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.     

Evaluation of a spiral nitinol temporary inferior vena caval filter

RATIONALE AND OBJECTIVES: The authors performed this study to evaluate the (a) ability of a prototype temporary inferior vena caval (IVC) filter to trap and retain emboli in an ex vivo flow circuit, (b) feasibility of filter placement and removal via a superficial vein in sheep, and (c) intermediate-term effects of the filter on the insertion vein and at the filter site. MATERIALS AND METHODS: In an iliocaval circuit, embolus capture with the prototype filter was compared to that with a Greenfield filter. In addition, prototype filters were placed into the infrarenal IVC in six sheep. Placement via a superficial venous route was initially attempted. Inferior vena cavography was performed weekly, and filters were removed after 2, 3, or 4 weeks (n = 2 each). Two weeks after the filters were removed, vena cavograms were obtained, the animals were sacrificed, and the IVC was evaluated at pathologic examination. RESULTS: The prototype filter captured all emboli, and the Greenfield filter captured 70%-100% of emboli. Successful placement via a superficial venous route was accomplished in only two sheep owing to small vein caliber; four filters were placed via a deep vein. Adverse events included perifilter thrombus, insertion site infection, and caudal migration. Two sheep died before filter removal owing to sepsis and anesthetic complications. The filters in the remaining four sheep were easily and successfully removed. Five sheep had stenosis at the filter site, and fibrosis with acute and chronic inflammation was seen at microscopic examination. CONCLUSION: The prototype filter trapped emboli as well as the Greenfield filter. Insertion via a superficial route, however, is possible only if the access vein is of an adequate size.     

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.     

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.     

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.     

In Vitro Studies of Temporary Vena Cava Filters

Purpose: To evaluate the clot trapping capacity of different temporary vena cava filters in a vena cava model. Methods: A vena cava flow model was built using PVC tubing, a hemodialysis membrane and a pulsatile pump. Blood was imitated by a Dextran 40 solution. Five different temporary vena cava filters and two prototypes were tested using human thrombi. The mechanism of clot capture was observed. Results: Decreasing rank order according to decreasing percentage of clots captured for the 21-mm diameter vena cava model was Cook (C) > Angiocor (A) > Cordis (CD) > Antheor (TF-6) > DIL for thrombi with a diameter of 3 mm and A > C > CD > TF-6 > DIL for 5-mm thrombi. In a cava with diameter of 28 mm, decreasing rank order was C > CD = A > TF-6 > DIL and C > CD = A > DIL > TF-6 for 3- and 5-mm thrombi, respectively. Two new prototypes, the TF-8 and TF-10 filters, achieved better results than the TF-6 filter and were in most conditions comparable to the A and CD filters. In most cases, thrombi were trapped between filter and cava wall. Conclusion: The vena cava flow model demonstrates significant differences in rates of clot capture (range 22%–98%) depending on cava diameter, thrombus size, and filter type.     

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 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.     

Fatal Complications After Self-Expandable Metallic Stent Placement for Inferior Vena Cava Syndrome

We present the case of a 71-year-old man with inferior vena cava syndrome due to metastatic lymph nodes from hepatocellular carcinoma with serious complications that were strongly suspected to result from rapid changes in hemodynamics after self-expandable metallic stent placement.     

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.     

Long-term results of vena cava filters: Experiences with the LGM and the Titanium Greenfield devices

Purpose: Vena cava filter (VCF) application is the method of choice to prevent recurrent pulmonary embolism in patients with deep venous thrombosis. Because of the reported complications after VCF placement we summarize our long-term follow-up results with the LGM and Titanium Greenfield (TG) devices. Methods: Eighty-seven LGM VCF and 17 TG VCF were placed in 104 patients (average age 64 years). The follow-up examinations were performed by color-coded duplex sonography, plain radiographs, cavography, and computed tomo-graphy (CT). The maximum observation time was 81 months. Results: Filter migration occurred in 11% (8/76) of the LGM VCF and 15% (2/13) of the TG VCF. Vena cava thrombosis was seen in 17% (13/76) of the patients with an LGM VCF and in 31% (4/13) of those with a TG VCF. The patency rate was 95% (72/76) for the LGM VCF and 92% (12/13) for the TG VCF. Pulmonary embolism was noted in 3 patients after LGM VCF insertion and in no patient after TG VCF insertion. Conclusion: A VCF should only be inserted in a patient after pulmonary embolism and when there is strict proof of the indication.     

