1. The changing role of IVC filters DR R Uberoi John Radcliffe Hospital Oxford

2. IVC filters The Mobin-Uddin umbrella filter was the first true intravascular device. Initially introduced in a surgical forum in 1967 and released for general use in 1973. Placement through the right internal jugular vein after surgical venotomy was the only approach. The Mobin-Uddin umbrella filter was the first true intravascular device. Initially introduced in a surgical forum in 1967 and released for general use in 1973. Placement through the right internal jugular vein after surgical venotomy was the only approach. The filter was introduced through a catheter- based carrier system with a 27F inner diameter (ID). The filter was introduced through a catheter- based carrier system with a 27F inner diameter (ID).

3. Permanent Stainless steel Greenfield filter (SGF) (Kimray- Greenfield filter) Stainless steel Greenfield filter (SGF) (Kimray- Greenfield filter) Titanium Greenfield filter (TGF) Titanium Greenfield filter (TGF) Stainless Steel Greenfield filter (12F SGF) Stainless Steel Greenfield filter (12F SGF) Vena Tech-LGM filter Vena Tech-LGM filter Vena Tech LP filter Vena Tech LP filter Simon nitinol filter Simon nitinol filter Bird's nest filter (BNF) Bird's nest filter (BNF) TrapEase filter TrapEase filter

4. Permanent filter 751 patients had a Trapease filter. 751 patients had a Trapease filter. 61.4% contraindication to anticoagulation, 5.6% complications,failure of anticoagulation and prophylaxis 27.8%. 61.4% contraindication to anticoagulation, 5.6% complications,failure of anticoagulation and prophylaxis 27.8%. 0.4% groin haematomas, 7.5% developed symptoms of PE including one death (0.1%) 0.4% groin haematomas, 7.5% developed symptoms of PE including one death (0.1%) CT in 219 patients, at 192 days showed PE in 6.8% (1/3 asymptomatic) CT in 219 patients, at 192 days showed PE in 6.8% (1/3 asymptomatic) Further follow up CT in 270 patients at 189 days showed filter fracture in 3%, thrombu in 25%, thrombus beyond the filter in 1.5% and caval occlusion in 0.7%. Further follow up CT in 270 patients at 189 days showed filter fracture in 3%, thrombu in 25%, thrombus beyond the filter in 1.5% and caval occlusion in 0.7%. Kalva et al, Trapease vena cave filter:experience in 751 patients. J Endovasc Ther, 13, 365-72, 2006.

6. Temporary filters Amplatz filter (discontinued) Amplatz filter (discontinued) Gunther Tulip filter Gunther Tulip filter Antheor filter Antheor filter Tempofilter Tempofilter Prolyser filter Prolyser filter Recovery Recovery ALN filter ALN filter SafeFlo filter SafeFlo filter OptEase OptEase Celect Celect

7. Celect Celect Improved retrievability Improved retrievability Improved resistance to tilting Improved resistance to tilting More even distribution of the secondary legs on deployment More even distribution of the secondary legs on deployment Larger diameter wire maintains support previously provided by loop Larger diameter wire maintains support previously provided by loop

8. Indications Unable to anticoagulate with PE Unable to anticoagulate with PE Break through PE Break through PE Paradoxical emboli Paradoxical emboli Prophylaxis ie Cor pulmonale and DVT, pre-surgery with DVT, following pulmonary embolectomy Prophylaxis ie Cor pulmonale and DVT, pre-surgery with DVT, following pulmonary embolectomy Pregnant patient with extensive DVT immediately prior to delivery Pregnant patient with extensive DVT immediately prior to delivery

9. Relative Indications Free floating emboli Free floating emboli Tumor patients with DVT Tumor patients with DVT Pelvic surgery with DVT Pelvic surgery with DVT Trauma patients with history of DVT Trauma patients with history of DVT Neuro- or Orthopaedic surgery and DVT Neuro- or Orthopaedic surgery and DVT

10. IVC filters Only one randomised trial of IVC filters in the management of Venous Thromboembolism has been published Decousus, H., et al (1998) A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. New England Journal of Medicine, 338, 409-415.

