经皮激光心肌血运重建术治疗缺血性心脏病的实验研究

The experimental research of percutaneous transmyocardial laser revascularization treating ischemic heart disease

目的 :探讨经皮激光心肌血运重建术 (PMR)治疗缺血性心脏病的疗效及其作用机制。方法 :犬 2 2只 ,用结扎冠状动脉左前降支法建立犬心肌缺血模型后 ,随机分为 PMR组和对照组 ,对照组不予处理 ,分别于术后 2 4h,1周 ,1,3月观察。应用单光子发射计算机体层摄影 (SPECT)、超声心动图 (U CG)及心肌病理组化染色观察打孔部位心肌的灌注、功能及激光孔道的变化。结果 :PMR组心肌灌注缺损较术前减轻 2～ 3分 ,对照组心肌灌注损伤仍为 2～ 3分 ,PMR组静息状态下心肌射血分数从术前 (4 0 .2± 3.5 ) %增加为术后 (5 1.6± 3.0 ) % ,对照组静息状态下心肌射血分数从术前 (4 2 .7± 2 .6 ) %增加为术后 (4 5 .3± 2 .8) % ;心肌打孔孔道急性期保持开放 ,但早在术后 1周即已闭塞 ,远期孔道及周边有新生小血管形成 ;组织化学染色显示打孔区域微血管密度为 46± 7条 /视野 (× 10 0 ) ,对照组为 16± 4条 /视野 (× 10 0 ) (P<0 .0 5 )。结论 :PMR使缺血心肌的供血和功能得到改善 ,通过通畅的激光孔道向缺血心肌供血可能不是 PMR的治疗机制 ,而激光孔道及其周围新生微血管的形成已发生导致心肌内固有的微循环及其辅助循环的结构重构 ,可能是

AIM:To investigate into the curative effect and action machanism of percutaneous transmyocardial laser revascularization(PMR) on ischemic myocardium by animal experiment. METHODS:22 dogs were divided into two groups:PMR group and control group after their left anterior descending branches had been ligated. Each group was observed on three time phase points as 24 h,1st week,1st,3rd month. The PMR groups was handled with PMR while the control group had no treatment. The changes of myocardial perfusion,function and laser channels were studied by applying SPECT,UCG and pathologic researsh. RESULTS:The myocardial perfusion defection in laser treated areas alleviated 2~3′ than before and the resting myocardium EF value changed from (40.2±3.5)% to (51.6±3.0)%. The density of microvessels in laser treated areas was 46±7 roots/field of vision (×100) while the control group′s was 16±4 roots/field of vision (×100)(*'P*'<0.05).CONCLUSION:PMR improve the blood-supply and function of ischemic myocardium. It may not be the just mechansim of PMR that the ischemic myocardium was reperfused through patency channel transporting blood from left ventricle to myocardium wall. On the contrary,the forming and grnerating of microvessels in or surrounding lased channel caused remodeling of inherent microcirculation and its aid circulation may be the true mechanism of PMR to improve perfusion and function of ischemic myocardium.