Horvath K A, Belkind N, Wu I, Greene R, Doukas J, Lomasney J W, McPherson D D, Fullerton D A
Division of Cardiothoracic Surgery, Northwestern University Medical School, Chicago, Illinois 60611, USA.
Ann Thorac Surg. 2001 Dec;72(6):1997-2002. doi: 10.1016/s0003-4975(01)03243-x.
As a result of the clinical benefit observed in angina patients treated by transmyocardial revascularization (TMR) with a laser, interest in mechanical TMR has been renewed. Although the injury induced by mechanical TMR is similar to laser TMR, the resultant impact on myocardial contractility is unknown. The purpose of this study was to determine whether mechanical TMR improves ventricular function as compared with laser TMR in chronically ischemic myocardium.
After establishing an area of chronic myocardial ischemia, 25 domestic pigs were randomized to treatment by: excimer laser (group I), a hot needle (50 degrees C) (group II), a normothermic needle (group III), an ultrasonic needle (40 KHz) (group IV), or no treatment (group V). All devices create a transmural channel of the same diameter; 22 +/- 1 transmural channels were created in each animal. Regional myocardial contractility was assessed by measuring ventricular wall thickening at rest and with dobutamine stress echocardiography. Six weeks after revascularization, the animals were restudied at rest and with stress. Postsacrifice and histologic analysis of angiogenesis and TMR effects was then assessed.
Laser TMR provided significant recovery of ischemic myocardial function. This improvement in contractility after laser TMR was a 75% increase over the baseline function of the ischemic zone (p < 0.01). Mechanical TMR provided no significant improvement in function posttreatment. In fact, TMR achieved with an ultrasonic needle demonstrated a 40% worsening of the contractility versus the pretreatment baseline (p < 0.05). Histologic analysis demonstrated a significant increase in new blood vessels in the ischemic zone after laser TMR, which was not demonstrated for any of the other groups (p < 0.05). Additionally, evaluation of the mechanical TMR channels demonstrated significant scarring, which correlated with the functional results.
Using devices to create an injury analogous to the laser, mechanical TMR failed to improve the function of chronically ischemic myocardium. Only laser TMR significantly improved myocardial function.
由于经心肌激光血运重建术（TMR）治疗心绞痛患者显示出临床益处，人们对机械性TMR的兴趣得以重新燃起。尽管机械性TMR造成的损伤与激光TMR相似，但对心肌收缩力的最终影响尚不清楚。本研究的目的是确定在慢性缺血心肌中，与激光TMR相比，机械性TMR是否能改善心室功能。
在建立慢性心肌缺血区域后，将25头家猪随机分为以下治疗组：准分子激光组（I组）、热针（50摄氏度）组（II组）、常温针组（III组）、超声针（40千赫兹）组（IV组）或不治疗组（V组）。所有器械制造的透壁通道直径相同；每只动物制造22±1个透壁通道。通过测量静息状态下及使用多巴酚丁胺负荷超声心动图时的心室壁增厚情况来评估局部心肌收缩力。血运重建术后6周，对动物在静息和负荷状态下再次进行研究。然后在处死动物后进行血管生成和TMR效应的组织学分析。
激光TMR使缺血心肌功能得到显著恢复。激光TMR后收缩力的改善比缺血区基线功能提高了75%（p<0.01）。机械性TMR治疗后功能无显著改善。事实上，超声针进行的TMR显示收缩力比治疗前基线恶化了40%（p<0.05）。组织学分析显示激光TMR后缺血区新生血管显著增加，其他组均未出现这种情况（p<0.05）。此外，对机械性TMR通道的评估显示有明显瘢痕形成，这与功能结果相关。
使用造成类似激光损伤的器械，机械性TMR未能改善慢性缺血心肌的功能。只有激光TMR显著改善了心肌功能。
