Por ocasião de um caso de anemia falciforme.

Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Departamento de Tocoginecologia, Curso de Medicina, Florianópolis, 197

Possible Migration and Histopathological Analysis of Injections of Polymethylmethacrylate in Wistar Rats

Objective. To evaluate the possible migration of polymethylmethacrylate after injections in various corporal compartments of Wistar rats. Methods. The experimental work consisted in the injection of PMMA in corporal compartments for later histopathological analysis of the locations of implants and of distant filtering organs. The dose applied in each implant was of 0.2 mL. The animals were divided into groups according to the location of the implant realized: group GB had intradermic injections in the glabella. Group SD had subdermal injections in dorsal subcutaneous tissue cells. Group IP had intraperitoneal injections in the abdomen. Group PD had intramuscular injections in the right rear leg. The rats were sacrificed 30 days after realization of the implants and tissue samples from the lung, liver, spleen, and kidney, and locations of implantation were removed for histopathological analysis. Results. Characteristic microspheres that were compatible with the presence of PMMA in any of the histological slides analyzed were not observed. One animal had an amorphous exogenous substance, with a histiocytic reaction. Twelve of the 16 lungs analyzed had locations of intraalveolar hemorrhaging. Two animals had nonspecific spleen alterations. Conclusion. The histopathological analysis of this study found no PMMA microspheres in any of the tissues analyzed

Expanded polytetrafluoroethylene and polypropylene in the repairing of abdominal wall defects in Wistar rats: comparative study Uso das telas de politetrafluoroetileno e polipropileno no reparo de defeitos da parede abdominal em ratos Wistar: estudo comparativo

PURPOSE: To compare the use of polypropylene and PTFE meshes in the treatment of incisional hernias made experimentally on Wistar rats. METHODS: The experiment used 24 Wistar rats divided into three cohorts: C-A (ressection of a segment of abdominal wall), E-A (ressection and placement of PTFEe mesh), E-B (resection and placement of polypropylene mesh). After 28 days, the mesh and the surrounding tissue were removed and submitted to macroscopic analysis (assessment of the abdominal wall for presence of abscess in the surgical wound and/or skin necrosis, and adhesions) as well as microscopic analysis (presence of fibrosis, necrosis and abscess, counting of macrophages, mononuclears and polymorphonuclears). RESULTS: Adhesions and abscesses in the surgical wound were observed more commonly associated to the group treated with PTFEe. The size of the fibrous tissue was greater in the group treated with polypropylene. Cohort E-A showed PTFEe mesh enveloped by organized fine connective tissue. No groups presented necrosis on the site of the insertion. The highest mononuclear inflammatory reaction occurred in association to PTFEe when compared to the control group, but the findings for the polypropylene mesh were also significant when compared to the control group. In the analysis of the results obtained for cohorts E-A and E-B, a minimal occurrence of polymorphonuclears was noticed in both groups, which indicates low tissue reactivity to both materials used in the present experiment. CONCLUSION: Even with epithelization and proliferation of connective tissue, anchorage between PTFEe and abdominal wall is insufficient, which can result in reherniations.<br>OBJETIVO: Comparar o uso de tela de PTFEe e polipropileno no tratamento de hérnias incisionais produzidas experimentalmente em ratos Wistar. MÉTODOS: 24 ratos Wistar foram distribuídos em três subgrupos: C-A (ressecção de segmento da parede abdominal), E-A (ressecção e colocação de tela de PTFEe), E-B (ressecção e colocação de tela de polipropileno). Após 28 dias, retirou-se a peça e procedeu-se à análise macroscópica (inspeção da parede abdominal, avaliando presença de abscesso na ferida operatória e/ou necrose de pele, e aderências) e microscópica (presença de fibrose, necrose e abscesso, e contagem de macrófagos, mononucleares e polimorfonucleares). RESULTADOS: Aderências e abscesso na ferida operatória foram observados mais intensamente no subgrupo tratado com PTFEe. O tamanho do tecido fibrótico foi mais acentuado no subgrupo tratado com polipropileno. Já o subgrupo E-A apresentou a tela de PTFEe envolvida por tecido conectivo fino organizado. Não houve necrose no local de inserção da prótese em todos os subgrupos. Maior reação inflamatória mononuclear ocorreu com o PTFEe quando comparado com o grupo controle, mas com o uso de polipropileno os achados foram significativos se comparados ao grupo controle. Na análise dos resultados obtidos com os grupos E-A e E-B verificou-se que houve ocorrência mínima de polimorfonucleares em ambos os grupos de animais analisados, indicando assim uma baixa reatividade tecidual de ambos materiais nestes animais experimentais. CONCLUSÃO: Mesmo ocorrendo epitelização e proliferação de tecido conjuntivo, a ancoragem entre o PTFEe e a parede abdominal é insuficiente, o que pode resultar numa maior recorrência de hérnias