11. Are filters indicated in patients receiving conventional anticoagulant therapy? VC filters are not indicated in unselected patients with VTE who will receive conventional anticoagulant therapy VC filters are not indicated in unselected patients with VTE who will receive conventional anticoagulant therapy (grade A, level Ib) British Committee for Standards in Haematology (grade A, level Ib)

12. IVC filters (38-77%) The only generally accepted indication for IVC filter insertion is the presence of a recent proximal DVT plus an absolute contraindication to therapeutic anticoagulation. The only generally accepted indication for IVC filter insertion is the presence of a recent proximal DVT plus an absolute contraindication to therapeutic anticoagulation. Contraindications to therapeutic anticoagulation might include: Contraindications to therapeutic anticoagulation might include: Current or recent active major bleeding that cannot be treated acutely Current or recent active major bleeding that cannot be treated acutely Frank intracranial bleeding in the past 5 days Frank intracranial bleeding in the past 5 days Need for a major surgical procedure in the next 2 weeks Need for a major surgical procedure in the next 2 weeks Severe, prolonged thrombocytopenia Severe, prolonged thrombocytopenia Streiff MB. Vena caval filters: a comprehensive review. Blood 2000; 95: 3669-3677. Streiff MB. Vena caval filters: a comprehensive review. Blood 2000; 95: 3669-3677.

13. Therapy DVT or PE in a patient with a complication of anticoagulation IVC filter placement is less commonly indicated in patients with a complication while they are receiving anticoagulation therapy. This indication accounts for 6- 18% of IVC filter placements.

14. Are filters indicated in patients with apparent anticoagulant failure? Patients who have new-onset PE or DVT while receiving anticoagulation therapy are candidates for IVC filter placement. Among patients with PE, 3-33% have a second embolic event during adequate intravenous heparin therapy or oral warfarin anticoagulation treatment. Patients who have new-onset PE or DVT while receiving anticoagulation therapy are candidates for IVC filter placement. Among patients with PE, 3-33% have a second embolic event during adequate intravenous heparin therapy or oral warfarin anticoagulation treatment.

15. Are filters indicated in patients with apparent anticoagulant failure? Alternative treatment options such as long-term high intensity VKA therapy (INR target 3.5) or LMWH therapy should be generally considered prior to VC filter placement particularly in patients with thrombophilic disorders (e.g., antiphospholipid syndrome) or cancer. Alternative treatment options such as long-term high intensity VKA therapy (INR target 3.5) or LMWH therapy should be generally considered prior to VC filter placement particularly in patients with thrombophilic disorders (e.g., antiphospholipid syndrome) or cancer. (grade C, level IV). British Committee for Standards in Haematology 2005(grade C, level IV).

16. Are IVC filters indicated for treatment of VTE during pregnancy? VC filter insertion may be considered in pregnant patients who have contraindications to anticoagulation or develop extensive VTE shortly before delivery (within 2 weeks). Retrievable filters should be considered. VC filter insertion may be considered in pregnant patients who have contraindications to anticoagulation or develop extensive VTE shortly before delivery (within 2 weeks). Retrievable filters should be considered. British Committee for Standards in Haematology 2005

17. Indications Free-floating iliofemoral or IVC thrombus has been associated with a 27-60% rate of PE. However, results have not been consistent. Free-floating iliofemoral or IVC thrombus has been associated with a 27-60% rate of PE. However, results have not been consistent. Studies have failed to show an increased incidence of PE with free-floating thrombus and no reduction in mortality with IVC filters. Studies have failed to show an increased incidence of PE with free-floating thrombus and no reduction in mortality with IVC filters. Decousus, H., et al(1998) A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. New England Journal of Medicine, 338, 409-415. Pacouret, G., et al (1997) Free-floating thrombus and embolic risk in patients with angiographically confirmed proximal deep venous thrombosis. A prospective study. Archives of Internal Medicine, 157, 305-308.

18. Are filters indicated in patients with free-floating thrombus? Free floating thrombus is not an indication for insertion of a VC filter Free floating thrombus is not an indication for insertion of a VC filter grade B, levelIII). British Committee for Standards in Haematology 2005(grade B, levelIII).

