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Difficult Retrieval of a Retrievable Inferior Vena Cava Filter Placed in an Inverted Orientation
Difficult Retrieval of a Retrievable Inferior Vena Cava Filter Placed in an Inverted Orientation Philip Chong-hei Kwok, FRCR, Wong Kan Wong, FRCR, Kam Wang Siu, FRCR, Albert Kwok-hung Lai, FRCR, and Susan Chi-hum Chan, FRCR The present report describes a technique of retrieving a retrievable inferior vena cava (IVC) filter placed in an inverted orientation that had attached to the IVC wall. The filter was removed with difficulty via a combined jugular and femoral venous approach. J Vasc Interv Radiol 2006; 17:153–155 Abbreviation:
IVC ⫽ inferior vena cava
THE OptEase inferior vena cava (IVC) filter (Cordis Europa, Roden, The Netherlands) is a retrievable filter. It is mounted inside a plastic cartridge before deployment and the same cartridge is used for transjugular and transfemoral approaches. The filter cartridge is printed with colored arrows and text, and the arrow of the desired access site should point into the introducer sheath (Fig 1). This filter is designed for retrieval via a femoral approach; the hook on the caudal side of the filter is snared and the filter is pulled back into the guiding sheath and removed. There are fixation barbs at the cranial ends of the struts to prevent cephalad migration. We describe the difficult retrieval of an OptEase filter via the transjugular approach in a patient who had the filter misplaced in an inverted orientation.
CASE REPORT The institutional review board at our institution does not require adFrom the Department of Radiology and Imaging, Queen Elizabeth Hospital, 30 Gascoigne Road, Kowloon, Hong Kong. Received June 10, 2005; accepted September 18. Address correspondence to P.C.K., E-mail: [email protected] None of the authors have identified a conflict of interest. © SIR, 2006 DOI: 10.1097/01.RVI.0000188749.09906.EA
Figure 1. The OptEase IVC filter cartridge is printed with colored arrows and text. The arrow of the desired access site should point into the introducer sheath.
vance approval for case reports. The patient was a 20-year-old man who was admitted after a motor vehicle accident in which he had sustained multiple fractures and intracranial hemorrhage. Deep vein thrombosis developed in the left common femoral and external iliac veins. Because systemic heparinization was contraindicated, an IVC filter placement was requested and an OptEase filter was placed via the right femoral vein. The operator misunderstood the meaning of the arrows and labels on the filter cartridge: thinking that the jugular arrow should point toward the jugular vein, the operator inserted the jugular side of the cartridge into the femoral sheath. The filter was therefore inserted in an inverted orientation, with the retrieval hook placed in the cranial side. Although venography was per-
formed after the procedure, the inverted position of the hook was not noticed. It was discovered the next day when another OptEase filter was placed by another radiologist with the same operator. An abdominal radiograph showed stable position with no evidence of migration. We attempted to remove the filter from the right internal jugular vein 6 days after the initial deployment, when consent was obtained from the family of the patient. Cavography showed no migration and there was no tilting of the filter. There was no clot or filling defect inside or adjacent to the IVC filter. A 25-mm Amplatz Goose Neck snare (Microvena, White Bear Lake, MN) was inserted through a 10-F straight guiding catheter (Cordis, Miami, FL). The hook and the upper basket cone of the OptEase filter could not be snared. Another 15-mm snare also failed to snare the hook. The snare just moved to the side of the filter and did not touch the hook. Because the patient was restless after sustaining a head injury, the procedure had to be abandoned. We did not obtain other orthogonal views to further identify the location of the filter. The clinical decision was made to leave the IVC filter in situ; as the filter had not moved for 6 days since its deployment, the chance of future migration was judged to be small.
