^(103)Pd支架预防血管成形术后再狭窄量效关系研究

The dose-effectiveness of ^(103) Pd radioactive stent for preventing post-angioplasty restenosis in rabbits

目的 探讨1 0 3Pd支架对血管成形术后再狭窄预防作用的量效关系及是否导致边缘再狭窄。方法 5 0只雄性新西兰兔随机分为普通支架组和核素支架各剂量组 (8只 组 )。支架植入术后 8周行腹主动脉血管内超声和造影检查。结果 核素支架组随剂量增加 ,支架段血管最小内径和支架段血管管腔切面积均增大 ,狭窄程度减小 ;核素支架 2 5及 35Gy组支架边缘段血管管腔内增生内膜切面积及外弹力板切面积变化 (缩小值 )均小于普通支架组 (P <0 .0 5 )。结论 1 0 3Pd支架可抑制支架内内膜增生 ,减轻支架内狭窄程度 ,且不引起边缘再狭窄。

Objective To investigate the dose response and optimal radioactivity dose of 103 Pd radioactive stent for preventing restenosis in rabbits, and to prove that it reduces in stent restenosis without edge restenosis. Methods The abdominal aorta of the rabbits randomized to common or radioactive stent groups (including 5,15,25 and 35 Gy subgroups)were balloon injured,followed by stenting. Intravascular ultrasound and angiography on abdominal aortae were performed 8 weeks after stenting. Results Both the minimal lumen diameter and in stent lumen area in 103 Pd radioactive stent groups [(1.94±0.21) mm and (5.99±0.43) mm 2, (2.17±0.12) mm and (7.01±0.93) mm 2, (2.43±0.22) mm and (8.09±0.89) mm 2, (2.56±0.27) mm and (8.49±0.54) mm 2 for the 5, 15, 25 and 35 Gy subgroups, respectively] were significantly improved corresponding with the stepwise escalating doses at the end of 8 weeks,revealing a dose dependent effect. At the edge segments, late lumen area loss (magnitude of stenosis), in stent neointimal area and the decrease of external elastic membrane (EEM) area in 25 and 35 Gy 103 Pd radioactive stent subgroups [(1.41±0.84), (0.65±0.60), (0.76±0.36) mm 2 and (1.32±1.02), (0.69±0.60), (0.64±0.53) mm 2, respectively] were lower than that in common stent group [(2.88±1.43), (1.68±1.30) and (1.20±0.41) mm 2, respectively, all P <0.05 versus control]. Conclusions 103 Pd radioactive stent could dose dependently restrain in stent neointimal hyperplasia, reduce the magnitude of in stent stenosis, and the optimal prescribed dose was 25 Gy.The possible mechanism of the preventive effects of 103 Pd radioactive stent on obvious edge restenosis could be both inhibition of in stent neointimal hyperplasia and arterial negative remodeling.