19. Are filters indicated in patients receiving thrombolytic therapy for DVT? Thrombolysis is not an indication for filter insertion. If a filter is used a retrievable filter should be used if available. Thrombolysis is not an indication for filter insertion. If a filter is used a retrievable filter should be used if available. (grade C, level IV). British Committee for Standards in Haematology 2005 (grade C, level IV).

22. Prophylaxis in high risk patients? Patients with chronic pulmonary hypertension and a marginal cardiopulmonary reserve Patients with chronic pulmonary hypertension and a marginal cardiopulmonary reserve Patients with cancer: In 1981, Moore et al reported 21 hemorrhagic events in 32 patients with malignancy. Of these patients, 8 had hemorrhage resulting in cessation of therapy or death. Patients with cancer: In 1981, Moore et al reported 21 hemorrhagic events in 32 patients with malignancy. Of these patients, 8 had hemorrhage resulting in cessation of therapy or death. However, this indication was disputed in 1998 by the American College of Chest Physicians Consensus Committee on Pulmonary Embolism. Its report stated that the routine use of IVC filters is not recommended in patients with cancer and DVT or PE. However, this indication was disputed in 1998 by the American College of Chest Physicians Consensus Committee on Pulmonary Embolism. Its report stated that the routine use of IVC filters is not recommended in patients with cancer and DVT or PE.

23. Prophylaxis in Trauma patients? In many of these patients, anticoagulation therapy is contraindicated because of the risk of hemorrhage. Although some studies have shown that the prophylactic placement of IVC filters prevents fatal PE in patients with trauma, other studies have not shown any significant reduction in the rate of PE. Additional studies of cost- effectiveness or risk-benefit considerations do not support prophylactic filter placement in patients with trauma. ie In many of these patients, anticoagulation therapy is contraindicated because of the risk of hemorrhage. Although some studies have shown that the prophylactic placement of IVC filters prevents fatal PE in patients with trauma, other studies have not shown any significant reduction in the rate of PE. Additional studies of cost- effectiveness or risk-benefit considerations do not support prophylactic filter placement in patients with trauma. ie Severe head injury with prolonged ventilator dependence Severe head injury with prolonged ventilator dependence Major abdominal or pelvic penetrating venous injury Major abdominal or pelvic penetrating venous injury Spinal cord injury with or without paralysis Spinal cord injury with or without paralysis Severe head injury with multiple lower extremity fractures Severe head injury with multiple lower extremity fractures Pelvic fracture with or without lower extremity fractures Pelvic fracture with or without lower extremity fractures

24. Are filters indicated in pre-operative patients for DVT? VC filters should be considered in any pre- operative patient with recent VTE (within1 month) in whom anticoagulation must be interrupted. Patients with DVT who are about to undergo surgery (lower-extremity orthopedic surgery, major abdominal surgery, neurosurgery) VC filters should be considered in any pre- operative patient with recent VTE (within1 month) in whom anticoagulation must be interrupted. Patients with DVT who are about to undergo surgery (lower-extremity orthopedic surgery, major abdominal surgery, neurosurgery) Retrievable VC filters should be considered where a temporary contraindication to anticoagulation exists Retrievable VC filters should be considered where a temporary contraindication to anticoagulation exists (grade C, level IV). British Committee for Standards in Haematology 2005 (grade C, level IV).

25. WHICH FILTER SHOULD BE USED No particular filter appears superior to others. Removable filters should be used, to anticoagulant therapy (e.g. approximately 2 weeks) No particular filter appears superior to others. Removable filters should be used, to anticoagulant therapy (e.g. approximately 2 weeks) (grade C, level IV). British Committee for Standards in Haematology 2005 (grade C, level IV).

26. Contraindications to IVC Filter Insertion Uncorrectable, severe coagulopathy Uncorrectable, severe coagulopathy Extensive IVC thrombosis such that placement of a filter above the thrombus is not possible Extensive IVC thrombosis such that placement of a filter above the thrombus is not possible Bacteremia Bacteremia

