Sun Shuching, Beitler Jonathan J, Ohki Takao, Calderon Tina M, Schechner Richard, Yaparpalvi Ravindra, Berman Joan W, Tellis Vivian A, Greenstein Stuart M
Department of Surgery, Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, New York, NY 10467, USA.
J Surg Res. 2003 Dec;115(2):200-8. doi: 10.1016/s0022-4804(03)00253-1.
To determine whether endovascular radiation can inhibit intimal hyperplasia in a swine model of hemodialysis access.
Polytetrafluoroethylene arteriovenous grafts (6 mm in diameter) were placed between the common carotid artery and the external jugular vein bilaterally in 8 pigs. Two days after the surgery, fistulography was performed. Gamma radiation (12 Gy) was delivered endovascularly to one of the grafts at the venous anastomosis by using an iridium(192) source. Thus, the other graft in each pig served as an untreated control. Fistulas were evaluated with fistulography or venography 6 week after radiation. All grafts were then harvested for histological and immunohistochemical examination.
Seven grafts on the treated side and 5 grafts on the control side remained patent for at least 6 weeks. Angiography demonstrated that the percentage stenosis at the venous anastomosis was significantly lower for the treated group (15.9 +/- 14.1 versus 32.6 +/- 16.7%, P = 0.045). Histopathologic analyses revealed that the mean intimal area and maximal intimal thickness were significantly lower with reduced smooth muscle cell proliferation at the venous anastomosis on the treated side compared to the control side (0.68 +/- 0.30 versus 1.06 +/- 0.29 mm(2), P = 0.017, and 0.18 +/- 0.08 versus 0.26 +/- 0.07 mm, P = 0.004, respectively). The residual lumen was significantly greater for the treated group (1.59 +/- 0.42 versus 1.06 +/- 0.37 mm(2), P = 0.031). No significant differences were found in the area, nor maximal thickness in the vein either proximal or distal to the anastomosis between the two groups.
In an animal model of hemodialysis access, brachytherapy with iridium(192) delivered 2 days after graft implantation reduces intimal hyperplasia and stenosis at the venous anastomosis. The reduced smooth-muscle cells found in the radiated veins suggests that brachytherapy may exert its effect on neointimal formation by inhibition of smooth muscle cell proliferation.
确定血管内放射治疗能否抑制猪血液透析通路模型中的内膜增生。
在8头猪双侧的颈总动脉和颈外静脉之间植入直径6mm的聚四氟乙烯动静脉移植物。术后两天进行瘘管造影。使用铱（192）源对其中一个移植物的静脉吻合口进行血管内γ射线照射（12Gy）。因此，每头猪的另一个移植物作为未治疗的对照。放射治疗6周后，通过瘘管造影或静脉造影评估瘘管情况。然后将所有移植物取出进行组织学和免疫组织化学检查。
治疗侧7个移植物和对照侧5个移植物至少保持通畅6周。血管造影显示，治疗组静脉吻合口处的狭窄百分比显著低于对照组（15.9±14.1对32.6±16.7%，P = 0.045）。组织病理学分析显示，与对照侧相比，治疗侧静脉吻合口处的平均内膜面积和最大内膜厚度显著降低，平滑肌细胞增殖减少（分别为0.68±0.30对1.06±0.29mm²，P = 0.017；0.18±0.08对0.26±0.07mm，P = 0.004）。治疗组的残余管腔显著更大（1.59±0.42对1.06±0.37mm²，P = 0.031）。两组在吻合口近端或远端静脉的面积和最大厚度方面均未发现显著差异。
在血液透析通路动物模型中，移植物植入2天后进行铱（192）近距离放射治疗可减少静脉吻合口处的内膜增生和狭窄。在接受放射治疗的静脉中发现平滑肌细胞减少，提示近距离放射治疗可能通过抑制平滑肌细胞增殖对新生内膜形成发挥作用。
