Filters Retrieved Research Articles

Relationship Between Language Spoken and Inferior Vena Cava Filter Retrieval Rates at a Single Center

The majority of inferior vena cava (IVC) filters placed are intended to be retrievable after the patient’s risk of pulmonary embolism has decreased. However, studies have shown that there are many factors that play into whether these filters are actually removed. Even socioeconomic factors such as insurance status, age, and race can influence retrieval rates. No study to date has identified a link between IVC retrieval rates and patient language although without proper interpretive services patient language may be a barrier to effective communication and may decrease the likelihood that patients have their filter removed. We performed a retrospective chart review of all patients who underwent IVC filter placement at our institution from January 1, 2017, to July 1, 2022. This time frame intentionally excluded the six most recent months to allow appropriate time for filter retrieval. Demographic, procedural, and comorbidity information was collected through the electronic medical record review. Patients who either had their filter removed or who died with the filter in place were counted as a retrieved filter, and those who did not have their filter removed and remained living were coded as filter remaining in place. The Pearson χ2 analysis was used to compare the groups. From January 1, 2017, to July 1, 2022, 150 patients underwent placement of an IVC filter. The overall filter modified (accounting for patient death) retrieval rate was 83%. There was a significantly decreased filter retrieval rate in patients who were listed as speaking a language other than English (61.5%) when compared with English speakers (85.4%, P < .05). Cantonese was the language with the lowest retrieval rate with just 20% of the filters retrieved in patients who spoke Cantonese. In patients whose filter was removed, there was no difference in average days the filter remained in place based on language. In our single institution study, patients who spoke a language other than English had a decreased rate of IVC filter retrieval. The identification of this difference is imperative to creating and implementing programs to ensure equal care across all socioeconomic backgrounds.

Factors Associated With Inferior Vena Cava Filter Placement and Retrieval for Patients With Cancer-Associated Thrombosis

BackgroundVenous thromboembolism is a leading cause of death in patients with cancer. Inferior vena cava filters are utilized to mitigate the risk of pulmonary embolism for patients who have contraindication to, or failure of, anticoagulation. MethodsWe reviewed an insurance claims database to identify adults receiving cancer-directed therapy and had a new diagnosis of venous thromboembolism. We then evaluated clinical and sociodemographic characteristics in patients with and without filter placement and retrieval. ResultsThere were 25,788 patients (mean [SD] age: 68.3 [12.7] years) who met the study inclusion criteria, with 2111 individuals (8.2%) undergoing filter placement. Filter placement was associated with the type of thrombosis, malignancy, recent surgery, comorbidities, and income. A total of 137 patients (6.5%) newly started anticoagulation within 3 days of filter placement, and 612 (29%) patients received anticoagulation within 30 days after filter placement. Despite this, only 159 (7.5%) patients had their filters retrieved during the study period. Patients with income of $75-99K (odds ratio 2.13, P = .012) or above $100K (odds ratio 1.8, P = .038) were more likely to have filter retrieval compared with those with income <$50K. Filter retrieval was also more likely in younger patients and those with fewer comorbidities or without central nervous system or lung malignancies. ConclusionsInferior vena cava filter placement and retrieval are associated with several sociodemographic factors. Filter retrieval rates are low despite re-initiation of anticoagulation in many patients. Efforts are needed to address disparities in filter use and improve retrieval rates.

Changes in inferior vena cava filter placement and retrieval practice patterns from a population health perspective.

Inferior vena cava (IVC) filters are placed to reduce venous thromboembolism (VTE)-related morbidity and mortality, though the evidence supporting this practice is limited. In 2010, the Food and Drug Administration (FDA) released a device safety advisory due to the risk of filter migration, fracture, and thrombosis with long-term use. The purpose of this study was to evaluate trends and predictors for IVCF placement and retrieval over a 10-year time period from a population health perspective. De-identified patient information from the State Inpatient Databases (SID) and the States Ambulatory Surgery and Services Databases (SASD) for Florida and California were used to identify all patients who underwent IVC filter placement from 2005 to 2014 and 2005 to 2011, respectively. Hospital practice patterns were assessed as a function of time as well as IVC filter placement and retrieval volume. Temporal trends were evaluated for statistical significance using the Cochran-Armitage test. A total of 181,260 IVC filters were placed in 178,327 patients over the study period. IVC filter placements peaked in 2010; following the FDA advisory in 2010, however, IVC filter placements monotonically decreased each subsequent year. The proportion of IVCF placement patients with both acute DVT and PE (17.6% vs 11.8%, P < 0.001) at the time of hospitalization increased; likewise, the proportion of IVCF patients with acute DVT or PE with a concomitant acute contraindication to anticoagulation at the time of hospitalization increased as well following 2010 (17.0% vs 11.9%, P < 0.001). From 2005 to 2014, there was a continual increase in both filter retrieval procedures as well overall percentage of filters retrieved. However, estimated retrieval rates remained low, with a retrieval rate of less than 6% in 2014. Following the FDA warning in 2010, there was a significant decrease in IVC filter placements, with filter placements more frequently performed in patients with poorer health. While retrieval rates increased over time, they remained low.

