超声引导下经胸激光消融室间隔的实验研究

The animal study of echocardiography-guided transthoracic laser ablation of the interventricular septum

目的观察并评估超声引导下激光经胸消融动物室间隔的安全性及长期效果,为梗阻性肥厚型心肌病(obstructive hypertrophic cardiomyopathy,HOCM)研究新疗法。方法将10只健康小尾寒羊随机均分为两组:实验组用鞘管穿刺并进行激光消融(能量:3 W,1000 J),对照组为假手术组(鞘管穿刺入室间隔相同位置,无消融)。在术前、术后即刻、术后1、3、6个月分别进行超声心动图、心电图随访,并分析左心室收缩及舒张功能、三维纵向应变、消融区所在节段与周围节段达峰时间差值等数据;在术前及术后1 h无菌采血行实验室检查。结果消融后即刻至术后6个月所有动物心功能均正常,未出现心包填塞或传导阻滞等严重并发症。术后1 h,实验组肌钙蛋白较对照组显著升高,差异有统计学意义(P<0.05)。M型超声示实验组术后6个月消融区室壁搏幅减低,与对照组比较差异有统计学意义P<0.05)。术后6个月消融部位室间隔厚度较术前室间隔厚度显著变薄[(3.23±1.21)mm对(8.53±0.44)mm,P<0.05];与对照组比较,实验组消融区搏幅及三维应变显示纵向应变显著减低,收缩期达峰时间明显延迟(P<0.05)。结论超声引导下激光消融室间隔是一种安全、有效的微创治疗方法,在不影响心功能条件下对室间隔厚度减容效果明显,有望成为梗阻性肥厚型心肌病治疗的新方法。

Objective To investigate the safety and long-term efficacy of a new treatment,echocardiography-guided transthoracic laser ablation of the animal interventricular septum(IVS),for obstructive hypertrophic cardiomyopathy(HOCM).Methods Ten healthy sheep were randomly divided into two groups:experimental group:sheath puncture with laser ablation(energy:3 W,1000 J),sham control group:sheath puncture only without laser ablation.Echocardiography and electrocardiogram(ECG)were recorded before operation,immediately after operation,and 1,3 and 6-month after the operation.Left ventricular systolic and diastolic function,longitudinal strain,difference of time to peak between the ablation segment and the surrounding segments were analyzed.Blood samples were collected before and one hour after the operation to examine the serological results.Results Immediately and 6 months after the operation,all animals survived with normal cardiac function.No severe complications such as cardiac tamponade or bundle branch block occurred.The Troponin I level was significantly elevated immediately after the operation(P<0.05).The thickness of the ablated IVS was significantly reduced 6 months after the operation compared with before the operation[(3.23±1.21)mm vs(8.53±0.44)mm,P<0.05].M-mode echocardiography showed that the amplitude of movement of the ablated region of the experimental group 6 months after the operation was significantly decreased compared with the control group(P<0.05).Three dimensional strain analysis showed that for the experimental group,the longitudinal strain of the ablation segment was significantly reduced and the difference of time to peak was significantly delayed,compared with the control group(P<0.05).Conclusions Echocardiography-guided transthoracic laser ablation of IVS is a safe,effective,and minimally invasive method.It is capable to reduce the volume of IVS without influencing the cardiac function,which makes it a potential alternative for HOCM treatment.