Larena-Avellaneda A, Dittmann G, Haacke C, Graunke F, Siegel R, Dietz U A, Debus E S
Department of Surgery I, University of Würzburg, Medical School, Würzburg, Germany.
Ann Vasc Surg. 2008 Jan;22(1):106-14. doi: 10.1016/j.avsg.2007.09.003.
We introduce a silicone-based vascular prosthesis that may be optimized in various ways. The current work describes the theoretical background, the fabrication process, and the mechanical properties of these new prostheses, allowing objectification and comparison of materials used in vascular surgery. A production process to coat polyester prostheses with silicone-rubber (polydimethylsiloxane, PDMS) was established. Further modifications (surface improvements, drug incorporation for release) can be performed wet-chemically. Measurement of the physical properties included longitudinal and circumferential stability and elasticity, suture retention strength and puncture resistance (tensile testing machine), permeability, and compliance (circulation model). Prostheses can be multiply coated with PDMS. Sufficiently low levels of permeability (<5 mL/cm(2)/min at 120 mm Hg) were achieved with a PDMS content >15 mg/cm(2). Considering stability, elasticity, and compliance, prostheses with a silicone-rubber content of 15-20 mg/cm(2) are comparable to conventional, primarily tight prostheses. Coating with PDMS decreases suture retention strength and puncture resistance compared to conventional alloplastic materials (collagen-coated polyester and expanded polytetrafluorethylene) materials. The silicone coating surrounds the passing threads ("self-sealing surface") and is resistant to clamping trauma. The complete measurement procedures described here allow for a comparison of new materials with conventional ones and allow the handling characteristics of implants to be objectified. The primarily tight, silicone-coated prostheses can be compared to conventional bovine-coated materials without drawbacks regarding physical properties.
我们介绍了一种可通过多种方式进行优化的硅基血管假体。当前的工作描述了这些新型假体的理论背景、制造工艺和机械性能，从而能够对血管手术中使用的材料进行客观化和比较。建立了一种用硅橡胶（聚二甲基硅氧烷，PDMS）涂覆聚酯假体的生产工艺。进一步的改性（表面改进、药物包埋以实现释放）可以通过湿化学方法进行。物理性能的测量包括纵向和周向稳定性及弹性、缝线保留强度和抗穿刺性（拉伸试验机）、渗透性和顺应性（循环模型）。假体可以多次涂覆PDMS。当PDMS含量>15 mg/cm²时，可实现足够低的渗透率水平（在120 mmHg下<5 mL/cm²/min）。考虑到稳定性、弹性和顺应性，硅橡胶含量为15 - 20 mg/cm²的假体与传统的、主要是紧密型的假体相当。与传统的异质材料（胶原涂覆的聚酯和膨体聚四氟乙烯）相比，涂覆PDMS会降低缝线保留强度和抗穿刺性。硅涂层环绕穿过的缝线（“自密封表面”），并且耐夹紧损伤。这里描述的完整测量程序允许将新材料与传统材料进行比较，并使植入物的操作特性得以客观化。主要是紧密型的硅涂层假体可以与传统的牛心包材料进行比较，在物理性能方面没有缺点。
