Long-term Retrieval Success Rate Profile for the Günther Tulip Vena Cava Filter

Inferior vena cava perforation during percutaneous filter removal

BACKGROUND

Percutaneous Inferior Venacava (IVC) filter retrieval can be challenging when the filter is grossly angulated, embedded in the wall or penetrates through the IVC. When conventional filter removal technique fails, the use of advanced retrieval techniques often improves the chances of percutaneous filter retrieval. These techniques, however, are associated with a high rate of complications.

METHODS

We report a case of 26-year-old female who had IVC filter placed on postpartum day 4. Attempted percutaneous filter retrieval 3 weeks later with loop snare technique and endobronchial forceps assisted filter removal technique resulted in gross filter deformity, malposition, and IVC perforation.

RESULT

Open IVC filter removal was performed with midline laparotomy and cavotomy with lateral venorrhapy. The deformed filter along with adherent thrombus was completely removed. The patient had an uneventful recovery with no immediate or long-term complications.

CONCLUSION

Use of advanced endovascular IVC filter retrieval techniques could result in serious complications like filter fracture, migration and IVC perforation. Since excessive tilt of the filter at the time of placement often results in difficult retrieval, it is important to ensure proper deployment of the filter with minimal tilt. If encountered with excessively tilted or embedded filter, one should refrain from excessive manipulation of the filter and consider open filter removal.

Ultraflexible Neural Probes for Multidirectional Neuronal Activity Recordings over Large Spatial and Temporal Scales

The widespread dissemination of ultraflexible neural probes depends on the development of advanced materials and implementation strategies that can allow reliable implantation of ultraflexible neural probes into targeted brain regions, especially deep and difficult-to-access brain regions. Here, we report ultraflexible and multidirectional probes that are encapsulated in a biocompatible polymer alloy with controllable dissolution kinetics. Our probes can be reliably implanted into targeted brain regions over large spatial scales, including deep hindbrain regions that are anatomically difficult-to-access in vivo. Chronically implanted probes can enable long-term, multidirectional recordings from several hundreds of neurons across distributed brain regions. In particular, our results show that 87.0% of chronically recorded neurons in the hindbrain are interneurons, whereas only 41.9% of chronically recorded neurons in the cortex are interneurons. These results demonstrate that our ultraflexible neural probes are a promising tool for large-scale, long-term neural circuit dissection in the brain.

Clinical outcomes of retrievable inferior vena cava filters for venous thromboembolic diseases

Aim: To identify literature evidence assessing retrievable inferior vena cava filter (rIVCF) for venous thromboembolic diseases. Methods: A systematic literature search was conducted to identify relevant references from the mainstay English and Chinese bibliographic databases (search period: January 2003 to October 2019). Results: 80 original studies with 11,413 patients were included in this review. The success rates of deploying the six types of rIVCFs ranged from 98.4 to 100.0%. Denali had the highest retrieval success rate (95.4-97.6%). The incidence rates of fracture and perforation associated with retrieving the six rIVCFs were less than 2%. Conclusion: The approved rIVCF had comparable clinical profiles, except that Denali was easier to be retrieved than other rIVCF.

Risk factors associated with complex inferior vena cava filter retrievals and complications: A 7-year retrieval database analysis and the impact on retrieval rates at an Australian tertiary centre

INTRODUCTION

Venous thromboembolism (VTE) affects approximately 17,000 Australians annually. While anticoagulation is the mainstay of treatment, inferior vena cava filters (IVCFs) are used in patients where this is contraindicated. The primary aim was to identify risk factors for complex retrievals and IVCF-related complications following the establishment of a database at a single tertiary centre. The secondary aim was to evaluate the IVCF retrieval rate and patients lost to follow-up.

METHODS

A retrospective study at a single tertiary centre was conducted on IVCFs inserted from 2012 to 2018. Logistic regression models were used to evaluate potential risk factors for filter-related complications and complex retrievals.

RESULTS

In total, 402 patients had an IVCF inserted. Of these, 308 patients (77%) had a retrieval attempted, 10 (3%) of which required more than one retrieval attempt (complex retrieval). Factors associated with filter-related complications included dwell time (OR 1.02, 95% CI: 1.01-1.04) and select indications for insertion, namely VTE requiring thrombolysis/thrombectomy (OR 2.29, 95% CI: 1.02-5.16) and iliocaval/free-floating iliofemoral DVT without thrombectomy/thrombolysis (OR 5.89, 95% CI: 1.53-22.71). After mutual adjustment for all variables, only dwell time remained a significant factor for filter-related complications (adjusted OR 1.03, 95% CI: 1.01-1.05) and complex retrieval (AOR 1.05, 95% CI: 1.02-1.08). The annual retrieval rate increased from 73% (2012) to 83% (2018), with an overall retrieval rate of 75%.

CONCLUSION

Dwell time is a potential risk factor for filter-related complications and complex retrievals. The annual IVCF retrieval rate was 75% since an Interventional Radiology-led database was established.

