The use of inferior vena cava filters in pediatric patients for pulmonary embolus prophylaxis

Purpose To report our experience with inferior vena cava (IVC) filters in pediatric patients. Methods Over a 19-month period, eight low-profile percutaneously introducible IVC filters were placed in four male and four female patients aged 6–16 years (mean 11 years). Indications were contraindication to heparin in six patients, anticoagulation failure in one, and idiopathic infrarenal IVC thrombosis in one. Six of the eight devices placed were titanium Greenfield filters. One LGM and one Bird's Nest filter were also placed. Two of the filters were introduced via the right internal jugular vein by cutdown, and the remainder were placed percutaneously via the right internal jugular vein or the right common femoral vein. Patients received follow-up abdominal radiographs from 2 to 13 months after IVC filter placement. Results All filters were inserted successfully without complication. Three of the patients died during the follow-up period: two due to underlying brain tumors at 2 and 12 months and a third at 6 weeks due to progressive idiopathic renal vein and IVC thrombosis. The remaining five patients were all alive and well at follow-up without evidence of IVC thrombosis, pulmonary emboli, or filter migration. Conclusion IVC filter placement using available devices for percutaneous delivery is technically feasible, safe, and effective in children.     

Inferior Vena Cava Filter Strut Penetration into the Vertebral Column: A Case of 10-Year Clinical Follow Up

BackgroundThe rate of vena cava (IVC) filter placement has increased over the past decade, especially in the orthopaedic trauma patient population. With the increasing use of IVC filters, radiologists and referring clinicians must be familiar with potential complications.Clinical CaseThis case report presents an 18-year-old polytraumatized patient who had an IVC filter placed and required T8-L2 posterior spinal fusion. At 4.5 years of follow-up, a computed tomography (CT) scan for painful spinal hardware incidentally found that the IVC filter had migrated into the L3 vertebral body. The patient eventually underwent removal of her spinal hardware, but the IVC filter migration was managed conservatively with routine surveillance. At 10 years follow-up, the patient continued to remain asymptomatic despite of filter penetration into the vertebral body.ConclusionThis case demonstrates, long term follow-up for an asymptomatic patient with IVC migration and vertebral body penetration. This case may suggest that attempt at complex IR filter retrieval is not necessarily warranted in scenarios of strut penetration.     

Removal of a Permanent IVC Filter

Inferior vena cava (IVC) filters are increasingly used for prevention of life-threatening pulmonary emboli in patients who have contraindications to anticoagulation therapy. We report a case of the removal of a permanent IVC filter, which was inadvertently inserted due to an incorrect ultrasound report.     

Asymptomatic Lumbar Vertebral Erosion from Inferior Vena Cava Filter Perforation

In 2002, a 24-year-old female trauma patient underwent prophylactic inferior vena cava filter placement. Recurrent bouts of renal stones prompted serial CT imaging in 2004. In this brief report, we describe erosion and ossification of the L3 vertebral body by a Greenfield filter strut.     

Bird’s Nest Filter Causing Symptomatic Hydronephrosis Following Transmural Penetration of the Inferior Vena Cava

We report a case of symptomatic hydronephrosis caused by transcaval penetration of a Birds Nest filter. Perforation of the wall of the inferior vena cava (IVC) following insertion of a caval filter is a well-recognized complication. Whilst two cases of hydronephrosis have been described with Greenfield filters, no case involving a Birds Nest filter has been reported previously.     

Suprarenal inferior vena cava filter placement prior to transcatheter arterial embolization (TAE) of a renal cell carcinoma with large renal vein tumor thrombus: Prevention of pulmonary tumor emboli after TAE

To prevent embolization of necrotic renal vein tumor after transcatheter embolization of a left renal cell carcinoma, we placed a suprarenal Bird’s nest inferior vena cava filter. The patient tolerated the procedure well and had extensive tumor infarction including the tumor thrombus on 6-month follow-up computed tomography.     

