Teng G J, Bettmann M A, Hoopes P J, Ermeling B L, Yang L, Wagner R J
Department of Radiology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, USA.
Acad Radiol. 1998 Aug;5(8):547-55. doi: 10.1016/s1076-6332(98)80206-7.
The authors attempted to determine the histologic processes that take place during development of stenosis after transjugular intrahepatic portosystemic shunt (TIPS) creation.
TIPS were created with metallic stents in 20 healthy domestic pigs (tantalum stents in 10, stainless steel stents in 10). The animals were sacrificed 2-16 days later. All the shunts were examined by means of venography both immediately after placement of the stents and before sacrifice. All histologic sections were assessed with modified Giemsa and basic fuchsin stains. Anti-smooth-muscle-cell alpha-actin stain was used in three specimens. The stenotic reaction was quantified by using standard planimetry techniques and a computerized image-analysis system.
Within 16 days after TIPS placement, 15 (75%) of the 20 shunts were completely occluded, four (20%) of 20 shunts were partially occluded, and one (5%) of 20 shunts remained widely patent (animal died of unknown cause 2 days after the TIPS procedure). Stent occlusion was caused primarily by pseudointimal hyperplasia, which was similar morphologically in the portal, middle, and hepatic portions of the stent. Myofibroblastic proliferation was the most striking feature of the pseudointimal hyperplasia. The average thickness of the proliferation was 2.14 mm, which was 67% of the total diameter of the stent. A mild fibrous or lymphocytic reaction occurred around the stent wires and between the pseudointimal hyperplasia and the liver parenchyma.
The histologic features of pseudointimal formation in this swine TIPS model closely resemble those in humans. This model may prove useful for evaluating stents and other devices and improving the understanding of restenosis after vascular interventions.
作者试图确定经颈静脉肝内门体分流术（TIPS）建立后狭窄形成过程中发生的组织学变化。
对20头健康家猪采用金属支架建立TIPS（10头使用钽支架，10头使用不锈钢支架）。术后2至16天处死动物。所有分流道在支架置入后即刻及处死前均通过静脉造影进行检查。所有组织切片采用改良吉姆萨染色和碱性品红染色进行评估。对三个标本使用抗平滑肌细胞α-肌动蛋白染色。采用标准的面积测量技术和计算机图像分析系统对狭窄反应进行定量分析。
TIPS置入后16天内，20个分流道中有15个（75%）完全闭塞，20个分流道中有4个（20%）部分闭塞，20个分流道中有1个（5%）仍保持通畅（该动物在TIPS术后2天死于不明原因）。支架闭塞主要由假内膜增生引起，在支架的门静脉段、中段和肝静脉段，其形态相似。肌成纤维细胞增殖是假内膜增生最显著的特征。增殖的平均厚度为2.14mm，占支架总直径的67%。在支架丝周围以及假内膜增生与肝实质之间出现轻度的纤维性或淋巴细胞反应。
该猪TIPS模型中假内膜形成的组织学特征与人类极为相似。该模型可能有助于评估支架及其他装置，并增进对血管介入术后再狭窄的理解。