Inferior vena cava filter tilting between placement and retrieval is associated with caval diameter and need for complex retrieval techniques

PURPOSE

Inferior vena cava (IVC) filter tilt may lead to apex embedment and need for advanced retrieval techniques. This study assesses factors associated with filter tilt change over time and need for complex retrieval procedures.

MATERIALS AND METHODS

252 consecutive patients underwent retrievable IVC filter placement and removal at a single academic institution over 58 months. 182 (72.2%) patients met inclusion criteria. IVC filters included 168 (92.3%) Gunther Tulip and 14 (7.7%) Option filters. The primary outcome was medial-to-lateral IVC filter tilt change between placement and retrieval. Secondary outcomes included advanced retrieval technique use and multiple retrieval attempts. Independent variables included demographics, IVC diameter, filter hook position relative to the renal veins, and dwell time. Associations were determined using student's t-tests, ANOVA, and linear and logistic regressions.

RESULTS

Mean IVC diameter at placement was 19.2 ± 3.3 mm. Mean filter tilts at placement and retrieval were 6.1 ± 4.9° and 5.2 ± 5.0°, respectively. Mean tilt change was 5.0 ± 5.0°. Larger IVC diameter was associated with greater filter tilt change (p = 0.0004). While IVC diameter did not independently predict retrieval difficulty, greater tilt change and prolonged dwell time were associated with increased advanced retrieval technique use (p = 0.01 and 0.002, respectively). Results were unchanged in a subgroup analysis of patients treated with Gunther Tulip filters.

CONCLUSION

Larger IVC diameter predicts increased filter tilt change, which in turn is associated with challenging retrievals. Attention to IVC diameter during filter placement may anticipate tilt-related complications.

Excimer Laser Sheath-Assisted Retrieval of "Closed-Cell" Design Inferior Vena Cava Filters

Background Numerous reports have shown that inferior vena cava filters are associated with clinically significant adverse events. Complicating factors, such as caval incorporation, may lead to technical challenges at retrieval. The use of advanced techniques including the laser sheath have increased technical success rates; however, the data are limited on which filter types necessitate and benefit from its use. Methods and Results From October 2011 to September 2019, patients with inferior vena cava filter dwell times >6 months or with prior failed retrievals were considered for laser sheath-assisted retrieval. Standard and nonlaser advanced retrieval techniques were attempted first; if the filter could not be safely or successfully detached from the caval wall using these techniques, the laser sheath was used. Technical success, filter type, necessity for laser sheath application based on "open" versus "closed-cell" filter design, dwell times, and adverse events were evaluated. A total of 441 patients (216 men; mean age, 54 years) were encountered. Mean dwell times for all filters was 56.6 months, 54.4 among closed-cell filters and 58.5 among open-cell filters (P=0.63). Technical success of retrieval was 98%, with the laser sheath required in 143 cases (40%). Successful retrieval of closed-cell filters required laser sheath assistance in 60% of cases as compared with 7% of open-cell filters (odds ratio, 20.1; P<0.01). In closed-cell inferior vena cava filters, dwell time was significantly associated with need for laser, requiring it in 64% of retrievals with dwell times >6 months (P=0.01). One major adverse event occurred among laser sheath retrievals when a patient required a 2-day inpatient admission for a femoral access site hemorrhage. Conclusions Closed-cell filters may necessitate the use of the laser sheath for higher rates of successful and safe retrieval.

Inferior Vena Cava Filter Evaluation and Management for the Diagnostic Radiologist: A Comprehensive Review Including Inferior Vena Cava Filter-Related Complications and PRESERVE Trial Filters

Inferior vena cava filters are commonly encountered devices on diagnostic imaging that were highlighted in a 2010 Food and Drug Administration safety advisory regarding their complications from long-term implantation. The Predicting the Safety and Effectiveness of Inferior Vena Cava Filters (PRESERVE) trial is an ongoing after-market study investigating the safety and utility of commonly utilized filters in practice today. While most of these filters are safe, prompt recognition and management of any filter-associated complication is imperative to prevent or reduce the morbidity and mortality associated with them. This review is aimed at discussing the appropriate utilization and placement of inferior vena cava filters in addition to the recognition of filter-associated complications on cross-sectional imaging. An overview of the PRESRVE trial filters is also provided to understand each filter's propensity for specific complications.

Bidirectional loop-snare technique for adherent inferior vena cava filter retrieval

Placement of a Günther Tulip Inferior Vena Cava (IVC) Filter™ (Cook, Bloomington, IN, USA) is an alternative treatment option to prevent pulmonary embolism in patients in whom anticoagulation therapy is contraindicated. Most patients require filter placement for only short periods, after which it can be retrieved. IVC filter retrieval becomes more difficult as the indwelling time increases. We developed a new method to retrieve the Günther Tulip IVC Filter™, namely, the bidirectional loop-snare technique (BLT). The key to the BLT procedure is to use 2 snares from both the jugular and femoral access routes. The jugular snare catches the filter hook and the femoral snare relieves the adhesion between the filter leg and IVC wall. Pulling from both the jugular and femoral ends increases the power to retrieve the IVC filter, and leads to successful filter retrieval. <Learning objective: An inferior vena cava (IVC) filter is placed in patients with a risk of pulmonary embolism. Most patients require filter placement for only short periods, after which it can be retrieved. Occasionally, IVC filter retrieval is difficult because of long-term placement. We developed a novel, simple method for filter retrieval, using a bidirectional approach and two snares simultaneously.>.

