Placement of a vena cava filter with an antecubital approach

RATIONALE AND OBJECTIVES: The authors performed this study to evaluate the use of an antecubital venous approach for inferior vena cava (IVC) filter placement. MATERIALS AND METHODS: An IVC filter was placed in 26 patients (15 men, 11 women) in whom the antecubital vein was the preferred access site. An antecubital vein was accessed with ultrasound guidance and used for IVC filter placement. This same access site was used to place a peripherally inserted central catheter (PICC) in 17 of the 26 patients. Access was obtained via the basilic vein in 15 patients (58%), brachial vein in eight (31%), and cephalic vein in three (12%). RESULTS: The IVC filter was successfully placed in the infrarenal vena cava in all 26 patients (100%) by using an antecubital vein for access. All filters deployed appropriately without complication. No complications occurred during PICC placement. CONCLUSION: The IVC filter can be safely placed via an antecubital vein. When clinically necessary, this site can provide convenient access for the PICC placement.     

In vivo evaluation of the adjustable temporary venous spring filter and the RF02 temporary filter: Comparative study

RATIONALE AND OBJECTIVES: The authors performed this study to compare the in vivo efficacies of the temporary venous spring filter and the RF02 filter in an animal model. MATERIALS AND METHODS: Either the spring filter or the RF02 filter was placed in the inferior vena cava of 10 pigs each, and two clots (5 x 20 mm) were funneled into the filters at 1-hour intervals. The second clots were funneled without removing the first clots captured by the filters. Clot-trapping ability, caval occlusion associated with the clot-trapping procedure, arterial blood gas concentrations, and changes in arterial and iliac venous pressures were evaluated. RESULTS: Placement of the RF02 filter caused elevation of iliac venous pressure with a maximum of 2.2 mm Hg (median) (n = 13, P = .003). Placement of the spring filter parallel to venous flow enabled capture of 90% (nine of 10) and 100% (six of six) of the first and second clots, respectively. The RF02 filter captured clots consistently. The difference between filters was not statistically significant. Both filters equally contributed to elevation of iliac venous pressure (median, 9.3 and 7.2 mm Hg [n = 9] with the spring filter and RF02 filter, respectively). Caval occlusion occurred in 17% (one of six) and 67% (six of nine) of animals after two clots were trapped in the spring filter and RF02 filter, respectively (P = .06). Other parameters were not influenced by the clot-trapping procedure. CONCLUSION: Although a larger version should be developed and better stability of the filter is needed, the spring filter proved to be an efficient filtering device and had a lower rate of caval occlusion compared with the RF02 filter.     

Pulse-spray thrombolysis of inferior vena cava thrombosis complicating filter placement

Inferior vena cava thrombosis is an uncommon but potentially serious complication of caval filter placement. A 34-year-old man with symptomatic caval thrombosis, which occurred 6 weeks after filter placement, was successfully treated with a combination of pulse-spray and local infusion of urokinase.     

In vitro evaluation of caval filters

This experiment demonstrated the clottrapping ability of two commercially available filters, the Mobin-Uddin and Greenfield, and three experimental filters developed by Amplatz, Günther, and Gianturco. Each filter was tested in a polyethylene tube simulating the inferior vena cava. Separate series of 10 clots, each 3 cm long and 6 mm or 9.2 mm in diameter, were exposed to the test filter. The Mobin-Uddin and Amplatz filters failed by overload: acutely elevated pressures forced clots outside the skirt of the former, and between the limbs of the latter. The Günther filter trapped all incident clots, but migrated downstream when occluded by clot. The Greenfield filter passed clots at normal pressures between its widely spaced legs. The Gianturco (bird's nest) passed clots at normal pressures as well. While filters performed suboptimally, strengthening the anchoring struts of the Günther filter would result in a secure, effective filter.     

Retrieving the Amplatz retrievable vena cava filter

The new Amplatz retrievable filter was placed 15 times into the inferior vena cava (IVC) of 7 dogs. Retrieval of the filter was attempted in 11 cases after 1 week and in 3 cases after 2 weeks. The retrieval was successful and without complication in all 14 cases. The 15th placement resulted in thrombotic occlusion of the IVC, and no retrieval was attempted.     

