Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
Lasers Med Sci. 2010 Nov;25(6):907-9. doi: 10.1007/s10103-010-0780-2. Epub 2010 Jul 20.
Endovenous laser ablation (EVLA) produces boiling bubbles emerging from pores within the hot fiber tip and traveling over a distal length of about 20 mm before condensing. This evaporation-condensation mechanism makes the vein act like a heat pipe, where very efficient heat transport maintains a constant temperature, the saturation temperature of 100 degrees C, over the volume where these non-condensing bubbles exist. During EVLA the above-mentioned observations indicate that a venous cylindrical volume with a length of about 20 mm is kept at 100 degrees C. Pullback velocities of a few mm/s then cause at least the upper part of the treated vein wall to remain close to 100 degrees C for a time sufficient to cause irreversible injury. In conclusion, we propose that the mechanism of action of boiling bubbles during EVLA is an efficient heat-pipe resembling way of heating of the vein wall.
静脉内激光消融 (EVLA) 会产生从热光纤尖端的孔隙中冒出的沸腾气泡，并在凝结之前沿约 20mm 的远端长度传播。这种蒸发-冷凝机制使静脉像热管一样，其中非常有效的热传递在存在这些不凝气泡的体积内保持恒定温度，即 100 摄氏度的饱和温度。在 EVLA 过程中，上述观察结果表明，一个长度约为 20mm 的静脉圆柱体积保持在 100 摄氏度。以几毫米/秒的后退速度，至少会使处理后的静脉壁的上部在足以引起不可逆转损伤的时间内保持接近 100 摄氏度。总之，我们提出，在 EVLA 过程中，沸腾气泡的作用机制是一种类似于热管壁加热的高效热管方式。
