Navegando por Palavras-chave "Polypropylenes"

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    Adhesion prevention in reabsorbable polyethylene glycol hydrogel (Coseal (R)) coated polypropylene mesh in rabbits
    (Acta Cirurgica Brasileira, 2013-12-01) Quinino, Reynaldo Martins e [UNIFESP]; Araujo-Filho, Irami; Lima, Francisco Piganataro; Barbosa, Andre Luis Costa; Maia, Tatiana de Carvalho; Goldenberg, Alberto [UNIFESP]; Rio Grande do Norte Fed Univ UFRN; UFRN; Universidade Federal de São Paulo (UNIFESP)
    PURPOSE: To evaluate of postoperative adhesion prevention and inflammatory response to polypropylene mesh, coated with reabsorbable hydrogel of polyethylene glycol (Coseal (R)) in contact with small bowel in an experimental model in rabbits.METHODS: Twenty female rabbits underwent laparotomy to implant two polypropylene meshes, 2x1cm, in the right and left flanks. The right mesh was protected with Coseal (R) spray (Group 1) and the left mesh received no treatment after implantation (Group 2). Thirty days after implantation, the rabbits underwent laparoscopy for adhesion analysis; the prosthesis were removed en bloc with the adjacent tissue for microscopic analysis of inflammation. Statistical analysis used the Mann-Whitney test.RESULTS: There was adhesion formation in five meshes (36%) from Group 1 and in 14 meshes (100%) from Group 2, with statistical significance (p<0.01). There were no differences in the inflammatory response, fibrosis, foreign body reaction, presence of collagen and type of inflammatory cells between the two groups.CONCLUSION: Polypropylene mesh coated with Coseal (R) showed a significantly lower rate of adhesion formation when compared with uncoated meshes, without interfering with inflammatory response.
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    Effects of the polypropylene mesh implanted through inguinotomy in the spermatic funiculus, epididium and testis of dogs
    (Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia, 2005-12-01) Goldenberg, Alberto [UNIFESP]; Paula, Joaquim Ferreira De; Universidade Federal de São Paulo (UNIFESP); FM; FAA
    PURPOSE: To investigate the effects of polypropylene mesh, implanted by inguinotomy, in the spermatic funiculus, epididium and testis of dogs. METHODS: Eighteen dogs were considered (12-23 Kg), separated in three groups. Group A (n=7): left side (with mesh) versus right side (without mesh); Group B (n=7): left side (without mesh) versus right side (with mesh) and Group C (n=4): without any surgical manipulation (control group). After being observed for 60 days, the animals were subjected to bilateral removal of the spermatic funiculus, epididium and testis that were submitted to histological analysis. During the re-operation, a macroscopic evaluation was performed. RESULTS: On the mesh side, we noted 100% of mesh adherence to the posterior wall of the inguinal canal, as well as the adherence of the spermatic funiculus to the mesh. A congestion of the pampiniform plexus was noted in three animals. Chronic inflammation reaction and foreign body reaction in the spermatic funiculus was observed in 100% of the animals. On the side that did not carry a mesh, chronic inflammatory reaction was observed in 71% of the animals. All the animals presented chronic inflammatory reaction in the deferent duct in the mesh side and in eleven animals in the side without the mesh. These alterations were not found in Group C. There was a considerable statistical reduction in the average difference of the diameter of the lumen of the deferent duct in the mesh side. In the epididium and testis, macro and microscopic alterations were not significant, although one animal presented a marked reduction of spermatogenesis on the mesh side. CONCLUSION: The polypropylene mesh, when in contact with the spermatic funiculus of dogs, causes a more intense chronic inflammatory reaction and a significant reduction in the diameter of the lumen of the deferent duct.