Temporary Vena Cava Filters and Ultrahigh Streptokinase Thrombolysis Therapy: A Clinical Study

Purpose: To assess the efficacy of temporary vena cava filters in patients undergoing ultrahigh-dose streptokinase thrombolysis for iliocaval thrombosis and to determine therapy success and filter and therapy complications. Methods: Forty-five patients were studied regarding extension and characteristics of thrombosis, duration, success, and complications of thrombolysis therapy, filter type, access route, pulmonary embolisms, and filter complications. Results: Complete recanalization was achieved in 57% of cases. Filters were inserted predominantly via a transbrachial route. One fatal pulmonary embolism (2%) occurred 1 day after starting thrombolysis. No other pulmonary embolism was noted. Other complications were induced by thrombolysis alone (n = 12), thrombolysis and filter (n = 9), and filter alone (n = 11). Conclusion: Fatal pulmonary embolisms as a complication of ultrahigh-dose treatment of pelvic or caval thrombosis can not safely be prevented by the temporary vena cava filters currently available. Filter design needs to be improved.     

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.     

In Vivo Evaluation of a Retrievable Vena Cava Filter—The Dibie-Musset Filter: Experimental Results

Purpose: To evaluate, in an animal model, the efficacy and safety of a 7 Fr percutaneous vena cava filter for temporary or permanent use. Methods: The Dibie-Musset (DM) filter is a wire preformed into a double-spiral shape with a spring effect. The experiment was performed in 15 adult sheep and consisted of the insertion of 45 filters, clot trapping tests, and filter retrieval. Follow-up in all sheep consisted of radiologic (abdominal radiograph, inferior vena cavogram, abdominal computed tomography), macroscopic, and microscopic examinations between days 8 and 386 after filter placement. Results: Of the 45 filters implanted in 15 sheep, 29 were retrieved between day 0 and day 15. Filtration efficiency was 100% for clots 4 × 4 × 20 mm. No long-term (1 year) side-effects were detectable. Microscopic examination of the vein wall showed only a dense intimal fibrosis without signs of acute inflammation at 1 year. Conclusion: These results support the efficiency and safety of the DM filter in an animal model.     

Experimental impeller fragmentation of iliocaval thrombosis under tulip filter protection: Preliminary results

Purpose To assess the efficacy of catheter fragmentation of massive caval thrombosis and of filter protection against procedure-related pulmonary embolism. Methods In 10 sheep, a self-expanding tulip-shaped filter made from Wallstent mesh (diameter 25 mm) was introduced from the right jugular approach into the proximal inferior vena cava. Experimentally induced massive iliocaval thrombosis was fragmented by an impeller catheter (expanded diameter 14 mm), which was advanced coaxially through the sheath of the expanded filter. Post-procedural cavography and pulmonary angiography were performed to document the extent of caval recanalization and pulmonary embolism. Results In all cases, impeller fragmentation cleared the inferior vena cava and the iliac veins of thrombi completely. Fragments washed downstream were trapped in the filter. In two of the first cases, parts of the clots caused pulmonary embolism before the filter was in place. Further events were avoided by a modification of the experimental setup. Except for some small peripheral perfusion defects in two cases, pulmonary angiograms did not show any incidence of pulmonary embolism. Conclusion Our preliminary results suggest that impeller fragmentation of iliocaval thrombi under tulip filter protection is effective and does not cause significant pulmonary embolism.     

First clinical results with a new caval filter

A new percutaeous inferior venacaval filter was used in 15 patients. The filter is constructed of stainless steel wires formed into a helical basket and anchoring legs. It can be inserted through a 10F catheter in an antegrade or retrograde fashion and can also be retrieved percutaneously. In a follow-up period of up to 13 months, the filter was well tolerated. One patient died of recurrent embolism despite filter protection. Local thrombogenicity was noted in 2 patients, but no other side effects were observed. Short-term heparinization following filter insertion is advisable. Heparin coating of the filter is under evaluation.     

Retrograde Tempofilter II? Placement within the Superior Vena Cava in a Patient with Acute Upper Extremity Deep Venous Thrombosis: the Filter Stands on Its Head

The Tempofilter II is a widely used temporary vena cava filter. Its unique design, which includes a long tethering catheter with a subcutaneous anchor, facilitates the deployment and retrieval of the device. Despite this, the Tempofilter II has been used only in the inferior vena cava of patients with lower extremity deep venous thrombosis. In this article, we present a case of superior vena cava filtering using the Tempofilter II in patients with upper extremity deep venous thrombosis.     

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.     

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