Inferior Vena Cava Filter Retrieval: Effectiveness and Complications of Routine and Advanced Techniques

PurposeTo investigate the success and safety of routine versus advanced inferior vena cava (IVC) filter retrieval techniques.Materials and MethodsA retrospective review was performed of patients who underwent IVC filter placement and/or a retrieval attempt over a 10-year period. Retrieval technique(s), preretrieval computed tomography, preretrieval venography, and clinical/imaging follow-up for 30 days after retrieval were analyzed. Mean filter dwell time was 134 days (range, 0–2,475 d).ResultsFilter retrieval was attempted 231 times in 217 patients (39% female, 61% male; mean age, 50.7 y), with success rates of 73.2% (169 of 231) and 94.7% (54 of 57) for routine and advanced filter retrieval techniques, respectively. The overall filter retrieval complication rate was 1.7% (four of 231); complications in four patients (with multiple complications in some cases) included IVC dissection, IVC intussusception, IVC thrombus/stenosis, filter fracture with embedded strut, IVC injury with hemorrhage, and vascular injury from complicated venous access. The rate of complications associated with filter retrievals that required advanced technique was significantly higher than seen with routine technique (5.3% vs 0.4%; P < .05). Longer dwell time, more transverse tilt, and presence of an embedded hook were associated with significantly increased rates of failed retrieval via routine technique (P < .05).ConclusionsIVC filters can be retrieved with a high overall success rate (98.2%) and a low complication rate (1.7%) by using advanced techniques when the routine approach has failed; however, the use of advanced techniques is associated with a significantly higher complication rate.     

Three-Dimensional Rotational Angiography of the Inferior Vena Cava as an Adjunct to Inferior Vena Cava Filter Retrieval

The objective of this study was to explore the role of three-dimensional (3-D) rotational angiography (RA) of the inferior vena cava (IVC; 3-D CV) before filter retrieval and its impact on treatment planning compared with standard anteroposterior cavography (sCV). Thirty patients underwent sCV and 3-D CV before IVC filter retrieval. Parameters assessed were: projection of filter arms or legs beyond the caval lumen, thrombus burden within the filter and IVC, and orientation of the filter within IVC. Skin and effective radiation doses were calculated. Statistical analysis was performed using paired Student t test and nonparametric McNemar’s test. Standard anteroposterior cavography detected 49 filter arms or legs projecting beyond the caval lumen in 25 patients. Three-dimensional CV demonstrated 89 filter arms or legs projecting beyond the caval lumen in 28 patients. Twenty-two patients had additional filter arms or legs projecting beyond the caval lumen detected on 3-D CV that were not detected on sCV (p < 0.001). Filter apex tilt detection differed significantly (p < 0.001) between sCV and 3-D CV, with 3-D CV being more accurate. The filter apex abutted the IVC wall in 10 patients (33%) on 3-D CV, but this was diagnosed in only 3 patients (10%) with sCV. Thrombus was detected in 8 patients (27%), 1 thrombus of which was seen only on 3-D CV, and treatment was changed in this patient because of thrombus size. Mean effective radiation doses for 3-D CV were approximately two times higher than for sCV (1.68 vs. 0.86 mSv), whereas skin doses were three times lower (12.87 vs. 35.86 mGy). Compared with sCV, performing 3-D CV before optional IVC filter retrieval has the potential to improve assessment of filter arms or legs projecting beyond the caval lumen, filter orientation, and thrombus burden.     

Significant Caval Penetration by the Celect Inferior Vena Cava Filter: Attributable to Filter Design?

This report describes transmural penetration of the inferior vena cava (IVC) by a newly introduced IVC filter within 9 days of its placement. A computed tomographic study demonstrated filter penetration with one of the primary struts lodging in the uncinate process of the pancreas. Because of the close resemblance of this new filter to another filter that has not been associated with penetration injuries, the key differences between the two designs were examined and the determination was made that the new filter, unlike the older one, has unprotected primary struts. Only filters with an unprotected primary strut design have been associated with penetration injuries such as the one described in this case.     

