Schafer Sebastian, Hoffmann Kenneth R, Noël Peter B, Ionita Ciprian N, Dmochowski Jacek
Department of Mechanical and Aerospace Engineering and Toshiba Stroke Research Center, SUNY at Buffalo, Buffalo, New York 14214, USA.
Med Phys. 2008 May;35(5):1884-92. doi: 10.1118/1.2903430.
The number of minimally invasive vascular interventions is increasing. In these interventions, a variety of devices are directed to and placed at the site of intervention. The device used in almost all of these interventions is the guidewire, acting as a monorail for all devices which are delivered to the intervention site. However, even with the guidewire in place, clinicians still experience difficulties during the interventions. As a first step toward understanding these difficulties and facilitating guidewire and device guidance, we have investigated the reproducibility of the final paths of the guidewire in vessel phantom models on different factors: user, materials and geometry. Three vessel phantoms (vessel diameters approximately 4 mm) were constructed having tortuousity similar to the internal carotid artery from silicon tubing and encased in Sylgard elastomer. Several trained users repeatedly passed two guidewires of different flexibility through the phantoms under pulsatile flow conditions. After the guidewire had been placed, rotational c-arm image sequences were acquired (9 in. II mode, 0.185 mm pixel size), and the phantom and guidewire were reconstructed (512(3), 0.288 mm voxel size). The reconstructed volumes were aligned. The centerlines of the guidewire and the phantom vessel were then determined using region-growing techniques. Guidewire paths appear similar across users but not across materials. The average root mean square difference of the repeated placement was 0.17 +/- 0.02 mm (plastic-coated guidewire), 0.73 +/- 0.55 mm (steel guidewire) and 1.15 +/- 0.65 mm (steel versus plastic-coated). For a given guidewire, these results indicate that the guidewire path is relatively reproducible in shape and position.
微创血管介入手术的数量正在增加。在这些介入手术中，各种器械被导向并放置在介入部位。几乎所有这些介入手术中使用的器械都是导丝，它作为所有输送到介入部位的器械的单轨。然而，即使导丝已就位，临床医生在介入过程中仍会遇到困难。作为理解这些困难并促进导丝和器械引导的第一步，我们研究了在血管模型中导丝最终路径在不同因素（用户、材料和几何形状）下的可重复性。使用硅管构建了三个血管模型（血管直径约4毫米），其曲折度与颈内动脉相似，并封装在西尔加德弹性体中。几名经过培训的用户在脉动血流条件下，将两根不同柔韧性的导丝反复穿过这些模型。导丝放置好后，采集旋转C形臂图像序列（9英寸II模式，像素尺寸0.185毫米），并对模型和导丝进行重建（512(3)，体素尺寸0.288毫米）。将重建的体积对齐。然后使用区域生长技术确定导丝和模型血管的中心线。导丝路径在不同用户之间看起来相似，但在不同材料之间则不然。重复放置的平均均方根差为0.17±0.02毫米（塑料涂层导丝）、0.73±0.55毫米（钢质导丝）和1.15±0.65毫米（钢质与塑料涂层导丝之间）。对于给定的导丝，这些结果表明导丝路径在形状和位置上相对可重复。