27. Anatomic variations These conditions may be important because they alter the location of filter deployment in 3-15% of patients. These conditions may be important because they alter the location of filter deployment in 3-15% of patients. Duplication of the IVC: is observed in 0.2-3% of individuals. When this anomaly is present, the left IVC usually is smaller than the right, although they can be equal in size. Duplication of the IVC: is observed in 0.2-3% of individuals. When this anomaly is present, the left IVC usually is smaller than the right, although they can be equal in size. Transposition of the IVC :Transposition of the IVC is observed in 0.2-0.5% of individuals. Transposition of the IVC :Transposition of the IVC is observed in 0.2-0.5% of individuals. Circumaortic and retroaortic left renal vein The incidence of circumaortic renal veins has been reported to be as high as 8.7%. Patients with circumaortic or multiple renal veins may have a large hilar communication, which provides an alternative conduit for emboli. Circumaortic and retroaortic left renal vein The incidence of circumaortic renal veins has been reported to be as high as 8.7%. Patients with circumaortic or multiple renal veins may have a large hilar communication, which provides an alternative conduit for emboli.

28. Supra-renal placement Renal vein thrombosis Renal vein thrombosis IVC thrombosis extending above the level of the renal veins IVC thrombosis extending above the level of the renal veins Thrombus in the infrarenal IVC that does not leave enough room for the filter between the thrombus and renal veins Thrombus in the infrarenal IVC that does not leave enough room for the filter between the thrombus and renal veins Recurrent PE despite infrarenal filter placement (in which upper extremity or superior vena cava [SVC] thrombosis should be excluded) Recurrent PE despite infrarenal filter placement (in which upper extremity or superior vena cava [SVC] thrombosis should be excluded) PE after ovarian vein thrombosis PE after ovarian vein thrombosis Pregnancy Pregnancy

29. IVC filters Reduces, but does not eliminate, the risk of symptomatic PE in patients with proximal DVT in the short-term Reduces, but does not eliminate, the risk of symptomatic PE in patients with proximal DVT in the short-term Does not prevent small PE Does not prevent small PE Patients have had PE (and fatal PE) after IVC filters (< 5%). Patients have had PE (and fatal PE) after IVC filters (< 5%). Not proven to reduce PE in the long-term. Large venous collaterals develop around an occluded IVC. Not proven to reduce PE in the long-term. Large venous collaterals develop around an occluded IVC. Little or no thrombogenic potential Little or no thrombogenic potential No evidence of a decrease in fatal PE No evidence of a decrease in fatal PE No all-cause mortality reduction No all-cause mortality reduction Increase in symptomatic DVT in patients with filters Increase in symptomatic DVT in patients with filters

30. Short-Term Complications Contrast reaction Contrast reaction Arrhythmia Arrhythmia Air embolism (especially with jugular insertion) Air embolism (especially with jugular insertion) Pneumothorax/hemothorax Pneumothorax/hemothorax Extravascular penetration of guidewire Extravascular penetration of guidewire Premature opening - iliac vein - SVC, heart, proximal IVC Premature opening - iliac vein - SVC, heart, proximal IVC Incomplete opening Incomplete opening Tilting/angulation Tilting/angulation Misplacement – iliac vein, renal vein, etc- proximal to renal veins when this was not planned Misplacement – iliac vein, renal vein, etc- proximal to renal veins when this was not planned - often requires placement of a second filter - often requires placement of a second filter Guide wire entrapment Guide wire entrapment Filter migration (3-69%) Filter migration (3-69%) Embolization of the filter (2-5%) – to heart, pulmonary artery Embolization of the filter (2-5%) – to heart, pulmonary artery Filter fracture Filter fracture Insertion site bleeding/hematoma – this will interfere with subsequent anticoagulation Insertion site bleeding/hematoma – this will interfere with subsequent anticoagulation Infection at insertion site Infection at insertion site Contrast-induced renal dysfunction Contrast-induced renal dysfunction A-V fistula A-V fistula *Failure or delay in anticoagulation, which may lead to progressive DVT, phlegmasia cerulea dolens, or *Failure or delay in anticoagulation, which may lead to progressive DVT, phlegmasia cerulea dolens, or venous gangrene venous gangrene *Insertion site thrombosis (2-35%) appears to be greater with femoral route *Insertion site thrombosis (2-35%) appears to be greater with femoral route Recurrent PE (0.5%-6%) Recurrent PE (0.5%-6%) Fatal PE – rare (<1%) Fatal PE – rare (<1%) Death – very rare (3/2,557) Death – very rare (3/2,557)