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

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

3:36 PM Abstract No. 286 Large-scale analysis of inferior vena cava filter placement and retrieval statistics over a 5-year period: evaluating trends and making predictions

To evaluate the utility of large scale databases IBM Watson Explorys and National Inpatient Sample Database (NIS) in describing trends in rates of IVC filter placement and retrieval between 2013-2017. Trends in the utility of these staple interventional radiology procedures were assessed. Hypothesized clinical associations with these trends are also discussed. A large-scale retrospective cross-sectional data analysis was performed using nationwide HIPAA-compliant patient de-identified databases NIS and IBM Watson Explorys. ICD and CPT code searches identified patients whom underwent IVC filter placement and retrieval between 2013-2017. Incidence of IVC filter placement, retrievals, and patient demographic and financial factors were recorded. Descriptive statistics were used to describe data trends from Explorys and NIS database. A total of 72,620 patients were identified to have IVC filter placement. IVC filter retrieval was performed in 14,670 patients. From 2013 to 2015, there was a 15.5% decrease in IVC filter placement in the total sample (N = 72,620). The updated IBM Explorys sample demonstrated a 33% decrease in IVC filter placement from 2013 to 2016 (N = 21,740). IVC filter retrieval rates have increased by 13% from 2013 to 2016. The year 2017 had the lowest rates of both IVC placement and retrieval rates in the sample. The ratio of IVC filters removed to IVC filters placed was highest in 2016 (39%) and 2017 (39%). Large health databases such as NIS and IBM Explorys serve as novel tools in evaluating procedural trends in interventional radiology. This study shows an overall decrease in the frequency of IVC filters placed and an increase in the frequency of IVC filters retrieved between 2013 to 2017. We speculate the trend in decreased placement to relate to improvements in medical anticoagulation. We hypothesize the increased retrieval rates and ratio to be attributed to improved interventional radiology clinic follow-up and increased patient awareness for removal.Tabled 1National Inpatient Sample20132014201520162017IVC filter placement111,895101,46596,005N/AN/AIBM-Watson ExplorysTotal20132014201520162017IVC filter placement2431062706040526041702570Total filter placement33367511816510750510126541702570IVC removal14,67012401350157016201010IVC filter removal/placement ratio20.2%19.8%22%29%39%39% Open table in a new tab

A survey of patients lost to follow-up after inferior vena cava filter placement

ObjectiveThe objective of this study was to determine the demographics and subjective rationale for failure to present for retrieval of patients who had an inferior vena cava (IVC) filter placed. MethodsBetween January 1, 2010, and September 12, 2017, there were 242 patients who had retrievable IVC filters placed. Demographics and indications for filter placement were retrospectively analyzed. All patients who failed to have the filter retrieved were contacted by Institutional Review Board-approved telephone survey to delineate the reason that the filter was not removed. ResultsOf 242 patients with IVC filters placed, 53 (22%) patients presented for filter retrieval at Abington-Jefferson Health. Patients who presented for filter retrieval were statistically younger (46 years vs 65 years; P < .001). The most common indication for filter placement in both groups was preoperative placement for bariatric surgery, but this percentage was higher in the group that presented for filter retrieval (70% [37/53] in the retrieved group vs 47% [88/189] in the nonretrieved group; P = .018). After telephone survey that reached 146 patients, it was determined that 46 (32%) patients who did not return for filter retrieval were told to keep the filter in place secondary to comorbidities, 28 (19%) did not remember being instructed to follow up for retrieval, and 18 (12%) did not want another procedure. Twenty-four patients were deceased at the time of telephone survey (16%). The remainder of the patients had the filter removed at an outside institution or gave another reason. ConclusionsOur study documented a disappointingly low rate of filter retrieval. Patients with IVC filters who failed to present for retrieval were more likely to be older and frequently did not understand the complications of leaving a filter in place and the need to have the filter retrieved. Patient education should be increased to better capture patients with IVC filters and to improve retrieval rates, but our study showed that a significant percentage of patients do not have filters retrieved because of comorbidities or they do not want another procedure.

