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Vena caval occlusion after bird’s nest filter placement
Vena Caval Occlusion after Bird’s Nest Filter Placement James H. Thomas, MD, Kelley M. Cornell, MD, Edward L. Siegel, MD, Charisse Sparks, BS, Stanton J. Rosenthal, MD, Kansas City, Kansas
BACKGROUND: Inferior vena caval thrombosis as a result of intracaval barrier devices occurs in 6.5% of patients with Greenfield filters. The incidence is less well defined in patients in whom bird’s nest filters have been placed. We reviewed our experience with bird’s nest filters to determine the incidence of filter-induced caval thrombosis. METHODS: The records of 140 patients with bird’s nest filters were reviewed, living patients were interviewed, and the inferior vena cava examined in 37 patients by duplex scanning. RESULTS: Ninety-three patients were available for evaluation. Five of these patients were found to have caval thrombosis by duplex scanning and 2 had clinical symptoms and signs compatible with caval thrombosis. The majority of these patients were on anticoagulants at the time of filter thrombosis. CONCLUSION: The incidence of filter-induced vena caval thrombosis in patients with bird’s nest filters (7%) is comparable with that of Greenfield filters. Because of the catastrophic manifestations of this complication and the increasing application of vena caval filters, the role of these filters in the treatment of thrombotic disease needs further critical evaluation. Am J Surg. 1998;176:598 – 600. © 1998 by Excerpta Medica, Inc.
migration are easily assessed and seem to be comparable in most IVCF systems.1 However, in contrast to the Greenfield filter, there are conflicting data regarding the risk of IVC thrombosis after BNF insertion.1– 4 The reported incidence ranges from 0% to 19% with the majority of these reports based on clinical data alone or radiographic studies limited to symptomatic patients. The only study where all patients were investigated by duplex scans of the IVC found no instances of IVC thrombosis.3 The following clinical investigation was designed to provide additional data regarding the incidence of IVC thrombosis in patients in whom BNF’s were placed.
T
One hundred forty BNFs were placed in 140 patients from January 1992 through June 1997. There were 56 females and 84 males. Ages ranged from 11 to 91 years, with a mean age of 53.5 years. The indications for BNF placement are reviewed in the Table. Thirty-six of the 140 patients (26%) had BNFs inserted prophylactically in clinical scenarios with documented increased risk of venous thromboembolism. Twenty of these patients had sustained multi-
he bird’s nest filter (BNF) can be repositioned during deployment into the inferior vena cava (IVC) providing a distinct advantage when compared with other inferior vena caval filters (IVCF) currently available. For this reason the BNF has become the IVCF preferred by many interventional radiologists. There are a number of nonfatal complications associated with IVCF placement, including (1) technical difficulties during placement, (2) deep vein thrombosis (DVT) at the insertion site, (3) filter migration, (4) erosion of the filter into the IVC wall, and (5) IVC obstruction from filter thrombosis. Technical difficulties, erosion of the filter into the IVC wall and filter
PATIENTS AND METHODS The medical records of all patients who underwent insertion of a BNF from January 1992 through June 1997 were reviewed. Data recorded included age, gender, risk factors for thromboembolism, indications for placement of the IVCF, and technical aspects of filter placement including location of deployment and complications. Follow-up data were obtained from medical records, and telephone or personal interviews with patients. Information documented included (1) anticoagulation status, (2) presence of lower extremity edema, (3) radiographic documentation of IVC thrombosis or pulmonary embolism (PE), and (4) cause of death. All living patients were requested to return for real-time gray scale and color and duplex Doppler scans to assess the IVC for thrombosis.
RESULTS
TABLE Indications for Bird’s Nest Filter Placement Number of Patients
From the Departments of Surgery and Radiology, the University of Kansas Medical Center, Kansas City, Kansas. Requests for reprints should be addressed to James H. Thomas, MD, Department of Surgery, University of Kansas Medical Center, 3901 Rainbow Boulevard, 4002 Murphy Building, Kansas City, Kansas 66160-7308. Presented at the 50th Annual Meeting of the Southwestern Surgical Congress, San Antonio, Texas, April 19 –22, 1998.
598
© 1998 by Excerpta Medica, Inc. All rights reserved.
