Proctor M C, Greenfield L J, Cho K J, Moursi M M, James E A
Department of Surgery, University of Michigan, Ann Arbor 48109, USA.
J Endovasc Surg. 1998 Aug;5(3):251-8. doi: 10.1177/152660289800500311.
To examine and elucidate the mechanisms for apparent "penetration" by Greenfield vena caval filters.
Two filters were placed in the inferior venae cavae (IVC) of four immature sheep and followed with cavography for 1 year. Two animals underwent computed tomography (CT) and laparoscopic examination. At necropsy, the vena cava and adjacent structures of all four animals were examined grossly and histologically.
Based upon cavography and CT imaging, all filters appeared to penetrate the vena cava at 12 months. However, at laparoscopy, no hooks or limbs were exposed, and the pericaval tissues remained intact; each hook or limb was within the adventitia or encapsulated in scar tissue. Histology of the tissue at the hook sites revealed remodeling of the intimal surface of the IVC and thinning of the adventitia.
Based upon these data, we hypothesize that the vena cava gradually adapts by medial and adventitial thinning and myointimal remodeling to the radial force exerted by a filter. This process allows increase in the filter base diameter while maintaining the integrity of the cava and protecting adjacent structures.
研究并阐明格林菲尔德腔静脉滤器出现明显“穿透”现象的机制。
将两个滤器放置于四只未成年绵羊的下腔静脉（IVC）中，并进行腔静脉造影随访1年。两只动物接受了计算机断层扫描（CT）和腹腔镜检查。尸检时，对所有四只动物的腔静脉及相邻结构进行大体和组织学检查。
根据腔静脉造影和CT成像，所有滤器在12个月时似乎都穿透了腔静脉。然而，在腹腔镜检查中，没有发现钩子或支腿暴露在外，腔静脉周围组织保持完整；每个钩子或支腿都位于外膜内或被包裹在瘢痕组织中。钩子部位组织的组织学检查显示，IVC内膜表面重塑，外膜变薄。
基于这些数据，我们推测腔静脉通过中膜和外膜变薄以及肌内膜重塑逐渐适应滤器施加的径向力。这一过程使得滤器基部直径增加，同时保持腔静脉的完整性并保护相邻结构。
