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Review sive-non-invasive-cardiology/IVC filter retrieval.M Jyotsna*, N LalitaDepartment of Cardiology, Nizam’s Institute of Medical Sciences (NIMS), Punjagutta, Hyderabad–TS IndiaAbstractIn this review article the major indications of Inferior Vena Caval (IVC) filter implantationand need for their retrievals are discussed. In addition to the routine methods of retrieval,the advanced methods are also described. Complications, precautions and various treatmentstrategies have been addressed. As this is an evolving field new advancements are expected infuture.Keywords: IVC filters, Retrieval, Pulmonary thromboembolism, Complications.Accepted on October 31, 2018IntroductionInferior Venal Caval (IVC) filters are of proven value forprevention of Pulmonary Thromboembolism (PTE) in subsetof patients with Deep Vein Thrombosis (DVT). After aninitial protection period of PTE is over and there is resolutionof DVT, the IVC filters need to be removed [1]. In literaturethe reported retrieval rates are as low as 8.5% [2]. Thedevelopment of dedicated service lines for patients with thesedevices has positively impacted retrieval rates. Minocha et al.study reporting an increase in retrieval rates from 29% to 60%after the establishment of a dedicated IVC filter service [3].Indications for IVF filter implantationOver the past 20 years there is a definite increase in theusage of IVC filters. Now it is used more frequently in DVT(prophylactic indication) than Pulmonary Thromboembolism(PTE) [4,5].12 Contraindication to anticoagulant-only therapy. Documented failure of agulation therapy).therapydespite Concurrent administration of fibrinolytic therapy. Pregnancy labor and delivery. Severe trauma to the head or spinal cord. Thrombolysis of acute ilio-caval venous thrombosis. Massive pulmonary embolism–if associated withinstability then filter implantation showed decreaseincidence of further PTE and mortality [6]. Whencombined thrombolysis and within 2 days of acuteDVT, implantation of filter in this fragile period isshown to be a better choice by Choi et al. [7]. Severe trauma to or multiple fractures of the longbones. Major pelvic or acetabular fractures iliofemoralvenous injury. Rosenthal et al. recommended bed sideimplantation IVC filters under ultrasound guidance insevere trauma patients for prevention of embolizationeven in the early stages [8]. Prolonged immobilization with multiple injuries. Prophylaxis in the setting of specific surgicalprocedures, such as malignancy resection, facial injuryrepair, or gastric bypass. Acute withdrawal of oral anticoagulants before generalsurgery. Period of transition to oral anticoagulants due toheparin-induced thrombocytopenia. Pulmonary embolus in the setting of diminishedcardiopulmonary reserve. Young patients at short-term high risk for pulmonaryembolus. Free-floating vascular thrombus on venography. Chronic thromboembolicpulmonary embolectomy). Thromboembolic disease with limited cardiopulmonaryreserve (corpulmonale). Filter complications-insertion site thrombosis.disease(undergoingTypes of filtersa. Permanent filters: In this article we are concentratingon retrieving of filters, so not much discussed aboutthese filters. If any filter related complications occursin these filter, then surgical removal is the choice ofremoval.b. Temporary filters: To overcome the disadvantages ofpermanent filters, temporary filters were introduced.These filters have an access outside as they remainattached to a wire or catheter. They can usually be leftJ Invasive Noninvasive Cardiol 2018 Volume 1 Issue 3

Citation: Jyotsna M, Lalita N. IVC filter retrieval. J Invasive Noninvasive Cardiol. 2018;1(3):12-19.for a week. As infection, thrombosis and migrationrate are high, filters are difficult to manage and do notserve the intented purpose properly, these filters arenot in use now.c. Retrieval filters: These filters can be retrieved oncethe need of filter coverage is over. There is changingtrends in implantation and retrievals of filters overtwo decades. In the past five years the retrieval rateswere increased from 12.0% to 17.7%. Implantationsand retrievals have been done with equal frequency byboth the cardiologists and radiologists (13.0%-13.8%)[9].Why should IVC filters be removed?IVC retrieval helps to reduce the risk associated withhaving a permanent IVC filter (a foreign body withinthe human body). The following complications can beameliorated by retrieval of the IVC filter.a. Occlusion of the filter due to thrombus is the mostfrequent complication of the filters. Incidence variesfrom 6% to 30% [10]. The filter related thrombosiswas more with first generation filters (especiallypermanent filters) [11]. The thrombosis wassignificantly decreased with the subsequently secondgeneration filters OPTEASE and GUNTHER TULIP(temporary filters) [12].b. IVC filters left in-situ for a long time have been foundto develop device-related complications such asfracture, device migration, organ penetration and IVCperforation. IVC perforation is suspected when thefilter components extend 3 mm beyond the IVC wallon CT scan [13].c. We had a case of retrieval filter implantation for massivePTE with DVT on oral anticoagulation. After twomonths, patient was admitted with acute abdominalpain and fall of hemoglobin. CT abdomen showedlarge