| Objective:Contrast the shrinkage rates and the foreign body reaction of lightweight polypropylene mesh (LWPP), heavyweight polypropylene mesh (HWPP) and polyester mesh in rat models to explore the changes of different meshes and their effect on the surrounding tissue in the body.Methods:Forty-five SD male rats, aging8-10weeks (8.9±0.9weeks), weight280-300g (287±4.5g), were divided into LWPP group, HWPP group and polyester mesh group according to random number table, there were15rats in each group, the abdominal wall hernia models of rats were made with different kinds of meshes. Five rats of each group were sacrificed after operation at1week,4weeks and12weeks. The specimens were stained by HE staining method and immunohistochemical staining method after frozen section. The data was collected and statistical analyzed by SPSS13.0statistic software pack. SNK-q was used for multiple sample mean comparison; paired-sample t-test was used for paired sample mean comparison; Kruskal-Wallis H test was used for the enumeration data.Results:1.1Comparison results of the foreign body reaction of the meshes in the body1.1.1The comparison results of the foreign body reaction among the groups at the same time point.1.1.1.1One week after surgery:The number of inflammatory cells:HWPP group(512.2±23.8), LWPP group (402.8±11.2)and polyester mesh group(532.7±27.8), the results showed significant differences among the three groups in the number of inflammatory cells, the number of inflammatory cells in polyester mesh group> HWPP group> LWPP group; The number of macrophages:HWPP group (402.8±11.2), LWPP group (227.6±9.5), polyester mesh group (320.1± 12.7). There are statistical differences in the number of macrophages between LWPP group (227.6±9.5) and HWPP group (402.8±11.2). Comparison between LWPP group (227.6±9.5) and polyester mesh group (320.1±12.7) in the number of macrophages showed significant differences. No statistical differences were detected between HWPP group (319.5±14.3) and polyester mesh group(320.1±12.7) in the number of macrophages (P=0.914); The number of lymphocytes:HWPP group(199.3±9.2), LWPP group(150.7±7.7) and polyester mesh group (208.5±10.7). There were significant differences in the number of lymphocytes among the three groups, the number of lymphocytes in polyester mesh group> HWPP group> LWPP group.1.1.1.2Four weeks after surgery:The number of inflammatory cells:HWPP group(459.4±21.5), LWPP (354.0±11.2)and polyester mesh (496.3±27.8). The number of inflammatory cells among the three groups showed significant differences, the number of inflammatory in polyester mesh group> HWPP group> LWPP group; The number of macrophages:HWPP group (225.1±14.6), the LWPP group (174.7±6.3) and polyester mesh (248.3±10.9). Significant differences were detected in the number of macrophages among the three groups, the number of macrophage in polyester mesh group> HWPP group> LWPP group; The number of lymphocytes:HWPP group (230.8±8.0), LWPP group(199.7±13.8) and polyester mesh group (235.2±7.3). There are statistical differences in the number of lymphocytes between LWPP group (199.7±13.8) and HWPP group (230.8±8.0) as well as with polyester mesh group (235.2±7.3), but no significant statistical differences were detected between HWPP group (238.8±8.0) and polyester mesh group (235.2±7.3), P=0.434.1.1.1.3Twelve weeks after surgery:The number of inflammatory cells:HWPP group (403.6±18.9), the LWPP group (293.8±17.9)and polyester mesh group (440.8±22.3). There were significant differences in the total number of inflammatory cells among the three groups, the number of inflammatory in polyester mesh group HWPP group> LWPP group; The number of macrophages:HWPP group (227.2±13.8), LWPP (156.4±8.2), polyester mesh(227.1±12.5). There are statistical differences in the number of macrophages between LWPP group and HWPP group as well as polyester mesh (227.1±12.5), but no statistical differences were detected between the HWPP group (227.2±13.8) and polyester mesh (227.1±12.5), P=0.985; The number of lymphocytes:HWPP group (165.1±10.1), LWPP group (123.8±6.8)and polyester mesh group (147.2±9.8). There were significant differences in the number of lymphocytes among the three groups, the number of lymphocytes in HWPP group> polyester mesh group> LWPP group.1.1.2The results of the foreign body reaction for the same kind of meshes in the body at different time points1.1.2.1Inflammatory response of the lightweight polypropylene at different times:The number of inflammatory cells:one week point (402.8±11.2), four weeks point (354.0±11.2) and twelve weeks point (293.8±17.9). The number of inflammatory cells showed significant differences at any of the three time points, the number of inflammatory at one week point> four weeks point> twelve weeks point; The number of macrophages:one week point(227.6±9.5), four weeks point(174.7±6.3) and twelve weeks point(156.4±8.2). There are statistical differences in the number of macrophages at any of the three time points, the number of macrophages at