Purpose

In vitro patient-specific flexible vascular models are helpful for understanding the haemodynamic changes before and after endovascular treatment and for effective training of neuroendovascular interventionalists. However, it is difficult to fabricate models of overall unified or controllable thickness using existing manufacturing methods. In this study, we developed an improved and easily implemented method by combining 3D printing and brush-spin–coating processes to produce a transparent silicone model of uniform or varied thickness.

Methods

First, a water-soluble inner-skeleton model, based on clinical data, was printed on a 3D printer. The skeleton model was subsequently fixed in a single-axis-rotation machine to enable continuous coating of silicone, the thickness of which was manually controlled by adsorption and removal of excess silicone in a brush-spinning operation. After the silicone layer was solidified, the inner skeleton was further dissolved in a hot water bath, affording a transparent vascular model with real geometry. To verify the controllability of the coating thickness by using this method, a straight tube, an idealised aneurysm model, a patient-specific aortic arch model, and an abdominal aortic aneurysm model were manufactured.

Results

The different thicknesses of the manufactured tubes could be well controlled, with the relative standard deviations being 5.6 and 8.1% for the straight and aneurysm tubes, respectively. Despite of the diameter changing from 33 to 20 mm in the patient-specific aorta, the thickness of the fabricated aortic model remains almost the same along the longitudinal direction with a lower standard deviation of 3.1%. In the more complex patient-specific abdominal aneurysm model, varied thicknesses were realized to mimic the measured data from the CT images, where the middle of the aneurysm was with 2 mm and abdominal aorta as well as the iliac arteries had the normal thickness of 2.3 mm.

Conclusion

Through the brush–spin–coating method, models of different sizes and complexity with prescribed thickness can be manufactured, which will be helpful for developing surgical treatment strategies or training neuroendovascular interventionalists.

中文翻译：

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通过耦合 3D 打印制造体外患者特异性血管模型的刷涂法

目的

体外患者特异性柔性血管模型有助于了解血管内治疗前后的血流动力学变化，有助于神经血管内介入医师的有效培训。然而，使用现有的制造方法很难制造出整体统一或可控厚度的模型。在这项研究中，我们开发了一种改进且易于实施的方法，通过结合 3D 打印和刷旋涂工艺来生产均匀或不同厚度的透明硅胶模型。

方法

首先，基于临床数据的水溶性内骨骼模型被打印在 3D 打印机上。随后将骨架模型固定在单轴旋转机器中，以实现有机硅的连续涂层，其厚度通过在刷旋转操作中吸附和去除多余的有机硅来手动控制。硅胶层固化后，将内骨架进一步溶解在热水浴中，得到具有真实几何形状的透明血管模型。为了验证使用该方法涂层厚度的可控性，制造了直管、理想化的动脉瘤模型、患者特定的主动脉弓模型和腹主动脉瘤模型。

结果

制造的管的不同厚度可以得到很好的控制，直管和动脉瘤管的相对标准偏差分别为5.6%和8.1%。尽管患者特定主动脉的直径从 33 毫米变为 20 毫米，但制造的主动脉模型的厚度沿纵向几乎保持不变，标准偏差较低，为 3.1%。在更复杂的患者特定腹部动脉瘤模型中，实现了不同的厚​​度以模拟来自 CT 图像的测量数据，其中动脉瘤的中部为 2 mm，腹主动脉和髂动脉的正常厚度为 2.3毫米。

结论

通过刷旋涂法，可以制作出不同大小、复杂程度、规定厚度的模型，这将有助于制定手术治疗策略或培训神经血管内介入医生。