扩张压力对兔颈外静脉移植物再狭窄的影响

Effects of distension on postoperative restenosis of rabbit external jugular vein graft

目的 研究不同扩张压力对兔颈外静脉内皮完整性及颈外静脉桥再狭窄的影响。方法 1 8只NZW兔 ,随机分为A、B、C组。每组兔颈外静脉分别以 50、1 0 0和 2 0 0mmHg(1mmHg=0 .1 33kPa)扩张 ,静脉内银染铺片法和扫描电镜进行内皮完整性评分。扩张后行颈外静脉颈总动脉移植 ,2 8d后测定静脉桥管腔面积和内膜厚度。结果 A组内皮完整性评分 (1 .42 )显著低于B组 (2 .67,P <0 .0 1 )和C组 (3 .83 ,P <0 .0 1 )。A组的静脉桥的管腔面积 (1 1 .3± 2 .0 )mm2 显著大于B组 [(6 .0± 1 .7)mm2 ,P =0 .0 0 1 ]和C组 [(4.5± 1 .2 )mm2 ,P <0 .0 0 1 ] ;A组的静脉桥的内膜厚度 (36 .2± 3 .4) μm显著小于B组 [(52 .3± 7.7) μm ,P =0 .0 0 1 ]和C组 [(53 .1± 5 .8) μm ,P <0 .0 0 1 ]。结论 50mmHg的扩张压力引起的兔颈外静脉桥再狭窄的程度明显轻于 1 0 0mmHg和2 0 0mmHg。

Objective To study the effects of different distension pressures on the integrity of the endothelium of rabbit external jugular vein and on vein graft restenosis.Methods Rabbit external jugular veins were distended under pressure of 50?mm?Hg (group A,n=6,1?mm?Hg=0.133?kPa), 100?mm?Hg (group B,n=6) and 200?mm?Hg (group C,n=6) respectively. Then the veins were cut into 2 segments. One was for endothelial integrity grading by results of intravascular silver staining and SEM examination. The other was grafted end to end into the common carotid arteries. Twenty eight days post operatively, vein grafts were removed. Luminal area and intimal thickness of the vein grafts were calculated.Results Veins in group A showed mildest EC denudation. Its endothelium grade was significantly lower than in group B (1.42 vs 2.67, P<0.01) and group C (1.42 vs 3.83, P<0.01). Twenty eight days after implantation, all were patent except one in group C. The mean luminal area of vein grafts in group A was significantly larger than in group B [(11.3±2.0)?mm 2 vs (6.0±1.7)?mm 2,P=0.001] and group C [(11.3±2.0)?mm 2 vs (4.5±1.2)?mm 2, P<0.001]. The intimal thickness of the vein grafts in group A was significantly lower than in group B [(36.2±3.4)?μm vs (52.3±7.7)?μm,P=0.001] and group C [(36.2±3.4)?μm vs (53.1±5.8)?μm, P<0.001].Conclusion Distension pressure of 50?mm?Hg caused significantly milder restenosis than that of 100?mm?Hg and 200?mm?Hg. The explanation of the difference may be that it preserved the structural integrity of veins better than the other two.