Permanent Inferior Vena Cava Filters Research Articles

Renal cell carcinoma invading the inferior vena cava: use of a “temporary” vena cava filter to prevent tumor emboli during nephrectomy

Renal cell carcinoma with tumor thrombus extension into the inferior vena cava (IVC) remains a difficult operative challenge. Placement of a suprarenal “temporary” IVC filter, with its ease of insertion and removal, makes it the ideal treatment to prevent pulmonary embolism in these difficult cases. We report the first 2 cases of temporary suprarenal IVC filters placed at the time of radical nephrectomy to eliminate the possibility of perioperative pulmonary embolus and avoid the potential long-term sequelae of a permanent suprarenal IVC filter.

Catheter Interventiohal Therapy in an Elderly Patient With Deep Vein Thrombosis and a Brain Tumor

A 92-year-old woman with a brain tumor developed swelling of the left lower extremity. Venography showed considerable thrombi from the left common iliac vein to the femoral vein. Following implantation of a temporary inferior vena cava filter, catheter aspiration therapy and catheter-directed thrombolysis were performed. Venography after 3 days showed disappearance of the thrombi and an improvement in vein flow. A permanent inferior vena cava filter was implanted. Local intensive thrombectomy and thrombolysis by catheter together with a temporary inferior vena cava filter were effective treatments in this elderly patient with deep vein thrombosis.

The 6-F Nitinol TrapEase Inferior Vena Cava Filter: Results of a Prospective Multicenter Trial

The authors report the first results of a new 6-F symmetrically designed permanent nitinol inferior vena cava (IVC) filter, the Cordis TrapEase, evaluated in a multicenter prospective study with 6-months of follow-up. A total of 65 patients (29 men, 36 women) who ranged in age from 37 to 96 years (mean age, 68 years) and who were at high risk of pulmonary embolism (PE) were enrolled in 12 centers in Europe and Canada. The study was approved by the institutional review boards at all centers. Study objectives were to evaluate filter effectiveness, filter stability, and caval occlusion. Indications for filter placement were deep vein thrombosis with recurrent thromboembolism and/or free-floating thrombus with contraindication to anticoagulation in 37 patients, and complications in achieving adequate anticoagulation in 28 patients. Follow-up included clinical examination, plain film, Doppler ultrasound, CT scan, and nuclear medicine. The analysis of the data revealed a technical success of 95.4% (three filter-system related implantations not at the intended site, no events of filter tilting) and a clinical success of 100% at 6 months (no cases of symptomatic PE), the study primary endpoint. There were no cases (0%) of filter migration, insertion site thrombosis, filter fracture, or vessel wall perforation. During the study period, there were two cases of filter thrombosis: one case of early symptomatic thrombosis that was successfully treated in the hospital, and one case of nonsymptomatic filter thrombosis detected at 1-month follow-up, with spontaneous recanalization at 3 months. In the latter patient, some residual thrombus was still detected at 6 months. Of the study population of 65 patients, there were 23 deaths. These deaths were not related to the device or the implantation procedure but to the underlying disease process. This study demonstrates the new nitinol permanent IVC filter to be a safe and an effective device, with a low overall complication rate, for use in patients with thromboembolic disease at high risk of PE.

Quality Improvement Guidelines for Percutaneous Permanent Inferior Vena Cava Filter Placement for the Prevention of Pulmonary Embolism

