超声辐照对兔移植静脉内膜增生的影响

摘要

目的 观察超声辐照对移植静脉内膜增生的影响,以期寻找防治内膜增生的新方法.方法 将32只实验兔随机分为超声辐照组和对照组,每组16只,建立兔自体颈内静脉移植替代颈总动脉模型.对照组仅常规术后处理,超声辐照组术后当天至第7天使用超声(2.190 W/cm2,0.8 MHz)辐照移植血管段,于术后第2、4周分别使用彩色多普勒超声和数字减影血管造影观察两组移植血管的通畅率;光、电镜观察两组移植静脉的组织形态学改变;增殖细胞核抗原(PCNA)免疫组织化学染色观察两组血管内膜平滑肌细胞(SMC)的增殖情况.结果 术后第4周,对照组、超声辐照组通畅率分别为87.5%及93.8%,两组比较差异无统计学意义(P>0.05);超声辐照组内膜厚度减少35%,与对照组比较差异有统计学意义(P<0.05);超声辐照组术后第2、4周PCNA阳性细胞数均明显低于对照组(5.7±0.5 vs.16.1±1.5,15.1±2.6 vs.50.2±5.3),两组比较差异有统计学意义(P<0.05).结论 在兔自体静脉移植模型上,超声辐照可以降低SMC的增殖,减轻内膜增生.因而,超声辐照可考虑作为一种防治静脉移植后再狭窄的治疗方法.%Objective To assess the effects of ultrasonic irradiation on intimal hyperplasia of vein graft in rabbits, and to find a new method to prevent and treat intimal hyperplasia. Methods Thirty - two rabbits were divided into ultrasonic irradiation group and control group randomly with 16 rabbits in each group. Common carotid artery interposition model with ipsilateral internal jugular vein was estahlished. The vein grafts were treated hy ultrasonic irradiation ( 2.190 W/cm2 , 0.8 MHz)from operation day to the 7th day after operation. The patency rate of two grafted veins were observed by color Doppler ultrasound and DSA at the 2nd and 4th week after operation. The histomorphology of the grafted veins was observed by light microscope and electron microscope. The proliferation of the SMCs was evaluated by PCNA immunohistochemistry stainning. Results At the 4th week after operation, the patency rate of control group and ultrasonic irradiation group was 87.5％ and 93. 8％ , respectively,there was no significant difference ( P ＞ 0. 05 ) . Compared with control group, 35％ intimal thickness in ultrasonic irradiation group was decreaced (P ＜0. 05). At the 2nd and 4th week, the number of PCNA positive cells was significantly reduced in ultrasonic irradiation group (5.7 ±0. 5 vs. 16. 1 ± 1. 5 , 15.1± 2. 6 vs. 50. 2 ±5. 3) , there was significant difference between the two groups ( P ＜ 0. 05 ). Conclusion In vein autograft model of rabbits, ultrasonic irradiation can decrease cellular proliferation and intimal hyperplasia, it can be considered as an effective treatment to prevent vein graft restenosis.