Session: 17-01-01: Research Posters

Paper Number: 143973

143973 - Evaluation of Irregular Motion in Endovascular Treatment 

Endovascular treatment using guidewires and catheters is widely performed. Appropriate guidewire and catheter operation methods rely on the operator's experience and intuition. Occasionally, unexpected and irregular motions of the device tip are observed that can damage the blood vessel wall. This phenomenon is called the "jumping phenomenon." In order to prevent such dangerous behavior, we investigated the effect of blood vessel shape on device behavior and effective operations for preventing the jumping phenomenon. Using an insertion device made in our laboratory, a guidewire was inserted at a constant speed into crank-shaped vascular phantoms with bending angles of 45°, 67.5°, and 90°. In order to examine the effect of the distance between the catheter and the guidewire, the catheter was fixed at an arbitrary position on the vascular phantom. Three fixation locations were chosen between the two bends. The motion of the guidewire was captured on video. For the quantitative evaluation of the jumping phenomenon, frames of five different situations were selected from the video. The first frame was when the insertion begins, the second frame was when the guidewire tip stops, the third frame was just before the jump, the fourth frame was just after the jump, and the last frame after the insertion has finished. The jumping phenomenon was evaluated using indices such as the time the guidewire tip was stopped before jumping, the number of jumps, the jumping distance, and the strain energy. In general, the longer the distance between the catheter and the guidewire tip, the longer the jumping distance and the greater the number of jumps. The time the guidewire tip was stopped before jumping was also long. The accumulated strain energy while the guidewire tip was stopped did not show a strong correlation with the jump distance. In the case of small bending angle, guidewire jumping was not seen in many cases. However, once a jump occurred, the jump distance tended to be long (4.0±2.4 mm). At that time, the accumulated strain energy was large. This means that the deformation before jumping was large. In the case of large bending angle, consecutive short jumps were seen. Among the multiple jumps, the distance of the last jump tended to be relatively longer (2.5 ± 1.3 mm). In this case, the deformation before the jump was small. These results show that when the bending angle is small, jumping can be suppressed by keeping the catheter close to the guidewire tip. Since the deformation before the jump is large, it is not difficult for the operator to identify its precursor. On the other hand, when the bending angle is large, the operator should prepare for the next jump as soon as a small jump is recognized. This is because it is difficult for the operator to recognize small deformations before a jump, and jumps tend to occur continuously. The evaluation method proposed in this study can be applied to blood vessels with more complex shapes. This method contributes to predicting the degree of risk during the jump stage and elucidating ways to prevent dangerous device behavior.

Presenting Author: Kengo Kobayashi Division of Mechanical Engineering, Graduate School of Science and Technology for Innovation, Yamaguchi University

Presenting Author Biography: Kengo Kobayashi is a Master's Student at Yamaguchi University. His research interests center on medical engineering, with a particular emphasis on vascular interventions.

Authors:

Kengo Kobayashi Division of Mechanical Engineering, Graduate School of Science and Technology for Innovation, Yamaguchi University
Kazuto Takashima Department of Biological Functions Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology
Naoki Toma Department of Neurosurgery, Mie University Graduate School of Medicine
Koji Mori Division of Mechanical Engineering, Graduate School of Science and Technology for Innovation, Yamaguchi University