An all titanium transcutaneous access device (TAD) for peritoneal dialysis

描述（由申请人提供）：腹膜透析（PD）和新兴医学治疗需要慢性经皮通路。由于经皮装置破坏了皮肤，而皮肤是细菌进入的正常屏障，因此长期感染是一个重大问题。该项目的目的是设计和测试一种全钛经皮通路装置（TAD），它将比现有的PD导管更能抵抗出口部位感染。该装置采用微孔金属钛（MTM）在出口部位获得稳定的上皮连接，抑制细菌进入，并有助于改善出口部位的卫生。MTM是一种应用于软组织的新型材料。多孔金属表面提供了一个复杂的三维矩阵，其内部几何形状是完全可调的。结缔组织增生进入多孔金属形成物理屏障，防止细菌进入，也限制上皮向下生长，导致窦道形成。初步研究表明，与传统PD导管上使用的聚合物纤维表面相比，这种材料引起的异物反应最小，几乎没有炎症。异物巨细胞未在材料附近发现，材料被包裹在一层薄的胶原组织胶囊中，其与材料的附着超过了组织的抗拉强度。这些特性使这种材料独特地适合于这种应用。在第一阶段，我们将设计、构建和测试全钛TAD，并在为期8周的研究中使用成年绵羊动物模型对其进行评估，并使用Tenckhoff PD导管作为对照。我们将描述出口部位的愈合情况，并采用细菌挑战测试来比较新设备与传统PD导管防止细菌进入的能力。慢性经皮通路是腹膜透析和新出现的医学治疗所必需的。由于经皮装置穿过皮肤，细菌进入的正常屏障，长时间的退出部位感染是一个重大问题。该计划的目的是设计和测试一种全钛经皮接入装置（TAD），旨在抵抗感染并提供稳定的皮肤界面。

DESCRIPTION (provided by applicant): Chronic transcutaneous access is needed for peritoneal dialysis (PD) and new emerging medical therapies. Since a transcutaneous device breeches the skin, the normal barrier to bacterial entry, infection is a significant problem over long periods. The objective of this program is the design and testing of an all-titanium transcutaneous access device (TAD) that will be significantly more resistant to exit site infection than existing PD catheters. The device employs microporous titanium metal (MTM) to obtain a stable epithelial junction at the exit site, inhibit bacterial entry, and facilitate improved exit site hygiene. MTM is a new material for soft tissue applications. The porous metal surface provides a complicated three-dimensional matrix whose internal geometry is fully adjustable. Connective tissue proliferation into the porous metal creates a physical barrier to prevent bacterial entry, and it also limits epithelial down-growth that can lead to sinus tract formation. In preliminary studies, it has been shown that this material provokes a minimal foreign body response with virtually no inflammation in comparison to polymer fiber surfaces used on conventional PD catheters. Foreign body giant cells are not found adjacent to the material, which is encapsulated in a thin, collagenous tissue capsule whose attachment to the material exceeds the tensile strength of the tissue. These are characteristics that make the material uniquely suitable for this application. In Phase I, we will design, build, and test the all-titanium TAD and evaluate it using an adult sheep animal model in studies of 8 week duration using Tenckhoff PD catheters as a control. We will characterize healing at the exit site, and a bacterial challenge test will be employed to compare the ability of the new device to prevent bacterial entry versus a conventional PD catheter. Chronic transcutaneous access is needed for peritoneal dialysis and new emerging medical therapies. As a transcutaneous device breeches the skin, the normal barrier to bacterial entry, exit site infection is a significant problem over long periods. The objective of this program is the design and testing of an all- titanium transcutaneous access device (TAD) designed to be resistant to infection and provide a stable skin interface.