Inferior vena cava filter – comprehensive overview of current indications, techniques, complications and retrieval rates

Summary: Inferior vena cava (IVC) filter has been used to manage patients with pulmonary embolism and deep venous thrombosis. Its ease of use and the expansion of relative indications have led to a dramatic increase in IVC filter placement. However, IVC filters have been associated with a platitude of complications. Therefore, there exists a need to examine the current indications and identify the patient population at risk. In this paper, we comprehensively reviewed the current indications and techniques of IVC filter placement. Further, we examined the various complications associated with either permanent or retrievable IVC filters. Lastly, we examined the current data on filter retrieval.

The Clinical Rationale for the Sentry Bioconvertible Inferior Vena Cava Filter for the Prevention of Pulmonary Embolism

The Sentry inferior vena cava (IVC) filter is designed to provide temporary protection against pulmonary embolism (PE) during transient high-risk periods and then to bioconvert after 60 days after implantation. At the time of bioconversion, the device’s nitinol arms retract from the filtering position into the caval wall. Subsequently, the stable stent-like nitinol frame is endothelialized. The Sentry bioconvertible IVC filter has been evaluated in a multicenter investigational-device-exemption pivotal trial (NCT01975090) of 129 patients with documented deep vein thrombosis (DVT) or PE, or at temporary risk of developing DVT or PE, and with contraindications to anticoagulation. Successful filter conversion was observed in 95.7% of patients at 6 months (110/115) and 96.4% at 12 months (106/110). Through 12 months, there were no cases of symptomatic PE. The rationale for development of the Sentry bioconvertible device includes the following considerations: (1) the period of highest risk of PE for the vast majority of patients occurs within the first 60 days after an index event, with most of the PEs occurring in the first 30 days; (2) the design of retrievable IVC filters to support their removal after a transitory high-PE-risk period has, in practice, been associated with insecure filter dynamics and time-dependent complications including tilting, fracture, embolization, migration, and IVC perforation; (3) most retrievable IVC filters are placed for temporary protection, but for a variety of reasons they are not removed in any more than half of implanted patients, and when removal is attempted, the procedure is not always successful even with advanced techniques; and (4) analysis of Medicare hospital data suggests that payment for the retrieval procedure does not routinely compensate for expense. The Sentry device is not intended for removal after bioconversion. In initial clinical use, complications have been limited. Long-term results for the Sentry bioconvertible IVC filter are anticipated soon.

Inferior Vena Cava Filter - Appropriate Use and Retrieval

Inferior vena cava (IVC) filters, first introduced in 1998, have been utilized to reduce risk of pulmonary embolism (PE) in the setting of an inability to anticoagulate patients. The use of IVC filters has increased and continues to rise, especially with the introduction of retrievable IVC filters. Since their initial introduction, guidelines have been developed on the appropriate use of IVC filters. According to the American College of Chest Physicians (ACCP), the use of an IVC filter is limited to patients with an absolute contraindication to therapeutic anticoagulation or failure or complication of anticoagulation in the setting an acute proximal venous thrombus. Relative indications for IVC filter placement include high clot burden in setting of low cardiopulmonary reserve, high risk patients, or severe trauma without documented thrombosis. In 2010, the FDA announced a safety communication recommending removal of retrievable IVC filters due to reports of several adverse clinical outcomes associated with retained filters including thrombus formation, recurrent PE, filter migration, erosion or perforation through the IVC wall, and filter fracture with fragment embolization. In 2014, the FDA recommended removal of the IVC filter within 2 months after filter placement if the patient's risk of thrombosis had passed. In this retrospective analysis of IVC filter management, we reviewed indications for placement according to current guidelines as set by the ACCP, initiation of appropriate anticoagulation, complication rates, and retrieval rates. In addition, we compared the data prior to the FDA recommendations in late 2014 and data after the recommendations to determine if there was a change in practice. After reviewing 179 patients, 89 patients in 2014 and 90 patients in 2015, who underwent IVC filter placement, only 81% (N=145) of patients had appropriate indications for IVC filter placement and 30% (N=54) of patients had inappropriate anticoagulation after IVC filter placement, given as prophylactic dosing of low molecular weight heparin. A comparison of retrieval rates prior to and after the FDA warning, showed a 19% (60% in 2014 vs 79% in 2015) improvement in IVC filter removals. There was an 11% complication rate, mainly related to IVC filter related acute DVT or IVC occlusion. A root cause analysis specifically for inappropriate IVC filter placement and appropriate anticoagulation and determined that familiarity of the guidelines and non-evidence based recommendations from consultants were major factors. Based on the analysis, we next plan to utilize the electronic health record system to help clinicians understand indications and when to initiate appropriate anticoagulation, with the opportunity for hematology consultants to be involved in situations that do not clearly fit within published guidelines. Disclosures No relevant conflicts of interest to declare.

A single center experience with retrievable IVC filters

Objective To evaluate retrievable IVC filters in our institution and assess their retrieval following a well-structured follow up program. Design Retrospective cohort study. Materials The medical records of patients implanted with retrievable IVC filters were reviewed. Methods All retrievable filter insertions between July 2007 and August 2011 at our institution were reviewed. Data was analyzed for age, gender, indication, complications, retrieval rate, and brand of filter inserted. Statistical analysis was done using SPSS software v19. Chi-square was used to compare discrete data and t-test for continuous data. P < 0.05 was significant. Results A total of 484 patients were reviewed of which 258 (53.1%) had a complete medical record. And 96 (37.2%) filters were placed as permanent at the time of insertion. An additional 40 (15.5%) filters were converted to permanent (total permanent filters 136; 52.7%). Death was reported in 26 (10%) patients and 96 (37.2%) out of the remaining 232 patients presented for potential retrieval. Also, 73 (28.2%) had an attempt to retrieve the filters, 69 (94.5%) were successful and 4 (5.4%) failed to retrieve. The remaining 23 (8.9%) patients declined retrieval. Filters studied include Celect (38%), Bard (31.4%), Option (26.2%), Tulip (4.1%), and Recovery (0.2%). Bard was more commonly used as a retrievable filter (80.9%). Retrieval on the first attempt was 90.4% ( n = 66) successful. Of the remaining seven filters, three were successfully retrieved on a second attempt, and four failed to retrieve due to filter tilt. The success rates of retrieval for Celect and Tulip were significantly lower than for Bard ( p = 0.04 and 0.023, respectively). Conclusion Our study showed that a variety of IVC filters can be retrieved successfully with minimal complication rates. In more than half of our patients, IVC filters were used as permanent. Failure of retrieval was most frequently due to filter tilting.

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.