Influence of Needle Insertion Speed on Backflow for Convection-Enhanced Delivery
Influence of Needle Insertion Speed on Backflow for Convection-Enhanced Delivery
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DOI：
10.1115/1.4006404
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发表时间：
2012-04-01
影响因子：
1.7
通讯作者：
Sarntinoranont, Malisa
中科院分区：
文献类型：
--
作者：
Casanova, Fernando;Carney, Paul R.;Sarntinoranont, Malisa
在将药物直接输注到脑组织中以用于诸如对流增强递送（CED）的过程期间，流体沿针的外表面沿着回流（回流）可能是一个显著的问题。本研究评价了针头插入速度（0.2和1.8 mm/s）以及针头直径和流速对回流程度和周围组织局部损伤的影响。在透明组织体模（0.6%（w/v）琼脂糖水凝胶）上进行输注实验，以观察回流。还进行了针插入实验，以评估针尖处的局部损伤，并在局部损伤不太严重的速度条件下收回周围介质中的预应力。预应力值，然后用于回流的分析模型。在较高的插入速度（1.8 mm/s）下，发现局部插入损伤减少，回流减少。针头-组织界面处的压缩预应力估计大致恒定（0.812 kPa），无论针头规格（22、26和32号）如何，回流距离均相似。分析模型低估了低输注流速下的回流距离，高估了较高流速下的回流。在较低的插入速度（0.2 mm/s）下，测量到显著的回流。这对应于观察到的针尖处的材料积聚，其在针和周围介质之间产生间隙。还在切除的大鼠脑组织中评价了局部组织损伤，并且插入测试显示在较低插入速度下针尖处的组织的类似速率依赖性累积。这些结果表明，通过使用适当的插入速度可以避免局部组织损伤和回流。[DOI电话：10.1115/1.4006404]
Fluid flow back along the outer surface of a needle (backflow) can be a significant problem during the direct infusion of drugs into brain tissues for procedures such as convection-enhanced delivery (CED). This study evaluates the effects of needle insertion speed (0.2 and 1.8 mm/s) as well as needle diameter and flow rate on the extent of backflow and local damage to surrounding tissues. Infusion experiments were conducted on a transparent tissue phantom, 0.6% (w/v) agarose hydrogel, to visualize backflow. Needle insertion experiments were also performed to evaluate local damage at the needle tip and to back out the prestress in the surrounding media for speed conditions where localized damage was not excessive. Prestress values were then used in an analytical model of backflow. At the higher insertion speed (1.8 mm/s), local insertion damage was found to be reduced and backflow was decreased. The compressive prestress at the needle-tissue interface was estimated to be approximately constant (0.812 kPa), and backflow distances were similar regardless of needle gauge (22, 26, and 32 gauge). The analytical model underestimated backflow distances at low infusion flow rates and overestimated backflow at higher flow rates. At the lower insertion speed (0.2 mm/s), significant backflow was measured. This corresponded to an observed accumulation of material at the needle tip which produced a gap between the needle and the surrounding media. Local tissue damage was also evaluated in excised rat brain tissues, and insertion tests show similar rate-dependent accumulation of tissue at the needle tip at the lower insertion speed. These results indicate that local tissue damage and backflow may be avoided by using an appropriate insertion speed. [DOI: 10.1115/1.4006404]