31. Long-Term Complications Increased risk of subsequent DVT Increased risk of subsequent DVT Physician assumption of long-term protection à failure to prophylax Physician assumption of long-term protection à failure to prophylax Migration: proximal or distal Migration: proximal or distal Penetration of the vein wall/perforation – retroperitoneal, aorta, ureter, bowel. Common, generally no adverse consequences Penetration of the vein wall/perforation – retroperitoneal, aorta, ureter, bowel. Common, generally no adverse consequences Filter fracture Filter fracture IVC occlusion (2-28%) with resultant chronic leg edema, hyperpigmentation and ulceration IVC occlusion (2-28%) with resultant chronic leg edema, hyperpigmentation and ulceration Venacaval syndrome Venacaval syndrome Risks associated with subsequent Rt heart/PA catheterization from femoral vein including temporary pacemakers Risks associated with subsequent Rt heart/PA catheterization from femoral vein including temporary pacemakers Lumbar pain from nerve impingement Lumbar pain from nerve impingement Pyophlebitis (very rare) Pyophlebitis (very rare)

32. Anticoagulation in Patients with IVC Filters As a general rule, the use of an IVC filter does not change the need for or duration of anticoagulation. Since As a general rule, the use of an IVC filter does not change the need for or duration of anticoagulation. Since most (or all) patients who have IVC filters inserted have a proximal DVT, therapeutic anticoagulation should be instituted as soon as it is considered safe to do so. While IVC filters may reduce the risk of PE in patients with DVT, they do not prevent extension of DVT, including extension through the filter. The duration of anticoagulation is the duration of anticoagulation for patients with DVT without a filter. The duration of anticoagulation is the duration of anticoagulation for patients with DVT without a filter. British Committee for Standards in Haematology(2005)

33. Temporary filters Over 2000 filters per year Over 2000 filters per year Major shift from permanent to temporary Major shift from permanent to temporary Lowering of the threshold for placement of IVC filters. Lowering of the threshold for placement of IVC filters. Increase use of temporary filters in the last 10 years. Increase use of temporary filters in the last 10 years. Up to 50% left in as permanent filters. Up to 50% left in as permanent filters. Limited follow up. Limited follow up.

34. Temporary filters 175 patients with trauma or undergoing neurosurgery with contra-indication to anticoagulation 175 patients with trauma or undergoing neurosurgery with contra-indication to anticoagulation Gunther tulip in 92 and OptEase in 83 patients Gunther tulip in 92 and OptEase in 83 patients No PE. No PE. 49% of the Gunther tulip removed, 70% of the OptEase. 49% of the Gunther tulip removed, 70% of the OptEase. Two failure of removal. Two IVC occlusion. Two failure of removal. Two IVC occlusion. Keller IS et al, Clinical comparison of two optional vena cava filters JVIR, April 18, 505-11 2007.

35. Retrievable filters 137 patients with Gunther tulip (49), Recovery (41) and OptEase ( 37). 137 patients with Gunther tulip (49), Recovery (41) and OptEase ( 37). Multi-trauma patients contraindication to anticoagulation. Multi-trauma patients contraindication to anticoagulation. 94.4% successful placement, 2.3% placed in iliac veins, 2.9% groin haematoma. 94.4% successful placement, 2.3% placed in iliac veins, 2.9% groin haematoma. 45 not removed, 41 due to contra-indications and 4 due to thrombus. 45 not removed, 41 due to contra-indications and 4 due to thrombus. No PE. No PE. Rosenthal et al, Retrievable inferior vena cava filters:initial clinical results. Ann Vasc Surg 20,157-65, 2006.

36. Retrievable IVC filters 147 patients had Gunter Tulip filter 147 patients had Gunter Tulip filter 45 with the intention of removal 45 with the intention of removal Successful placement in 100% Successful placement in 100% 9 (20%) failure of retrieval (time 33.6 days) 9 (20%) failure of retrieval (time 33.6 days) Filter stuck to the wall (5), extreme tilt(2) and extensive thrombus (4). Filter stuck to the wall (5), extreme tilt(2) and extensive thrombus (4). Pneumothorax (4), failure of filter expansion(1) PE (1). Pneumothorax (4), failure of filter expansion(1) PE (1). Looby s, et al Gunther tulip retrievable inferior vena cava filters:indications, efficacy, retrieval and complications. CVIR, 30, 59- 65, 2007.

