伴有动静脉瘘的静脉狭窄模型的建立

目的　评价一种新的静脉狭窄模型的建立方法。方法　用手术方法在 6只成年实验猪的两侧颈动静脉之间建立了 12个动静脉瘘。然后在距吻合口上下 1～ 2cm处的颈静脉上用手指或镊子挤压造成局部损伤。分别在术后 3周、6周做血管造影随访 ,并处死动物 ,获取动静脉吻合、受损颈静脉的组织作病理学检查。狭窄程度用血管造影评价。结果　造影片上 ,12个动静脉吻合口有 6个保持通畅 ,无明显狭窄 ,5个通畅但有明显狭窄 ,1个完全闭塞。 2 4处被损伤的静脉点有 17处可见直径大于5 0 %的狭窄。组织学检查显示狭窄由局部组织增生所致。结论　动静脉瘘加局部静脉损伤可建成高血流量、增生性静脉狭窄。这一模型可能特别适用于研究发生在无肾功能、长期血透患者身上的血透管静脉狭窄。

Venous stenosis model induced by local mechanical injury with the presence of surgical arteriovenous fistula in swine

Objective To evaluate a new animal model of venous stenosis induced by local mechanical injury with the presence of surgical arteriovenous fistula (AVF).Methods Twelve arteriovenous (AV) fistulae were surgically formed between the carotid artery and internal jugular vein in six adult pigs, one on each side of the neck. Direct mechanical injury was made by crush injury with fingers or forceps to the jugular vein at the sites 1-2cm above and below the AV anastomosis. Angiographic follow up was performed at 3 and 6 weeks, and the animals were sacrificed. Fistulae and injured veins were harvested for histopathology. Results At angiography six AV anastomoses were patent without stenosis, five were stenosed and one had occluded. Eleven of twelve venous injury sites with open AV anastomosis and six of ten venous injury sites with AV anastomotic stenoses developed greater than 50% diameter stenosis. Dilation was found in the non injury segment of eight jugular veins. Stenoses were caused by neointimal hyperplasia as seen on histologic examination.Conclusions Neointimal venous stenosis can be induced by creation of a surgical AV fistula and local venous mechanical injury. This model may be used to study methods to reduce or inhibit neointimal hyperplasia, with particular reference to venous stenoses that occur in arteriovenous shunts created for dialysis access.