Inferior Vena Cava Filters: Current Indications, Techniques, and Recommendations

The vena cava filter (VCF) is intended to prevent the progression of deep venous thrombosis to pulmonary embolism. Recently, the indications for VCF placement have expanded, likely due in part to newer retrievable inferior vena caval filters and minimally invasive techniques. This article reviews the available VCFs, the indications for use, the techniques for placement, and possible outcomes and complications.

Denali, Tulip, and Option Inferior Vena Cava Filter Retrieval: A Single Center Experience

PURPOSE

To compare the technical success of filter retrieval in Denali, Tulip, and Option inferior vena cava filters.

MATERIALS AND METHODS

A retrospective analysis of Denali, Gunther Tulip, and Option IVC filters was conducted. Retrieval failure rates, fluoroscopy time, sedation time, use of advanced retrieval techniques, and filter-related complications that led to retrieval failure were recorded.

RESULTS

There were 107 Denali, 43 Option, and 39 Tulip filters deployed and removed with average dwell times of 93.5, 86.0, and 131 days, respectively. Retrieval failure rates were 0.9% for Denali, 11.6% for Option, and 5.1% for Tulip filters (Denali vs. Option p = 0.018; Denali vs. Tulip p = 0.159; Tulip vs. Option p = 0.045). Median fluoroscopy time for filter retrieval was 3.2 min for the Denali filter, 6.75 min for the Option filter, and 4.95 min for the Tulip filter (Denali vs. Option p < 0.01; Denali vs. Tulip p < 0.01; Tulip vs. Option p = 0.67). Advanced retrieval techniques were used in 0.9% of Denali filters, 21.1% in Option filters, and 10.8% in Tulip filters (Denali vs. Option p < 0.01; Denali vs. Tulip p < 0.01; Tulip vs. Option p < 0.01).

DISCUSSION

Filter retrieval failure rates were significantly higher for the Option filter when compared to both the Denali and Tulip filters. Retrieval of the Denali filter required significantly less amount of fluoroscopy time and use of advanced retrieval techniques when compared to both the Option and Tulip filters. The findings of this study indicate easier retrieval of the Denali and Tulip IVC filters when compared to the Option filter.

The Successful Removal of Two Retrievable Inferior Vena Cava (IVC) Filters after 67 Days in a Patient with a Double IVC

We herein present a case in which two retrievable inferior vena cava (IVC) filters, which were implanted to treat deep-vein thrombosis caused by the compression of a double IVC, were successfully removed on the 67th day after placement. The filters were individually placed in both the left and right IVCs. With a prevalence of only 0.2%, a double IVC is an extremely rare anatomical variation. The long-term effects of IVC filters are unknown, and the placement of a filter potentially introduces the risk of complications. Thus, if the patient's clinical condition allows, the endovascular retrieval of the filter should be considered within a few months after implantation.

Analysis of the Final DENALI Trial Data: A Prospective, Multicenter Study of the Denali Inferior Vena Cava Filter

PURPOSE

To report the final 2-year data on the efficacy and safety of a nitinol retrievable inferior vena cava (IVC) filter for protection against pulmonary embolism (PE).

MATERIALS AND METHODS

This was a prospective multicenter trial of 200 patients with temporary indications for caval filtration who underwent implantation of the Denali IVC filter. After filter placement, all patients were followed for 2 years after placement or 30 days after filter retrieval. The primary endpoints were technical success of filter implantation in the intended location and clinical success of filter placement and retrieval. Secondary endpoints were incidence of clinically symptomatic recurrent PE, new or propagating deep vein thrombosis (DVT), and filter-related complications including migration, fracture, penetration, and tilt.

RESULTS

Filter placement was technically successful in 199 patients (99.5%). Filters were clinically successful in 190 patients (95%). The rate of PE was 3% (n = 6), with 5 patients having a small subsegmental PE and 1 having a lobar PE. New or worsening DVT was noted in 26 patients (13%). Filter retrieval was attempted 125 times in 124 patients and was technically successful in 121 patients (97.6%). The mean filter dwell time at retrieval was 200.8 days (range, 5-736 d). There were no instances of filter fracture, migration, or tilt greater than 15° at the time of filter retrieval or during follow-up.

CONCLUSIONS

The Denali IVC filter exhibited high success rates for filter placement and retrieval while maintaining a low complication rate in this clinical trial.

A Critical Review of Available Retrievable Inferior Vena Cava Filters and Future Directions

Inferior vena cava filters have been placed in patients for decades for protection against pulmonary embolism. The widespread use of filters has dramatically increased owing at least in part to the approval of retrievable vena cava filters. Retrievable filters have the potential to protect against pulmonary embolism and then be retrieved once no longer needed to avoid potential long-term complications. There are several retrievable vena cava filters available for use. This article discusses the different filter designs as well as the published data on these available filters. When selecting a filter for use, it is important to consider the potential short-term complications and the filters' window for retrieval. Understanding potential long-term complications is also critical, as these devices are approved for permanent placement and many filters are not retrieved. Finally, this article will address research into new designs that may be the future of vena cava filtration.

