Photothermal Ablation with the Excimer Laser Sheath Technique for Embedded Inferior Vena Cava Filter Removal: Initial Results from a Prospective Study

Inferior vena cava filter retrievals using advanced techniques: a systematic review

This study aimed to assess the safety of complex inferior vena cava (IVC) filter retrieval techniques through a systematic review of published literature. Using PubMed, a systematic review was conducted in line with the 2020 Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines to identify articles published through April 2020 that reported on complex IVC filter retrieval techniques in >5 patients. Case reports, review papers, and studies that did not report on primary outcomes or variables of interest were excluded. Risk of bias was assessed using a modified Newcastle-Ottawa Quality Assessment scale. Pooled success and complication rates were calculated for the overall number of complex retrieval attempts as well as for each filter type and each complex retrieval method. Sixteen fair-quality and three good-quality studies met the inclusion criteria, with 758 patients (428 female) who had undergone 770 advanced retrieval attempts. The mean age of the patients was 46.5 ± 7.1 years (range: 14.1-90), and the mean dwell time was 602.5 ± 388.6 days (range: 5-7336). Regarding filters, 92.6% (702/758) were retrievable and 7.4% (56/758) were permanent. Indications for complex retrieval included the failure of standard retrieval (89.2%; 676/758) and tilting or embedding in the caval wall (53.8%; 408/758); 92.6% (713/770) of the advanced retrieval attempts were successful. The pooled success rate was 92.0% (602/654) for retrievable filters and 96.4% (53/55) for permanent filters (P = 0.422). Only 2.8% (21/758) of patients experienced major complications, and the major complication rate was not significantly associated with filter type (P = 0.183). Advanced techniques for IVC filter retrieval appear safe for the retrieval of retrievable filters and certain permanent filters, with a low short-term major complication rate. Further studies on complex retrieval techniques used to remove permanent filters should be conducted to clarify their safety with respect to filter type.

Retrieval of a Cook Celect inferior vena cava (IVC) filter after prolonged dwell time of 5,117 days: Factors to consider for retrieval of long-dwell IVC filters

Inferior vena cava (IVC) filters are used in certain patients to help prevent the occurrence of pulmonary embolism (PE). IVC filters are generally recommended to be removed once PE prophylaxis is no longer required. Long-dwelling IVC filters are associated with higher complication rates (Vasa 2020; 49: 449), being more difficult to retrieve and associated with higher retrieval complications (Cardiovasc Diagn Ther 2016; 6: 632). This report describes the pre-procedural work-up and removal of an IVC filter with a prolonged dwell time of 5,117 days (14 years, 3 days) using the loop snare advanced retrieval technique. As far as the authors are aware this case is the longest-described successful retrieval of a Cook Celect IVC filter at 5,117 days.

Safety and Success Rates of Excimer Laser Sheath-Assisted Retrieval of Embedded Inferior Vena Cava Filters

IMPORTANCE

Despite historically high rates of use, most inferior vena cava (IVC) filters are not retrieved. The US Food and Drug Administration safety communications recommended retrieval when the IVC filter is no longer indicated out of concern for filter-related complications. However, failure rates are high when using standard techniques for retrieval of long-dwelling filters, and until recently, there have been no devices approved for retrieval of embedded IVC filters.

OBJECTIVE

To evaluate the safety and success of excimer laser sheath-assisted retrieval of embedded IVC filters.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective, multicenter, clinical cohort study of excimer laser sheath-assisted IVC filter retrievals from 7 US sites was conducted between March 1, 2012, and February 28, 2021, among 265 patients who underwent IVC filter retrieval using the laser. Patients were substratified between a high-volume single center and a multicenter data set. A blinded physician committee adjudicated reported complications and their association with use of the laser.

EXPOSURES

Retrieval of IVC filters using excimer laser sheath.

MAIN OUTCOMES AND MEASURES

The primary safety end point was device-related major complication rate (Society of Interventional Radiology categories C to F, which included any adverse event associated with morbidity or disability that increases the level of care, results in hospital admission, or substantially lengthens the hospital stay). The primary success end point was technical success of IVC filter retrieval. The primary end points were compared with literature-derived, meta-analysis-suggested target performance goals.