Use of Retrievable Compared to Permanent Inferior Vena Cava Filters: A Single-Institution Experience

The purpose of this study was to review the use, safety, and efficacy of retrievable inferior vena cava (IVC) filters in their first 5 years of availability at our institution. Comparison was made with permanent filters placed in the same period. A retrospective review of IVC filter implantations was performed from September, 1999, to September, 2004, in our department. These included both retrievable and permanent filters. The Recovery nitinol and Günther tulip filters were used as retrievable filters. The frequency of retrievable filter used was calculated. Clinical data and technical data related to filter placement were reviewed. Outcomes, including pulmonary embolism, complications associated with placement, retrieval, or indwelling, were calculated. During the study period, 604 IVC filters were placed. Of these, 97 retrievable filters (16%) were placed in 96 patients. There were 53 Recovery filter and 44 Tulip filter insertions. Subjects were 59 women and 37 men; the mean age was 52 years, with a range of from 18 to 97 years. The placement of retrievable filters increased from 2% in year 1 to 32% in year 5 of the study period. The total implantation time for the permanent group was 145,450 days, with an average of 288 days (range, 33–1811 days). For the retrievable group, the total implantation time was 21,671 days, with an average of 226 days (range, 2–1217 days). Of 29 patients who returned for filter retrieval, the filter was successfully removed in 28. There were 14 of 14 successful Tulip filter retrievals and 14 of 15 successful Recovery filter retrievals. In one patient, after an indwelling period of 39 days, a Recovery nitinol filter could not be removed secondary to a large clot burden within the filter. For the filters that were removed, the mean dwell time was 50 days for the Tulip type and 20 days for the Recovery type. Over the follow-up period there was an overall PE incidence of 1.4% for the permanent group and 1% for the retrieval group. In conclusion, there was an increase in the use of retrievable filters over the study period and an overall increase in the total number of filters implanted. The increased use of these filters appeared to be due to expanded indications predicated by their retrievability. Placement and retrieval of these filters have a low risk of complications, and retrievable filters appeared effective, as there was low rate of clinically significant pulmonary embolism associated with these filters during their indwelling time.     

“Recovery™” Vena Cava Filter: Experience in 96 Patients

The purpose of the study was to assess the clinical safety and efficacy of the “Recovery^TM” (Bard) inferior vena cava (IVC) filter. We retrospectively evaluated the clinical and imaging data of patients who had a “Recovery^TM” IVC filter placed between January 2003 and December 2004 in our institution. The clinical presentation, indications, and procedure-related complications during placement and retrieval were evaluated. Follow-up computed tomography (CT) examinations of the abdomen and chest were evaluated for filter-related complications and pulmonary embolism (PE), respectively. “Recovery” filters were placed in 96 patients (72 males and 24 females; age range: 16–87 years; mean: 46 years). Twenty-four patients presented with PE, 13 with deep vein thrombosis (DVT) and 2 with both PE and DVT. The remaining 57 patients had no symptoms of thromboembolism. Indications for filter placement included contraindication to anticoagulation (n = 27), complication of anticoagulation (n = 3), failure of anticoagulation (n = 5), and prophylaxis (n = 61). The device was successfully deployed in the infrarenal (n = 95) or suprarenal (n = 1) IVC through a femoral vein approach. Retrieval was attempted in 11 patients after a mean period of 117 days (range: 24–426). The filter was successfully removed in nine patients (82%). Failure of retrieval was due to technical difficulty (n = 1) and the presence of thrombus in the filter (n = 1). One of the nine patients who had the filter removed developed IVC thrombus after retrieval and another had an intimal tear of the IVC. Follow-up abdominal CT (n = 40) at a mean of 80 days (range: 1–513) showed penetration of the IVC by the filter arms in 11, of which 3 had fracture of filter components. In one patient, a broken arm migrated into the pancreas. Asymmetric deployment of the filter legs was seen in 12 patients and thrombus within the filter in 2 patients. No filter migration or caval occlusion was encountered. Follow-up chest CT (n = 27) at a mean of 63 days (range: 1–386) showed PE in one patient (3%). During clinical follow-up, 12 of 96 patients developed symptoms of PE and only 1 of the 12 had PE on CT. There was no fatal pulmonary embolism in our group of patients following “Recovery” filter placement. However, the current version of the filter is associated with structure weakness, a high incidence of IVC wall penetration, and asymmetric deployment of the filter legs.     

