35. IVC Filter Placement and Removal

Bradley J. Bowles¹ and Matthew R. Smeds¹

(1)

Department of Surgery, Division of Vascular and Endovascular Surgery, Saint Louis University, St. Louis, MO, USA

Bradley J. Bowles

Email: bradley.bowles@health.slu.edu

Matthew R. Smeds (Corresponding author)

Email: matt.smeds@health.slu.edu

Keywords

IVC filterPlacementRetrievalThromboembolismPulmonary embolismInferior vena cava

The number of inferior vena cava (IVC) filters placed to prevent pulmonary embolism has dramatically increased since their inception. This chapter covers the general principles for IVC filter placement and removal including a discussion on standard approaches, imaging, and supplies needed. Advanced techniques to use in cases of complex removal, including balloon repositioning, wire loops, and the use of forceps or laser extractors are outlined.

Introduction

Inferior vena cava (IVC) filters have been used since the 1970s to prevent catastrophic pulmonary embolism in patients with venous thromboembolism for whom anticoagulation cannot be used or has failed [1]. The filters initially used were permanent, but subsequent modifications have resulted in retrievable filters that can be placed percutaneously from either femoral or jugular access [2]. There are many different filter designs, but most depend on laminar flow within the IVC and assume that large embolic debris will be travelling in the center of this flow. These filters are often conical in design, with large spaces in the periphery to allow continued blood flow and a central apical portion that captures the clot. A hook, usually on the cranial portion of the filter, is present to allow retrieval (Fig. 35.1). The target location for delivery is optimally in an infrarenal vein, with the tip extending just caudal to the renal veins in the central portion of the vein (without tilting). This ensures unobstructed flow from the renal veins, avoiding the devastating complication of renal vein thrombosis and simplifying retrieval if needed. This chapter discusses standard techniques for placement and retrieval of IVC filters and of adjuncts that may be used for complicated cases.

../images/60971_2_En_35_Chapter/60971_2_En_35_Fig1_HTML.jpg — Fig. 35.1

A representative illustration of an inferior vena cava (IVC) filter shows its conical nature and central hook

IVC Filter Placement

General Principles

Preoperative imaging of the planned access vessels, most commonly with venous ultrasound, is necessary to ensure patency, lack of thrombus, and ease of sheath placement in the presence of external factors such as a cervical collar or extremity external fixators. Computed tomographic (CT) venography is not commonly done, but it can identify evidence of IVC or iliac vein thrombus and can delineate the size of these vessels and the location of renal veins, as well as the presence of any anatomical variants such as a duplicated IVC.

The recommended supply list is similar regardless of the planned approach:

Jugular or femoral-oriented filter delivery kit (includes filter, sheath, dilators, delivery catheter).
Ultrasound with probe cover.
Local anesthetic (with needles, syringe).
Micropuncture set (needle, wire, 4- or 5-French sheath).
#11 scalpel
Short (80 cm), 0.035″ medium stiff wire with a floppy tip (eg, Bentson wire).
Contrast and heparinized saline.
Dressings (eg, gauze and tape).

The patient is placed supine on the interventional table. If femoral access is used, most operators will stand to the patient’s right side with the C-arm located to the patient’s left side and will place the entry sheath in the right common femoral vein. In this case, both groins are prepped to the belly button and draped into the field to allow access to either leg as needed. If jugular access is entertained, the operator stands to the patient’s head or to the right side of the head, with entry planned in the right jugular vein. The patient’s head is turned to the left for the procedure, and the neck is prepped from jaw to clavicle and draped as appropriate.

Transfemoral Approach

The femoral pulse is palpated, and ultrasound guidance is used to locate the femoral vein medial to the artery at the level of the femoral head. Patency is confirmed with gentle compression. The optimal puncture location is caudal to the entry of the greater saphenous vein, below the inguinal ligament and before the femoral vein dives beneath the femoral artery to become the iliac vein. Local anesthetic is injected subcutaneously. Using a micropuncture access needle under ultrasound guidance, the femoral vein is punctured in preparation of the Seldinger technique to gain access. A micropuncture wire is advanced into the iliac vein, a small skin incision is made directly next to the needle with a #11 scalpel to allow easy passage of the sheath, and the needle is removed over the wire, with gentle pressure held on the groin. A 4- or 5-French micropuncture sheath is then advanced into the femoral vein over the wire (Fig. 35.2).

