心血管介入器械检测要点

结论：模拟路径的试验最能反映实际使用中的问题

心血管介入器械（导管、导丝、支架系统、球囊）的共同特点是：经血管路径从穿刺点送到治疗部位，途中要通过迂曲的血管、狭窄的部位、以及各种角度的分支。

这个过程中的问题——推送困难、器械变形、涂层脱落、断裂——在静态的台架试验中往往看不出来。

所以模拟血管路径的试验是这类产品检测的核心。 用模拟实际解剖结构的模型，让器械按实际方式通过，观察通过性、操控性、以及器械的完整性。

项目的组织

模拟路径试验的设计

路径模型。 模拟目标血管的解剖结构，包括弯曲半径、分支角度、直径变化。

介质与温度。 模拟血液的介质、体温条件。润滑涂层的性能与介质和温度强相关，干态或常温的测试不能代表实际。

操作方式。 按实际的临床操作方式推送、旋转、回撤。

评价内容。 推送力、跟踪性、操控性（扭矩传递）、以及通过后的器械状态。

反复通过。 模拟实际中可能的多次进出。

配合使用。 导管、导丝、鞘管的配合，实际使用中它们是组合使用的。

「配合使用的试验」比单件试验更贴近实际。 导丝在导管内的通过性、球囊在鞘内的通过性，这些配合关系是临床操作的实际情形。

表面与涂层的考察

很多介入器械有润滑涂层，涂层的考察是重点：

润滑性能。 涂层带来的摩擦力降低程度。

润滑的持久性。 反复通过后润滑性能是否保持。

涂层完整性。 通过模拟路径后涂层是否完好。

微粒释放。 涂层脱落产生的微粒，这是血管内的异物，可能造成栓塞。

涂层的结合强度。 涂层与基体的结合。

「微粒释放」是这类产品的关键安全项。 涂层在通过迂曲路径时受摩擦和剪切，可能剥落形成微粒。应当在模拟路径通过后收集介质并分析微粒的数量和尺寸。

力学性能的考察

拉伸强度。 各连接部位的抗拉，特别是接头处。

扭转。 扭矩传递能力和抗扭断裂。

抗折。 弯曲时是否折弯或塌陷，折弯会导致管腔堵塞。

爆破压。 有腔器械的耐压能力。

球囊相关。 额定爆破压、顺应性、疲劳（反复充放）。

回撤力。 球囊或器械回撤时的阻力。

「接头处的抗拉」是常见的失效位置，因为接头是不同材料或不同结构的过渡，应力在此集中。

血液相容性的考察

与血液接触的器械，相关的评价项目包括：

溶血。 对红细胞的破坏。

凝血相关。 对凝血系统的影响。

血小板相关。 血小板的黏附和活化。

补体激活。 免疫系统的反应。

血栓形成。 器械表面的血栓倾向。

试样应当是最终状态 ——含涂层、经过灭菌。未经处理的基材测出的结果不代表实际产品。

显影性的考察

介入器械需要在影像下可见：

显影标记。 标记的位置和可见度。

器械本体的显影。 部分器械本体需要可见。

在不同厚度组织下的可见度。

标记的牢固性。 显影标记不应脱落。

「标记的牢固性」与微粒释放相关，脱落的标记是血管内的异物。

无菌与包装

灭菌方式。 与材料和涂层的相容性。某些灭菌方式可能影响涂层性能。

灭菌后的性能。 涂层润滑性、力学性能在灭菌后是否保持。

包装。 保护器械形状（很多介入器械是盘绕包装）、无菌屏障。

有效期。 涂层和材料的长期稳定性。

「灭菌对涂层的影响」需要专门验证，因为涂层是这类产品的关键性能，而某些灭菌方式可能使涂层降解或改变润滑性。

送检准备的建议

提供配套器械。 导丝、鞘管等配合使用的部件。

说明适用的血管路径。 影响模拟模型的设计。

提供操作说明。 按实际操作方式测试。

提供涂层信息。 涂层的类型和位置。

准备足够样品。 模拟路径试验和破坏性试验消耗较多。

说明配合的其他产品。 与哪些产品组合使用。

特定功能的验证

不同类型的介入器械有各自的功能项：

球囊导管。 扩张性能、顺应性曲线、额定爆破压、反复扩张的耐久、回缩后的外形（便于回撤）。

支架系统。 释放的可靠性、释放后的支架形态、径向支撑力、回缩率、再通过性。

导丝。 头端柔软度、支撑力、塑形保持、扭矩传递。

导引导管。 支撑力、内腔通过性、头端柔软度。

抽吸类器械。 抽吸效率、堵塞时的表现。

「支架释放的可靠性」是关键项，释放不完全或位置偏差在临床中都是严重问题，应当在模拟路径的远端位置做释放试验，而不只在直管中释放。

与配合产品的兼容

介入操作是多个器械配合的，兼容性要验证：导丝与导管内腔的配合；球囊与导引导管的通过；支架系统与鞘管的配合；以及各接头的通用性。

兼容范围应当在资料中明确，说明可以与哪些规格的产品配合使用。

我们的做法

承接介入器械委托时，我们建议模拟路径试验在模拟血液介质和体温条件下进行，因为润滑涂层的性能对介质和温度很敏感，干态常温的数据偏乐观。

微粒释放是我们建议必做的项目，在模拟路径通过后收集介质分析微粒 ——这一项对应的是血管内异物的实际风险。

另外，灭菌前后的涂层性能对比我们也建议做，确认灭菌过程没有影响涂层的关键性能。

如果你有介入类产品需要安排检测，想先理清项目和模拟路径的设计，可以把产品资料和适用路径发过来一起讨论，或者直接联系：132 4819 8029。能力范围见服务介绍，送检要求见送检要求，流程见检测流程。