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Follow-up ultrasonography showed resolution of the clot in the femoral and external iliac veins, and the clinical situation was reevaluated. It was decided to try once more to remove the filter, as it was no longer necessary in this young patient and there are potential longterm complications of IVC filters. In case the filter could not be retrieved, it would be left as a permanent filter. We attempted retrieval again 10 days later, this time under general anesthesia. We failed again to snare the hook of the basket cone from the right internal jugular vein. The straight catheter of the snare was exchanged for a 6-F multipurpose guiding catheter with an angle in the hopes that the snare may catch the hook if it approached from different angles. However, this attempt also failed. Venography in a frontal projection and fluoroscopy in other oblique projections showed that the axis of the filter was central in position and there was no tilting. The right femoral vein was then punctured and a 6-F sheath was inserted. A 5-F Headhunter catheter (Terumo, Tokyo, Japan) was passed through the IVC filter and the catheter tip was easily snared with a 25-mm snare in the upper IVC. The Headhunter catheter was rotated so the catheter shaft was positioned next to the hook (Fig 2). The snare was advanced caudally along the catheter, but it never caught the hooks. We thought the hook was likely covered by some fibrinous tissue attached to the venous wall; this might explain why the snares failed to engage the hook. The Headhunter catheter was then exchanged for the 6-F catheter of the snare and the catheter tip was wedged inside the tip of the upper basket cone (Fig 3). A hydrophilic guide wire (Terumo) was steered through the hole just under the hook of the IVC filter and the guide wire was snared in the upper IVC. While the guide wire was fixed tightly with the snare, the lower snare catheter, wedged in the inner side of the upper basket cone, was pulled back in short vigorous caudal motions with the guide wire. The upper basket of the IVC filter was deformed briefly while the lower basket was held stable by the caudally pointed barbs (Fig 4). The hook could now be snared easily: the guiding catheter was advanced to the position
Figure 2. The Headhunter catheter shaft was situated next to the hook of the retrievable IVC filter. The snare followed the catheter, but it did not catch the hooks.
of the hook and the IVC filter was pulled back and collapsed inside the 10-F guiding catheter. Immediate cavography showed no extravasation of contrast medium and no obvious intimal injury to the vena cava. Computed tomography was not performed to show if there was any retroperitoneal hemorrhage. The filter was released from the guiding catheter. Whitish fibrinous tissue was seen attached to the upper and lower ends of the IVC filter.
DISCUSSION The OptEase filter is mounted inside a plastic cartridge that is used for jugular and femoral insertion. Because the IVC filter collapses inside the cartridge before deployment, there are labels and arrows on the cartridge to guide insertion of filter into the delivery sheath. The filter has two conical baskets connected by six straight par-
January 2006
JVIR
Figure 3. A straight catheter was wedged inside the tip of the upper basket cone. A hydrophilic guide wire was steered through the hole just under the hook of the filter and the guide wire was snared in the upper IVC.
allel struts. In the caudal basket, there is a T-shaped hook at the nose of the cone for retrieval, and there is a hole large enough for a 0.035-inch guide wire to pass through. In the cranial cone, a similar hole is also present at the nose of the cone, and there are fixation barbs at the cranial ends of the parallel struts to prevent cephalad migration. The design is basically symmetric to allow self-centering and easy retrieval with a snare. Because of the nearly symmetric shape, a filter deployed in an inverted position may be undetected if the images obtained after deployment are not carefully evaluated. An inverted filter poses a risk for cranial migration because, in that position, there are no fixation barbs to prevent it. The misplaced OptEase filter is held against the IVC wall only by the expansile strength of the baskets and struts. The lumen of the IVC may expand as a result of various disease processes; if the expansion is larger than the size of the filter, the filter may migrate cranially. Although migration of an inverted OptEase filter has not
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Kwok et al
Figure 4. While the guide wire was held tightly with the snare, the catheter was pulled back in short vigorous caudal motions with the guide wire (a). The upper basket of the IVC filter was deformed briefly while the lower basket was held in stable position by the caudally pointed barbs (b). The movements of the catheter and the outward deformity of the basket cone are indicated by the arrows. The hook could then be snared easily.