Contraindications to anticoagulation Venous thromboembolism while on anticoagulation Location and/or characteristics of thrombus Prophylactic insertion
72
Total patients
140
24 8 36
0002-9610/98/$19.00 PII S0002-9610(98)00285-2
VENA CAVAL OCCLUSION AFTER BIRD’S NEST FILTER PLACEMENT/THOMAS ET AL
system trauma. In the remaining 104 patients, BNFs were placed for documented thromboembolism. Seventy-two of these 104 (69%) BNFs were inserted because of contraindications to IV anticoagulation in the presence of thromboembolism. These contraindications included (1) central nervous system abnormalities in 19 patients (13%); (2) gastrointestinal bleeding on anticoagulation in 20 patients (14%); (3) early (,48 hours) postoperative thromboembolism in 20 patients (14%); (4) bleeding from other sites in 8 patients (6%); (5) heparin-induced thrombocytopenia in 3 patients (2%); and (6) existing coagulopathy secondary to liver disease in 2 patients (1%). BNFs were inserted in 12 patients (9%) who experienced PE and 12 patients (9%) who developed DVT while on anticoagulation. An IVC barrier was considered necessary in 8 patients in addition to IV anticoagulation because of the location and extension of documented venous thrombosis. Thromboembolic conditions for which BNFs were placed included deep vein thrombosis (DVT) in 56 patients (40%), pulmonary embolism (PE) in 25 patients (18%), iliac vein thrombosis in 5 patients (4%), and combined DVT/PE in 35 patients (25%). Underlying clinical risk factors for thromboembolism included malignancy (51 patients, 36%), trauma (32 patients, 23%), recent operation (22 patients, 16%), morbid obesity (11 patients, 8%), and other miscellaneous conditions (24 patients, 18%) with 1 patient having a documented protein S deficiency. BNF Placement IVCFs were deployed in the suprarenal vena cava in 4 patients because of the extent of IVC thrombosis. In the remaining 136 patients, the BNF was placed in the infrarenal vena cava. Complications at the time of insertion of the BNF included prolapse of wires beyond the superior struts into the cava adjacent to or above the renal vein in 5 patients. Struts were located in either the renal vein, in 1 patient, or the right iliac vein, in 4 patients. One filter was found to have migrated 7 days following placement and two filters perforated the IVC. Clinical Follow-up Forty-seven of the 140 patients (34%) were lost to followup. Ninety-three patients had clinical evaluations by either telephone interview alone (33 patients, 35%), clinic/office visits (23 patients, 25%), or duplex scans (37 patients, 40%). Thirty-three of the 93 patients (37%) were placed on warfarin sodium (Coumadin) and adequately anticoagulated following placement of the IVCF. Two patients developed recurrent PE and 2 patients were noted to have significant bilateral lower extremity edema. The 2 patients with PE underwent duplex scanning of the IVC and one was found to have IVC thrombosis. Thirty-five other patients agreed to return for duplex studies of the IVC at a mean of 12.4 months (range 2 to 38) after BNF insertion. Four patients were found to have IVC thrombosis at a mean of 7.8 months (range 2 to 8) after BNF placement. Thus, 5 of the 93 patients (5%) had documented evidence of caval thrombosis by duplex scanning and an additional 2 patients (2%) who did not undergo a duplex evaluation of the IVC had bilateral lower extremity edema, a clinical
sign consistent with caval thrombosis.5 Three of these 4 patients who developed inferior vena caval filter thrombosis and 1 of the 2 patients who developed a PE were on warfarin sodium at the time of recurrent thromboembolism. Forty-two (45%) of the 93 patients died at a mean of 4.2 months (range 4 days to 39 months) after BNF insertions. Thirty of these patients died secondary to underlying malignancies (71%). Other causes of death included cardiac disease in 6 patients (14%).