English version

Conclusion. Cardiovascular interventional devices, including catheters, guidewires, stent systems and balloons, share the characteristic of travelling from a puncture site through the vasculature to a treatment site, passing tortuous vessels, narrowed segments and branches at various angles. Problems arising in that passage, including difficult advancement, device deformation, coating detachment and fracture, often do not appear in static bench testing. Simulated pathway testing is therefore central for these products: using models reproducing the actual anatomy, the device is passed as it would be clinically, and trackability, handling and device integrity are observed.

Organising the items. Dimensions cover outer and inner diameter, length and usable length. Mechanical items cover tensile, torsional and kink resistance and burst pressure. Trackability covers advancement and tracking through a simulated pathway. Surfaces and coatings cover lubricity, coating integrity and particulates. Blood contact covers haemocompatibility. Biocompatibility covers the other material endpoints. Sterility covers sterilisation validation and sterility testing. Packaging covers barrier, integrity and shelf life. And specific functions cover balloon inflation, stent deployment and the like.

Designing simulated pathway testing. The pathway model should reproduce the target vasculature's anatomy, including bend radii, branch angles and diameter transitions. Medium and temperature should simulate blood at body temperature, since lubricious coating performance depends strongly on medium and temperature and dry or ambient testing does not represent reality. Manipulation should follow actual clinical technique in advancement, rotation and withdrawal. Evaluation covers push force, trackability, handling as torque transmission, and device condition afterwards. Repeated passage should simulate the multiple insertions that may occur. And combined use should reflect that catheters, guidewires and sheaths are used together clinically. Testing in combination is closer to reality than testing components alone: guidewire passage within a catheter and balloon passage within a sheath are the actual clinical situations.

Examining surfaces and coatings. Many interventional devices carry lubricious coatings, and their examination is a focus. Lubricity covers the reduction in friction the coating provides. Durability of lubricity covers whether it is retained after repeated passage. Coating integrity covers its condition after passing the simulated pathway. Particulate release covers particles generated by coating detachment, which are foreign bodies within the vasculature and may cause embolism. And coating bond strength covers adhesion to the substrate. Particulate release is the critical safety item for these products: coatings experience friction and shear when passing tortuous pathways and may shed. Collect the medium after simulated pathway passage and analyse particle number and size.

Mechanical examination. Tensile strength covers each joint, particularly hub connections. Torsion covers torque transmission and torsional failure. Kink resistance covers whether the device kinks or collapses when bent, since kinking occludes the lumen. Burst pressure covers pressure resistance of lumened devices. Balloon items cover rated burst pressure, compliance and fatigue through repeated inflation. And withdrawal force covers resistance during retraction. Joint tensile strength is a common failure location, since joints are transitions between materials or constructions where stress concentrates.

Haemocompatibility. For blood-contacting devices, evaluation covers haemolysis, meaning damage to red cells; coagulation effects on the clotting system; platelet adhesion and activation; complement activation as an immune response; and thrombogenicity, meaning the surface's tendency to form thrombus. Specimens must be in final condition, with coatings applied and sterilised: results from untreated substrate do not represent the actual product.

Radiopacity. Interventional devices must be visible under imaging. Radiopaque markers require appropriate position and visibility. Device body radiopacity is needed for some devices. Visibility must be assessed through different tissue thicknesses. And marker security matters, since markers must not detach. Marker security relates to particulate release, a detached marker being a foreign body within the vasculature.

Sterility and packaging. The sterilisation method must be compatible with materials and coatings, since some methods affect coating performance. Post-sterilisation performance covers retention of coating lubricity and mechanical properties. Packaging must protect the device's shape, many interventional devices being coiled, and provide a sterile barrier. And shelf life covers the long-term stability of coatings and materials. The effect of sterilisation on coatings needs specific verification, since coatings are these products' key performance and some methods may degrade them or alter lubricity.

Preparing for submission. Provide the accompanying devices including guidewires and sheaths used together. Describe the intended vascular pathway, which informs the model design. Provide operating instructions so that testing follows actual technique. Provide coating information covering type and location. Prepare enough samples, since pathway and destructive testing consume a good number. And describe other products used in combination.

How we handle it. For interventional devices we suggest conducting simulated pathway testing in a blood-simulating medium at body temperature, since lubricious coating performance is sensitive to both and dry ambient data read optimistically. Particulate release is an item we suggest always including, collecting and analysing the medium after pathway passage, since it addresses the real risk of intravascular foreign bodies. We also suggest comparing coating performance before and after sterilisation to confirm that the process has not affected key properties.

Send us the product documentation and intended pathway and we will work through the items and model design. Phone or WeChat: +86 132 4819 8029.