Steffen W, Fishbein M C, Luo H, Lee D Y, Nita H, Cumberland D C, Tabak S W, Carbonne M, Maurer G, Siegel R J
Division of Cardiology, Cedars-Sinai Medical Center, Los Angeles, California 90048.
J Am Coll Cardiol. 1994 Nov 15;24(6):1571-9. doi: 10.1016/0735-1097(94)90157-0.
This study assessed the efficacy of a new high intensity, low frequency therapeutic coronary ultrasound catheter for thrombus dissolution in vitro and in vivo in canine coronary arteries.
Therapeutic ultrasound has been shown to dissolve thrombi in vitro and in peripheral arteries in vivo. There have been no previous studies on in vivo coronary thrombus dissolution by ultrasound.
In vitro, we exposed 1- to 4-h old human blood clots for 3 min to pulsed-wave ultrasound. Clot dissolution under various conditions was evaluated. In vivo occlusive coronary thrombi were induced in 18 dogs.
In vitro irrigation alone (10 ml/min of normal saline solution) and ultrasound alone each contributed to a reduction of clot weight by 47.1 +/- 11.4 mg and 84.6 +/- 25.6 mg, respectively, after 3 min (p < 0.001). Ultrasound plus irrigation resulted in a reduction of clot weight by 216.5 +/- 31.5 mg after 3 min (p < 0.001). The magnitude of clot dissolution was considerably amplified when ultrasound energy was combined with irrigation, probably because of cavitational effects. In vivo, in three dogs mechanical passage of the unactivated probe failed to recanalize the artery, and the arteries remained thrombotically occluded. After passage of the activated ultrasound probe, angiography revealed widely patent coronary arteries in 13 of 15 dogs and partial recanalization with filling defects indicative of residual thrombus in 2 of 15 dogs. Three of 15 coronary arteries were histologically free of residual thrombi. Mural thrombi extending to < or = 10% of the vessel circumference were seen in 10 of 15 dogs. Residual thrombi > or = 50% of the vessel circumference were found in two cases. There was no histologic evidence of ultrasound-mediated vessel damage.
Catheter-delivered therapeutic ultrasound effectively dissolves clots in vitro and in canine coronary arteries in vivo. Thus, therapeutic catheter-delivered ultrasound has the potential to serve as an adjunct or alternative treatment for thrombus-mediated coronary ischemic syndromes or myocardial infarction.
本研究评估了一种新型高强度、低频治疗性冠状动脉超声导管在体外及犬冠状动脉体内溶解血栓的疗效。
治疗性超声已被证明可在体外及外周动脉体内溶解血栓。此前尚无关于超声在体内溶解冠状动脉血栓的研究。
在体外，我们将1至4小时龄的人血凝块暴露于脉冲波超声下3分钟。评估了各种条件下的血栓溶解情况。在18只犬中诱导形成体内闭塞性冠状动脉血栓。
体外单独冲洗（10毫升/分钟的生理盐水溶液）和单独超声在3分钟后分别使血栓重量减少47.1±11.4毫克和84.6±25.6毫克（p<0.001）。超声加冲洗在3分钟后使血栓重量减少216.5±31.5毫克（p<0.001）。当超声能量与冲洗相结合时，血栓溶解的程度显著增强，这可能是由于空化效应。在体内，3只犬中未激活的探头机械通过未能使动脉再通，动脉仍因血栓而闭塞。激活的超声探头通过后，血管造影显示15只犬中有13只冠状动脉广泛通畅，15只犬中有2只部分再通，有充盈缺损提示残留血栓。15只冠状动脉中有3只在组织学上无残留血栓。15只犬中有10只可见延伸至血管周长≤10%的壁血栓。2例发现残留血栓≥血管周长的50%。没有超声介导的血管损伤的组织学证据。
导管输送的治疗性超声在体外及犬冠状动脉体内能有效溶解血栓。因此，导管输送的治疗性超声有潜力作为血栓介导的冠状动脉缺血综合征或心肌梗死的辅助或替代治疗方法。