Retrieval of Inferior Vena Cava Filters Temporarily Placed in a Suprarenal Position: A Review of 13 Patients.

To evaluate the safety and efficacy of retrieval of inferior vena cava filters (IVCF) temporarily placed in a suprarenal position. Retrieval of IVCF placed in a suprarenal position was performed in 13 patients (5 men and 8 women; mean age: 45.1 ± 13.8 years) between July 2006 and May 2018 using either a loop snare technique or endobronchial forceps. Electronic medical records were reviewed for patient demographics and procedural information. Inferior vena cava filters retrieved included Option Elite (n = 9, 69%) and Günther Tulip (n = 4, 31%). Caval thrombosis was not detected in any patients on pre- or postretrieval cavogram. Eleven suprarenal IVCF (84%) were retrieved during the first retrieval attempt after a median indwelling time of 1.8 months (range, 0.03-12.10 months). Retrieval was initially unsuccessful in 2 (16%) patients with Option Elite filters, but both were successfully removed on second attempt using endobronchial forceps. Thirteen suprarenal IVCF (100%) were ultimately retrieved. Endovascular retrieval of IVCF temporarily placed in a suprarenal position is safe and efficacious.

Social and Demographic Factors Influencing Inferior Vena Cava Filter Retrieval at a Single Institution in the United States.

Retrievable inferior vena cava filters (IVCFs) are associated with long-term adverse events that have increased interest in improving filter retrieval rates. Determining the influential patient social and demographic factors affecting IVCF retrieval is important to personalize patient management strategies and attain optimal patient care. Seven-hundred and sixty-two patients were retrospectively studied who had a filter placed at our institution between January 2011 and November 2013. Age, gender, race, cancer history, distance to residence from retrieval institution, and insurance status were identified for each patient, and those receiving retrievable IVCFs were further evaluated for retrieval rate and time to retrieval. Of the 762 filters placed, 133 were permanent filters. Of the 629 retrievable filters placed, 406 met the inclusion criteria and were eligible for retrieval. Results revealed patients with Medicare were less likely to have their filters retrieved (p = 0.031). Older age was also associated with a lower likelihood of retrieval (p < 0.001) as was living further from the medical center (p = 0.027). Patients who were white and had Medicare were more likely than similarly insured black patients to have their filters retrieved (p = 0.024). The retrieval rate of IVCFs was most influenced by insurance status, distance from the medical center, and age. Race was statistically significant only when combined with insurance status. The results of this study suggest that these patient groups may need closer follow-up in order to obtain optimal IVCF retrieval rates.

Abstract No. 476 - Optional inferior vena cava filters in neurosurgery patients: retrieval rates and clinical outcomes

Venous thromboembolism (VTE) in neurosurgery patients can be challenging to treat, especially because systemic anticoagulation is often contraindicated. The use of optional inferior vena cava (IVC) filters in this patient population has increased despite limited data for their use. The purpose of this study was to assess the retrieval rates and clinical outcomes in neurosurgery patients treated with optional IVC filters. In this single institution retrospective study, 192 consecutive neurosurgery patients (M:F = 115:77, median age 60 years) treated with optional IVC filters between January 2011 and April 2013 were identified. Institutional IVC filter database review was used to identify demographic data (age, gender), clinical history (central nervous system pathology, malignancy), indication for IVC filtration (proven VTE or prophylaxis) and IVC filter type. Patients were followed until IVC filter removal or conversion into a permanent device. 96% (n=184) of optional IVC filters were placed for classic or extended indications (proven VTE) and 4% (n=8) were placed prophylactically. Central nervous system pathologies included: intracranial hemorrhage (60%), intracranial lesion(s) (8%) and other (32%). Despite having a dedicated IVC filter clinic, only 19% (n=36) had their filters retrieved. Older patient age (P=0.018) and malignancy (P=0.047) were statistically associated with keeping optional filters as permanent devices. Intracranial hemorrhage (P=0.828), intracranial lesion(s) (P=0.155) and filter type did not predict retrievability. Only older patient age was confirmed as significant in multivariate analysis (P=0.023) while there was a trend toward significance with malignancy (P=0.064). Retrieval of optional IVC filters in neurosurgery patients can be challenging. Older neurosurgery patients requiring IVC filters have a significantly lower likelihood of filter retrieval and may benefit from permanent devices to avoid excessive resource utilization and possible device-related complications. Additional studies are required to better understand the role of IVC filters in this patient population.