Experimental study comparing the tensile strength of different surgical meshes following aponeurotic-muscle deformity synthesis on Wistar rats Estudo experimental comparando a resistência tênsil de diferentes tipos de telas cirúrgicas após síntese de defeito músculo-aponeurótico em ratos Wistar

PURPOSE: To assess the tensile strength of polypropylene and polypropylene associated with polyglactin meshes (Vypro II® - Ethicon®, Somerville, NJ, USA) in a situation of partial separation of abdominal muscle aponeurosis on rats. METHODS: Thirty rats were used of the Wistar strain, which were randomized into two groups of 15 specimens each. In both groups an aponeurotic-muscle deformity was created on the abdominal wall measuring 3.0 x 1.0 cm, which was closed with polypropylene mesh (polypropylene group) or Vypro® mesh (vypro group). After 28 days the rats underwent euthanasia and an area was removed from the abdominal wall with which a strip was made measuring 2.0 cm in length and 6.0 cm in width comprising the abdominal muscles with the implanted mesh. This sample was placed in a mechanical test machine in which a constant force was applied contrary to the tissue strips. Maximum force expressed in Newton was considered until full rupture of the sample occurred. The non-parametric Kruskal - Wallis test was used for statistical analysis admitting p<0.05. RESULTS: Out of the thirty animals, there were two deaths in the vypro group and one unit in the polypropylene group was lost. One animal in the polypropylene group developed hernia during the study and another one developed granuloma of the abdominal wall. All animals in both groups developed epiplon adherence to the mesh. The average force was 48.08 N for the polypropylene group and 45.32 for the vypro® group. CONCLUSION: In these experimental conditions it could be observed that there is no statistically significant difference in the rupture force of the polypropylene and Vypro® meshes (p=0.54).<br>OBJETIVO: Avaliar a resistência tênsil das telas de polipropileno e polipropileno associado à poliglactina (Vypro II® - Ethicon®, Somerville, NJ, USA) em situação de afastamento parcial da aponeurose dos músculos abdominais em ratos. MÉTODOS: Foram utilizados trinta ratos da linhagem Wistar randomizados em dois grupos de quinze exemplares cada um. Em ambos os grupos criou-se um defeito músculo-aponeurótico na parede abdominal medindo 3,0 x 1,0 cm que foi fechado com tela de polipropileno (grupo polipropileno) ou Vypro® (grupo vypro). Após 28 dias, foi feita a eutanásia e retirou-se uma área da parede abdominal com a qual fez-se uma tira medindo 2,0 cm de comprimento por 6,0 cm de largura englobando os músculos abdominais com a tela implantada. Essa amostra foi presa em máquina de ensaios mecânicos na qual se aplicou força constante contrária às tiras de tecido. Foi considerada a força máxima expressa em Newton até ocorrer a ruptura total da amostra. Para a análise estatística, utilizou-se teste não paramétrico de Kruskal - Wallis admitindo-se p<0,05. RESULTADOS: Ocorreram dois óbitos do grupo vypro e uma unidade do grupo polipropileno foi perdida no teste mecânico. Um animal do grupo polipropileno desenvolveu hérnia durante o período do estudo e outro desenvolveu um granuloma de parede abdominal. Todos os animais de ambos os grupos desenvolveram aderência de epíplon à tela. A média das forças foi de 48.08 N para o grupo polipropileno e 45.32 N para o grupo vypro®. CONCLUSÃO: A tela de polipropileno apresentou uma força média de resistência à tração maior quando comparada com a de Vypro® nessas condições experimentais