兔髂动脉腔内照射预防血管成形术后再狭窄实验研究初报

Intra arterial brachytherapy prevents restenosis in a rabbit iliac artery following percutaneous transluminal angioplasty

目的评价兔髂动脉内近距离治疗预防经皮经腔血管成形术（ＰＴＡ）后再狭窄的可行性及作用。方法２９只兔髂动脉进行ＰＴＡ后制成动脉狭窄模型，４周后将狭窄病灶分为３个组：（１）８只作为对照组，仅作ＰＴＡ；（２）９只ＰＴＡ后１９２Ｉｒ腔内照射１０Ｇｙ；（３）１２只ＰＴＡ后１９２Ｉｒ腔内照射１８Ｇｙ。全部兔饲养４周后活杀，取病理组织学标本进行分析。结果新内膜面积１～３组分别为（１３．８５±６．９２）μｍ２，（１４．７９±３．３４）μｍ２，（５．１０±２．１２）μｍ２（Ｐ＜０．０５）；管腔面积１～３组分别为（４．２４±１．４９）μｍ２，（３．５８±３．３７）μｍ２，和（１２．３１±５．５７）μｍ２（Ｐ＜０．０５）；狭窄面积１～３组分别为（０．６３±０．４０）μｍ２，（０．７８±０．１５）μｍ２，（０．５４±０．１４）μｍ２（Ｐ＜０．０５）；管腔壁最大厚度１～３组分别为（７９９．５０±１８４．５７）μｍ，（８９１．６０±１３７．００）μｍ，（３１２．３３±５６．８０）μｍ（Ｐ＜０．０５）。对各组内膜、中膜的平滑肌细胞中的肌动蛋白（Ａｃｔｉｎ）含量积分吸光度和单位平均吸光度的测定，１８Ｇｙ组数值明显低于对照组及１０Ｇｙ组（Ｐ＜?

Objective To evaluate the role of intra arterial brachytherapy to prevent the iliac artery restenosis in the rabbit following percutaneous transluminal angioplasty (PTA). Methods Twenty nine iliac arteries in the rabbit underwent artery angiography. One segment of the iliac artery was chosen as the target for balloon injury and was built into an artery stenosis model. Four weeks later, the stenotic lesions were divided into three groups. In eight and twelve rabbits, a ribbon of 192 Ir was positioned at the target segment and 10 Gy,18Gy was delivered at the vessel wall separately.Before that,overdilation balloon angioplasty had been performed at the irradiated segment.All animals survived and were sacrificed on D 28. Histopathologic analysis was performed. Results In the control group, the neointimal area (mean ±SD) was (13.85±6.92)μm 2 as compared with (14.79±3.34)μm 2 of the 10Gy irradiated group and (5.10±2.12)μm 2in the 18Gy group (P< 0.05 ).In the control group, the lumen area (mean ±SD) was (4.24±1.49)μm 2 as compared with (3.58±3.37)μm 2 of the 10Gy group , (12.31±5.57)μm 2 of the 18Gy group (P< 0.05 ).In the control group,the stenotic area (mean ±SD) was (0.63±0.40)μm 2 as compared with the (0.78±0.15)μm 2 of the 10Gy group and (0.54±0.14)μm 2 of the 18Gy group (P< 0.05 ).In the control group,the thickness (mean ±SD) of most lumen walls was (799.50±184.57)μm as compared with (891.60±137.00)μm of the 10Gy group and (312.33±56.80)μm of the 18Gy group. In the 18Gy group ,the mean integral absorbance and mean unit absorbance VSMCs actin were obviously less than the control and 10Gy groups(P< 0.05 ).In the 18Gy group, PCNA positive rate of VSMCs was less than the control and 10Gy groups( P< 0.05 ).Conclusions Administration of intra arterial irradiation with a 192 Ir source is technically feasible and compatible with an angioplasty laboratory environment .A dose of 18Gy is able to effectively induce long term inhibition of neointimal hyperplasia.