The Mid-Term Efficacy and Safety of a Permanent Nitinol IVC Filter (TrapEase)

Objective

1) To evaluate the mid-term efficacy and safety of a permanent nitinol inferior vena cava (IVC) filter; 2) to evaluate filter effectiveness, filter stability and caval occlusion.

Materials and Methods

A prospective evaluation of the TrapEase IVC filter was performed on 42 patients (eight men, 34 women) ranging in age from 22 to 78 years (mean age 66 years). All patients were ill with a high risk of pulmonary embolism (PE). Indications for filter placement were: 1) deep vein thrombosis with recurrent thromboembolism; 2) and/or free-floating thrombus with contraindication to anticoagulation; and 3) complications in achieving adequate anticoagulation. Follow-up evaluations (mean: 15.4 months, range: 2 to 28 months) were performed at 6- and 12-month intervals after the procedure and included clinical histories, chart reviews, plain film, Doppler ultrasounds, and contrasted abdominal CT scans.

Results

In follow-up evaluations, the data analysis revealed no cases of symptomatic PE. There were no cases of filter migration, insertion site thrombosis, filter fracture, or vessel wall perforation. During the study, there was one case of filter thrombosis; early symptomatic thrombosis that was successfully treated in the hospital. Of the 42 subjects, eight died. These deaths were not related to the filter device or the implantation procedure, but to the underlying disease.

Conclusion

This study demonstrates that the TrapEase permanent IVC filter is a safe and an effective device with low complication rates and is best used in patients with thromboembolic disease with a high risk of PE.     

CT fluoroscopy-guided placement of inferior vena cava filters: feasibility study in pigs

Purpose

To evaluate the feasibility of computed tomography (CT)–guided placement of inferior vena cava (IVC) filters in a swine model.

Materials and Methods

Five domestic pigs (60–70 kg) underwent transfemoral and transjugular IVC filter placement under real-time CT fluoroscopic guidance. Filter position was confirmed by contrast-enhanced CT and digital subtraction angiography. Filter tilt, distance to target position, and fluoroscopy time were analyzed.

Results

A total of 10 filters were successfully implanted (five via transfemoral approach, five via transjugular approach) without complications. The mean distance to the target position was 0.3 cm ± 0.2. Mean filter tilt was 3.2° ± 2.3 (range, 0°–7°), without differences between deployment techniques (P = .8486). Average fluoroscopy time was 25.9 s ± 6.9 per procedure.

Conclusions

CT fluoroscopy–guided placement of IVC filters is safely feasible. Use of this technique may avoid the need to move critically ill patients.     

National Trends in Inferior Vena Cava Filter Placement and Retrieval Procedures in the Medicare Population Over Two Decades