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    Estudo comparativo da deposição do colágeno tipo 1 e tipo 3 nos períodos precoce e tardio entre as telas de polipropileno de alta densidade, polipropileno de baixa densidade, polipropileno revestido por celulose, e politetrafluoretileno expandido: modelo experimental em ratos
    (Universidade Federal de São Paulo (UNIFESP), 2020-10-29) Maeda, Carlos Toshinori [UNIFESP]; Linhares, Marcelo Moura [UNIFESP]; Universidade Federal de São Paulo
    Introduction: Abdominal wall hérnia is the most prevalent disease of surgical treatment worldwide. Nowadays, the prostheses reinforcement is the standard treatment, However the ideal mesh for the different scenarios is still a controversial topic in the literature. It is known that the final surgery outcome depends directly of the healing tissues quality induced by the meshes and that could be basically assessed quantifying 1 collagen type 1, collagen type 3, as well as the proportion between these two proteins. Objectives: Evaluate in the Early and Late Periods, the deposition of collagen 1, collagen 3 and the proportion of collagen 1 over collagen 3, between four types of meshes. Methods: Eighty Wistar rats were submitted to a ventral hernia model surgery with mesh placement. They were primarily divided into four large groups: Group PPA (high density polypropylene mesh); Group PPB (low density polypropylene mesh); Group PPCE (low density polypropylene encapsulated with polydioxanone and coated with oxidized cellulose); and Group PTFE (expanded polytetrafluoroethylene mesh). These groups were then subdivided into Early Period (submitted to euthanasia on the 7th postoperative day) and Late Period (submitted to euthanasia on the 28th postoperative day). For immunohistochemical analysis, polyclonal anti-collagen 1 and anti-collagen 3 antibodies were used and evaluated using a semi-quantitative scale. To analyze the proportion of collagens, picrosirius staining method with differentiation by the birefringence method was used, and analysis was made with the “Image J” software. The results were compared between meshes and between periods. Results: In the Early Period, Group PPCE had a higher collagen 1 mean than group B (p=0.003) and Group PTFE (p=0.001), the was no difference between groups in collagen 3 means. In the Late Period the Group PPB present higher mean than Group PPA (p = 0.005) and Group PTFE (p=0.002), and again there was no difference comparing collagen 3. When comparing Early and Late Periods, Groups PPA (p=0.022) and PPB (p<0.001) showed an increase of collagen 1 quantification, while Group PPCE (p= 0.01) showed an increase collagen 3 mean. In the analysis of the proportions of type 1 collagen over type collagen 3 using the picrosirius method, there was no statistical differences in the Early and Late Periods; When comparing Early and Late Periods, Group PPA (p=0.001); and PPB (p=0.018) showed an increase mean of this proportion. Conclusions: In the Early xvii Period, deposition of type 1 collagen was higher in cellulose-coated polypropylene mesh than low-density polypropylene and expanded polytetrafluoroethylene mesh, while in the Late Period, low-density polypropylene mesh showed greater collagen 1 deposition when compared to high density polypropylene and expanded polytetrafluoroethylene mesh. There was no difference in collagen 3 deposition of between the prostheses, in both Periods. The high and low density polypropylene meshes showed an increase collagen 1 deposition, while the polypropylene mesh coated with cellulose showed an collagen 3 increased between the Early and Late Periods. The ratio of collagens 1 over 3 was similar between prostheses in the studied periods. However, high and low density polypropylene meshes showed an increase ratio in the Late Period.
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    ESTUDO COMPARATIVO DO EFEITO DAS TELAS DE POLITETRAFLUOROETILENO EXPANDIDO E DE POLIPROPILENO, COLOCADAS POR LAPAROSCOPIA, EM HÉRNIAS VENTRAIS PRODUZIDAS EM COELHOS
    (Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia, 1999-04-01) Aydos, Ricardo Dutra; Silva, Iandara Schettert; Goldenberg, Saul [UNIFESP]; Goldenberg, Alberto [UNIFESP]; Simões, Manuel de Jesus [UNIFESP]; Takita, Luiz Carlos; Nigro, Amaury José Teixeira [UNIFESP]; Universidade Federal de Mato Grosso do Sul (UFMS); Universidade para o Desenvolvimento do Estado e da Região do Pantanal (UNIDERP); Universidade Federal de São Paulo (UNIFESP)
    The objective is to study the effect of polytetrafluoroethylene (PTFE) and polypropylene (PP) mesh in the repair of incisional hernias with laparoscopy. Were used 45 new Zeland white rabbits, with weight between 2700g and 3100g. In 15 PTFE mesh was used, in 15 PP mesh was used and in the other 15, that were called the control group, nothing was used. All of them were submitted to standardized incisional hernias, they were repaired by laparoscopy with PTFE and PP mesh in the first and second groups, and in the control group has just done the adhesions. On the 35th day the animals were submitted to laparoscopy, this was done to see if there were adhesions in the mesh (in groups PP and PTFE) or in the hernia (in the control group ), if there were any intestinal adhesions and if the mesh was wrinkled or stretched. One segment of the abdominal wall was submitted to an intended rupture force and another segment was submitted to a histologic evaluation with colagens fibres count. On the 35th and 70th days, the control group showed lesser adhesions than the other two groups, (PTFE and PP mesh groups), and PTFE mesh group showed less adhesions than the PP mesh group. The PP mesh group showed a lot more colagen's fibres than the other two groups and the PTFE mesh group showed more colagen's fibres than the control group. The hernias didn't recidived in the treated groups and have concluded that the mesh used was effective in the hernias treatment and the PP mesh determined more adhesions.