been described in the literature to our knowledge, an inverted OptEase filter should be removed and a new one placed in the correct orientation if the inverted filter is discovered early, when the struts are not yet fixed to the caval wall by intimal overgrowth. If the filter has been left in situ for some time and there is no migration, there should be intimal overgrowth on the struts; theoretically, it may be left in situ as a permanent filter. Because the inverted filter has a self-centering design, it should be easily removed from the jugular approach with use of a snare in most cases. The struts of the IVC filter may be fixed to the IVC wall if the filter has been in place for a long enough time, causing difficulty in retrieval (1). The
product information recommends removal within 12 days. Removal of retrievable IVC filters has been reported after intervals longer than the suggested retention period; a recent report (2) described removal of a Gu¨nther Tulip retrievable IVC filter (Cook, Bloomington, IN) after 317 days. We removed the filter in this case after 16 days, a period that should be acceptable if there is no indication for continued filtration, especially in a young patient. There is the possibility of long-term complications of an IVC filter. Fibrinous tissue causing difficult IVC filter removal has not been reported to our knowledge, and we do not know whether this is related to the rarity of inverted filter orientation. In
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animal studies, intimal proliferation is seen around the struts, but we are aware of no reports of fibrous tissue formed around the cones (1,3–5). Although we could not see any filling defects around the filter on the venogram, we postulated that some fibrin might have formed around the hook and this fibrin sheath or string was attached to the IVC wall, which persistently deflected the snare away. The presence of whitish fibrinous soft tissue adhering to the retrieved filter supported our postulation. The short, vigorous caudal motions of the snared guide wire and catheter deform the upper basket, and the fibrinous tissue is torn away from the IVC wall. We acknowledge that there is a potential risk of caval injury if this maneuver is performed with too much force. However, subsequent venography showed no evidence of major injury in this case. We think this method is equally applicable to other patients with correctly placed OptEase IVC filters in whom difficulty is encountered with removal from the usual femoral approach. In summary, we have shown a way to remove an OptEase filter when a snare fails to engage the retrieval hook easily. This case may be avoided if caution is exercised and the device is inserted appropriately. References 1. Reekers JA, Hoogeveen YL, Wijnands M, et al. Evaluation of the retrievability of the OptEase IVC filter in an animal model. J Vasc Interv Radiol 2004; 15: 261–267. 2. Binkert CA, Bansal A, Gates JD. Inferior vena cava filter removal after 317day implantation. J Vasc Interv Radiol 2005; 16:395–398. 3. de Gregorio MA, Gimeno MJ, Tobio R, et al. Animal experience in the Gu¨nther Tulip retrievable inferior vena cava filter. Cardiovasc Intervent Radiol 2001; 24:413–417. 4. Neurerburg JM, Handt S, Beckert K, et al. Percutaneous retrieval of the Tulip vena cava filter: feasibility, short- and long-term changes—an experimental study in dogs. Cardiovasc Intervent Radiol 2001; 24:418–423. 5. Hoekstra A, Hoogeveen Y, Elstrodt JM, et al. Vena cava filter behavior and endovascular response: an experimental in vivo study. Cardiovasc Intervent Radiol 2003; 26:222–226.
IVC ⫽ inferior vena cava
THE OptEase inferior vena cava (IVC) filter (Cordis Europa, Roden, The Netherlands) is a retrievable filter. It is mounted inside a plastic cartridge before deployment and the same cartridge is used for transjugular and transfemoral approaches. The filter cartridge is printed with colored arrows and text, and the arrow of the desired access site should point into the introducer sheath (Fig 1). This filter is designed for retrieval via a femoral approach; the hook on the caudal side of the filter is snared and the filter is pulled back into the guiding sheath and removed. There are fixation barbs at the cranial ends of the struts to prevent cephalad migration. We describe the difficult retrieval of an OptEase filter via the transjugular approach in a patient who had the filter misplaced in an inverted orientation.
CASE REPORT The institutional review board at our institution does not require adFrom the Department of Radiology and Imaging, Queen Elizabeth Hospital, 30 Gascoigne Road, Kowloon, Hong Kong. Received June 10, 2005; accepted September 18. Address correspondence to P.C.K., E-mail: [email protected] None of the authors have identified a conflict of interest. © SIR, 2006 DOI: 10.1097/01.RVI.0000188749.09906.EA
Figure 1. The OptEase IVC filter cartridge is printed with colored arrows and text. The arrow of the desired access site should point into the introducer sheath.