Evidence-Based Evaluation of Inferior Vena Cava Filter Complications Based on Filter Type

Many inferior vena cava (IVC) filter types, along with their specific risks and complications, are not recognized. The purpose of this study was to evaluate the various FDA-approved IVC filter types to determine device-specific risks, as a way to help identify patients who may benefit from ongoing follow-up versus prompt filter retrieval. An evidence-based electronic search (FDA Premarket Notification, MEDLINE, FDA MAUDE) was performed to identify all IVC filter types and device-specific complications from 1980 to 2014. Twenty-three IVC filter types (14 retrievable, 9 permanent) were identified. The devices were categorized as follows: conical (n = 14), conical with umbrella (n = 1), conical with cylindrical element (n = 2), biconical with cylindrical element (n = 2), helical (n = 1), spiral (n = 1), and complex (n = 1). Purely conical filters were associated with the highest reported risks of penetration (90-100%). Filters with cylindrical or umbrella elements were associated with the highest reported risk of IVC thrombosis (30-50%). Conical Bard filters were associated with the highest reported risks of fracture (40%). The various FDA-approved IVC filter types were evaluated for device-specific complications based on best current evidence. This information can be used to guide and optimize clinical management in patients with indwelling IVC filters.

Impact of Physician Education and a Dedicated Inferior Vena Cava Filter Tracking System on Inferior Vena Cava Filter Use and Retrieval Rates Across a Large US Health Care Region

PURPOSE

To evaluate the effects of physician familiarity with current evidence and guidelines on inferior vena cava (IVC) filter use and the availability of IVC filter tracking infrastructure on retrieval rates.

MATERIALS AND METHODS

Fourteen continuing medical education-approved in-hospital grand rounds covering evidence-based review of the literature on IVC filter efficacy, patient-centered outcomes, guidelines for IVC filter indications, and complications were performed across a large United States (US) health care region serving more than 3.5 million members. A computer-based IVC filter tracking system was deployed simultaneously. IVC filter use, rates of attempted retrieval, and fulfillment of guidelines for IVC filter indications were retrospectively evaluated at each facility for 12 months before intervention (n = 427) and for 12 months after intervention (n = 347).

RESULTS

After education, IVC filter use decreased 18.7%, with a member enrollment-adjusted decrease of 22.2%, despite an increasing IVC filter use trend for 4 years. Reduction in IVC filter use at each facility strongly correlated with physician attendance at grand rounds (r = -0.69; P = .007). Rates of attempted retrieval increased from 38.9% to 54.0% (P = .0006), with similar rates of successful retrieval (82.3% before education and 85.8% after education on first attempt). Improvement in IVC filter retrieval attempts correlated with physician attendance at grand rounds (r = 0.51; P = .051). IVC filter dwell times at first retrieval attempt were similar (10.2 wk before and 10.8 wk after).

CONCLUSIONS

Physician education dramatically reduced IVC filter use across a large US health care region, and represents a learning opportunity for physicians who request and place them. Education and a novel tracking system improved rates of retrieval for IVC filter devices.

Retrievable inferior vena cava filters can always be removed using "fall-back" techniques

OBJECTIVE

Retrievable inferior vena cava filters (IVCFs) left in place for a prolonged period can lead to complications including filter migration, fracture, and caval thrombosis. "Fall-back" techniques for IVCF retrieval that can be used when standard snaring is unsuccessful have been recently described. The purpose of this study was to analyze how incorporation of these new techniques affected the outcomes of IVCF retrievals at our institution during the past 5 years.

METHODS

Data were collected of all patients undergoing IVCF removal by vascular surgeons at a tertiary academic medical center between 2009 and 2013, including demographics and procedural and filter characteristics. A standard technique of snaring the retrieval hook was attempted first in all cases; if this was unsuccessful, a number of fall-back techniques were employed, including the use of endoscopic graspers, 18F sheaths, and snaring a second wire below the collar of the filter to collapse it into the sheath.

RESULTS

IVCF retrieval was attempted in 275 patients; 3 were excluded intraoperatively because of thrombus in the filter. Most filters (97%) were Günther Tulips (Cook Medical, Bloomington, Ind); 70% had been placed prophylactically before bariatric surgery. A total of 268 filters (98.5%) were retrieved successfully, 213 (79%) by standard snaring and 55 (21%) with fall-back techniques. In patients undergoing fall-back techniques, technical success was achieved 100% of the time. The median time since insertion was significantly longer in the fall-back group (173 days vs 83 days; P < .0001). Four intraoperative complications occurred; fractured wires embolized to the right atrium or pulmonary artery and were successfully removed endovascularly. The majority of the procedures (80%) were performed under sedation in both groups.

