Hughes G C, Kypson A P, Annex B H, Yin B, St Louis J D, Biswas S S, Coleman R E, DeGrado T R, Donovan C L, Landolfo K P, Lowe J E
Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Ann Thorac Surg. 2000 Aug;70(2):504-9. doi: 10.1016/s0003-4975(00)01569-1.
Transmyocardial laser revascularization (TMR) is an emerging treatment for end-stage coronary artery disease. A variety of lasers are currently available to perform the procedure, although their relative efficacy is unknown. The purpose of this study was to compare changes in myocardial blood flow and function 6 months after TMR with holmium:yttrium-aluminum-garnet (holmium:YAG), carbon dioxide (CO2), and xenon chloride excimer lasers in a model of chronic ischemia.
Miniswine underwent subtotal (90%) left circumflex coronary stenosis. Baseline positron emission tomography and dobutamine stress echocardiography were performed to document hibernating myocardium in the left circumflex coronary artery distribution. Animals were then randomized to sham redo-thoracotomy (n = 5) or TMR using a holmium:YAG (n = 5), CO2 (n = 5) or excimer (n = 5) laser. Six months postoperatively, the positron emission tomography and dobutamine stress echocardiography studies were repeated and the animals sacrificed.
In animals undergoing TMR with holmium: YAG and CO2 lasers, a significant improvement in myocardial blood flow to the lased left circumflex regions was seen. No significant change in myocardial blood flow was seen in sham- or excimer-lased animals. There was a significant improvement in regional stress function of the lased segments 6 months postoperatively in animals undergoing holmium:YAG and CO2 laser TMR that was consistent with a reduction in ischemia. There was no change in wall motion in sham- or excimer-lased animals. Significantly greater neovascularization was observed in the holmium:YAG and CO2 lased regions than with either the sham procedure or excimer TMR.
Transmyocardial laser revascularization with either holmium:YAG or CO2 laser improves myocardial blood flow and contractile reserve in lased regions 6 months postoperatively. These changes were not seen following excimer TMR or sham thoracotomy, suggesting that differences in laser energy or wavelength or both may be important in the induction of angiogenesis.
心肌激光血运重建术（TMR）是终末期冠状动脉疾病的一种新兴治疗方法。目前有多种激光可用于实施该手术，但其相对疗效尚不清楚。本研究的目的是在慢性缺血模型中比较钬：钇铝石榴石（钬：YAG）、二氧化碳（CO2）和氯化氙准分子激光进行TMR术后6个月心肌血流和功能的变化。
小型猪接受左回旋支冠状动脉90%的次全狭窄。进行基线正电子发射断层扫描和多巴酚丁胺负荷超声心动图检查，以记录左回旋支冠状动脉分布区的冬眠心肌。然后将动物随机分为假再次开胸手术组（n = 5）或使用钬：YAG（n = 5）、CO2（n = 5）或准分子激光（n = 5）进行TMR组。术后6个月，重复进行正电子发射断层扫描和多巴酚丁胺负荷超声心动图检查，然后处死动物。
在接受钬：YAG和CO2激光TMR的动物中，可见激光照射的左回旋支区域心肌血流有显著改善。假手术或准分子激光照射的动物心肌血流未见明显变化。接受钬：YAG和CO2激光TMR的动物术后6个月，激光照射节段的局部应激功能有显著改善，这与缺血减轻一致。假手术或准分子激光照射的动物壁运动无变化。在钬：YAG和CO2激光照射区域观察到的新生血管形成明显多于假手术或准分子激光TMR。
钬：YAG或CO2激光心肌激光血运重建术可在术后6个月改善激光照射区域的心肌血流和收缩储备。准分子激光TMR或假开胸术后未见这些变化，提示激光能量或波长或两者的差异可能在诱导血管生成中起重要作用。