RESULTS

The single-center experience included 139 participants (mean [SD] age, 52 [16] years; 78 female participants [56.1%]), and the multicenter experience included 126 participants (mean [SD] age, 52 [16] years; 75 female participants [59.5%]). The device-related major complication rate was 2.9% (4 of 139; 95% CI, 0.8%-7.2%; P = .001) for the single-center experience and 4.0% (5 of 126; 95% CI, 1.3%-9.0%; P = .01) for the multicenter experience, both of which were significantly lower than the primary safety performance goal (10%). No major complications were considered to be definitively associated with use of the laser. The technical success rate was 95.7% (133 of 139; 95% CI, 90.8%-98.4%; P = .007) for the single-center experience and 95.2% (120 of 126; 95% CI, 89.9%-98.2%; P = .02) for the multicenter experience, both of which were significantly higher than the primary performance goal (89.4%).

CONCLUSIONS AND RELEVANCE

This cohort study demonstrated high technical success and low complication rates of excimer laser sheath-assisted retrieval of embedded IVC filters in centers with variable case volume and experience, which suggests a wide applicability of the technique with proper training. The excimer laser sheath offers physicians a valuable tool for retrieval of challenging embedded IVC filters.

An expert spotlight on inferior vena cava filters

Introduction: Inferior vena cava (IVC) filters are mechanical filtration devices designed as an alternative to surgical ligation/plication of the IVC. Their use has been controversial, especially with the introduction of retrievable filters and expanded/prophylactic indications.Areas covered: Authors discuss the types of available IVC filters, indications for placement, evidence on their effectiveness in general and specific patient populations, procedural considerations, off-label use, complications, and filter retrieval. This review is based on manuscripts/abstracts published from 1960 to 2021 on venous thromboembolism and IVC filters.Expert opinion: Despite the limited data on their effectiveness and survival benefit, IVC filters continue to play an important role in the treatment of patients with venous thromboembolism (VTE) who cannot receive standard anticoagulation. There is no role of IVC filters in patients without VTE. While retrievable filters are desirable for short-term use, a dedicated team-based approach, and advanced training are required for their successful removal. Newer devices are promising in improving patient safety . The device manufacturers and regulatory agencies should consider specific approaches to track device-related adverse events. Population-based studies are required to establish optimal patient population who would benefit from these devices. .

Permanent IVC filter strut penetration into an abdominal aortic aneurysm

An 85-year-old man with a known history of abdominal aortic aneurysm (AAA) presented to a vascular surgery clinic with a severely swollen, tender and erythematous left leg. An urgent CT angiogram demonstrated a left-sided, proximal deep vein thrombosis, and a permanent, Bird's Nest inferior vena cava (IVC) filter (Cook, Inc., Bloomington, Ind.) penetrating his AAA. The patient was treated with a course of apixaban 5 mg two times per day and the decision was made to closely observe his IVC filter and AAA, given his numerous comorbidities and age. This case highlights the unique considerations associated with an approach to permanent IVC filter complications among patients with AAAs.

Impact of Advanced Technique on Improvement in the Retrievable Inferior Vena Cava Filter Retrieval Rate

BACKGROUND

It is recommended to remove retrievable inferior vena cava filters (r-IVCFs) when they are no longer needed because their presence may give rise to serious complications related to prolonged placement of the filter. An advanced filter retrieval technique may help improve the retrieval rate.Methods and Results:107 consecutive patients (mean age; 61±18 years, male 53%) in whom r-IVCF retrieval was attempted were prospectively enrolled between April 2012 and December 2018. The frequently used advanced techniques were sling technique and biopsy forceps dissection technique. Retrieval success was 75% with standard retrieval technique alone; however, the overall retrieval success rate improved to 98% with advanced techniques. We observed few serious complications related to the retrieval procedure. Logistic multivariate analysis identified prolonged indwelling time (P=0.0011) and embedded hook in the caval wall (P=0.0114) as independent predictors, and the cutoff value for the indwelling time for requirement of advanced technique was 80 days.

CONCLUSIONS

Advanced retrieval techniques helped improve the retrieval rate without serious complications. We may need to consider the referral of patients to centers with expertise in advanced retrieval techniques when the indwelling time is >80 days, and pre-retrieval CT image shows a hook embedded in the vessel wall.

