Hassenstein S, Haase K K, Wehrmann M, Karsch K R
Abteilung III, Universität Tübingen.
Z Kardiol. 1991 Aug;80(8):500-5.
To investigate the effect of radiofrequency energy (600 kHz) on atherosclerotic tissue, high frequency current was applied on 160 specimens of human abdominal and iliac artery autopsies with various duration and energy density. All experiments were performed in air, saline, and blood. Application of 5 to 30 joule resulted in coagulation of the intima and the media. Time dependent a shrinking of the vessel wall did occur at energy rates above 30 joule. At higher energies vaporization was found. In blood coagulation at the catheter tip became evident at 30 joule and higher energies. Histologic cross sections showed distending of intimal layers at 25 joule, additional shrinking of medial layers at 50 joule, vacuoles at 75 joule and separation of intima layers from underlying layers at 200 joule. In vitro application of high frequency current on atherosclerotic tissue results in thermal effects only. The extent of these effects seems to be unpredictable because of the ever changing composition of the tissue, resulting in changes of energy delivery at the tip tissue interface. On calcified plaques an energy dependent contraction mainly of adjacent vessel wall could be seen. Because of the non-predictable effects and adverse side effects on adjacent normal vessel wall the method seems not to be useful for clinical application.
为研究射频能量（600千赫）对动脉粥样硬化组织的影响，将高频电流以不同持续时间和能量密度施加于160例人体腹主动脉和髂动脉尸检标本上。所有实验均在空气、生理盐水和血液中进行。施加5至30焦耳能量会导致内膜和中膜凝固。当能量速率高于30焦耳时，血管壁会随时间出现收缩。在更高能量下会出现汽化现象。在血液中，导管尖端在30焦耳及更高能量时会出现凝血现象。组织学横截面显示，25焦耳时内膜层扩张，50焦耳时中膜层进一步收缩，75焦耳时出现空泡，200焦耳时内膜层与下层分离。在体外对动脉粥样硬化组织施加高频电流仅产生热效应。由于组织成分不断变化，导致尖端组织界面处能量传递发生改变，这些效应的程度似乎无法预测。在钙化斑块上，可以看到主要是相邻血管壁的能量依赖性收缩。由于存在不可预测的效应以及对相邻正常血管壁的不良副作用，该方法似乎不适用于临床应用。
