造血干细胞动员对移植静脉近期通畅率的影响

Effects of Haemopoietic Stem Cell Mobilization on Improving Vein Graft Patency

目的研究造血干细胞动员对移植静脉近期通畅率和吻合口内膜增生程度的影响。方法将24只新西兰大白兔随机分为实验组和对照组,每组12只,每只兔建立双侧颈动-静脉移植模型,其中一侧移植静脉于移植前采用0.25%胰蛋白酶去内皮细胞处理。实验组兔静脉移植后24h开始皮下注射分泌型基因重组人粒细胞集落刺激因子(rhG-CSF,100μg/kg),连续10d;对照组兔注射等量生理盐水。术后观察造血干细胞动员情况,包括外周血有核细胞计数,单个核细胞比率,移植静脉的近期通畅和吻合口内膜增生情况。结果实验组术后5d外周血有核细胞计数(t=8.406,P=0.000)和单个核细胞比率(t=31.267,P=0.000)较对照组明显增加。两组内皮完整移植静脉均有较高的通畅率;去内皮移植静脉的通畅率明显降低,实验组通畅率高于对照组(67%vs.30%)。实验结束实验组去内皮移植静脉吻合口搏动指数(PI)明显低于对照组(t=2.958,P=0.009)。术后4周病理检查显示,两组移植静脉吻合口内膜均有不同程度地增生,去内皮移植静脉内膜增生程度较重,实验组去内皮移植静脉再内皮化完全,吻合口内膜增生程度明显轻于对照组(t=3.413,P=0.004)。结论造血干细胞动员对移植静脉有保护作用,可促进移植静脉的再内皮化,提高近期通畅率,预防吻合口内膜增生引起的再狭窄。

Objective To investigate the effects of haemopoietic stem cell mobilization on vein graft patency and intimal hyperplasia of anastomosis. Methods Twenty-four New Zealand rabbits were randomly divided into experimental group and control group, 12 rabbits in each group. A double side of carotid artery-vein transplantation model was made in each rabbit. One side of vein graft was digested by 0. 25% trypsin for complete endothelial denudation before transplantation. Recombinant human granulocyte colony-stimulating factor was given by subcutaneous injection 24 hours after operation, once per day in successive 10 days in experimental group, saline was given in the same way in control group. Bone marrow stem cells mobilization was observed after operation, including karyote counts and mononuclear cell proportion in peripheral blood. The patency rate of vein grafts and the degree of anastomosis intimal hyperplasia were observed too. Results The karyote counts （t= 8. 406, P= 0. 000）and mononuclear cell proportion（t= 31. 267 ,P= 0. 000） in peripheral blood of experimental group increased significantly 5 days after operation than those in control group. The vein grafts with intact endothelium had higher patency rate in both groups. In the vein grafts with complete endothelial denudation, the patency rate were obviously lower, but it was higher in experimental group than those in control group （67% vs. 30%）. In the end of experiment, the pulsatility index of the vein grafts anastomosis with complete endothelial denudation was lower in experimental group than that in control group （t = 2. 958,P = 0. 009）. Pathological examination showed that various degrees of intimal hyperplasia in all anastomoses of vein grafts were observed 4 weeks after operation. The degree of anastomosis intimal hyperplasia was more severe in vein grafts with complete endothelial denudation. Compared with control group, re-endothelization occurred completely in vein grafts with complete endothelial denudation of experimental group and the degree of anastomosis intimal hyperplasia was relatively lower （P ~ 0. 05）. Conclusion Haemopoietic stem cell mobilization can provide protective effects on vein grafts by accelerating reendothelization which might increase vein grafts patency rate in the near future after operation and reduce anastomosis restenosis caused by intimal hyperplasia.