Weber H, Enders S, Coppenrath K, Murray A B, Schad H, Mendler N
Division of Cardiology, Hospital Munich-Bogenhausen, Federal Republic of Germany.
Lasers Surg Med. 1990;10(2):133-9. doi: 10.1002/lsm.1900100205.
Laser coagulation of arrhythmogenic myocardium proved to be an effective surgical therapy for refractory arrhythmias. To determine the influence of Nd: YAG laser coagulation of myocardium on coronary vessels, a total of 48 transcatheter laser impacts (10 W, 10 sec, 7 W mm2) were directed to the left ventricular free wall via endocardial (24 lesions in 2 dogs) or epicardial (24 lesions in 2 dogs) approach. In 8 of 24 endomyocardial lesions (2 and 6 months old) coronary vessels with a diameter of greater than 50 microns were found within the coagulation zones. The volume of these lesions was significantly (P less than 0.01) smaller (139 +/- 43 mm3) than those (n = 16) with coronary vessels measuring less than 50 microns (311 +/- 87 mm3). Volumes of epimyocardial lesions (1-2 hours old) produced by transcoronary irradiation with normal coronary blood flow were significantly (P less than 0.01) smaller (31 +/- 17 mm3) than with reduced (73 +/- 22) or interrupted (119 +/- 34 mm3) blood flow (n = 8, each). Both directly irradiated coronary vessels and those found within the coagulation zones and scars appeared histologically normal through all layers with an intact intima without fibrosis or thrombosis. The ultrastructure of irradiated arteries, even with total interruption of blood flow, was no different from that of non-irradiated controls. Thus, coronary artery blood flow significantly reduces the volume of coagulated myocardium, whereas the vessels themselves appear to remain undamaged by laser irradiation as used for myocardial coagulation.
结果表明，激光凝固致心律失常心肌是治疗难治性心律失常的一种有效手术方法。为了确定钕钇铝石榴石激光凝固心肌对冠状动脉的影响，通过心内膜（2只犬，24个损伤）或心外膜（2只犬，24个损伤）途径，将总计48次经导管激光冲击（10瓦，10秒，7瓦/平方毫米）作用于左心室游离壁。在24个心内膜损伤中的8个（损伤形成2个月和6个月），凝固区内发现直径大于50微米的冠状动脉。这些损伤的体积（139±43立方毫米）明显（P＜0.01）小于冠状动脉直径小于50微米的损伤（n = 16）（311±87立方毫米）。在正常冠状动脉血流情况下经冠状动脉照射产生的心外膜损伤（形成1 - 2小时）的体积（31±17立方毫米）明显（P＜0.01）小于血流减少（73±22立方毫米）或血流中断（119±34立方毫米）时的损伤体积（每组n = 8）。直接照射的冠状动脉以及在凝固区和瘢痕内发现的冠状动脉在组织学上各层均表现正常，内膜完整，无纤维化或血栓形成。即使血流完全中断，照射动脉的超微结构与未照射的对照动脉并无差异。因此，冠状动脉血流可显著减小凝固心肌的体积，而用于心肌凝固的激光照射似乎不会损伤血管本身。