The Günther temporary inferior vena cava filter for short-term protection against pulmonary embolism

Purpose To evaluate clinically the Günther temporary inferior vena cava (IVC) filter. Methods Eleven IVC filters were placed in 10 patients. Indications for filter placement were surgical pulmonary embolectomy in seven patients, pulmonary embolism in two patients, and free-floating iliofemoral thrombus in one patient. Eight filters were inserted from the right femoral approach, three filters from the left. Follow-up was by plain abdominal radiographs, cavography, and duplex ultrasound (US). Eight patients received systemic heparinization. Follow-up, during 4–60 months after filter removal was by clinical assessment, and imaging of the lungs was performed when pulmonary embolism (PE) was suspected. Patients received anticoagulation therapy for at least 6 months. Results Ten filters were removed without complications 7–14 days (mean 10 days) after placement. One restless patient pulled the filter back into the common femoral vein, and a permanent filter was placed. In two patients a permanent filter was placed prior to removal. One patient developed sepsis, and one an infection at the insertion site. Clinically no recurrent PE developed with the filter in place or during removal. One patient had recurrent PE 7 months after filter removal. Conclusion The Günther temporary IVC filter can be safely placed for short-term protection against PE. The use of this filter is not appropriate in agitated or immunocompromised patients.     

Prophylactic implantation of inferior vena cava filter during endovascular therapies for deep venous thrombosis of the lower extremity: is it necessary?

Background: There is strong controversy as to whether to use filters temporarily in the inferior vena cava (IVC) during endovascular therapies for deep venous thrombosis (DVT) in the lower extremity.

Purpose: To evaluate the necessity of implantation of a retrievable inferior vena cava filter during treatment of DVT in the lower extremity using various endovascular techniques.

Material and Methods: Studied were all 37 consecutive sessions of endovascular treatments performed in 34 patients with symptomatic lower-limb DVT between April 2001 and October 2006. In all sessions, a Gunther tulip retrievable vena cava filter (GTF) was implanted during the procedures. The degree of trapped thrombus in the filter was evaluated by repeated venocavography.

Results: Implantation of a total of 66 GTFs was successfully performed in 37 sessions. Worsening of or new formation of pulmonary embolism was avoided in all patients. In 20 (54.1%) of the 37 sessions, a trapped thrombus in the filter was observed. In 14, the trapped thrombus was large, filling more than half the height of the filter.

Conclusion: Temporary implantation of filters is effective in preventing pulmonary emboli during endovascular treatment of DVT in the lower extremities.     

可回收下腔静脉滤器预防肺栓塞实验研究

目的：评价新型可回收下腔静脉滤器(RNIVCF)的稳定性、血栓捕获能力、可回收性及安全性。方法：体外实验评定RNIVCF捕获直径2．5、3和4mm混合血栓的能力。实验犬12只，10只经股静脉注入直径2．5mm自体不透X线混合血栓，评价RNIVCF血栓捕获能力；2只在置入RNIVCF后第7天尝试取出。摄腹部及胸部平片验证滤过效果。结果：体外实验证实RNIVCF捕获了直径3和4mm混合血栓的100%，直径2．5mm混合血栓的95％～100％。成功地在12只犬下腔静脉(IVC)经皮置入13枚RNIVCF，其中1只犬为双IVC，置入2枚滤器。lO只犬体内的11枚RNIVCF成功地捕获了经股静脉注入的直径2．5mm的混合血栓，无一死亡。2枚滤器在置入后第7夫经皮回收没有困难。结论可回收滤器既可以长期留置，又可以临时置入，更为实用。优点：①可经皮经5F输送器置入及回收；②滤器无钩刺，对腔静脉壁无损伤；③置入后稳定；④捕获小血栓有效。     

Complications of the nitinol vena caval filter.

Simon nitinol vena caval filters were placed percutaneously in 20 patients. Follow-up (average, 14 months) data were available for 16 patients, and four patients were lost to follow-up. There were no proved or suspected cases of pulmonary embolism after filter insertion. Complications encountered included caval penetration (n = 5, one acute and four at follow-up), caval thrombus (n = 4, two determined radiologically and two clinically), postplacement deep venous thrombosis (n = 2, one radiologic and one clinical), filter migration (n = 1), and delayed fracture of a filter leg (n = 2). Although no deaths or significant morbidity resulted from any complication, the relatively high complication rate, especially of significant caval penetration (documented in 25% of filter insertions), merits continued short- and long-term assessment of patient status after filter placement.     

In vitro evaluation of a new temporary venous filter: The spring filter

Purpose To evaluate in vitro the functional efficacy of a new variable-sized, temporary venous filter, the Spring filter (SF).Methods The SF was tested in a flow phantom, using flexible, thin-walled polyethylene tubes 12, 14, and 16 mm in diameter to simulate veins. Clots of three sizes were used: 6 × 10 mm, 6 × 20 mm, 9 × 20 mm. Filter deployment was performed, ensuring that its functional diameter after placement was a predetermined multiple of the radius r of the tube: 3.0r, 2.8r, 2.6r, 2.4r. The terminal coil was visually examined for changes in configuration. Clot retention by the filter for a period of 3 min was recorded as a success. The baseline intraluminal pressure and the maximum pressure reached after clot introduction were recorded. The trapping ability was calculated from the results for 10 clots. The effect of the following parameters on filter function were studied: size of embolus, caliber of simulated vein, and functional diameter of filter.Results The filter configuration was stable. Not a single instance of axial tilting occurred on deployment. Functional diameter was the major determinant of filter function. One hundred percent of clots were trapped irrespective of clot size and tube caliber when the functional diameter was 3.0r. Only 73% (95% confidence interval (CI): 57%–88%) and 77% (95% CI: 61%–92%) of small emboli were held up by the filter when the functional diameters were 2.6r and 2.4r, respectively (p = 0.0001). A significant reduction in clot trapping was encountered even with medium clots when the functional diameter was 2.4r (p = 0.02).Conclusion Against the background of available data on retrievable vena caval filters, the current model of SF warrants further investigation.     