../images/60971_2_En_35_Chapter/60971_2_En_35_Fig2_HTML.png — Fig. 35.2

Seldinger access technique for placement of a micropuncture catheter. A microneedle is used to access the vein. A micropuncture wire is advanced through this needle. After removal of the microneedle, a micropuncture catheter is advanced over the wire into the vein

The micropuncture wire and dilator are removed, and a venogram is performed through the micropuncture sheath to confirm patency of the iliac vein and IVC, usually with an injection by hand of 4–5 cc of contrast and 4 cc of heparinized saline in a 10-cc syringe. A medium-stiff wire with a floppy tip (eg, a Bentson wire) is placed in the micropuncture sheath and gently advanced into the IVC under fluoroscopic guidance. The micropuncture catheter is removed, and the access site is sequentially dilated with the included dilators placed over the Bentson wire to the size of the device sheath used. The filter delivery sheath is then advanced over the Bentson wire under fluoroscopic guidance to below the location of the renal veins. (The tip of the sheath would be at approximately L2 to L3.) A venogram of the IVC is performed to identify the location of the renal veins, which are then marked on the imaging screen. Given the direction of blood flow, the renal veins may not completely enhance; in fact, voids of flow may be seen as indentations in the IVC where the renal veins enter the IVC. Maneuvers can be done to identify the renal vein origins by asking the patient to hold his or her breath and bear down during the venogram.

The sheath is positioned at the level of the renal veins or slightly above them, and the Bentson wire is removed. The IVC filter is advanced to the end of the sheath, and the apex is fluoroscopically confirmed to be just above the lowest renal vein. Proper positioning of the apex is in the middle of the vessel lumen, not tilted toward one wall or the other. Most devices use a “pin and pull” method to deliver the filter, in which the back end of the filter delivery device is held in place (“pinned”) while the sheath is “pulled” back to unsheath the filter (Fig. 35.3).

../images/60971_2_En_35_Chapter/60971_2_En_35_Fig3_HTML.jpg — Fig. 35.3

Deployment of an IVC filter: most devices use a “pin and pull” method to deploy the filter. (a) The sheath is positioned just above the lowest renal vein identified by venogram or via bony landmarks at around spinal level L2. (b) The sheath is pulled back to expose the filter. Some filters require additional steps to fully deploy

Some devices require an additional step to release the filter from the device after appropriate positioning is confirmed and the filter has been unsheathed. The delivery system is then removed from the sheath. At the discretion of the operator, a completion venogram is sometimes performed through the sheath to confirm IVC patency and filter placement below the renal veins, with the apex just caudal to the lowest vein. This position allows for a lower incidence of IVC filter thrombosis due to flow from both renal veins. The sheath is removed, and pressure is held gently to the access site to ensure hemostasis prior to placement of a sterile dressing over the puncture site.

Transjugular Approach

Most IVC filters come in either transfemoral or transjugular orientation. The steps for deployment are very similar. Under ultrasound guidance, the jugular vein is accessed at the lower portion of the neck above the clavicle, and the micropuncture sheath is placed as outlined above. Through this micropuncture sheath, a medium-stiff wire with a floppy tip (eg, a Bentson wire) is advanced through the internal jugular vein into the brachiocephalic vein and superior vena cava (SVC), and into the IVC under fluoroscopic guidance. The right jugular vein is more of a “straight shot” to the IVC, but either side may be used. Deviation of the wire toward the left side is seen when the wire is passing into the right ventricle. If ectopic beats are seen on EKG monitoring, the wire should be pulled back into the SVC and redirected. The wire should advance directly caudal in a straight line toward the abdomen. Deviation of the wire to the right side may indicate positioning in the hepatic vein. Once the wire is in the IVC, the sheath is advanced to the level of the renal veins and a venogram is performed as above to confirm the location at approximately L2. The sheath is positioned below the renal veins, which are marked on the screen, and the filter is deployed via the same mechanism as outlined above.