hematoma in the wall of the large bowel alongwith peri-filter IVC hematoma. After stabilizationsurgical removal of the filter was done. Similar caseof duodenal involvement was reported [14].d. Post thrombotic syndrome.e. Patients with the anti-phospholipid syndrome-Usuallypermanent filters are used and patient requireslifelong anticoagulation in this group. But Baig et al.demonstrated that the safety of retrieval of IVC filterswith continuation of anticoagulation [15].When to remove the IVC filters?a. Normally IVC filter to be removed as soon as theunderlying indication for filter deployment was over,preferably within 30 days [16].b. For the patients who cannot take anticoagulationtemporarily, like immediate postoperative period, theimplanted IVC filter should be removed once patientbecomes eligible to take anticoagulation.c. When IVC filter implantation was done for prophylacticreasons like immobilization, then filter to be oncepatient is ambulated.d. Special attention should be paid to prophylactic filtersplaced in trauma patients, a situation in which thefilter can typically be removed within a relativelyshort time interval as patients begin to ambulate or aretransitioned to anticoagulation [17].In earlier studies it was thought that prolonged dwelltime after IVC filter implantation is predictor for failure ofretrieval. Eventually with the development of different filterspecific retrieval devices, even in the longer dwell time cases,filters could be are successfully revived [18-21]. In general,patients of retrieval IVC filters should be followed regularlyand all attempts should be made to remove the filter once thecrisis period of implanted is tide over [22]. An Informaticsapproach to facilitate tracking the patient has been proposedby Juluru K [23].Conditions where advanced retrival techniques arerequireda. Embedded hookb. Severe tiltc. Filter strut penetration into the caval walld. Prolonged dwelling timee. Advanced agef. Filter head positiong. Filter designMethods of IVC filter removal- percutaneousRoute of removalConical shape filters like GUNTHER TULIP (WILLIAMCOOK EUROPE APS) are to be removed from internaljugular approach only. Polyhedron designed filters likeOPTEASE to be removed from the femoral route. Helicaldesigned filters like Crux can be removed in both routes.Usually internal jugular approach is preferred over femoralapproach for implantation of IVC filters as filter tilt and filtertip abutment is better, but Choi disproved that. In additionthey showed that the femoral route takes less fluoscopic time[24].Simple retrieval-routine techniqueIt is always advisable to have a contrast venogram to ruleout the presence of thrombus in addition to previous noninvasive tests to see for IVC or filter thrombus (Figure 1). Wecan use usual snares or separate retrieval kits provided by thecompanies to remove the filters.The essential steps in removal are:J Invasive Noninvasive Cardiol 2018 Volume 1 Issue 313

Jyotsna/LalitaPTCA wireFigure 2. In house devices for IVC filter retrieval.Figure 1. First step in IVC filter retrival - Contrast venogram – Nothrombus.i. Hold the hook with snare. Usually the filter collapses ifdwell time is shorter. If not sheath manipulations are requiredfor the retrieval.ii. A sheath to facilitate coaxial collapse of the filter anddisengagement from the caval wall. Pushing the sheath overthe filter with simultaneous pull on the filter to be done.iii. Once the filter partially enters into the sheath care to betaken not to release the pull on the snare. A constant pullingforce on the filter is required till the whole of collapsed filterenters into the sheath.Complex retrieval-modification in the retrievalprocedureA complex retrieval was defined as one requiring morethan standard sheath and snare technique [25].i.Loop or sling technique: Snares can be used tohold the filter hook and retrieve the filter. To hold the filterhook instead of snare, we can use the peripheral 0.35 incheswire (called as Stiff Wire-Displacement Technique) or evencoronary wire also can be used. (Figure 2). In the casecoronary wire loop more sheath push on the filter is requiredto separate the filter from the IVC wall. Pull on the hook ofthe filter by coronary wire may not generate sufficient forcefor IVC collapse, on other hand may distort or break the wire[26].Attention: If your catheter looks as if it is in IVC, but snaredose not reach the filter tip means catheter is a branch thanin proper IVC lumen. Then check with contrast in separateviews and reposition the sheath (Figure 3).ii. Balloon displacement: With snare to hold the hook,a peripheral balloon is passed between the filter andIVC wall to dislodge the filter.Figure 3. Diagrams showing the improper position of sheath whileretiving the filter.iii. Dissection technique (Endomyocardial/Endobronchialforceps dissection techniques): These instruments areused to hold the hook.iv. Hangman technique: This is a modified loop snaretechnique. In this a 5-F reverse curve catheter (ex: SOSOmni Catheter from AngioDynamics) and Glidewire(like Terumo wire from Radifocus are used to create awire loop between the filter neck and IVC wall (hencethe name “Hangman”), as opposed to between thefilter legs. This method is more suitable when there issevere tilt or embedded hook [27].J Invasive Noninvasive Cardiol 2018 Volume 1 Issue 314