CONCLUSIONS

Incorporation of fall-back techniques may allow 100% technically successful and safe removal of retrievable IVCFs and is especially useful in removing filters with prolonged dwell time.

Improving the retrieval rate of inferior vena cava filters with a multidisciplinary team approach

OBJECTIVE

The option to retrieve inferior vena cava (IVC) filters has resulted in an increase in the utilization of these devices as stopgap measures in patients with relative contraindications to anticoagulation. These retrievable IVC filters, however, are often not retrieved and become permanent. Recent data from our institution confirmed a historically low retrieval rate. Therefore, we hypothesized that the implementation of a new IVC filter retrieval protocol would increase the retrieval rate of appropriate IVC filters at our institution.

METHODS

All consecutive patients who underwent an IVC filter placement at our institution between September 2003 and July 2012 were retrospectively reviewed. In August 2012, a multidisciplinary task force was established, and a new IVC filter retrieval protocol was implemented. Prospective data were collected using a centralized interdepartmental IVC filter registry for all consecutive patients who underwent an IVC filter placement between August 2012 and September 2014. Patients were chronologically categorized into preimplementation (PRE) and postimplementation (POST) groups. Comparisons of outcome measures, including the retrieval rate of IVC filters along with rates of retrieval attempt and technical failure, were made between the two groups.

RESULTS

In the PRE and POST groups, a total of 720 and 74 retrievable IVC filters were implanted, respectively. In the POST group, 40 of 74 filters (54%) were successfully retrieved compared with 82 of 720 filters (11%) in the PRE group (P < .001). Furthermore, a greater number of IVC filter retrievals were attempted in the POST group than in the PRE group (66% vs 14%; P < .001). No significant difference was observed between the PRE and POST groups for technical failure (17% vs 18%; P = .9).

CONCLUSIONS

The retrieval rate of retrievable IVC filters at our institution was significantly increased with the implementation of a new IVC filter retrieval protocol with a multidisciplinary team approach. This improved retrieval rate is possible with minimal dedication of resources and can potentially lead to a decrease in IVC filter-related complications in the future.

Inferior vena cava filters: current best practices

Venous thromboembolism (VTE) is a common cause of inpatient and outpatient morbidity and mortality. While anticoagulant therapy is considered the primary means of prevention and treatment of VTE, inferior vena cava filters (IVCFs) are often used as an alternative or adjunct to anticoagulation. With the advent of retrievable filters indications have liberalized, to include placement for primary prophylaxis in high-risk patients. However, this practice is based on limited evidence supporting their efficacy in preventing clinically relevant outcomes. Since indiscriminate use of IVCFs can be associated with net patient harm and increased health care costs, knowledge of the literature surrounding IVCF utilization is critical for providers to adopt best practices. In this review, we will provide an overview of the literature as it relates to specific clinical questions that arise when considering IVCF utilization in the prevention and treatment of VTE. Practice-based recommendations will be reviewed to provide the clinician with guidance on challenging clinical scenarios.

Internal jugular and common femoral venous access for the removal of a long-term embedded vena cava filter

We describe an inferior vena cava filter retrieval technique requiring triple venous access performed in a 35-year-old male who was referred for filter removal 16 months after its insertion. The filter showed a right-sided tilt with endothelialization of the distal filter struts into the caval wall. Access was required via both internal jugular veins to straighten the filter using a snared-loop technique. Further 18 F right common femoral vein access was required to snare and remove the filter, which could not be completely collapsed distally due to endothelialized tissue, precluding normal removal via the jugular venous route.

Preparation and experimental research into retrievable rapamycin- and heparin-coated vena cava filters: a pilot study

The use of retrievable vena cava filters (RVCFs) was once commonplace, but filter retrieval was often very difficult. Most unsuccessful retrieval was due to intimal hyperplasia of the inferior vena cava and in-filter thrombosis. This pilot study aimed to design a drug-eluting RVCF. The hypothesis was that coated drugs could be released continuously to inhibit vena intimal hyperplasia and thrombosis, and thus improve the retrieval rates of RVCFs. Various concentrations of polycaprolactone (PCL)/chloroform solution were made from a mixture of Rapamycin and Heparin according to the quality of PCL. The drug was coated onto the surface of the filters by a process of dipping. In vitro tests were performed to check stability and in vitro drug release. Animals receiving filter implantation were divided into 4 groups, the experimental intervention group (EI), experimental laparotomy group (EL), control intervention group (CI), and control laparotomy group (CL). Filters were retrieved by laparotomy in the EL and CL groups, and by interventional operation in the EI and CI groups at 10, 20 and 30 days after implantation. Pathological endothelia biopsies were performed with wood grain-eosin (HE) staining and immunohistochemical examination, with the proliferating cell nuclear antigen (PCNA) index, and the results were compared between the experimental and control groups. The weight of thrombus within the filters was also measured by scale and compared. The coating concentration that succeeded in completely covering the surface was 0.2 g/ml. There was better coverage by SEM at this concentration, and the coated drugs had no obvious loss after filter release. The drug release curves showed that the amount of Heparin released was more than 50 % at day 1; Rapamycin released little in the first few days, beginning in earnest at 20 to 30 days. The filters were easy to retrieve at 10 days for both groups, while neither could be retrieved at 30 days. However, at 20 days the filter in the EI group could be retrieved with some difficulty, but the filter in the CI group couldn't be removed at all. The pathological examination and immunohistochemical PCNA examination results showed that the use of drug-eluting filters could effectively inhibit endothelial hyperplasia at 10 and 20 days, but was less effective at 30 days. There was no apparent difference in the total weight of blood clots between the experimental and control groups. We successfully conducted a pilot study into preparing Rapamycin- and Heparin-coated RVCFs. In vitro and in vivo tests further proved the possibility of improving the retrieval rates of RVCFs by effectively inhibiting vein endothelial proliferation, but the anticoagulation and antithrombosis effects of Heparin were unsatisfactory.

