可降解壳聚糖血管外周支持与静脉移植物早期结构的变化

目的　探讨可降解壳聚糖血管外周支持 (CES)对静脉移植物 (VG)早期结构变化的影响 ,为临床提高VG通畅率提供新的治疗方法。　方法　将兔右颈内静脉端 端吻合于同侧颈总动脉建立静脉移植模型 ,以有无CES干预分为支架组与无支架组 (每组 2 4只兔 )。术后 1、2、4周分别切除移植静脉 ,计算机图像分析系统测量和计算内膜、中膜厚度和面积 ,免疫组织化学法检测增殖细胞核抗原 (PCNA)指数观察平滑肌细胞增殖程度。　结果　CES在术后 2周开始降解。支架组VG ,术后 1～ 2周内膜、中膜的厚度和面积、PCNA指数在术后 1周轻度增加 ,1～ 2周维持稳定 ,术后 2周分别为(2 6 3± 3 7) μm、(2 6 0± 1 9) μm、(0 5 6± 0 0 8)mm2 、(0 34± 0 0 5 )mm2 与 (11 5± 2 1) % ,明显低于无支架组的 (5 6 4± 9 4 ) μm、(47 6± 4 9) μm、(1 17± 0 0 8)mm2 、(1 2 0± 0 4 3)mm2 与 (36 6± 2 9) % (P <0 0 1) ;术后 4周虽然又增加 ,分别为 (31 7± 1 6 ) μm、(31 7± 1 6 ) μm、(0 72± 0 12 )mm2 、(0 4 2± 0 0 6 )mm2 与 (13 4± 1 2 ) % ,但仍低于无支架组的 (76 8± 8 0 ) μm、(5 7 4± 9 5 ) μm、(1 2 7± 0 17)mm2 、(1 2 7± 0 0 9)mm2 与 (16 8± 2 2 ) % (P <0 0 5 )。结论　CES

Effect of the biodegradable chitosan external stent on the early changes in the rabbit vein grafts

Objectives To investigate the effect of chitosan biodegradable external stent (CES)on the early changes of rabbit vein graft(VG). Methods Rabbit vein grafting models were divided into S group(with perivenous CES) and NS group (without perivenous CES).The VG were harvested in 1 week,2 weeks,4 weeks after operation,respectively.The expression of proliferating cell nuclear antigen (PCNA) was used for evaluating the proliferation of the smooth muscle cell(SMC). The thickness,area of neointima and media of the VG were calculated by computer imaging analysis system. Results CES began to degrade in 2 weeks after operation. The thickness,area of both neointima and media of the VG in S group,increased mildly in 1 week after operation,and kept steady in 1 or 2 weeks after grafting,which was significantly less than NS group(both P <0.01),then increased mildly in 4 weeks after grafting but still less than NS group ( P <0.05). The expression of PCNA of SMC decreased significantly in comparison with NS group though increasing mildly in four weeks after operation. Both neointimal formation and cell proliferation in the graft wall were significantly reduced by external stenting as compared to the results with unstented grafts. Conclusions CES may reduce early intimal and medial hyperplasia,and may be beneficial in improving the long term patency of the VG. The biodegradable characteristics of the CES may influence its effect.