PULMONARY embolism (PE) continues to be a major cause of morbidity and mortality in the United States. Estimates of the incidence of nonfatal PE range from 400,000 to 630,000 cases per year, and 50,000 to 200,000 fatalities per year are directly attributable to PE (1–4). The current preferred treatment for deep venous thrombosis and PE is anticoagulation therapy. However, as many as 20% of these patients will have recurrent PE (1,5,6). Interruption of the inferior vena cava (IVC) for the prevention of PE was first performed in 1893 with use of surgical ligation (7). Over the years, surgical interruption took many forms (ligation, plication, clipping, or stapling) but IVC thrombosis was a frequent complication after these procedures. Endovascular approaches to IVC interruption became a reality in 1967 after the introduction of the Mobin-Uddin filter (8). Many devices have since been developed for endoluminal caval interruption but, currently, there are six devices commercially available in the United States. These devices are designed for permanent placement. For detailed information regarding each of these filters, the reader is referred to several published reviews (9–12). Selection of a device requires knowledge of the clinical settings in which filters are used, evaluation of the clot trapping efficiency of the device, occlusion rate of the IVC and access vein, risk of filter migration, filter embolization, structural integrity of the device, and ease of placement. Percutaneous caval interruption can be performed as an outpatient or inpatient procedure. However, practically speaking, most filter placements will occur in the inpatient population because of ongoing medical therapy for acute thromboembolic disease or underlying illness. The IVC should be assessed with imaging before placement of a filter, and the current preferred imaging method is vena cavography. Before filter selection and placement, the infrarenal IVC length and diameter should be measured, the location and number of renal veins determined, IVC anomalies (eg, duplication) defined, and intrinsic IVC disease such as preexisting thrombus or extrinsic compression excluded. The ideal placement for the prevention of lower extremity and pelvic venous thromboembolism is the infrarenal IVC. The apex or superior aspect of any filtration device should be at or immediately inferior to the level of the renal veins according to the manufacturers’ recommendations. In specific clinical circumstances, other target locations may be appropriate. Percutaneous caval interruption is commonly accomplished through right femoral and right internal jugular vein approaches; however, other peripheral and central venous access sites can be used. Filters can be placed in veins other than the vena cava to prevent thromboembolism. Implant sites have included iliac veins, subclavian veins, superior vena cava, and IVC (suprarenal and infrarenal). This document will provide quality improvement guidelines for filter placement within the inferior vena cava because of the limited data available for implantation sites other than the IVC. The patient’s clinical condition, the type of filter available, the alternative access sites available, and the expertise of the treating physician should always be considered when the decision to place an IVC filter has been made. These guidelines are written to be used in quality improvement programs to assess percutaneous interruption of the IVC to prevent pulmonary embolism. The most important processes of care are (a) patient selecThis article first appeared in J Vasc Interv Radiol 2001; 12:137–141.

Temporary Inferior Vena Cava Filters: In Vitro Comparison with Permanent IVC Filters

An in vitro comparison of clot-trapping abilities of permanent and temporary inferior vena cava (IVC) filters. A flow model was used to simulate the IVC. Two permanent IVC filters, the titanium Greenfield and LG-Medical (LGM), were compared with two temporary filters, the Filcard International and Gunther. Clot sizes used were 2.5 x 2.5 mm, 2.5 x 5 mm, 5 x 5 mm, 5 x 10 mm, and 5 x 20 mm. Individual clots were presented to the filters with the simulated IVC in a horizontal or vertical orientation. Clot-trapping dynamics and pressure gradient changes during the injection of multiple, sequential clots were also examined. As clot size diminished, all filters trapped fewer clots; however, the temporary filters trapped more small clots than the permanent filters. Very little difference was observed in clot-trapping abilities among the filters for clots of 5 x 10 mm or greater. In the horizontal orientation, the permanent filters trapped 38% of all clots delivered, while the temporary filters trapped 73%, chi 2 = 24.8 (P < .001). In the vertical orientation, the overall clot-trapping abilities of the filters improved, with the permanent filters trapping 73% of all clots delivered, while the temporary filters trapped 95%, chi 2 = 18 (P < .001). During trapping of multiple clots, the temporary filters allowed fewer clots to pass. The temporary filters performed better than the permanent filters in both individual clot-trapping orientations. During multiple clot-trapping experiments, fewer clots were allowed to pass by the temporary filters. The temporary filters demonstrated the ability to capture clots both inside and outside the wire struts.