Klinge U, Klosterhalfen B, Müller M, Anurov M, Ottinger A, Schumpelick V
The Department of Surgery, IZKF-BIOMAT, The Technical University of Aachen, Germany.
Biomaterials. 1999 Apr;20(7):613-23. doi: 10.1016/s0142-9612(98)00211-7.
Regarding oversized mechanical properties of most of the currently available materials a new mesh was developed (ETHICON, Norderstedt, Germany) and exactly adopted to the physiology of the human abdominal wall by reducing the amount of polypropylene (weight of <30 g/m2; mesh A). The consecutive increase of pores size as well as the use of multifilaments led to a pronounced increase of flexibility. To improve the handling during operation the initial stiffness of this low-weight large pores mesh was increased by strengthening with different amounts of absorbable polyglactin (combination of glycolide and lactide) in various forms: by coating (mesh B), adding multifilament polyglactin filaments (mesh C, Vypro) or both (mesh D), respectively. To test the consequences of the different supplementary techniques all mesh variants are implanted in a rat model. Over implantation intervals of 3, 7, 14, 21 and 90 days we measured the tensile strength, the resulting stiffness and surveyed the tissue response, particularly in regard to the extent of inflammation and to the induced fibrosis. The results proved a sufficient mechanical stability of the material reduced and pure polypropylene mesh A without restriction of the mobility of the abdominal wall compared with a group that had simple laparotomy and closure. The histological analysis of the interface showed a minor inflammatory reaction and a dense vascularisation. The addition of polyglactin multifilaments (mesh C) reduces the number of macrophages and granulocytes as indicators for acute inflammation, showing generally a scar formation limited merely to the perifilamentary region. The abdominal wall compliance remained unchanged compared with mesh A. The coating of the polypropylene with polyglactin (mesh B and D) appeared to change the tissue reaction remarkably, favouring the formation of a connective tissue capsule around the whole mesh. The mechanical testing revealed an apparent protrusion with an increase of curvature of the artificial abdominal wall at rising intraabdominal pressures. The entire coating of the polypropylene surface with polyglactin induces an all embedding scar plate, filling out the pores and forming a tissue capsule. The complex interaction of tissue and implanted biomaterials with their distinct alterations of the tissue response confirms the necessity of in vivo experiments even after 'minor' modifications. Whereas the addition of polyglactin filaments appears to be favourable, the coating of polypropylene with polyglactin seems to hinder the incorporation of the mesh.
针对目前大多数可用材料过大的机械性能，开发了一种新的网片（德国诺德施泰特的爱惜康公司），通过减少聚丙烯用量（重量<30 g/m²；网片A）使其完全适应人体腹壁的生理特性。孔隙尺寸的连续增加以及复丝的使用导致柔韧性显著提高。为了改善手术过程中的操作性能，通过以不同形式添加不同量的可吸收聚乙交酯丙交酯（乙交酯和丙交酯的组合）来增强这种低重量大孔隙网片的初始刚度：分别通过涂层（网片B）、添加复丝聚乙交酯丙交酯丝（网片C，Vypro）或两者兼用（网片D）。为了测试不同补充技术的效果，将所有网片变体植入大鼠模型。在3、7、14、21和90天的植入间隔期内，我们测量了拉伸强度、产生的刚度，并观察了组织反应，特别是炎症程度和诱导的纤维化情况。结果证明，与单纯开腹和缝合的组相比，减少了的纯聚丙烯网片A具有足够的机械稳定性，且不限制腹壁的活动度。界面的组织学分析显示炎症反应轻微且血管化密集。添加聚乙交酯丙交酯复丝（网片C）减少了作为急性炎症指标的巨噬细胞和粒细胞数量，总体显示仅在丝周区域形成有限的瘢痕。与网片A相比，腹壁顺应性保持不变。用聚乙交酯丙交酯对聚丙烯进行涂层（网片B和D）似乎显著改变了组织反应，有利于在整个网片周围形成结缔组织包膜。力学测试显示，随着腹腔内压力升高，人工腹壁的曲率增加，出现明显的突出。用聚乙交酯丙交酯对聚丙烯表面进行全涂层会诱导形成一个完全包埋的瘢痕板，填充孔隙并形成组织包膜。组织与植入生物材料之间复杂的相互作用以及它们对组织反应的明显改变证实，即使是“微小”的修改后进行体内实验也是必要的。虽然添加聚乙交酯丙交酯丝似乎是有利的，但用聚乙交酯丙交酯对聚丙烯进行涂层似乎会阻碍网片的植入。