PurposeTo assess trends in inferior vena cava (IVC) filter placement and retrieval procedures in Medicare beneficiaries over the last two decades.MethodsUsing Physician/Supplier Procedure Summary Master Files from 1994 through 2015, we calculated utilization rates for IVC filter placement and retrieval procedures in Medicare fee-for-service beneficiaries. Services were stratified by provider specialty group and site of service.ResultsIVC filter placement rates increased from 1994 to 2008 (from 65.0 to 202.1 per 100,000 beneficiaries, compound annual growth rate [CAGR] +8.4%) and then decreased to 128.9 by 2015 (CAGR −6.2%). This decrease was observed across all specialty groups and sites of service. From 1994 to 2015, placement procedure market share increased for radiologists (from 45.1% to 62.7%) and cardiologists (from 2.5% to 6.7%) but decreased for surgeons (from 46.6% to 27.9%). Overall, procedures shifted slightly from the inpatient (from 94.5% to 86.5% of all procedures) to outpatient hospital (from 4.9% to 14.9%) settings. Between 2012 and 2015, retrieval rates increased from 12.0 to 17.7 (CAGR +13.9%). Retrievals as a percentage of placement procedures were similar across specialties in 2015 (range 13.0%-13.8%).ConclusionDespite prior dramatic growth, the utilization of IVC filters in Medicare beneficiaries markedly declined over the last decade, likely relating to evolving views regarding efficacy and long-term safety. This decline was accompanied by several filter-related market shifts, including increasing placement by radiologists and cardiologists, increasing outpatient placement procedures, and increasing retrieval rates.     

Vena cava filter insertion and angiographic diagnosis of pulmonary embolism

Insertion of a vena cava filter is a therapeutic alternative for patients in whom anticoagulation is not effective or appropriate. The Greenfield filter is associated with a 95% long-term patency rate and a low incidence of mortality or recurrent embolization. Although insertion can be done through the femoral or jugular route, the right femoral vein is the easiest, most direct approach to the inferior vena cava (IVC). Pulmonary arteriography remains, the “gold standard” for establishing the diagnosis of pulmonary embolism.     

Prevalence and Characterization of Interaction of Retrievable Inferior Vena Cava Filters with the Spine in Patients Undergoing Complex Filter Removal

PurposeTo examine spinal interaction types and prevalence of inferior vena cava (IVC) filters in patients presenting for complex filter removal.Materials and MethodsThe records of 447 patients presenting for complex removal of IVC filters were reviewed, including patient demographics, IVC filter dwell time, filter fracture status, and computed tomography (CT) evidence of filter interaction with the spine. Spinal interaction was defined as a filter strut touching or penetrating into the vertebral body or disc. Patients with evidence of filter penetration and spinal interaction had abdominal CT that preceded filter removal assessed by 2 interventional radiologists to categorize the type of spinal interaction, including bony reaction and osteophyte formation.ResultsCT evidence of spinal interaction by the filter was found in 18% of patients (80/447). Interaction with the spine was more common in single point of fixation filters than filters with rails (P = .007) and was more likely in filters with round wires than flat wires (P = .0007). Patients with interaction had longer dwell times (mean [SD] 5.7 [4.46] y) compared with patients without interaction (mean [SD] 3.2 [3.85] y); this relationship was significant (P < .0001). Women were more likely than men to experience filter/spine interaction (P = .04). Filters with spinal interaction were more likely to be fractured (P = .001). Filter interaction was found in 38% (30/78) of patients with symptoms, including chest and back pain, compared with 14% (50/369) of patients without symptoms (P < .0001, odds ratio 3.99).ConclusionsRetrievable IVC filters may interact with the spine. These interactions are associated with longer filter dwell times, female sex, and round wire filter construction.     

Endovascular Removal of Fractured Inferior Vena Cava Filter Fragments: 5-Year Registry Data with Prospective Outcomes on Retained Fragments

Purpose

To evaluate the safety and efficacy of attempted percutaneous filter fragment removal during retrieval of fractured inferior vena cava (IVC) filters and to report outcomes associated with retained filter fragments.