vance approval for case reports. The patient was a 20-year-old man who was admitted after a motor vehicle accident in which he had sustained multiple fractures and intracranial hemorrhage. Deep vein thrombosis developed in the left common femoral and external iliac veins. Because systemic heparinization was contraindicated, an IVC filter placement was requested and an OptEase filter was placed via the right femoral vein. The operator misunderstood the meaning of the arrows and labels on the filter cartridge: thinking that the jugular arrow should point toward the jugular vein, the operator inserted the jugular side of the cartridge into the femoral sheath. The filter was therefore inserted in an inverted orientation, with the retrieval hook placed in the cranial side. Although venography was per-
formed after the procedure, the inverted position of the hook was not noticed. It was discovered the next day when another OptEase filter was placed by another radiologist with the same operator. An abdominal radiograph showed stable position with no evidence of migration. We attempted to remove the filter from the right internal jugular vein 6 days after the initial deployment, when consent was obtained from the family of the patient. Cavography showed no migration and there was no tilting of the filter. There was no clot or filling defect inside or adjacent to the IVC filter. A 25-mm Amplatz Goose Neck snare (Microvena, White Bear Lake, MN) was inserted through a 10-F straight guiding catheter (Cordis, Miami, FL). The hook and the upper basket cone of the OptEase filter could not be snared. Another 15-mm snare also failed to snare the hook. The snare just moved to the side of the filter and did not touch the hook. Because the patient was restless after sustaining a head injury, the procedure had to be abandoned. We did not obtain other orthogonal views to further identify the location of the filter. The clinical decision was made to leave the IVC filter in situ; as the filter had not moved for 6 days since its deployment, the chance of future migration was judged to be small.
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Retrieval of an IVC Filter Placed in an Inverted Orientation
Follow-up ultrasonography showed resolution of the clot in the femoral and external iliac veins, and the clinical situation was reevaluated. It was decided to try once more to remove the filter, as it was no longer necessary in this young patient and there are potential longterm complications of IVC filters. In case the filter could not be retrieved, it would be left as a permanent filter. We attempted retrieval again 10 days later, this time under general anesthesia. We failed again to snare the hook of the basket cone from the right internal jugular vein. The straight catheter of the snare was exchanged for a 6-F multipurpose guiding catheter with an angle in the hopes that the snare may catch the hook if it approached from different angles. However, this attempt also failed. Venography in a frontal projection and fluoroscopy in other oblique projections showed that the axis of the filter was central in position and there was no tilting. The right femoral vein was then punctured and a 6-F sheath was inserted. A 5-F Headhunter catheter (Terumo, Tokyo, Japan) was passed through the IVC filter and the catheter tip was easily snared with a 25-mm snare in the upper IVC. The Headhunter catheter was rotated so the catheter shaft was positioned next to the hook (Fig 2). The snare was advanced caudally along the catheter, but it never caught the hooks. We thought the hook was likely covered by some fibrinous tissue attached to the venous wall; this might explain why the snares failed to engage the hook. The Headhunter catheter was then exchanged for the 6-F catheter of the snare and the catheter tip was wedged inside the tip of the upper basket cone (Fig 3). A hydrophilic guide wire (Terumo) was steered through the hole just under the hook of the IVC filter and the guide wire was snared in the upper IVC. While the guide wire was fixed tightly with the snare, the lower snare catheter, wedged in the inner side of the upper basket cone, was pulled back in short vigorous caudal motions with the guide wire. The upper basket of the IVC filter was deformed briefly while the lower basket was held stable by the caudally pointed barbs (Fig 4). The hook could now be snared easily: the guiding catheter was advanced to the position
Figure 2. The Headhunter catheter shaft was situated next to the hook of the retrievable IVC filter. The snare followed the catheter, but it did not catch the hooks.
of the hook and the IVC filter was pulled back and collapsed inside the 10-F guiding catheter. Immediate cavography showed no extravasation of contrast medium and no obvious intimal injury to the vena cava. Computed tomography was not performed to show if there was any retroperitoneal hemorrhage. The filter was released from the guiding catheter. Whitish fibrinous tissue was seen attached to the upper and lower ends of the IVC filter.
DISCUSSION The OptEase filter is mounted inside a plastic cartridge that is used for jugular and femoral insertion. Because the IVC filter collapses inside the cartridge before deployment, there are labels and arrows on the cartridge to guide insertion of filter into the delivery sheath. The filter has two conical baskets connected by six straight par-
January 2006
JVIR
Figure 3. A straight catheter was wedged inside the tip of the upper basket cone. A hydrophilic guide wire was steered through the hole just under the hook of the filter and the guide wire was snared in the upper IVC.