国产ZQL型可回收式腔静脉滤器的初步临床应用与观察

目的　探讨自行开发的可回收式腔静脉滤器 (国产ZQL型可回收式腔静脉滤器 ,以下简称滤器 )预防肺动脉栓塞的临床应用价值。方法　对 2 4例下肢深静脉血栓形成 (deepveinthrombosis,DVT)和 (或 )肺动脉栓塞 (pulmonaryembolism ,PE)的患者经右侧颈内静脉或经健侧股静脉置入滤器 ,并同时行肺动脉造影。术后第 3和第 7天摄腹部平片。术后 3、6、12、18个月摄腹部平片及行下腔静脉、肺动脉造影。如果在 2周内下肢深静脉血栓完全清除 ,则取出滤器 ,取出前摄腹部平片及行下腔静脉、肺动脉造影 ;如果在 2周内下肢深静脉血栓未能完全清除则将滤器长期留置于下腔静脉内。如果随访期间出现病情变化 ,则需随时复查。所有影像资料经 2位主任医师采用盲法进行评价。结果　 2 4例患者的下腔静脉滤器均成功置入预定部位 ,其中肾静脉水平以下 2 3例 ,肾静脉水平以上1例 ,2例患者置于肾静脉水平以下的滤器分别于术后第 7天和第 9天顺利取出。中位随访期为 6个月。未发生滤器展开不良、滤器移位 (>10mm)、滤器倾斜 (>10°)、滤器断裂或滤器穿透静脉壁造成血肿等。除 1例腔静脉滤器捕获栓子外 ,未发生滤器血栓形成 ,无下腔静脉闭塞发生 ,随访期内全部患者未再发生肺动脉栓塞。结论　国产滤器置入操作简便、定位准确、稳定性     

自制可回收下腔静脉滤器预防急性肺栓塞的实验研究

目的 探讨一种新型可回收下腔静脉滤器预防急性肺栓塞的有效性、安全性.方法 12只犬制备成髂股深静脉血栓模型,分为滤器组(实验组)与无滤器组(对照组),每组6只.滤器组在深静脉血栓脱落前于对侧股静脉置入下腔静脉滤器,其后使血栓脱落;对照组直接使血栓脱落即形成肺动脉栓塞.通过血栓脱落前后的肺动脉造影、肺动脉测压以及动脉血氧饱和度测定评价滤器的血栓捕获性能.结果 滤器组均成功捕获脱落的深静脉血栓,无一例发生肺动脉栓塞,8 h后滤器均能成功回收;而对照组在推注血栓后均发生了肺动脉栓塞.结论 自制可回收下腔静脉滤器能有效预防下肢深静脉急性血栓脱落引起的肺动脉栓塞,其置入和回收简便.     

Results of a multicenter study of the retrievable Tulip vena cava filter: Early clinical experience

Purpose To evaluate clinically a new, retrievable vena caval filter in a multicenter study. Methods The Tulip filter is a stainless steel half-basket that is suitable for antegrade or retrograde insertion via an 8.5 Fr introducer sheath. The filter can be retrieved via the jugular approach using an 11 Fr coaxial retrieval system. Forty-eight filters were implanted via the femoral approach and 38 via the jugular approach in 83 patients. Follow-up examinations (plain films, colorcoded duplex sonography) were performed up to 3 years after filter insertion (mean 136 days) in 75 patients. Twenty-seven patients were screened by colorcoded duplex sonography for insertion site thrombosis. Results An appropriate filter position was achieved in all cases. Insertion problems occurred in 3 cases; these were not due to the filter design but to an imperfect prototype insertion mechanism that has now been modified (n=2) or a manipulation error (n=1). In 2 of these cases the filters were replaced percutaneously; 1 patient required venotomy for filter removal. No further complications due to filter insertion occurred. Two filters were used as temporary devices and were successfully removed after 6 and 11 days, respectively. There was 1 fatal recurrent pulmonary embolism (PE) and 2 non-fatal PE, 5 complete and 3 partial caval occlusions, and 3 caudal migrations of the filter. Insertion site venous thrombosis was not seen in the 27 patients monitored for this complication. Conclusion Precise placement of the Tulip filter is feasible by either access route and the device appears mechanically stable. Further observations are needed to confirm that safe filter removal is practical up to 10 days after its insertion.     