Fracture and Migration of Celect Inferior Vena Cava Filters: A Retrospective Review of 741 Consecutive Implantations

PurposeTo determine the incidence of fracture and migration of the Celect inferior vena cava (IVC) filter at a single tertiary-care center.Materials and MethodsImages obtained after placement of Celect IVC filters between August 2007 and January 2013 were retrospectively reviewed for evidence of device fracture and migration. The probability of filter fracture at 6 and 12 months after filter placement was estimated, and a 95% upper confidence bound was constructed.ResultsA total of 741 consecutive Celect filters were placed, and the following studies were subsequently evaluated: 301 abdominal radiographs, 282 abdominal computed tomography (CT) scans, 154 cavagrams, 19 lumbar spine radiographs, 462 chest radiographs, 108 chest CT scans, and 31 pelvic radiographs. The mean imaging follow-up interval was 5.78 months ± 8.80 (range, 0.01–56.03 mo). There was no filter fracture or en-bloc migration outside the IVC. Upper 95% confidence bounds for the probability of fracture were 1.8% at 6 months and 4.3% at 12 months. Intracaval filter migration of more than 2 cm (mean, 2.43 ± 0.12 cm; range, –2.54 to 2.99 cm) was seen in 3.9% of patients (21 of 534; 12 cranial and nine caudal).ConclusionsNo fracture of a Celect filter was observed in this large cohort over a relatively short follow-up interval. The results also suggest that the Celect filter has an adequate securing mechanism to prevent distant en-bloc or significant intracaval migration.     

Long-Term Retrievability of IVC Filters: Should We Abandon Permanent Devices?

Thromboembolic disease produces a considerable disease burden, with death from pulmonary embolism in the UK alone estimated at 30,000–40,000 per year. Whilst it is unproven whether filters actually improve longevity, the morbidity and mortality associated with thromboembolic disease in the presence of contraindications to anticoagulation is high. Thus complications associated with filter insertion, and whilst they remain in situ, must be balanced against the alternatives. Permanent filters remain in situ for the remainder of the patient’s life and any complications from the filters are of significant concern. Filters that are not permanent are therefore attractive in these circumstances. Retrievable filters, to avoid or decrease long-term filter complications, appear to be a significant advance in the prevention of pulmonary embolism. In this review, we discuss the safety and effectiveness of both permanent and retrievable filters as well as the retrievability of retrievable inferior vena cava (IVC) filters, to explore whether the use of permanent IVC filters can be abandoned in favor of retrievable filters. Currently four types of retrievable filters are available: the Recovery filter (Bard Peripheral Vascular, Tempe, AZ, USA), the Günther Tulip filter (Cook, Bloomington, IN, USA), the OptEase Filter (Cordis, Roden, The Netherlands), and the ALN filter (ALN Implants Chirurgicaux, Ghisonaccia, France). Efficacy and safety data for retrievable filters are as yet based on small series, with a total number of fewer than 1,000 insertions, and follow-up is mostly short term. Current long-term data are poor and insufficient to warrant the long-term implantation of these devices into humans. The case of fractured wire from a Recovery filter that migrated to the heart causing pericardial tamponade requiring open heart surgery is a reminder that any new endovascular device remaining in situ in the long term may produce unexpected problems. We should also bear in mind that the data on permanent filters are much more robust, with reports on over 9,500 cases with follow-up of up to 8 years. The original implantation time of 10–14 days has been extended to more than 100 days as the mean implantation time with some of the filter types. Follow-up (preferably prospective) is necessary for all retrievable filters, whether or not they are retrieved. Until these data become available we should restrict ourselves to the present indications of permanent and retrievable filters. If long-term follow-up data on larger numbers of cases confirm the initial data that retrievable filters are as safe and effective as permanent filters, the use of the retrievable filters is likely to expand. V. Berczi and J. Bottomley have contributed equally to this paper.     

Penetration of a fractured Bird's Nest filter strut into the liver parenchyma: report of two cases

This report deals with two rare but similar cases of asymptomatic fracture of a Bird's Nest inferior vena cava (IVC) filter strut, penetrated into the liver parenchyma. Follow-up over 4 and 6 years, respectively, could not reveal any changes in the position of the fragmented strut in the liver parenchyma or any evidence of clinical symptoms owing to the migrated strut fragment.