Role of Inferior Vena Cava Filter Retrieval in Patients on Chronic Anticoagulation Therapy

Purpose of review

Describe the role of inferior vena cava filter (IVCF) retrieval in patients on chronic anticoagulation given the overlap of these treatment options in the management of patients with venous thromboembolic disease.

Recent findings

Despite the increase in IVCF retrievals since the Food and Drug Administration safety communications in 2010 and 2014, retrieval rates remain low. Previous studies have shown that longer filter dwell times are associated with greater risk for filter complications and more difficulty with filter retrievals. Recent findings suggest that complications are more frequent in the first 30 days after placement.

Summary

The decision to retrieve an optional IVCF is individualized and requires diligent follow-up with consistent re-evaluation of the need for the indwelling IVCF, particularly in those on long-term anticoagulation therapy.

A 7-year retrospective review of the technical success of the "low-profile" hangman technique for complicated inferior vena cava (IVC) filter retrievals

PURPOSE

We aimed to assess the safety and effectiveness of a modified low-profile hangman technique.

METHODS

We performed a retrospective review of all filter retrieval procedures performed at a major trauma center, from 2012 to 2019. Records were reviewed for patient demographics, device type, device dwell time, device tilt, embedded hook, success of device retrieval, evidence of caval injury and occurrence of complications.

RESULTS

From 2012 to 2019 there were 473 filter retrieval attempts. An advanced technique was documented in 66 (14%). The low-profile hangman technique alone was documented in 23 procedures (5% of all procedures, 35% of advanced technique procedures). Average screening time was 28 minutes. At the time of retrieval attempt, 9 patients (41%) were anticoagulated. The hangman technique was employed as isolated maneuver in 23 patients and was successful on initial attempt in 22 cases (96%). The average dwell time of filters retrieved by the hangman technique was 228 days (range, 40-903 days; median, 196 days). No procedure-related complications occurred.

CONCLUSION

The retrieval of IVC filters is an important part of offering an IVC filter service. Advanced techniques to retrieve caval filters are multiple, and the risk of complications is increased in these cases. We demonstrate the safety and effectiveness of a new modified and lower-profile hangman technique. This new technique could be performed with only an 11 French venous access sheath using off-the-shelf equipment and it remains a cost-effective approach to complex filter retrieval.

Contemporary management of chronic indwelling inferior vena cava filters

OBJECTIVE

Despite increasing retrieval rates of the inferior vena cava (IVC) filter, less than one-third are removed within the recommended timeline. Prolonged filter dwell times may increase the technical difficulty of retrieval and filter-related complications. We sought to evaluate the contemporary outcomes of patients with chronic indwelling IVC filters at a tertiary care center.

METHODS

A retrospective analysis was performed from August 2015 through August 2019 of all patients who were referred for removal of a prolonged IVC filter with a dwell time >1 year. Descriptive analysis was used to evaluate patients' characteristics and procedural outcomes, which were reviewed through electronic medical records. Data were expressed as median with interquartile range (IQR) or number and percentage, as appropriate.

RESULTS

A total of 47 patients were identified with a median filter dwell time of 10.0 years (IQR, 6-13 years); 34 patients underwent IVC filter removal, and 13 patients refused retrieval. The median age of patients was 54.9 years (IQR, 42.5-64.0 years); the majority were female (57%) and white (53%). The most common indication for filter placement was high risk despite anticoagulation (49%), followed by venous thromboembolism prophylaxis (21%). The majority of patients were symptomatic (72%). If symptomatic, the most common reason for retrieval was IVC penetration (94%), and the chief complaint was pain (56%). Retrieval success was 97%, with a median length of stay of 0 days. The majority of retrievals were performed through an endovascular approach (97%). There was one postprocedural complication (3%).

CONCLUSIONS

Despite prolonged dwell times, IVC filter retrieval can be performed safely and effectively in carefully selected patients at a tertiary referral center.