The CIRSE Retrievable IVC Filter Registry: Retrieval Success Rates in Practice

CIRSE established a registry of retrievable filter use with the primary aim of determining the success of IVC Filter retrieval and associated complications. Secondary endpoints included filter indications, imaging strategies before retrieval, filter dwell times, and anticoagulation status. A web-based electronic registry was hosted between 01/12/2010 and 30/06/2012. Data entry occurred at the date of IVC filter retrieval and included items such as filter type, indication for filter insertion, access route, dwell time, retrieval success, complications, reasons for failed retrieval, and anticoagulation status. 671 filter retrievals were entered (male:female 333:295, mean age 55, median 57). Retrieval data were not entered in 43/671 leaving 628 patients for analysis. The 4 commonest retrievable filters used were the Celect in 182 patients, the OPTEASE in 161, ALN in 120, and Gunther Tulip in 98. Filters were inserted for absolute indications 40%, relative indications in 31%, and prophylactic in 24%, with 5% missing. Mean filter dwell time was 90 days. Filters were successfully retrieved in 576/628 patients (92%). The mean dwell time for successful retrievals was 85 days versus 145 days for unsuccessful retrievals (p = 0.001). Major complications occurred in 2 patients (0.03%). In summary, the CIRSE retrievable filter registry demonstrates a retrieval rate of 92% across a range of filter types, with a low major complication rate, reflecting current practice. There is an increase in trend of retrievable filter use for relative and prophylactic indications.

Midterm follow-up after retrievable inferior vena cava filter placement in venous thromboembolism patients with or without malignancy

BACKGROUND

A clear indication and strategy for placement of retrievable inferior vena cava filters (IVCFs) have not been established. This study was designed to evaluate the efficacy and disadvantages of the retrievable IVCF use particularly in venous thromboembolism (VTE) patients with malignancy.

HYPOTHESIS

Retrievable IVCFs might be safe and useful in VTE patients with malignancy.

METHODS

The study population consisted of 56 consecutive patients undergoing IVCF placement at our institution from January 1, 2008 to December 31, 2011. Prognostic data were retrospectively reviewed in April 2013.

RESULTS

Mean follow-up period was 584.6 (range, 1-1857) days. Twenty-six of the 56 patients had a malignancy. In 16 of the 30 patients without malignancy, the filter was retrieved, whereas the other 14 patients eventually received permanent implantation. There was no significant difference in the survival rate between the retrieval group and the nonretrieval group in the nonmalignancy patients (1-year survival rates, 94% vs 85%). In patients with malignancy, the nonretrieval group showed a significantly lower survival rate (P < 0.01). The 1-year and 2-year survival rates were 100% vs 46% and 100% vs 18%, respectively. There was no medical record of pulmonary thromboembolism occurrence or recurrence. All deaths in the patients with malignancy were malignancy related. In 4 of 5 malignancy patients who could undergo tumor resection surgery, adequate thrombus regression enabled us to retrieve the IVCF after surgery.

CONCLUSIONS

Permanent use of a retrievable IVCF is relatively safe in short- or midterm follow-up regardless of malignancy status. Retrievable filter use might be reasonable in malignancy patients.

The DENALI Trial: an interim analysis of a prospective, multicenter study of the Denali retrievable inferior vena cava filter

PURPOSE

To assess safety and effectiveness of a nitinol retrievable inferior vena cava (IVC) filter in patients who require caval interruption to protect against pulmonary embolism (PE).

MATERIALS AND METHODS

Two hundred patients with temporary indications for an IVC filter were enrolled in this prospective, multicenter clinical study. Patients undergoing filter implantation were to be followed for 2 years or for 30 days after filter retrieval. At the time of the present interim report, all 200 patients had been enrolled in the study, and 160 had undergone a retrieval attempt or been followed to 6 months with their filter in place. Primary study endpoints included technical and clinical success of filter placement and retrieval. Patients were also evaluated for recurrent PE, new or worsening deep vein thrombosis, and filter migration, fracture, penetration, and tilt.

RESULTS

Clinical success of placement was achieved in 94.5% of patients (172 of 182), with a one-sided lower limit of the 95% confidence interval of 90.1%. Technical success rate of filter placement was 99.5%. Technical success rate of retrieval was 97.3%; 108 filters were retrieved in 111 attempts. In two cases, the filter apex could not be engaged with a snare, and one device was engaged but could not be removed. Filter retrievals occurred at a mean indwell time of 165 days (range, 5-632 d). There were no instances of filter fracture, migration, or tilt greater than 15° at the time of retrieval or 6-month follow-up.