A “fall-back” technique for difficult inferior vena cava filter retrieval

The purpose of this study was to describe the results of an alternative technique for inferior vena cava filter (IVCF) retrieval that can be used when the retrieval hook cannot be snared. Retrospective review of all patients undergoing attempted IVCF retrieval by a single surgeon between March 2009 and March 2011 was undertaken. After December 2009, in cases where the retrieval hook could not be snared, an 18F/85 cm sheath was inserted into the internal jugular vein and a Bentson wire (Cook Medical, Bloomington, Ind) and snare were advanced across separate interstices of the filter. The resulting "lasso" was pulled up below the collar at the top of the filter, and the filter collapsed into the sheath. Over 28 months, 34 patients underwent attempted retrieval of Günther Tulip filters (Cook Medical). Patients were 44±15 years old; 59% were women (n=20). Filters were placed for venous thromboembolism with contraindication to anticoagulation in seven cases and prophylactically in 27 cases. Of the prophylactic cases, 18 (67%) were placed before planned bariatric surgery. Before December 2009, the success rate was 86% (6 of 7): the retrieval hook of one filter could not be snared and seemed to be embedded in the wall of the cava. After adoption of the described technique, the success rate was 96% (26 of 27): one patient refused further attempts at central venous catheterization after multiple unsuccessful attempts. Filters retrieved conventionally by snaring the hook (n=18) were implanted on average for 4.8±3.7 months and 12.1±10.1 months for those retrieved using the new technique (n=14; P=.02). All patients were discharged on the day of the procedure without complication. The one patient in whom the retrieval hook could not be snared before December 2009 has refused another attempt at retrieval. The method of IVCF retrieval described here was successful in every instance in which it was attempted. It was associated with no morbidity despite the customary use of an 18F sheath in the internal jugular vein. The approach constitutes an appropriate "fall-back" technique when the retrieval hook of a removable IVCF cannot be snared.

Improving Inferior Vena Cava Filter Retrieval Rates: Impact of a Dedicated Inferior Vena Cava Filter Clinic

To test the hypothesis that an inferior vena cava (IVC) filter clinic increases the retrieval rate of optional IVC filters. Patients who had optional IVC filters placed at the authors' institution between January 2000 and December 2008 were identified and retrospectively studied. A dedicated IVC filter clinic was established at this institution in January 2009, and there is a comprehensive database of prospectively acquired data for patients seen in the IVC filter clinic. Patients were chronologically classified into preclinic and postclinic groups. The number of optional filters retrieved and failed retrieval attempts were recorded. In the preclinic and postclinic periods, 369 and 100 optional IVC filters were placed. Median (interquartile range) number of optional filters placed per month for preclinic and postclinic periods was 3 (range 2-5) and 10 (range 6.5-10.5) (P < .001). Retrieval rates in preclinic and postclinic periods were 108 of 369 (29%) and 60 of 100 (60%) (P < .001). The median time to filter retrieval in the postclinic group was 1.5 months (95% confidence interval 1.2-1.8). The number of failed retrieval attempts in preclinic and postclinic periods was 23 of 369 (6%) and 5 of 100 (5%) (P = .823). The retrieval rate of optional IVC filters at this institution was significantly increased by the establishment of a dedicated IVC filter clinic. This retrieval increase is not related to a decrease in technical failures but more likely relates to more meticulous patient management and clinical follow-up.