Feasibility and Acute Safety Study of Radiofrequency Energy Delivery to the Vena Caval Wall via an IVC Filter in Swine

Retrievable inferior vena cava (IVC) filters are self-expanding metallic devices implanted in the IVC to prevent migration of thrombi from the deep veins of the legs and pelvis to the lungs. The risk of complications from the filters increases with duration of implantation, but retrieval may be difficult due to intimal hyperplasia around the components of the filter. In this study, the potential for delivery of radiofrequency (RF) energy to the IVC wall via the filter was investigated. IVC filters were deployed in 4 swine while attached to a snare connected to a 480 kHz RF generator. Energy ranging from 0 to 48 kJ was applied via the filter followed by re-sheathing and withdrawal of the filter while connected to a force measurement device. Resheathing forces for the 0-energy cohort and pooled data from the 6-24 kJ cohorts were 4.50±0.70 N and 4.50±0.75 N, respectively. Petechial hemorrhages and variable non-occlusive thrombi were noted in some cohorts including the 0-energy cohort, consistent with delivery and acute retrieval of an IVC filter. Histologically, the extent of RF-induced injury was subtle at 6 kJ with focal areas of homogenized collagen while the 12 kJ cohort showed segmental tissue charring with coagulation necrosis which was more extensive for the 24 kJ cohort. The 48 kJ energy caused more extensive and non-target organ damage. The study demonstrated feasibility of delivery of RF to the IVC wall via a deployed filter, supporting further study of the ability of local RF heating of the IVC wall to inhibit the neointimal hyperplasia or as an aid in retrieval.

A survey of vascular specialists' practice patterns of inferior vena cava filter placement and retrieval

OBJECTIVES

The placement of inferior vena cava filters (IVCF) continues to rise. Vascular specialists adopt different practices based on local expertise. This study was performed to assess the attitudes of vascular specialists towards the placement and retrieval of IVCF.

METHODS

An online survey of 28 questions related to practice patterns regarding IVCF was administered to 1429 vascular specialists. Vascular specialists were categorized as low volume if they place less than three IVCF per month and high volume if they place at least three IVCF per month. The responses of high volume and low volume were compared using two-sample t-tests and Chi-square tests.

RESULTS

A total of 259 vascular specialists completed the survey (18% response rate). There were 191 vascular surgeons (74%) and 68 interventional radiologists (26%). The majority of responders were in academic practice (67%) and worked in tertiary care centers (73%). The retrievable IVCF of choice was Celect (27%) followed by Denali (20%). Forty-two percent used a temporary IVCF and left it in situ instead of using a permanent IVCF. Eighty-two percent preferred placing the tip of the IVCF at or just below the lowest renal vein. Thirty-one percent obtained a venous duplex of the lower extremities prior to retrieval while 24% did not do any imaging. There were 132 (51%) low volume vascular specialists and 127 (49%) high volume vascular specialists. Compared to low volume vascular specialists, significantly more high volume vascular specialists reported procedural times of less than 30 min for IVCF retrieval (57% vs. 42%, P = 0.026). There was a trend for high volume to have fewer unsuccessful attempts at IVCF retrieval but that did not reach statistical significance ( P = .061). High volume were more likely to have attempted multiple times to retrieve an IVCF (66% vs. 33%, P < .001), and to have used bronchoscopy forceps (32% vs. 14%, P = .001) or a laser sheath (14% vs. 2%, P < .001) for IVCF retrieval. In general, vascular specialists were not comfortable using bronchoscopy forceps (65%) or a laser sheath (82%) for IVCF retrieval.

CONCLUSIONS

This study underscores significant variability in vascular specialists practice patterns regarding IVCF. More studies and societal guidelines are needed to define best practices.

Is external compression on the IVC a risk factor for IVC filter abutment? A single center experience of 141 infrarenal celect filter insertions

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Tilt of the IVC filter is the major problem for the filter retrieval rate.

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External compression on the IVC wall can cause filter tilting.

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Identifying external compression factors are necessary before insertion of IVC filter.

Objectives

To investigate risk factors for inferior vena cava (IVC) filter abutment, including external compression on the IVC wall, using venous phase computed tomography (CT).

Methods

One-hundred-forty-one cases of Celect IVC filter insertion between January 2009 and April 2017 were retrospectively reviewed. On pre-procedural CT, IVC diameter and morphological classifications were measured. Filter tilt angle, IVC angle, vertical position, and filter tip abutment to the IVC wall were analyzed on post-procedural CT. IVC compression was examined by pre- and post-procedural CT analysis. Multiple logistic regression analysis was conducted to find factors related to IVC filter abutment.