CONCLUSIONS

In this interim report, the nitinol retrievable IVC filter provided protection against pulmonary embolism, and the device could be retrieved with a low rate of complications.

Factors affecting Cook Gunther Tulip and Cook Celect inferior vena cava filter retrieval success

OBJECTIVE

Success rates vary for the retrieval of inferior vena cava filters (IVCFs). The optimal retrieval time and factors influencing retrieval success remain unproven. This study aims to determine optimal time and evaluate factors related to successful IVCF retrieval.

METHODS

An institutional prospectively maintained database was reviewed for all IVCF retrieval attempts from 2006 to 2012. Patient demographics, comorbidities, indications for procedure, placement technique, IVCF type, presence of angulation, and time to retrieval were evaluated with respect to success or failure of retrieval. Statistical analyses (t-test, χ(2), correlations, and Kaplan-Meier plots) were performed comparing successful and unsuccessful retrievals.

RESULTS

Of 121 attempted IVCF retrievals, 92 (76%) were successful and 29 (24%) were unsuccessful. There were no significant differences between the successful and unsuccessful attempts in terms of patient demographics, comorbidities, indications for procedure, placement technique, or IVCF type, which included 93 Celect (77%) and 28 Gunther Tulip (23%). Time since IVCF placement was significantly different (P = .025) between the successful and unsuccessful retrieval groups (medians were 105 [7-368] and 162 [43-379] days, respectively). Time since IVCF placement greater than 117 days correlated significantly with unsuccessful IVCF retrieval (R = 0.218; P = .017; odds ratio, 2.88; P = .02). Angulation greater than 20 degrees on anteroposterior radiograph was noted in seven of 29 (24%) unsuccessful retrievals compared with seven of 92 (8%) successful retrievals and was significant (P = .012).

CONCLUSIONS

Cook Gunther Tulip and Celect IVCF retrieval is most likely to be successful within 3 to 4 months of placement. Unsuccessful retrieval attempts are more likely to occur when IVCF position is angulated.

Clinical review: inferior vena cava filters in the age of patient-centered outcomes

Inferior vena cava filter (IVCF) use continues to increase in the United States (US) despite questionable clinical benefit and increasing concerns over long-term complications. For this review we comprehensively examine the randomized, prospective data on IVC filter efficacy, compare relative rates of IVCF placement in the US and Europe, compare commonly considered guidelines for IVCF indications, and the current data on IVCF complications. Searches of MEDLINE and Cochrane databases were conducted for randomized prospective IVCF studies. Only three randomized prospective studies for IVCFs were identified. Commonly cited IVCF guidelines were reviewed with attention to their evolution over time. No evidence has shown a survival benefit with IVCF use. Despite this, continued rising utilization, especially for primary prophylactic indications, is concerning, given increasing evidence of long-term filter-related complications. This is particularly noted in the US where IVCF placements for 2012 are projected to be 25 times that of an equivalent population in Europe (224,700 versus 9,070). Pending much-needed randomized controlled trials that also evaluate long-term safety, we support the more stringent American College of Chest Physicians (ACCP) guidelines for IVCF placement indications and advocate a close, structured follow-up of retrievable IVCFs to improve filter retrieval rates.

Three-year experience of prophylactic placement of inferior vena cava filters in women with gynecological cancer

Objective

To evaluate the outcomes of prophylactic placement of inferior vena cava (IVC) filters to prevent pulmonary embolism (PE) in women undergoing surgery and chemotherapy for gynecological cancer.

Methods and materials

Thirty-eight IVC filters were placed in 38 women between January 2008 and January 2010; 25 of these were placed in gynecological cancer patients for prevention of PE during surgery and the postoperative period. The patients’ electronic medical records, follow-up computed tomography scans, and outpatient follow-up notes were retrospectively reviewed for incidence of PE and adverse events.

Results

After 6 months of follow-up, no PE was observed and there was no mortality. Nine filters were retrieved uneventfully, and there were no clinical complications associated with any indwelling filter.

Conclusion

IVC filters are safe and beneficial towards preventing PE in women undergoing surgery and chemotherapy for gynecological cancer.

Retrievable inferior vena cava filters for venous thromboembolism

Inferior vena cava (IVC) filters are used as an alternative to anticoagulants for prevention of fatal pulmonary embolism (PE) in venous thromboembolic disorders. Retrievable IVC filters have become an increasingly attractive option due to the long-term risks of permanent filter placement. These devices are shown to be technically feasible in insertion and retrieval percutaneously while providing protection from PE. Nevertheless, there are complications and failed retrievals with these retrievable filters. The aim of the paper is to review the retrievable filters and their efficacy, safety, and retrievability.

Preliminary Experience With Option Inferior Vena Cava Filter

Objectives:

To evaluate the safety and efficacy of Option inferior vena cava (IVC) filter during placement and short-term follow-up.

