de Gregorio M A, Gimeno M J, Tobio R, Lostalé F, Mainar A, Beltrán J M, Madariaga B, Alfonso E R, Medrano J, Viloria A
Department of Interventional Radiology, University of Zaragoza, Spain.
Cardiovasc Intervent Radiol. 2001 Nov-Dec;24(6):413-7. doi: 10.1007/s00270-001-0063-1. Epub 2001 Nov 8.
To assess the retrievability of the Günther Tulip temporary inferior vena cava filter from a technical viewpoint, and consider the histopathologic changes that occur at the anchoring site of the filter prongs to the vein endothelium in Landrace pigs.
Twenty-two Günther Tulip retrievable filters were inserted in 22 experimental Landrace pigs via the jugular vein. Device implantation time was 0, 3, 7, 12, 14, 15, 16, 20, 30, 35 and 56 days. Study subjects were divided into two groups. In one group the filter was retrieved percutaneously via the jugular vein whereas in the other group it was removed surgically. The specimens obtained (vena cava and filter) were histopathologically examined. Prior to filter retrieval, a venacavography was obtained in all cases. Degree of retrieval difficulty was rated as follows: no difficulty (N), slight (S), mild (M), high (H) and unretrievable (U).
Of the 22 implanted filters, 11 should have been removed percutaneously but this was impossible in three cases (U). In four cases the device was retrieved with no difficulty (N); in two cases the degree of difficulty was mild (M) and in other two it was high (H) and slight (S) respectively. Retrieval difficulties were observed after 16 days. Starting from day 20, there was evidence of fibrosis with thick intimal proliferation and total filter prong involvement, which accounts for the difficulty in retrieving the device.
It is advisable not to exceed a filter retrieval time of 16 days in view of the fibrotic changes reported. It might be necessary to perform a larger study with more animals and with retrieval times between 14 and 20 days.
从技术角度评估 Günther Tulip 临时下腔静脉滤器的可回收性，并研究长白猪体内滤器尖端与静脉内皮锚固部位发生的组织病理学变化。
通过颈静脉将 22 个 Günther Tulip 可回收滤器植入 22 只实验用长白猪体内。器械植入时间分别为 0、3、7、12、14、15、16、20、30、35 和 56 天。研究对象分为两组。一组通过颈静脉经皮回收滤器，另一组则通过手术取出。对获取的标本（腔静脉和滤器）进行组织病理学检查。在回收滤器之前，所有病例均进行了腔静脉造影。回收难度分级如下：无困难（N）、轻微（S）、轻度（M）、高度（H）和无法回收（U）。
在植入的 22 个滤器中，11 个本应经皮取出，但 3 例无法取出（U）。4 例滤器顺利取出（N）；2 例取出难度为轻度（M），另外 2 例分别为高度（H）和轻微（S）。16 天后出现回收困难。从第 20 天开始，有证据表明存在纤维化，伴有内膜增厚和滤器尖端完全受累，这是导致器械回收困难的原因。
鉴于所报道的纤维化变化，建议滤器回收时间不要超过 16 天。可能有必要进行一项更大规模的研究，使用更多动物，并将回收时间设定在 14 至 20 天之间。