Left femoral vein approach for the percutaneous placement of the Bird's Nest Filter

The Bird's Nest Filter femoral catheter set has proven to be too short in some patients to permit placement in close proximity to the renal veins via the left femoral vein approach. The use of the longer, but otherwise identical Bird's Nest Filter jugular catheter set via the left femoral vein eliminates this problem.     

New retrievable percutaneous vena cava filter: Experimentalin vitro andin vivo evaluation

A new retrievable percutaneous vena cava filter was testedin vitro andin vivo in 15 foxhounds.In vitro, the new vena cava filter was compared with the standard Kimray-Greenfield filter and the Günther basket filter. The new filter is a stainless steel half-basket filter and is suitable for percutaneous antegrade or retrograde insertion through a 8.5 Fr introducer sheath.In vitro testing showed the filter causing no significant flow alterations and being highly effective in capturing medium- and large-sized thrombi; furthermore, fatigue testing revealed no breakage of the new filter, whereas the Günther basket filter showed breakage of the struts.In vivo studies showed no occlusion, major perforation, or filter migration during follow-up of 2 weeks to 6 months. Tilting of the filter postimplantation occurred in two out of 28 filters. Ten of 11 filters were successfully retrieved by the transjugular approach 2 weeks after implantation. The device seems to be suitable for temporary or permanent protection against pulmonary embolism. This article is based in part on the thesis written by Kirsten Tonn, and was presented at the CIRSE'92 Annual Meeting in Stiges, Barcelona, Spain on August 30, 1992     

自制下腔静脉滤器的体外实验

目的 评估自制的下腔静脉滤器(DDIVCF)捕获猪血栓子的效果及其定位稳定性.方法 ①将DDIVCF滤器和进口Antheor临时性下腔静脉滤器分别置入于直径为20和25 mm的下腔静脉(IVC)血液循环模型中,观察模型处于水平位时滤器对3 mm×20 mm,3 mm×30 mm,6 mm×20 mm,6 mm×30 mm 4种大小不同的猪血栓子的捕获效果,并计算其捕获率.②测量滤器捕获大量6 mm×30 mm栓子后相对位移的距离,观察滤器的定位稳定性.结果 ①DDIVCF滤器在直径20和25 mm的IVC模型中对4种猪血栓子的捕获率分别为34%,56%,82%,94%和26%,38%,56%,86%;Antheor的捕获率分别为54%,64%,86%,96%和38%,44%,68%,90%.对3 mm×30 mm,6 mm×20 mm,6 mm×30 mm猪血栓子的捕获率两者间差异无统计学意义(P＞0.05).②在直径20和25 mm的IVC模型中DDIVCF滤器捕获猪血栓子后相对位移距离分别为(0.6±0.3)cm和(1.0±0.1)cm.Antheor的相对位移距离分别为(0.4±0.1)cm和(0.8±0.3)cm,两者差异无统计学意义(P＞0.05).结论 DDIVCF在体外模型实验中具有较高的血栓捕获率和定位稳定性,可与进口Antheor临时性下腔静脉滤器媲美,其体内应用情况尚需进一步动物实验研究.     

Impact of unilateral common iliac vein occlusion on trapping efficacy of the Greenfield filter: an in vitro study

RATIONALE AND OBJECTIVES: The purpose of this study was to assess the effect of unilateral common iliac vein occlusion on the capturing efficacy of the Greenfield filter in vitro. MATERIALS AND METHODS: A stainless steel over-the-wire Greenfield filter was placed in the Silastic inferior vena cava module of a pulsatile circuit. Three 30-mm blood clots in sets of five were injected through the module's right iliac limb with the circuit in four experimental conditions: vertical position, both iliac limbs patent (VP); vertical position, left iliac limb occluded (VOC); horizontal position, both iliac limbs patent (HP); and horizontal position, left iliac limb occluded (HOC). Each experiment was repeated 15 times, resulting in 75 clots per condition and a total of 300 clot introductions. RESULTS: Clot trapping efficacy was 36 of 75 (48%) for VP, 41 of 75 (55%) for VOC, 32 of 75 (43%) for HP, and 26 of 75 (35%) for HOC. Cross comparisons of the four conditions revealed a marginally significant difference (P = .0138 with a corrected test-wise alpha = .0125) only between horizontal and vertical positions with unilateral common iliac limb occlusion. CONCLUSION: Unilateral common iliac vein occlusion decreases the capturing efficacy of the Greenfield filter in the horizontal position in vitro. In patients with unilateral common iliac vein occlusion, use of inferior vena cava filters with higher capturing efficacy may be considered.