Results

Of 141 IVC filter insertion cases, 52 were classified in the filter tip abutment group and 89 in the non-abutting group. IVC tilt angle (11.7 ± 5.5° vs. 6.4 ± 5.4°), presence of external compression (14/52, 27% vs. 9/89, 9%), and IVC morphology were different between the groups (p < 0.05). In multiple logistic regression analysis, filter-tilt angle over 9.25° and external compression on the IVC were found to be independent predictors of filter abutment (odds ratios: 4.56, 10.18, respectively).

Conclusion

IVC filter tilt, external compression on IVC wall, and IVC morphology were significantly different between the filter tip abutment and non-abutment groups. External compression and filter tilt over 9.25° were risk factors for filter tip abutment in multiple logistic regression analysis. By identifying these factors, we may be able to reduce filter tilting by preventing the filter from being deployed in a dangerous area.

Endobronchial Forceps-Assisted and Excimer Laser-Assisted Inferior Vena Cava Filter Removal: The Data, Where We Are, and How It Is Done

The recognition of inferior vena cava filter related complications has motivated increased attentiveness in clinical follow-up of patients with inferior vena cava filters and has led to development of multiple approaches for retrieving filters that are challenging or impossible to remove using conventional techniques. Endobronchial forceps and excimer lasers are tools for designed to aid in complex inferior vena cava filter removals. This article discusses endobronchial forceps-assisted and excimer laser-assisted inferior vena cava filter retrievals.

The Role of Inferior Vena Cava Filters in Pulmonary Embolism

Pulmonary embolism (PE) is a cause of significant morbidity and mortality, with an estimated 600,000 cases of clinically significant PE in the United States annually, and roughly 200,000 deaths per annum directly attributable to PE. By far the most frequent cause of PE is deep vein thrombosis originating in the lower extremities, which travels to the pulmonary vasculature. The mainstay of treatment is anticoagulation, but multiple additional treatments exist for patients in whom anticoagulation is inadequate or contraindicated. The absolute indications for inferior vena cava (IVC) filtration are narrow, but many filters are placed in patients with relative indications. There is growing concern for overuse of IVC filters, with a relatively low rate of retrieval. It is essential for interventional radiologists to understand the appropriate and correct use and retrieval of IVC filters. Familiarity with placement techniques, protocols and techniques for retrieval, current and emerging technologies, and the clinical model for management of venous thromboembolism, will ensure that interventional radiologists remain an integral member of the care team for these often complex patients.

Bidirectional Pull-Back Technique for Retrieval of Strut-Embedded Cylinder-Shaped Filters in Inferior Vena Cava

BACKGROUND IVC filters have been widely accepted as an effective method to prevent pulmonary embolism (PE) in patients with deep venous thrombosis (DVT). However, the placement of IVC filters is associated with significant complications and filter retrieval can be challenging when the filter struts are embedded into the caval wall. MATERIAL AND METHODS Over 26 months, we reviewed the safety and efficacy of the bidirectional pull-back technique for removing strut-embedded IVC filters in 15 consecutive patients. Retrieval procedural data such as in-dwell time, retrieval time, and fluoroscopy time were recorded. Clinical outcomes and procedure-related complications were evaluated by venography or enhanced computed tomography. Histologic tissue was analyzed to reveal the pathologic effects of chronic filter implantation. All patients underwent routine clinical follow-up at a mean time of 12 months (range, 8-14 months). RESULTS Technical success of filter retrieval was achieved in 100%, with mean implantation of 46.6 days (range, 27-66 days). Filter types were as follows: OptEase (n=11) and Aegisy (n=4). The mean retrieval time and fluoroscopy time were 21.43±5.42 min and 7.63±2.67 min, respectively. Immediate postprocedure venography showed no procedure-related complications. Thirteen patients discontinued previously prescribed lifelong anticoagulation. There were no long-term complications during follow-up. CONCLUSIONS The bidirectional pull-back technique is safe and efficient for filter retrieval. This complex technique can be particularly useful in selected patients to remove strut-embedded cylindrical-shaped IVC filters previously considered irretrievable.

