Estudo das telas cirúrgicas de polipropileno/poliglecaprone e de polipropileno/polidioxanona/celulose oxidada regenerada na cicatrização de defeito produzido na parede abdominal de ratos Study of surgical meshes of polypropylene/polyglecaprone and polypropylene/polydioxanone/oxidized regenerated cellulose on the healing of defects produced in abdominal wall of rats

RACIONAL: O uso de telas cirúrgicas para a correção de defeitos da parede abdominal vem ocupando cada vez mais espaço nas operações no mundo todo. OBJETIVO: Estudar duas telas cirúrgicas distintas (Proceed® e Ultrapro®) na cicatrização de defeito produzido em parede abdominal de ratos avaliando-se macroscopia, tensiometria e microscopia. MÉTODO: A amostra foi constituída por 32 ratos Wistar, divididos em dois grupos de 16 animais e quatro subgrupos de oito, submetidos à eutanásia com 15 dias e 30 dias para avaliação. As variáveis macroscópicas foram: presença de hematoma nos bordos da sutura da tela cirúrgica na parede abdominal, união entre a tela e a borda da ferida, presença de infecção no sítio cirúrgico, presença de fístulas de vísceras com a tela cirúrgica, presença de aderências dentro da cavidade abdominal e presença de hérnia incisional. Na microscopia avaliaram-se as fases do processo inflamatório da cicatrização, e na tensiometria a força tênsil necessária para ruptura do material. RESULTADOS: A união entre a tela cirúrgica e a borda da ferida foi melhor no subgrupo Ultrapro 15 dias que no Proceed 15 dias; com 30 dias foi igual nos dois subgrupos. Não houve diferença significativa quanto às demais variáveis da macroscopia. Os dois grupos nos dois momentos tiveram a mesma proporção de casos com processo inflamatório crônico, mas houve maior escore de inflamação do Ultrapro 15 dias que do Ultrapro 30 dias. O subgrupo Ultrapro 15 dias mostrou força de ruptura maior que o subgrupo Proceed 15 dias, mas em 30 dias não houve diferença. Ultrapro mostrou força de ruptura igual para os dois momentos, mas Proceed 30 dias mostrou força de ruptura maior que Proceed 15 dias. CONCLUSÃO: As telas são semelhantes nas variáveis analisadas.<br>BACKGROUND: The use of surgical meshes for the repair of abdominal wall defects has been increasing its share in surgeries worldwide. AIM: To study two different surgical meshes (Proceed® and Ultrapro®) on the healing of defects produced in abdominal wall of rats evaluating the macroscopic, microscopic and tensiometric parameters. METHOD: Thirty two Wistar rats were divided into two groups of 16 animals and four groups of eight animals euthanized within 15 and 30 days for evaluation. The macroscopic variables were: the presence of hematoma at the edges of the sutures of the surgical mesh in the abdominal wall; the knitting of the surgical mesh and the edge of the wound; presence of infection at the surgical site; presence of viscera fistulas on the surgical mesh; presence of adhesions in the abdominal cavity; presence of incisional hernia. During microscopy the stages of the inflammatory process of healing where evaluated, and tensiometry evaluated the tensile force required to rupture the material. RESULTS: The knitting of the mesh and the edge of the surgical wound was better in the 15 days Ultrapro subgroup than in the 15 days Proceed subgroup; within 30 days the knitting was similar in both subgroups. There was no significant difference for the variable of macroscopy. Both groups in both periods had the same proportion of cases with chronic inflammation, but there were higher scores of inflammation in the 15 days Ultrapro subgroup than the 30 days Ultrapro subgroup. The subgroup 15 days Ultrapro showed greater rupture strength than the subgroup 15 days Proceed, but in 30 days there were no difference. Ultrapro showed equal rupture strength in both periods, but 30 days Proceed showed greater rupture strength than 15 days Proceed. CONCLUSION: The meshes are similar in variables

The effects of upper limb loading on spinal shrinkage during treadmill walking

Everyday activities such as walking either loaded or unloaded may elicit spinal shrinkage in an order of magnitude that has been related to lower back pain. The present study aims to compare the effects of unloaded treadmill walking with walking carrying loads representing everyday shopping tasks. Walking tasks were performed on 7 healthy males, consisting of unloaded walking and walking carrying 7.5% and 15% of body weight. Motion analysis was used to track four reflective markers at 100Hz, dividing the spine into three segments and static data was collected in 5 minute intervals over a 30 minute period. Total spine and segment length changes were compared to original length in the sagittal plane and the effects of load, time and their interaction were analysed using ANOVA. Total spinal length and lumbar segment decreased with respect to time (p < 0.001). Load affected the percentage length change at each spinal segment (p < 0.005), with the lumbar segment showing greatest height loss at the highest load. Inter-segmental variations in length resulted in the non-significant effect of load on the percentage length change of the total spine (P = 0.263). The upper and lower thoracic segments showed greater anterior lean with the heavier loads (p = 0.000) and the lumbar segment showed the opposite trend (p = 0.000). Results suggest that the body adopts less anterior lean with an immediate load bearing demand, to decrease the flexion moment arm of the load about the lumbar spine and thus decrease the necessary extension moment generated by the spinal extensors for spinal stability. Further postural alteration in the same direction is observed with prolonged loading. In combination with lumbar spinal shrinkage, such postural changes are likely to increase the loading on the facet joints with potential deleterious consequences for low back pai