Methods:

A total of 165 patients (mean age: 60-years) who received Option IVC filter from June 2009 to July 2011 were included. In all, 42 patients presented with deep vein thrombosis (DVT), 26 with pulmonary embolism (PE), and 17 with both. All outcomes were examined until April 30, 2012.

Results:

The filters were successfully deployed in 161patients. During follow-up (mean, 9.5 ± 0.68months), 10 patients were diagnosed with post-filter PE and 13 patients with DVT. There were no instances of fatal PE. Follow-up abdominal computed tomography was available in 60 patients and demonstrated filter-related problems in 8 patients (2: penetration of filter legs, 5:  asymptomatic nonocclusive thrombus, and 1: caval occlusion). There were no instances of filter migration or fracture. In total, 27 filters were successfully retrieved after a mean of 5.27 ± 0.76 months.

Conclusion:

The Option filter was effective and safe during implantation and short-term follow-up and associated with high technical success at retrieval.

Systematic review of the use of retrievable inferior vena cava filters

PURPOSE

To review the available literature on retrievable inferior vena cava (IVC) filters to examine the effectiveness and risks of these devices.

MATERIALS AND METHODS

Investigators searched MEDLINE for clinical trials evaluating retrievable filters and reviewed the complications reported to the Manufacturer and User Facility Device Experience (MAUDE) database of the U.S. Food and Drug Administration (FDA).

RESULTS

Eligibility criteria were met by 37 studies comprising 6,834 patients. All of the trials had limitations, and no studies were randomized. There were 11 prospective clinical trials; the rest were retrospective studies. Despite the limitations of the evidence, the IVC filters seemed to be effective in preventing pulmonary embolism (PE); the rate of PE after IVC placement was 1.7%. The mean retrieval rate was 34%. Most of the filters became permanent devices. Multiple complications associated with the use of IVC filters were described in the reviewed literature or were reported to the MAUDE database; most of these were associated with long-term use (> 30 days). At the present time, the objective comparison data of different filter designs do not support superiority of any particular design.

CONCLUSIONS

In high-risk patients for whom anticoagulation is not feasible, retrievable IVC filters seem to be effective in preventing PE. Long-term complications are a serious concern with the use of these filters. The evidence of the effectiveness and the risks was limited by the small number of prospective studies.

Current status and trends in the treatment of acute pulmonary thromboembolism

Untreated acute pulmonary thromboembolism (APTE) is associated with high mortality, which is reduced by prompt treatment. Anticoagulation is fundamental in the treatment of APTE and should be initiated from suspicion. The efficacy and safety of novel anticoagulant drugs, such as oral anti-Xa and anti-IIa inhibitors, are topics in the treatment of APTE and are now under investigation. Thrombolytic therapy is a widely accepted treatment strategy for massive APTE, but its use for submassive APTE is controversial. Catheter intervention, percutaneous cardiopulmonary support and surgical embolectomy are also necessary and effective for some patients with APTE. A retrievable inferior vena cava filter is preferred for transient protection against APTE. Some studies have demonstrated the feasibility of outpatient treatment in patients with APTE after risk stratification.

Inferior vena cava filters: a concise review

Venous thromboembolic disease is associated with significant morbidity and mortality. Anticoagulation has been the mainstay of treatment and prevention. Unfortunately, anticoagulation frequently fails or is contraindicated. Use of inferior vena cava filters can be an effective alternative in these scenarios. Though inferior vena cava filters have been used for > 4 decades, the evidence behind their use is limited. Use of IVC filters is associated with both minor and major complications. More randomized prospective trials are needed to evaluate these devices. In this article, we review issues concerning the use of inferior vena cava filters.

Use of retrievable filters in alternative common iliac vein location in high-risk surgical patients

PURPOSE

To evaluate the use of retrievable filters placed in bilateral common iliac veins in high-risk surgical patients.

MATERIALS AND METHODS

During the 4-year study period, 10 patients received bilateral common iliac vein placement of retrievable filters for pulmonary embolism (PE) prophylaxis. These patients were at risk for venous thromboembolism (VTE) but had no evidence of VTE at the time of filter placement. In nine patients undergoing bariatric surgery, placement of a filter in the inferior vena cava (IVC) was impossible because of megacava (defined as caval diameter ≥ 3.0 cm). In one patient who had planned dissection of an extensive retroperitoneal tumor, there was concern that IVC location of the filter would be prone to complications secondary to intraoperative manipulation. Filter placement and retrieval were evaluated. All patients were followed clinically until 4-6 weeks after filter retrieval.

RESULTS

There were 20 filters placed in 10 attempts, 18 (nine patients) through the right internal jugular vein and 2 (one patient) through bilateral femoral veins. The mean (± standard deviation) dwell time of the filters was 40 days ± 10 (range 30-71 days). All filters were successfully removed. There were no procedural complications. No clinically evident PE was noted.

CONCLUSIONS

Use of retrievable filters in the bilateral common iliac veins was found to be feasible and effective in preventing PE in patients with contraindications to filter placement in the IVC.