Novel and Advanced Techniques for Complex IVC Filter Retrieval

OPINION STATEMENT

Inferior vena cava (IVC) filter placement is indicated for the treatment of venous thromboembolism (VTE) in patients with a contraindication to or a failure of anticoagulation. With the advent of retrievable IVC filters and their ease of placement, an increasing number of such filters are being inserted for prophylaxis in patients at high risk for VTE. Available data show that only a small number of these filters are retrieved within the recommended period, if at all, prompting the FDA to issue a statement on the need for their timely removal. With prolonged dwell times, advanced techniques may be needed for filter retrieval in up to 60% of the cases. In this article, we review standard and advanced IVC filter retrieval techniques including single-access, dual-access, and dissection techniques. Complicated filter retrievals carry a non-negligible risk for complications such as filter fragmentation and resultant embolization of filter components, venous pseudoaneurysms or stenoses, and breach of the integrity of the caval wall. Careful pre-retrieval assessment of IVC filter position, any significant degree of filter tilting or of hook, and/or strut epithelialization and caval wall penetration by filter components should be considered using dedicated cross-sectional imaging for procedural planning. In complex cases, the risk for retrieval complications should be carefully weighed against the risks of leaving the filter permanently indwelling. The decision to remove an embedded IVC filter using advanced techniques should be individualized to each patient and made with caution, based on the patient's age and existing comorbidities.

Resolution of Metallic Biliary Stent Allergic Reaction After Partial Stent Removal in a Patient with Nickel Sensitivity

Local and systemic reactions to implanted metallic devices, particularly to those containing nickel, are well documented. Metal ions are released due to exposure of the metal to blood, proteins, other body fluids, and sheer mechanical stress. Metal ions then complex with native proteins and become antigens, which can elicit hypersensitivity reactions. Another case report depicts a specific allergic complication (early stent occlusion) related to metallic biliary stent implantation. We present a case of allergic symptoms, associated with eating, in a patient who developed nickel sensitivity after biliary metal stent placement confirmed by allergic skin testing to the same metallic biliary stent placed one year earlier. Symptoms resolved following partial removal of the non-epithelialized portion of the biliary stent.

Can Pre-Retrieval Computed Tomography Predict the Difficult Removal of an Implementing an Inferior Vena Cava Filter?

Purpose:

Implementing an inferior vena cava (IVC) filter is a relatively safe procedure but potential negative long-term effects. The complications for filter retrieval have been noted. We examined filter characteristics on pre-retrieval computed tomography (CT) that were associated with complicated retrieval (CR) of IVC filters.

Materials and Methods:

A retrospective review of IVC filter retrievals between January 2008 and June 2014 was performed to identify patients who had undergone a pre-retrieval CT for IVC filter retrieval. CR was defined as the use of nonstandard techniques, procedural time over 30 min, filter fractures, filter tip incorporation into the IVC wall, and retrieval failure. Pre-retrieval CT images were evaluated for tilt angle in the mediolateral and anteroposterior directions, tip embedding into the IVC wall, degree of filter strut perforation, and distance of the filter tip from the nearest renal vein.

Results:

Of seventy-six patients, twenty-four patients (31.6%) with CRs and 56 patients (73.7%) with non-CR were evaluated for pre-retrieval CT. For IVC filter retrieval with a dwelling time of over 45 days, a tilt of over 15 degrees, the appearance of tip embedding and grade 2 perforation were associated with CR on multivariate analysis. However, for IVC filter retrievals with a dwelling time of less than 45 days, there were no factors associated with CR.

Conclusion:

Pre-retrieval CTs may be more effective for IVC filters with a dwelling time of over 45 days. Therefore, a pre-retrieval CT may be helpful in predicting CR of IVC filters with long dwelling times.

Efficacy and Retrievability of Aegisy Vena Cava Filter: A Single Center Experience in 213 Patients

BACKGROUND

The aim of this study was to retrospectively evaluate the safety, efficacy, and retrievability of the Aegisy vena cava filter (LifeTech Scientific Co. Ltd, Shenzhen, China).

METHODS

Data from all patients who underwent Aegisy vena cava filter placement for pulmonary embolism (PE) prophylaxis during catheter-directed thrombolysis (CDT) or aspiration thrombectomy for the proximal deep venous thrombosis (DVT) were included and analyzed.

