Background

In palliated single ventricle patients aortopulmonary collateralization is a cause for significant loss of cardiovascular efficiency. In larger vessels, device occlusion becomes an alternative to embolization with multiple coils. The physical characteristics of the Amplatzer ™ Vascular Plug Type IV (AVPIV) are potentially conducive to oversizing the device allowing coverage of a longer portion of vessel. Despite the widespread use of the AVPIV, little published data exists describing the behavior of the device as it is constrained in different vessel sizes.

Methods

4–8 mm AVPIV devices were measured in glass tubing in diameters ranging from 1 to 8 mm internal diameter. Radial force was measured by constraining the devices to the desire diameters from 1 to 7 mm and measuring the force the device exerted to one of the constraining walls. This force vs. diameter relationship was evaluated for each device and compared across different devices.

Results

The devices range in length from 12.36 to 31.24 mm. The 4 mm device lengthened 3.44 mm from unconstrained to 1 mm diameter (12.36 to 15.80 mm), while the 8 mm AVP IV lengthened 14.74 mm from unconstrained to 1 mm diameter constraint (16.50–31.24 mm, 89% lengthening). The highest overall radial force (1.38 N), radial force at 50% compression (1.25 N), and average stiffness (0.95 N/mm) was found in the 5 mm diameter device.

Conclusions

The AVP IV device has a reliable length for diameter relationship. A counterintuitive property of the AVP IV with regards to radial force for device size was found. The 5 mm AVPIV was found to exert the highest radial force and stiffness compared to the other devices. The 7 and 8 mm AVPIV devices were consistently found to exert less radial force. This property suggests that oversizing an AVP IV could be safe and effective, potentially decreasing total devices used, cost, and overall procedure time.

中文翻译：

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IV型Amplatzer™血管塞的长度与直径的关系和径向力特性：尺寸过大的观察结果。

背景

在苍白的单心室患者中，肺上支配位是严重降低心血管效率的原因。在较大的血管中，装置闭塞成为多个线圈栓塞的替代方法。IV型Amplatzer™血管塞（AVPIV）的物理特性可能会导致设备尺寸过大，从而覆盖较长的血管。尽管AVPIV的广泛使用，但很少有公开的数据描述设备的行为，因为它受不同血管大小的限制。

方法

在玻璃管中测量了4–8 mm AVPIV设备，其内径范围为1至8 mm。通过将装置约束到1至7 mm的所需直径并测量装置施加到约束壁之一上的力来测量径向力。对每个设备评估了力与直径的关系，并在不同设备之间进行了比较。

结果

该设备的长度范围从12.36到31.24 mm。4毫米设备的直径从不受限制的长度增加了3.44毫米（12.36到15.80毫米），而8毫米AVP IV的直径从不受限制的长度增加了14.74毫米到1毫米（16.50-31.24毫米，增加了89％）。在直径为5 mm的装置中发现最高的总径向力（1.38 N），50％压缩时的径向力（1.25 N）和平均刚度（0.95 N / mm）。

结论

AVP IV装置具有可靠的长度以适应直径关系。发现AVP IV相对于装置尺寸的径向力有违反直觉的特性。与其他设备相比，发现5毫米AVPIV具有最大的径向力和刚度。始终发现7和8毫米AVPIV装置施加的径向力较小。此属性表明，过大的AVP IV可能是安全有效的，可能会减少使用的设备总数，成本和整个过程时间。