allel struts. In the caudal basket, there is a T-shaped hook at the nose of the cone for retrieval, and there is a hole large enough for a 0.035-inch guide wire to pass through. In the cranial cone, a similar hole is also present at the nose of the cone, and there are fixation barbs at the cranial ends of the parallel struts to prevent cephalad migration. The design is basically symmetric to allow self-centering and easy retrieval with a snare. Because of the nearly symmetric shape, a filter deployed in an inverted position may be undetected if the images obtained after deployment are not carefully evaluated. An inverted filter poses a risk for cranial migration because, in that position, there are no fixation barbs to prevent it. The misplaced OptEase filter is held against the IVC wall only by the expansile strength of the baskets and struts. The lumen of the IVC may expand as a result of various disease processes; if the expansion is larger than the size of the filter, the filter may migrate cranially. Although migration of an inverted OptEase filter has not
Volume 17
Number 1
Kwok et al
Figure 4. While the guide wire was held tightly with the snare, the catheter was pulled back in short vigorous caudal motions with the guide wire (a). The upper basket of the IVC filter was deformed briefly while the lower basket was held in stable position by the caudally pointed barbs (b). The movements of the catheter and the outward deformity of the basket cone are indicated by the arrows. The hook could then be snared easily.
been described in the literature to our knowledge, an inverted OptEase filter should be removed and a new one placed in the correct orientation if the inverted filter is discovered early, when the struts are not yet fixed to the caval wall by intimal overgrowth. If the filter has been left in situ for some time and there is no migration, there should be intimal overgrowth on the struts; theoretically, it may be left in situ as a permanent filter. Because the inverted filter has a self-centering design, it should be easily removed from the jugular approach with use of a snare in most cases. The struts of the IVC filter may be fixed to the IVC wall if the filter has been in place for a long enough time, causing difficulty in retrieval (1). The
product information recommends removal within 12 days. Removal of retrievable IVC filters has been reported after intervals longer than the suggested retention period; a recent report (2) described removal of a Gu¨nther Tulip retrievable IVC filter (Cook, Bloomington, IN) after 317 days. We removed the filter in this case after 16 days, a period that should be acceptable if there is no indication for continued filtration, especially in a young patient. There is the possibility of long-term complications of an IVC filter. Fibrinous tissue causing difficult IVC filter removal has not been reported to our knowledge, and we do not know whether this is related to the rarity of inverted filter orientation. In
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155
animal studies, intimal proliferation is seen around the struts, but we are aware of no reports of fibrous tissue formed around the cones (1,3–5). Although we could not see any filling defects around the filter on the venogram, we postulated that some fibrin might have formed around the hook and this fibrin sheath or string was attached to the IVC wall, which persistently deflected the snare away. The presence of whitish fibrinous soft tissue adhering to the retrieved filter supported our postulation. The short, vigorous caudal motions of the snared guide wire and catheter deform the upper basket, and the fibrinous tissue is torn away from the IVC wall. We acknowledge that there is a potential risk of caval injury if this maneuver is performed with too much force. However, subsequent venography showed no evidence of major injury in this case. We think this method is equally applicable to other patients with correctly placed OptEase IVC filters in whom difficulty is encountered with removal from the usual femoral approach. In summary, we have shown a way to remove an OptEase filter when a snare fails to engage the retrieval hook easily. This case may be avoided if caution is exercised and the device is inserted appropriately. References 1. Reekers JA, Hoogeveen YL, Wijnands M, et al. Evaluation of the retrievability of the OptEase IVC filter in an animal model. J Vasc Interv Radiol 2004; 15: 261–267. 2. Binkert CA, Bansal A, Gates JD. Inferior vena cava filter removal after 317day implantation. J Vasc Interv Radiol 2005; 16:395–398. 3. de Gregorio MA, Gimeno MJ, Tobio R, et al. Animal experience in the Gu¨nther Tulip retrievable inferior vena cava filter. Cardiovasc Intervent Radiol 2001; 24:413–417. 4. Neurerburg JM, Handt S, Beckert K, et al. Percutaneous retrieval of the Tulip vena cava filter: feasibility, short- and long-term changes—an experimental study in dogs. Cardiovasc Intervent Radiol 2001; 24:418–423. 5. Hoekstra A, Hoogeveen Y, Elstrodt JM, et al. Vena cava filter behavior and endovascular response: an experimental in vivo study. Cardiovasc Intervent Radiol 2003; 26:222–226.