Department of General, Visceral and Vascular Surgery, Friedrich-Schiller-University, Jena, Germany.
J Vasc Surg. 2011 Jun;53(6):1661-7. doi: 10.1016/j.jvs.2011.01.061. Epub 2011 Apr 2.
The long-term prognosis of arteriovenous (AV) polytetrafluoroethylene (PTFE) hemodialysis grafts is dissatisfying. Responsible for the poor outcome is a stenosis of the venous anastomosis. This originates from both pseudointimal (PI) and neointimal hyperplasia (IH) development. Although cuffed grafts have a better short-term prognosis than straight grafts, the late results of both types are poor. This current study aimed to compare both arteriovenous straight and Venaflo-type (Bard, Tempe, Ariz) prostheses in an animal study with regard to patency, PI, and IH development.
Sixteen iliac arteriovenous expanded polytetrafluoroethylene (ePTFE) loops were inserted into 16 pigs. Animals were randomized into two groups. Group 1 animals received straight configured ePTFE grafts and group 2 animals received grafts with a Venaflo-type cuffed venous anastomosis. After insertion of the shunts and immediately before graft harvest, the shunt flows were measured. Six weeks after implantation, patency rates and development of pseudointima (PI) within the grafts were noted. The thickness of the venous intimal hyperplasia was measured using digital planimetry.
Patency rates after 6 weeks were 25% for straight and 62% for Venaflo-type grafts. In both groups a significant decrease of the graft blood flow compared with the preoperative levels was observed, which was attributed to the marked development of pseudointima. The reduction in flow at graft harvest was greater in the straight ePTFE group (658 ± 68 vs 260 ± 42 mL/min, P < .05) than for the Venaflo-type grafts (770 ± 107 vs 661 ± 284 mL/min, P = ns), but the differences between the groups were statistically not significant. A marked pseudointima developed in the Venaflo cuff. The PI development was significantly higher in the graft hood (2.9 ± 0.6 mm) than in the heel (2.5 ± 0.4 mm, P < .05). In both groups, an intimal hyperplasia formed on the vein wall just opposite to the graft inflow. The intimal hyperplasia development was more pronounced in the straight configured shunts.
The results of the present study confirm the inferior clinical results of ePTFE grafts used for hemodialysis access. Although the patency rates of cuffed grafts were superior, in both graft types a significant pseudointima leading to subtotal graft stenosis was observed in all grafts. Both straight and Venaflo-grafts. The Venaflo grafts have a slightly bettertype cuffed ePTFE grafts have major hemodynamic drawbacks that have to be addressed in future graft design efforts.
动静脉（AV）聚四氟乙烯（PTFE）人造血管移植物的长期预后并不令人满意。静脉吻合口狭窄是导致不良预后的原因，这种狭窄源于假内膜（PI）和新生内膜（IH）的发展。虽然带袖套的移植物的短期预后优于直型移植物，但两种类型的晚期结果都很差。本研究旨在通过动物研究比较动静脉直型和 Venaflo 型（Bard，Tempe，Ariz）假体的通畅率、PI 和 IH 的发展。
将 16 个髂动静脉扩张聚四氟乙烯（ePTFE）环插入 16 头猪。动物随机分为两组。第 1 组动物接受直型配置的 ePTFE 移植物，第 2 组动物接受具有 Venaflo 型带袖套静脉吻合的移植物。在插入分流器后和在移植物取出前立即测量分流器流量。植入后 6 周，记录通畅率和移植物内 PI 的发展情况。使用数字平面度计测量静脉内膜增生的厚度。
植入 6 周后，直型和 Venaflo 型移植物的通畅率分别为 25%和 62%。两组均观察到与术前水平相比，移植物血流明显减少，这归因于明显的 PI 形成。在直型 ePTFE 组（658 ± 68 比 260 ± 42 mL/min，P <.05），在 Venaflo 型移植物组（770 ± 107 比 661 ± 284 mL/min，P = ns），在移植物取出时的流量减少更为明显，但两组之间的差异无统计学意义。Venaflo 袖口形成明显的 PI。移植物罩部（2.9 ± 0.6 mm）的 PI 发展明显高于鞋跟部（2.5 ± 0.4 mm，P <.05）。在两组中，静脉壁正对移植物流入处形成内膜增生。直型配置的移植物中，内膜增生更为明显。
本研究结果证实了用于血液透析通路的 ePTFE 移植物的临床效果较差。尽管带袖套移植物的通畅率较高，但在两种移植物类型中，所有移植物均观察到明显的 PI，导致移植物总狭窄。直型和 Venaflo 型移植物都存在严重的血流动力学缺陷，这在未来的移植物设计中需要解决。
Zotero 插件