Clinical study of domestic ZQL-type retrievable vena cava filter

Background Pulmonary thromboembolism (PTE) is a serious disease often leading to disability and death. Percutaneous placement of an inferior vena cava (IVC) filter is an effective method to prevent fatal PTE caused by lower extremity deep venous thrombosis (LEDVT). We developed the ZQL-type retrievable vena cava filter. The aim of this study was to evaluate the safety and effectiveness of the ZQL-type filter for prevention of fatal PTE. Methods A total of 144 patients with indications for placement of an IVC filter received insertion of filters via a femoral (n=37) or jugular (n=107) vein approach. Abdominal X-ray and color Doppler ultrasonography of IVC were regularly performed to visualize the position and condition of the IVC filter following filter placement. If thrombi in the lower extremity deep veins were removed within 2 weeks, the filter retrieval procedure was performed after an abdominal radiograph, an inferior vena cavogram and a pulmonary angiography. Otherwise, the filter should be kept permanently in place with regular follow-up inspections. Results One hundred and forty-four filters were implanted at the target sites with a success rate of 98.61% for one-time placement and 100% for two-time placement. Of the 137 patients followed up (follow-up rate, 95.14%), 43 patients had filters retrieved during a period of between 7 and 14 days (median, 12 days) following filter placement. The remaining 94 patients were followed for 7 days to 39 months (median follow-up period, 17 months). No filter migration or tilt, filter fracture or IVC perforation was observed. No obstruction of IVC occurred. No symptomatic PTE developed during the follow-up period. Conclusion The ZQL-type retrievable vena cava filter is a safe and effective device to prevent PTE. This filter possesses a distinctive stent-shape, stable design, high capture efficacy, and is easy to insert and retrieve and thus is suitable for clinical application.

Bard Recovery Filter: Evaluation and Management of Vena Cava Limb Perforation, Fracture, and Migration

To report on the evaluation and management of Bard Recovery filter limb perforation, fracture, and migration. In 2007, all patients who received a Bard Recovery filter at a single institution were contacted for consultation and evaluation by noncontrast computed tomography. Rates of limb perforation, fracture, and migration were evaluated on early (<180 days) and final images. Retrieval success and complications were evaluated. Fourteen of 16 patients with Bard Recovery filters were evaluated. The early images in nine patients (mean, 30 days; range, 0-126 d +/- 40) demonstrated arm perforations in 56% (n = 5), leg perforation in 11% (n = 1), and no early fractures or migrations. Final images (mean, 899 days; range, 119-1,218 d +/- 320) demonstrated filter arm perforations in all 14 patients. Leg perforations were seen in 36% of patients (n = 5), and there were a total of four fractures with migration in 21% of patients (n = 3). All fractures occurred in arms that had perforated the vena cava on early images. Two patients had already had their filters retrieved at 119 and 302 days, respectively; the remaining 12 patients elected to have their filters retrieved after evaluation. All 12 filters were retrieved at a mean of 1,021 days (range, 119-1,242 d +/- 134). Leg hook fractures occurred during eight of 12 filter retrieval procedures (67%). Recovery filter limb perforation of the vena cava increases over time and is associated with a 21% incidence of filter arm fracture and migration. Follow-up imaging is recommended. Filter retrieval has a high success rate and is the authors' preferred management strategy.

Assessment of Snared-Loop Technique When Standard Retrieval of Inferior Vena Cava Filters Fails

To identify the success and complications related to a variant technique used to retrieve inferior vena cava filters when simple snare approach has failed. A retrospective review of all Cook Günther Tulip filters and Cook Celect filters retrieved between July 2006 and February 2008 was performed. During this period, 130 filter retrievals were attempted. In 33 cases, the standard retrieval technique failed. Retrieval was subsequently attempted with our modified retrieval technique. The retrieval was successful in 23 cases (mean dwell time, 171.84 days; range, 5-505 days) and unsuccessful in 10 cases (mean dwell time, 162.2 days; range, 94-360 days). Our filter retrievability rates increased from 74.6% with the standard retrieval method to 92.3% when the snared-loop technique was used. Unsuccessful retrieval was due to significant endothelialization (n = 9) and caval penetration by the filter (n = 1). A single complication occurred in the group, in a patient developing pulmonary emboli after attempted retrieval. The technique we describe increased the retrievability of the two filters studied. Hook endothelialization is the main factor resulting in failed retrieval and continues to be a limitation with these filters.

Single Institution Experience with Inferior Vena Cava Filters.

