Madhavan Rajesh Kumar, Faryami Ahmad, Tappen Nathan, Gopalakrishnan Pranav, Ajaz Shaheer H, Harris Carolyn A
Department of Biological Sciences, Wayne State University, Detroit, MI, United States.
Department of Biomedical Engineering, Wayne State University, Detroit, MI, United States.
Front Bioeng Biotechnol. 2025 Jan 29;12:1519499. doi: 10.3389/fbioe.2024.1519499. eCollection 2024.
Although many ventricular catheter designs exist for hydrocephalus treatment, few standardized studies assess outflow resistance and the impact of design modifications on shunt drainage. This study represents the assessment of various architectural modifications on catheter flow rate and pressure, focusing on bulk outflow dynamics and occlusion with whole blood-inoculated cerebrospinal fluid.
Catheters were manufactured utilizing a novel catheter production setup with 16 variations from standard catheters, including but not limited to changes in: hole number, hole dimensions, catheter lumen dimension, and catheter lumen impingement. These catheters were tested in a portable custom-made ventricular catheter testing device to analyze relative resistance to flow between catheter designs. A subset of catheters with varying lumen diameters was tested in 0.30 mL/min saline flow with 2.5% blood to simulate early blood exposure.
With increasing hole and lumen diameter, we found a significant decrease in overall catheter relative resistance using DIH0 ( < 0.001 and P < 0.002 respectively, n = 5). With increasing lumen diameters, blood assays showed a significant increase in the time to complete obstruction ( = 0.027, n = 5). Lumen impingement, representing one obstruction-based pinch point in the lumen, showed a considerable increase in relative resistance as obstruction diameter increased and lumen diameter at the pinch point decreased ( = 0.001, n = 5). Removal of specific catheter hole rows trended toward an increase relative resistance after 75% of catheter holes were blocked, but the effect in relative outflow resistance is otherwise minimal ( > 0.05, n = 5) and no effect was observed with blocking segments.
This study implemented a novel method of rapid catheter manufacturing to systematically produce ventricular catheters with specific catheter architecture. By testing variables independently, we found that catheters with changes to the lumen diameter had the most dramatic shifts in overall relative resistance between catheter designs. Similarly, testing in the acute blood assay demonstrated that smaller diameter catheters have a higher propensity to obstruct with blood compared to catheters with larger diameter. Relative resistance impacts fluid outflow efficiency, which may translate to clinical outcomes for hydrocephalus patients. These findings help us understand catheter architectural effects on resistance and inform future designs for specific ventricle morphologies.
尽管存在多种用于脑积水治疗的脑室导管设计，但很少有标准化研究评估流出阻力以及设计修改对分流引流的影响。本研究旨在评估各种结构修改对导管流速和压力的影响，重点关注整体流出动力学以及全血接种脑脊液导致的堵塞情况。
利用一种新型导管生产装置制造导管，与标准导管相比有16种变体，包括但不限于以下方面的变化：孔数、孔尺寸、导管内腔尺寸以及导管内腔冲击。这些导管在便携式定制脑室导管测试装置中进行测试，以分析不同导管设计之间的相对流动阻力。对一组具有不同内腔直径的导管，在流速为0.30 mL/min的含2.5%血液的盐水中进行测试，以模拟早期血液接触情况。
随着孔直径和内腔直径的增加，我们发现使用DIH0时，导管总体相对阻力显著降低（分别为<0.001和P<0.002，n = 5）。随着内腔直径的增加，血液检测显示完全堵塞的时间显著增加（= 0.027，n = 5）。内腔冲击代表内腔中一个基于堵塞的收缩点，随着堵塞直径增加且收缩点处的内腔直径减小，相对阻力显著增加（= 0.001，n = 5）。在75%的导管孔被堵塞后，去除特定的导管孔排，相对阻力有增加趋势，但对相对流出阻力的影响极小（>0.05，n = 5），堵塞节段未观察到影响。
本研究采用了一种新型的快速导管制造方法，系统地生产具有特定导管结构的脑室导管。通过独立测试变量，我们发现内腔直径发生变化的导管在不同导管设计之间的总体相对阻力变化最为显著。同样，在急性血液检测中发现，与较大直径的导管相比，较小直径的导管更容易被血液堵塞。相对阻力会影响液体流出效率，这可能会转化为脑积水患者的临床结果。这些发现有助于我们理解导管结构对阻力的影响，并为未来针对特定脑室形态的设计提供参考。
