis is not possible. An alternative treatment may be the use of porcine small intestinal submucosa (SIS). It has been used as graft material for bioengineering applications and to promote tissue regeneration. The aim of this study was to evaluate whether SIS grafts improved tracheal tissue regeneration in a rabbit model of experimental tracheostomy. METHODS: Sixteen rabbits were randomized into two groups. Animals in the control group underwent only surgical tracheostomy, while animals in the SIS group underwent surgical tracheostomy with an SIS graft covering the defect. We examined tissues at the site of tracheostomy 60 days after surgery using histological analysis with hematoxylin and eosin (H&E) staining and analyzed the perimeter and area of the defect with Image-Pro® PLUS 4.5 (Media Cybernetics). RESULTS: The average perimeter and area of the defects were smaller by 15.3% (p = 0.034) and 21.8% (p = 0.151), respectively, in the SIS group than in the control group. Histological analysis revealed immature cartilage, pseudostratified ciliated epithelium, and connective tissue in 54.5% (p = 0.018) of the SIS group, while no cartilaginous regeneration was observed in the control group. CONCLUSIONS: Although tracheal SIS engraftment could not prevent stenosis in a rabbit model of tracheal injury, it produced some remarkable changes, efficiently facilitating neovascularization, reepithelialization, and neoformation of immature cartilage.

Myocardial regeneration after implantation of porcine small intestinal submucosa in the left ventricle.

INTRODUCTION: Most cardiomyocytes do not regenerate after myocardial infarction. Porcine small intestinal submucosa has been shown to be effective in tissue repair. OBJECTIVE: To evaluate myocardial tissue regeneration and functional effects of SIS implantation in pigs after left ventriculotomy. METHODS: Fifteen pigs were assigned to two groups: porcine small intestinal submucosa (SIS) (N=10) and control (N=5). The SIS group underwent a mini sternotomy, left ventriculotomy and placement of a SIS patch. The control group underwent a sham procedure. Echocardiography was performed before and 60 days after the surgical procedure. Histological analysis was performed with hematoxylin-eosin stain and markers for actin 1A4, anti sarcomeric actin, connexin43 and factor VIII. RESULTS: Weight gain was similar in both groups. Echocardiography analysis revealed no difference between groups regarding end diastolic and systolic diameters and left ventricular ejection fraction, both pre (P=0.118, P=0.313, P=0.944) and post procedure (P=0.333, P=0.522, P=0.628). Both groups showed an increase in end diastolic (P<0,001 for both) and systolic diameter 60 days after surgery (P=0.005, SIS group and P=0.004, control group). New cardiomyocytes, blood vessels and inflammatory reactions were histologically identified in the SIS group. CONCLUSION: SIS implantation in pigs after left ventriculotomy was associated with angiomuscular regeneration and no damage in cardiac function.

Myocardial regeneration after implantation of porcine small intestinal submucosa in the left ventricle / Regeneração miocárdica após implante de submucosa intestinal suína no ventrículo esquerdo

Introduction: Most cardiomyocytes do not regenerate after myocardial infarction. Porcine small intestinal submucosa has been shown to be effective in tissue repair. Objective: To evaluate myocardial tissue regeneration and functional effects of SIS implantation in pigs after left ventriculotomy. Methods: Fifteen pigs were assigned to two groups: porcine small intestinal submucosa (SIS) (N=10) and control (N=5). The SIS group underwent a mini sternotomy, left ventriculotomy and placement of a SIS patch. The control group underwent a sham procedure. Echocardiography was performed before and 60 days after the surgical procedure. Histological analysis was performed with hematoxylin-eosin stain and markers for actin 1A4, anti sarcomeric actin, connexin43 and factor VIII. Results: Weight gain was similar in both groups. Echocardiography analysis revealed no difference between groups regarding end diastolic and systolic diameters and left ventricular ejection fraction, both pre (P=0.118, P=0.313, P=0.944) and post procedure (P=0.333, P=0.522, P=0.628). Both groups showed an increase in end diastolic (P<0,001 for both) and systolic diameter 60 days after surgery (P=0.005, SIS group and P=0.004, control group). New cardiomyocytes, blood vessels and inflammatory reactions were histologically identified in the SIS group. Conclusion: SIS implantation in pigs after left ventriculotomy was associated with angiomuscular regeneration and no damage in cardiac function. .

Introdução: A grande maioria dos cardiomiócitos não tem capacidade de regeneração após o infarto do miocárdio. A submucosa do intestino porcino tem-se mostrado eficiente como reparador tecidual. Objetivo: Analisar a capacidade de regeneração tecidual miocárdica e o efeito funcional do implante da submucosa do intestino porcino após ventriculotomia esquerda em porcos. Métodos: Quinze porcos foram separados em dois grupos: submucosa (N=10) e controle (N=5). Os animais do grupo submucosa foram submetidos a uma mini esternotomia inferior e ao implante da submucosa porcina na ventriculotomia esquerda. No grupo controle, foi realizada apenas a mini-esternotomia. Foi realizada análise ecocardiográfica no pré-operatório e 60 dias após o procedimento cirúrgico. A análise histológica foi feita com hematoxilina-eosila e marcadores para Actina 1A4, anti-actina sarcomérica, conexina43 e fator VIII. Resultados: O ganho de peso foi semelhante entre os grupos. Considerando a análise ecocardiográfica, não foi identificada diferença estatisticamente significativa entre os grupos com relação ao diâmetro sistólico final, diâmetro diastólico final e fração de ejeção ventricular esquerda, tanto no pré (P=0.118, P=0.313, P=0.944) quanto no pós-operatório (P=0.333, P=0.522, P=0.628). Ambos os grupos mostraram um aumento no diâmetro sistólico final (P=0.005, grupo submucosa e P=0.004, grupo controle) e diâmetro diastólico final (P<0,001 para ambos) 60 dias após a cirurgia. À histologia, identificou-se a presença de novos cardiomiócitos, fibras musculares lisas, vasos sanguíneos e reação inflamatória no grupo submucosa. Conclusão: O implante de submucosa intestinal porcina após ...