one week point> four weeks point> twelve weeks point; The number of lymphocytes:one week point (150.7±7.7), four weeks point (199.7±13.8) and twelve weeks point (123.8±6.8). It showed significant differences in the number of lymphocytes at any of the three time points, the number of lymphocytes at four weeks point> one week point> twelve weeks point.1.1.2.2Inflammatory response of the heavyweight polypropylene at different time points:The number of inflammatory cells:one week point (512.2±23.8), four weeks point (459.4±21.5) and twelve weeks point (403.6±18.9). There were significant differences in the total number of inflammatory cells at any of the three time points, the number of inflammatory at one week point> four weeks point> twelve weeks point; The number of macrophages:one week point (319.5±14.3), four weeks point (225.1±14.6), twelve weeks point (227.2±13.8). It showed significant statistical differences in the number of macrophages between one week point (319.5±14.3) and four weeks point (225.1±14.6) as well as with the twelve weeks point (227.2±13.8), the number of macrophages at one week point> four weeks point and twelve weeks point; The number of lymphocyte:one week point (199.3±9.2), four weeks point (238.8±8.0) and twelve weeks point (165.1±10.1). It showed significant statistical differences in the number of lymphocytes at any of the three time points, the number of lymphocytes at four weeks point> one week point> twelve weeks point.1.1.2.3Inflammatory response of the polyester mesh at different time points:The number of inflammatory cells:one week point (532.7±27.8), four weeks point (496.3±27.8) and twelve weeks point (440.8±22.3). There were significant differences in the total number of inflammatory cells at any of the three time points, the number of inflammatory cells at one week point> four weeks point> twelve weeks point; The number of macrophages:one week point (320.1±12.7), four weeks point (248.3±10.9) and twelve weeks point (227.1±12.5). It showed significant statistical differences in the number of macrophages at any of the three time points, the number of macrophages at one week point> four weeks point> twelve weeks point; The number of lymphocytes:one week point (208.5±10.7), four weeks point(235.2±7.3) and twelve weeks point (147.2±9.8). There were significant differences in the number of lymphocyte at any of the three time points, the number of lymphocytes at four weeks point>one week point>the twelve weeks point.1.2The results of mesh shrinkage rates in the body Shrinkage rate=[(original size-present size)/original size] X100%1.2.1The comparison results of the shrinkage rates for the same kind of meshes in the body at the different time points 1.2.1.1No statistical differences in shrinkage were detected of the HWPP group at one week point[(0.7+0.2)%],P=0.056, but there are statistical differences in shrinkage rates at four weeks point [(4.0±0.3)%] and twelve weeks [(14.8±2.2)%],P4w=0.000,P12w=0.000.1.2.1.2It showed no statistical differences in shrinkage rates of the LWPP group at one week point [(0.2±0.2)%;P=0.099], but there are significant statistical differences in shrinkage rates at four weeks point [(3.0±0.6)%] and twelve weeks point [(5.7±1.6)%],P4w=0.000,P12w=0.001.1.2.1.3No significant statistical differences in shrinkage rates were detected of polyester mesh group at one week point [(1.3±1.3)%;P=0.084], but there are significant statistical differences in shrinkage rates at four weeks point [(3.2±0.5)%] and twelve weeks points [(6.4±0.7)%],P4w=0.000, P12w=0.000.1.2.2The comparison results of the shrinkage rates for the different kinds of meshes in the body at the same time point1.2.2.1There are no statistical differences of mesh shrinkage rates at one week among the three kinds of meshes [(0.7±0.2)%vs.(0.2±0.2)%vs.(1.3±1.3)%;P=0.092].1.2.2.2At four weeks point, it showed significant statistical differences in mesh shrinkage rate between HWPP group [(4.0±0.3)%] and LWPP group [(3.0±0.6)%],P=0.007, as well as with polyester mesh group [(3.2±0.5)%], P=0.034, but there are no statistical differences between LWPP group [(3.0±0.6)%] and polyester mesh group [(3.2±0.5)%],P=0.429.1.2.2.3At twelve weeks point, it showed significant statistical differences in mesh shrinkage rate between HWPP group [(14.8±2.2)%] and LWPP group [(5.7±1.6)%],P=0.000, as well as with polyester mesh group [(6.4±0.7)%], P=0.000; but no significant statistical differences between LWPP group [(5.7±1.6)%] and polyester mesh group [(6.4±0.7)%],P=0.51.Conclusion:1The foreign body reaction caused by polyester mesh is the most serious, HWPP group takes the second place, and LWPP group is minimal.2The meshes in this experiment among the all groups show significant shrinkage at four weeks point, the shrinkage rates of twelve weeks point are higher than that of four weeks point; the shrinkage of heavyweight polypropylene mesh is the most serious, polyester mesh takes the second place, and lightweight polypropylene mesh is the minimal. |
PDF Full Text Request