Inferior vena cava (IVC) filters are used in patients (pts.) with Deep Venous Thrombosis (DVT) to prevent pulmonary embolism (PE) when anticoagulation cannot be administered. The purpose of this study was to analyze the use and outcomes of IVC filters in a community hospital. We reviewed the medical records of all pts. who had IVC filters implanted at William W. Backus Hospital between May 2003 and May 2005. Follow up information was obtained up to August 2005 by mailings from the attending physicians. 125 IVC filters were implanted in 121 pts., ages 18 to 93, with 61 males and 60 females. The indications for implantation were contraindication as follows: to anticoagulation in 72 pts. (58%), up coming surgical procedures in 33 pts. (26%), and severity of clot burden in 20 pts. (16%). 123 (98%) filters were deployed into an infrarenal position and 2 into a suprarenal position due to extensive clot in the IVC. Of the 105 filters that were not retrieved 60 were Gunther Tulip (GT) retrievable IVC filters, 42 were Cordis Trapease (CT) permanent IVC filters, 2 were stainless steel Greenfield IVC filters, and 1 was a Cordis Optease (CO) IVC filter. Of the 20 retrieved filters 19 were GT retrievable IVC filters and 1 was a CO IVC filter. Of the 125 filters, 74 were intended to be permanent filters (59%) and 51 (41%) were inserted with intention of retrieval. 31/51 (60%) were eventually not retrieved because of various reasons: need for additional surgery (12), poor pulmonary reserve (5), high-risk of bleeding (5), severity of clot burden (4), short life expectancy (4), and extremely high risk of recurrent DVT (1). Short-term and long-term anticoagulation was used in conjunction with the IVC filters in 21 and 81 pts. respectively. 38 (31%) of the 121 pts. experienced recurrent venous thromboembolism (VTE), 37 developed symptomatic DVT and 1 had a symptomatic PE. 3/20 (15%) of the pts. who had their filters retrieved developed recurrent DVT (18, 22, and 76 days after filter retrieval) compared with 34/105 (32%) pts. who had permanent filters. The only objectively documented symptomatic PE occurred in a pt. with a permanent filter. This pt. had a recurrent PE 7 months post GT IVC filter insertion diagnosed by chest CT scan with PE protocol. Complications were as follows: 1 pt. had transient hypertension immediately after IVC insertion and 1 pt. developed a transient low-grade fever after retrieval. 1 pt. developed retroperitoneal hematoma upon retrieval 75 days after implantation as documented by an IVC Gram and this pt. recovered without need for any intervention and there were no adverse clinical consequences. The implantation periods ranged from 2 to 104 days in the 20 retrieved filters with mean/median of 20/9 days. 4 of the 20 retrieved filters (20%) contained trapped emboli and none of these pts. subsequently developed PE. The GT retrievable IVC filter is now the filter of choice at our institution and can be implanted permanently or with retrieval in mind. Conclusion: Retrievable filters were removed up to 104 days post insertion in this series of pts. and the incidence of complications was negligible. Retrievable IVC filters may be substituted for permanent IVC filters to preserve the option of retrieval, and retrieval of filters beyond 3 months post implantation is feasible and should be studied further.

Retrieving “Nonretrievable” Inferior Vena Caval Greenfield Filters: A Therapeutic Option for Filter Malpositioning

Filter malpositioning is a possible complication of inferior vena caval (IVC) filter insertion that may result in inadequate protection from pulmonary embolism. For nonretrievable filters, this is traditionally managed with either observation or additional filter placement. The purpose of this study is determine the incidence of filter malpositioning after bedside insertion under duplex ultrasound (DUS) or intravascular ultrasound (IVUS) guidance, and to report techniques for retrieving and repositioning IVC filters previously considered nonretrievable. All IVC filter insertions performed under DUS or IVUS guidance over an 8-year period were identified. Data regarding insertion technique, device used, and technical success were retrospectively collected. Cases of IVC filter malpositioning were determined and form the basis of this study. Technical details for IVC filter retrieval and repositioning are described. Of 486 patients undergoing DUS (n = 435) or IVUS (n = 51) guided IVC filter insertion, 12 patients (2.4%) had inadequate positioning as determined by postoperative radiography. Two of these patients had no further filter manipulation, three had a second filter placed under fluoroscopic guidance, and the most recent five had filters retrieved and repositioned under fluoroscopic guidance. Of those patients undergoing retrieval and repositioning, all five had Greenfield filters, which are not traditionally regarded as retrievable. All attempted retrievals or replacements were technically successful without additional filter-related complications. Bedside IVC filter insertion under DUS or IVUS guidance has a low incidence of filter misplacement. Although not traditionally regarded as retrievable, Greenfield filters can be safely retrieved and repositioned using advanced endovascular techniques in the event of malpositioning.