下腔静脉人工血管置换术后放疗对血管内膜的影响

目的 观察术后放疗对犬下腔静脉人工血管置换术后人工血管内膜的影响.方法 犬16只完全随机法分为对照组(n=8)和放疗组(n=8),均行下腔静脉膨体聚四氟乙烯(ePTFE)人工血管置换术.放疗组于术后第2N行体外35 Gy放疗,对照组术后不予放疗.2N犬均于术后第8N采集标本,观察人工血管通畅率,并行HE染色、人工血管内膜厚度测量,增殖细胞核抗原(PCNA)及CD34免疫组化检测,计算人工血管内膜100μm内皮细胞数.结果 术后第8周,放疗组人工血管通畅率为100%(8/8),对照组为75%(6/8).放疗组各段人工血管内膜厚度较对照组明显减少近心端:(610.69±32.90)μm比(753.39+10.36)μm,中段:(530.51±32.14)μm比(636.55±20.23)μm,远心端:(544.52±41.99)μm比(710.39±30.92)μm,均P＜0.01].放疗组各段人工血管内膜的PCNA阳性细胞百分率较对照组减低近心端:(45.1±7.5)%比(56.3±7.8)%,中段:(29.2±4.1)%比(36.6±4.9)%,远心端:(33.8±5.5)%比(40.7±6.7)%,均P＜0.05].2组人工血管内膜100μm内皮细胞数的比较差异无统计学意义(P＞0.05).结论 下腔静脉人工血管术置换后35 Gy体外放疗不影响移植人工血管通畅率,对内膜血管平滑肌细胞的覆盖亦无明显影响,但可抑制人工血管内膜增生和PCNA的表达.

Effects of postoperative irradiation on the neointima of artificial blood vessel after prosthetic vessel replacement of inferior vena cava

Objective To investigate the effects of postoperative irradiation on the neointima of artificial blood vessel after prosthetic vessel replacement of inferior vena cava in dogs.Methods Sixteen dogs underwent ePTFE (expended poly-tetra fluoroethylene) prosthetic vessel replacement of inferior vena cava and were then randomly divided into radiotherapy group and control group (n=8 each).For the radiotherapy group, external radiation (35 Gy) was given at two weeks after surgery.Samples were then collected from these two groups on week 8 for study of patency rate of the artificial blood vessel.In addition,HE staining, measurement of neointima thickness, PCNA (proliferating cell nuclear antigen) and CD34 stained immunohistochemistry were performed, and number of endothelial cells (ECs) within 100 Jim neointima were counted.Results The patency rate was 100% (8/8) in radiotherapy group and 75% (6/8)in control group on week 8.The neointima thickness at each segment of artificial blood vessel was significantly decreased in radiotherapy group compared with those in the control group proximal segment:(610.69±32.90)μm vs(753.39±10.36)μm; mid segment: (530.51 ±32.14 )jun vs(636.55?0.23)μm; distal segment: (544.52±41.99)μm vs (710.39±30.92)μm, all P＜0.01].The percentage counts of PCNA positive cells in each segment of artificial blood vessel were lowered in the radiotherapy group compared with those in the control group proximal segment: (45.1±7.5)% vs(56.3±7.8)% ; mid segment: (29.2 ±±4.1)% vs(36.6±4.9)%; distal segment: (33.8±5.5)% vs (40.76±.7)%, all P＜0.05].There was no statistical difference in number of ECs within 100 p,m neointima between two groups (P>0.05).Conclusion External radiation (35 Gy) after prosthetic vessel replacement of inferior vena cava has no significant impact on the patency of artificial blood vessel, nor on linings of vascular smooth muscle cells in neointima, but may inhibit the neointima proliferation and PCNA expression.