IVC Filter Retrieval

Despite an increase in placement of retrievable IVC filters, many are not removed, with the most common reason being loss of the patient to follow-up [3]. Many interventionalists place IVC filters, but adequate follow-up and evaluation for continued filter need is often lacking. Other reasons for continued filter usage include contraindications to anticoagulation and a continued need for embolic protection, or failed retrieval. The risks and benefits of IVC filter retrieval should be discussed with the patient, and most filters should be removed as soon as possible [4].

The traditional approach for IVC filter removal is from access in the internal jugular vein, most commonly on the patient’s right side. Most filters are conical in design with a retrieval hook placed in cranial orientation, but there are exceptions with filter placement in the SVC or dual-apex designs such as the Cordis OPTEASE® (Cordis, Santa Clara, CA), for which the hook can be at either end of the device.

Standard Retrieval Technique

Retrieval kits are available from some manufacturers; it is beyond the scope of this chapter to describe each kit. They most commonly include venous dilators, a large access sheath, and a snare system to capture the cranial device hook. A standard technique using off-the-shelf components requires a large sheath (typically 9 to 11 French) and a single or tri-lobed snare with associated catheter. The patient’s internal jugular vein is accessed using Seldinger technique with a micropuncture kit, as described previously. Once access is obtained and a medium-stiff wire with a floppy tip is placed in the IVC, the jugular vein is dilated with prepackaged dilators to the appropriate size, followed by advancement of the sheath into the IVC just above the level of the filter, which is seen on fluoroscopy. A venacavogram is obtained through the sheath to verify patency of the filter, without a filling defect to suggest retained clot. Evidence of thrombus within the filter is a contraindication for retrieval because collapse of the filter into the retrieval sheath can shower thrombus cranially. The snare catheter is advanced into the IVC via the sheath, and the snare is opened by extending it beyond the snare catheter (Fig. 35.4). It is vitally important to keep the loop(s) of the snare above the levels of the filter prongs to prevent inadvertent capture of the filter limbs below the cranial hook; doing so would cause the filter to tilt. Coordinated manipulation of the sheath, catheter, and snare is used to direct a single loop over the apex of the filter. Simultaneous withdrawal of the snare on the hook and advancement of the snare catheter captures the hook of the filter. Sometimes you capture the apex but not the hook; do not attempt to resheath the filter if the hook has not been snared. As you pull back, the tip might not be in the sheath and you could shear the cava wall instead. At this point, while keeping the hook captured by the snare and catheter, the sheath is advanced over the filter, with subsequent collapse of the filter struts and complete encasement by the sheath. The operator should take caution not to pull the filter into the sheath, as doing so can cause the filter prongs to shear the caval wall. It helps to push the sheath forward as you collapse the filter to push the struts off the wall. Once the filter is completely in the sheath, it can be removed simultaneously with the sheath. A completion venacavogram may not be required if the filter hooks were easily disengaged from the IVC wall, but it is recommended to verify caval integrity. This can be achieved by initially placing a 9-French sheath within a larger sheath and withdrawing the filter via the smaller sheath, leaving the larger sheath in the IVC to perform a venogram. Once all sheaths are removed, direct pressure should be placed over the venous access site for hemostasis. The timeframe depends on the coagulation status of the patient; it should be at least 5 minutes. An occlusive dressing is placed, and the site should be monitored in the recovery area for bleeding or hematoma formation.

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Tags: Vascular Reconstructions Anatomy Exposures and Techniques

Jul 25, 2021 | Posted by admin in CARDIOLOGY | Comments Off

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Filter Placement and Removal

35. IVC Filter Placement and Removal

Introduction