RESULTS

From October 2006 to September 2015, a total of 213 patients were included in this study. All the filters were successfully placed without any difficulty. Filter removal was attempted in 112 (52.6%) patients after a median duration of 12 days (range 9-15) of placement, and were successful in 107 (95.5%) patients. Venography was performed pre- and post-filter removal, severe tilt was seen in 5 (4.5%, 5/112) patients, and neither filter migration nor deformity was seen in any of the patients. No procedure-related complication was observed in any of the patients. A total of 47 (22.1%) patients underwent thorax or pulmonary computed tomography for cancer or other reasons before the filters were retrieved, and no segmental PE was seen. Also, no symptomatic PE breakthrough was seen in any of the patients after the filter placement.

CONCLUSIONS

Aegisy vena cava filter is a safe and effective device for PE prophylaxis during CDT or aspiration thrombectomy for the proximal DVT. Although only half patients presented for removal, the retrievability of Aegisy vena cava filter is high.

IVC filter retrieval in adolescents: experience in a tertiary pediatric center

BACKGROUND

Inferior vena cava (IVC) filters are commonly implanted with the intent to prevent life-threatening pulmonary embolism in at-risk patients with contraindications to anticoagulation. Various studies have reported increases in the rate of venous thromboembolism within the pediatric population. The utility and safety of IVC filters in children has not yet been fully defined.

OBJECTIVE

To describe the technique and adjunctive maneuvers of IVC filter removal in children, demonstrate its technical success and identify complications.

MATERIALS AND METHODS

A retrospective 10-year review was performed of 20 children (13 male, 7 female), mean age: 15.1 years (range: 12-19 years), who underwent IVC filter retrieval. Eleven of 20 (55%) were placed in our institution. Electronic medical records were reviewed for filter characteristics, retrieval technique, technical success and complications.

RESULTS

The technical success rate was 100%. Placement indications included: deep venous thrombosis with a contraindication to anticoagulation (10/20, 50%), free-floating thrombus (4/20, 20%), post-trauma pulmonary embolism prophylaxis (3/20, 15%) and pre-thrombolysis pulmonary patient (1/20, 5%). The mean implantation period was 63 days (range: 20-270 days). Standard retrieval was performed in 17/20 patients (85%). Adjunctive techniques were performed in 3/20 patients (15%) and included the double-snare technique, balloon assistance and endobronchial forceps retrieval. Median procedure time was 60 min (range: 45-240 min). Pre-retrieval cavogram demonstrated filter tilt in 5/20 patients (25%) with a mean angle of 17° (range: 8-40). Pre-retrieval CT demonstrated strut wall penetration and tip embedment in one patient each. There were two procedure-related complications: IVC mural dissection noted on venography in one patient and snare catheter fracture requiring retrieval in one patient. There were no early or late complications.

CONCLUSION

In children, IVC filter retrieval can be performed safely but may be challenging, especially in cases of filter tilt or embedding. Adjunctive techniques may increase filter retrieval rates.

Retrievable Filter Update: The Denali Vena Cava Filter

Over the past decade, there has been a gradual evolution of the retrievable inferior vena cava (IVC) filter, as the indications for caval filtration have expanded since the first such filters came into use. However, the particular design of retrievable or optional filters has introduced a subset of both symptomatic and asymptomatic device failures that have prompted a reassessment in the approach to patient selection as well as a new lexicon of technical considerations when considering retrieval. The Denali Vena Cava Filter (Bard Peripheral Vascular, Inc., Tempe, AZ) represents one of the latest filters to come to market that specifically addresses the various issues of its predecessors. While the body of published experience with this filter is still relatively sparse, the incidence of filter tilt, strut perforation, strut fracture, and filter migration appears acceptably low and the filters remain relatively easy to retrieve even after long dwell times.

Iatrogenic percutaneous vascular injuries: clinical presentation, imaging, and management

Vascular interventional radiology procedures are relatively safe compared with analogous surgical procedures, with overall major complication rates of less than 1%. However, major vascular injuries resulting from these procedures may lead to significant morbidity and mortality. This review will discuss the etiology, clinical presentation, diagnosis, and management of vascular complications related to percutaneous vascular interventions. Early recognition of these complications and familiarity with treatment options are essential skills for the interventional radiologist.

Excimer Laser–Assisted Removal of Embedded Inferior Vena Cava Filters

Background—

Although chronically implanted inferior vena cava filters may result in filter-related morbidity, there is currently no routine option for removing such filters when they become firmly embedded along the vena cava endothelium.