37. Retrievable filters 197 patients, 143 (72.5%) Gunther tulip, 54 (27.5%) Recovery filter. 197 patients, 143 (72.5%) Gunther tulip, 54 (27.5%) Recovery filter. 94 (47.7%) attempted removal 94 (47.7%) attempted removal Gunther tulip 11 days and Recovery at 28 days Gunther tulip 11 days and Recovery at 28 days 80( 85.1%) successful, failures due to thrombus (7) and adhesion or tilt(7). 80( 85.1%) successful, failures due to thrombus (7) and adhesion or tilt(7). No PE. No PE. Ray CE et al, Outcome with retrievable inferior cava filters:a multicentre study, 17, 1595-604, 2006.

38. Retrievable filters 35 patients had Gunther Tulip filter with an intention to retrieve at 30 days. 35 patients had Gunther Tulip filter with an intention to retrieve at 30 days. Two IVC thrombosis prior to attempted removal Two IVC thrombosis prior to attempted removal One failure to remove. One failure to remove. 79% no difficulty in removal, 13% moderate and 6% great difficulty. 79% no difficulty in removal, 13% moderate and 6% great difficulty. De Gregorio MA et al Retrieval of Gunther Tulip filter optional vena cava filter 30 days after implantation:a prospective clinical study JVIR 17, 1781-9, 2006.

39. Risks of Retrievable filter Perforation Perforation Migration Migration PE PE Thrombosis Thrombosis Other Other In Vitro Study with Optional filter recovery, Guther tulip and OptEase. In Vitro Study with Optional filter recovery, Guther tulip and OptEase. 25% and 4%, 22% and 13% and 43% and 0% of clot retrieval with 1g or >1g trapped thrombus 25% and 4%, 22% and 13% and 43% and 0% of clot retrieval with 1g or >1g trapped thrombus Kolbeck K et al Optional inferior vena cava filter retrieval with retained thrombu: an Vitro mode. JVIR, 17, 685-91, 2006.

43. Risks of Retrievable filters 33 patients with Neuhaus protect (13) and Antheor (20). 33 patients with Neuhaus protect (13) and Antheor (20). No PE. No PE. Filter thrombus in four patients Filter thrombus in four patients Complications in nine patients, filter dislocation (4), catheter fracture (3) and infection (1) Complications in nine patients, filter dislocation (4), catheter fracture (3) and infection (1) One require removal at venotomy. One require removal at venotomy. Miyahara T et al Clinical outcome and complications of temporary inferior vena cava filter placement, J Vasc Surg, 44,620-4, 2006.

44. Risks of Retrievalbe filters 96 patients with the Recovery filter. 96 patients with the Recovery filter. Contraindication to anticoagulation in 27, complication in 3, failure in 5 and prophylaxis in 61. Contraindication to anticoagulation in 27, complication in 3, failure in 5 and prophylaxis in 61. Retrieval attempted in 11, two failures, one IVC thrombosis post removal and one intimal tear. Retrieval attempted in 11, two failures, one IVC thrombosis post removal and one intimal tear. 40 had follow up CT at 80 days showed perforation in 11 and 3 fracture with one migration into the pancreas. 40 had follow up CT at 80 days showed perforation in 11 and 3 fracture with one migration into the pancreas. Asymmetric filter deployment seen in 12 patients. Asymmetric filter deployment seen in 12 patients. Chest CT at 63 days showed PE in 1 patient. On clinical follow up 12 had syptoms of PE but only one had PE on CT. Chest CT at 63 days showed PE in 1 patient. On clinical follow up 12 had syptoms of PE but only one had PE on CT. Kalva SP et al Recovery vena cava filter:experience in 96 patients. CVIR 29, 559-64.

45. BSIR Filter Registry Are current indications for filter placement correct? Are current indications for filter placement correct? How effective are they in preventing PE? How effective are they in preventing PE? How many temporary filters are removed? How many temporary filters are removed? How many temporary filters left in? why? How many temporary filters left in? why? Are temporary filters as effective as permanent? Are temporary filters as effective as permanent?