A Parametric Study of Flushing Conditions for Improvement of Angioscopy Visibility

Journal of Functional Biomaterials

Kazunori Horie¹  Simon Tupin²  Hitomi Anzai²  Kohei Mitsuzuka²  Yujie Li²  Haoran Wang²  Makoto Ohta²  Daisuke Goanno²  Mingzi Zhang²  Toshio Nakayama³ 

[1] Department of Cardiology, Sendai Kousei Hospital, 4-15 Hirose, Aoba-ku, Sendai 980-0873, Japan;Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan;National Institute of Technology, Nara College, 22 Yatacho, Yamatokoriyama 639-1080, Japan;

关键词: coronary angioscopy;    flush conditions;    CFD;    two-phase flow;    dextran injection;   

DOI  :  10.3390/jfb13020069

来源: DOAJ

【 摘 要 】

During an angioscopy operation, a transparent liquid called dextran is sprayed out from a catheter to flush the blood away from the space between the camera and target. Medical doctors usually inject dextran at a constant flow rate. However, they often cannot obtain clear angioscopy visibility because the flushing out of the blood is insufficient. Good flushing conditions producing clear angioscopy visibility will increase the rate of success of angioscopy operations. This study aimed to determine a way to improve the clarity for angioscopy under different values for the parameters of the injection waveform, endoscope position, and catheter angle. We also determined the effect of a stepwise waveform for injecting the dextran only during systole while synchronizing the waveform to the cardiac cycle. To evaluate the visibility of the blood-vessel walls, we performed a computational fluid dynamics (CFD) simulation and calculated the visible area ratio (VAR), representing the ratio of the visible wall area to the total area of the wall at each point in time. Additionally, the normalized integration of the VAR called the area ratio (AR_VAR) represents the ratio of the visible wall area as a function of the dextran injection period. The results demonstrate that the AR_VAR with a stepped waveform, bottom endoscope, and three-degree-angle catheter results in the highest visibility, around 25 times larger than that under the control conditions: a constant waveform, a center endoscope, and 0 degrees. This set of conditions can improve angioscopy visibility.

【 授权许可】

Unknown