Methods and Results—

During a 3-year period, 100 consecutive patients were prospectively enrolled in a single-center study. There were 42 men and 58 women (mean age, 46 years; limits, 18–76 years). Retrieval indications included filter-related acute inferior vena cava thrombosis, chronic inferior vena cava occlusion, and pain from retroperitoneal or bowel penetration. Filter retrieval was also performed to prevent risks from prolonged implantation and to potentially eliminate the need for lifelong anticoagulation. After standard methods failed, photothermal tissue ablation was attempted with a laser sheath powered by a 308-nm xenon chloride excimer laser. Applied forces were recorded with a digital tension meter before and during laser activation. Laser-assisted retrieval was successful in 98.0% (95% confidence interval [CI], 93.0%–99.8%) with mean implantation of 855 days (limits, 37–6663 days; >18 years). The following filter types were encountered in this study: Günther-Tulip (n=34), Celect (n=12), Option (n=17), Optease (n=20, 1 failure), TrapEase (n=6, 1 failure), Simon-Nitinol (n=1), 12F Stainless Steel Greenfield (n=4), and Titanium Greenfield (n=6). The average force during failed standard retrievals was 7.2 versus 4.6 pounds during laser-assisted retrievals ( P <0.0001). The major complication rate was 3.0% (95% CI, 0.6%–8.5%), the minor complication rate was 7.0% (95% CI, 0.3%–13.9%), and there were 4 adverse events (2 coagulopathic hemorrhages, 1 renal infarction, and 1 cholecystitis; 4.0%; 95% CI, 1.1%–9.9%) at mean follow-up of 500 days (limits, 84–1079 days). Scar tissue ablation was histologically confirmed in 96.0% (95% CI, 89.9%–98.9%). Successful retrieval allowed cessation of anticoagulation in 30 of 30 (100%) patients and alleviated morbidity in 23 of 24 patients (96%).

Conclusions—

Excimer laser–assisted removal is effective in removing embedded inferior vena cava filters refractory to standard retrieval and high force. This method can be safely used to prevent and alleviate filter-related morbidity.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01158482.

MMPI drug-eluting IVC filter decreases adhesion between caval wall and filter

The implantation of inferior vena cava (IVC) filter was a safe and effective therapy for preventing fatal pulmonary embolism. However, there are risks associated with long-term implantation of filters. Retrievable filters are designed to be removed, but may also remain permanently. Retrieval can reduce risk of long-term complications. The difficulty or impossibility of retrieval is still an issue of retrieval filter. The major causes of filters retrieval failure were intimal overgrowth and severely tilted filter with apex embedded into the caval wall. Matrix metalloproteinases (MMPs) play a key role in neointimal hyperplasia. It is documented that neointimal hyperplasia can be reduced by inhibiting MMP activity and hence smooth muscle cell migration. MMP inhibitors (MMPI) can potently inhibit the activity of MMPs. We hypothesize that a drug-eluting filter which contains MMPI may inhibit IVC neointimal hyperplasia and decrease the adhesion between vascular wall and filter struts. After implantation of drug-eluting retrieval filter, MMPI is released slowly at the sites where the filter struts are in contact with the caval wall; the activity of MMPs of caval wall will be inhibited, injury in basement membrane is decreased, migration of SMC maybe reduced, and the release of extracellular matrix maybe lessened. Finally, neointimal hyperplasia maybe inhibited, the adhesion between vascular wall and filter maybe weakened, the success rate maybe increased, and the vascular injury during retrieval maybe reduced. The hypothesis might improve the long-term prognosis of venous thromboembolism patients.

Improving retrieval rates for retrievable inferior vena cava filters

The introduction of retrievable inferior vena cava (IVC) filters was an important step in the evolution of deep vein thrombosis/pulmonary embolism management. Their removability makes them preferred to permanent filters in many cases. IVC filter retrieval often occurs at a suboptimal rate, leading to complications associated with long-term placement. Improving retrievability includes solutions for patients being lost to follow-up, filter malpositioning, need arising for permanent IVC filtration, filtration requiring longer than the filter's window of retrievability, and filter compromise by the presence of a large trapped clot. This review explores these strategies for retrieval in detail in hopes of improving IVC filter retrieval rates.