Ohtake H, Misaki T, Watanabe G, Mukai K, Matsunaga Y, Tsubota M, Kawasuji M, Watanabe Y
Department of Surgery, Kanazawa University, School of Medicine, Japan.
Pacing Clin Electrophysiol. 1994 Oct;17(10):1627-31. doi: 10.1111/j.1540-8159.1994.tb02356.x.
To investigate whether the efficacy of intraoperative laser ablation therapy is affected by myocardial blood perfusion, we irradiated 11 canine hearts through the epicardium with a Nd:YAG laser (10, 20, and 30 J/mm2) using air as the medium. Compared coagulated myocardial depth, width, and volume obtained in the red beating heart was compared with those in the white nonbeating heart infused with 0 degrees C saline (cardioplegic model) via the coronary artery. Histologically, the macro- and microscopical findings were very similar. At each level of energy, the width and volume of red myocardium coagulated were significantly larger than those of white myocardium (P < 0.01). At 30 J/mm2, the depth of coagulation of red myocardium was significantly larger than that of white myocardium (P < 0.01). The coagulated volume of the white myocardium was about 60% of that of the red myocardium. Nd:YAG laser energy was absorbed by blood (red color = hemoglobin), and more energy was transferred in the higher temperature myocardium. During intraoperative Nd:YAG laser ablation, the presence of blood perfusion in cardiac tissue is thought to be an important factor affecting safe irradiation.
为了研究术中激光消融治疗的疗效是否受心肌血流灌注的影响，我们以空气作为介质，用钕:钇铝石榴石激光（10、20和30 J/mm²）经心外膜照射11只犬心脏。将红色跳动心脏中获得的凝固心肌深度、宽度和体积与通过冠状动脉注入0℃盐水的白色停跳心脏（心脏停搏模型）中的进行比较。组织学上，大体和微观表现非常相似。在每个能量水平下，红色心肌凝固的宽度和体积均显著大于白色心肌（P < 0.01）。在30 J/mm²时，红色心肌的凝固深度显著大于白色心肌（P < 0.01）。白色心肌的凝固体积约为红色心肌的60%。钕:钇铝石榴石激光能量被血液吸收（红色 = 血红蛋白），并且在温度较高的心肌中传递的能量更多。在术中钕:钇铝石榴石激光消融期间，心脏组织中血流灌注的存在被认为是影响安全照射的一个重要因素。