COMMENTS Currently, 30,000 to 40,000 caval filters are placed each year in the United States.6 The use of IVC filters has expanded in spite of inadequate evaluation of the classical contraindications to anticoagulation and the lack of studies comparing the safety and efficacy of caval filters and anticoagulation. IVC filters are now placed prophylactically, particularly in trauma patients.7 Decousus et al8 have recently demonstrated in a prospective study comparing IVC filters with anticoagulation for the treatment of DVT, an increase in recurrence of DVT in patients with IVCF, and no difference in mortality rates in nontrauma patients. Thrombosis at the filter site was found in 16 of 37 patients with symptomatic recurrent thromboembolism, 12 with recurrent DVT, and 4 with concomitant PE and recurrent DVT. Fifteen percent of the 196 patients in this randomized study received a BNF. However, no data were provided for this subset of patients. As previously noted the incidence of caval thrombosis ranged from a low of zero in Lord and Benn’s report3 of 37 patients with BNF, to a high of 19% described by Roehm et al.2 It is unlikely that the low incidence described by Lord and Benn3 is accurate. It is also probable that the inordinately high incidence of 19% reported by Roehm et al2 in 1988 reflects an early experience with this filter. Our study was designed to provide additional information about the frequency of filter thrombosis in unselected symptomatic and asymptomatic patients. Thirty-seven patients underwent duplex evaluation of the IVC and an additional 56 patients were followed up by either telephone interview or clinic visits. Clinical symptoms and signs developed in 4 of the 93 patients, consistent with recurrent thromboembolization, and thrombosis of the IVC was confirmed by duplex scanning in 5 patients, 4 asymptomatic patients, and 1 of the 2 symptomatic patients studied. Three of these 5 patients (60%) were adequately anticoagulated at the time of IVC thrombosis. It is probable that the study reported herein, and all such studies, underestimate the frequency of IVC thrombosis owing to the high early mortality rate of patients in whom IVCFs are placed and because clinical symptoms are unreliable in predicting the presence of IVC thrombosis. However, the results of this study suggest that the incidence of caval thrombosis in patients with BNF is comparable with that of Greenfield filters, which was reported by Becker et al1 to be 6.5%. Since only 40% of our patients agreed to return for follow-up duplex evaluation, these conclusions are limited by the small number of patients who underwent direct objective evaluation of the IVC filter site. Filter thrombosis, in spite of the low risk documented for most IVCFs, can be catastrophic. The occurrence of a
THE AMERICAN JOURNAL OF SURGERY® VOLUME 176 DECEMBER 1998
599
VENA CAVAL OCCLUSION AFTER BIRD’S NEST FILTER PLACEMENT/THOMAS ET AL
disabling IVC thrombosis with compromise of renal function in a 20-year-old man in whom a BNF had been placed prophylactically has convinced the authors that well-designed clinical studies are mandatory if these devices are to be appropriately used in the management of patients with thromboembolism.
REFERENCES 1. Becker DM, Philbrick JT, Selby JB. Inferior vena cava filters. Arch Intern Med. 1992;152:1985–1993. 2. Roehm JOF Jr, Johnsrude IS, Barth MH, Gianturco C. The bird’s nest inferior vena cava filter: progress report. Radiology. 1988;168:745–749. 3. Lord RSA, Benn I. Early and late results after bird’s nest filter
600
placement in the inferior vena cava: clinical and duplex ultrasound follow up. Aust NZ J Surg. 1994;64:106 –114. 4. Mohan CR, Hoballah JJ, Sharp WJ, et al. Comparative efficacy and complications of vena caval filters. J Vasc Surg. 1995;21:235– 245. 5. Tardy B, Mismetti P, Page Y, et al. Symptomatic inferior vena cava filter thrombosis: clinical study of 30 consecutive cases. Eur Respir J. 1996;9:2012–2016. 6. Magnant JG, Walsh DB, Juravsky LI, Cronenwett JL. Current use of inferior vena cava filters. J Vasc Surg. 1992;16:701–706. 7. Rohrer MJ, Scheidler MG, Wheeler HB, Cutler BS. Extended indications for placement of an inferior vena cava filter. J Vasc Surg. 1989;10:44 –50. 8. Decousus H, Leizorovicz A, Parent F. A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. NEJM. 1998;338:409 – 415.
THE AMERICAN JOURNAL OF SURGERY® VOLUME 176 DECEMBER 1998
BACKGROUND: Inferior vena caval thrombosis as a result of intracaval barrier devices occurs in 6.5% of patients with Greenfield filters. The incidence is less well defined in patients in whom bird’s nest filters have been placed. We reviewed our experience with bird’s nest filters to determine the incidence of filter-induced caval thrombosis. METHODS: The records of 140 patients with bird’s nest filters were reviewed, living patients were interviewed, and the inferior vena cava examined in 37 patients by duplex scanning. RESULTS: Ninety-three patients were available for evaluation. Five of these patients were found to have caval thrombosis by duplex scanning and 2 had clinical symptoms and signs compatible with caval thrombosis. The majority of these patients were on anticoagulants at the time of filter thrombosis. CONCLUSION: The incidence of filter-induced vena caval thrombosis in patients with bird’s nest filters (7%) is comparable with that of Greenfield filters. Because of the catastrophic manifestations of this complication and the increasing application of vena caval filters, the role of these filters in the treatment of thrombotic disease needs further critical evaluation. Am J Surg. 1998;176:598 – 600. © 1998 by Excerpta Medica, Inc.
migration are easily assessed and seem to be comparable in most IVCF systems.1 However, in contrast to the Greenfield filter, there are conflicting data regarding the risk of IVC thrombosis after BNF insertion.1– 4 The reported incidence ranges from 0% to 19% with the majority of these reports based on clinical data alone or radiographic studies limited to symptomatic patients. The only study where all patients were investigated by duplex scans of the IVC found no instances of IVC thrombosis.3 The following clinical investigation was designed to provide additional data regarding the incidence of IVC thrombosis in patients in whom BNF’s were placed.
T
One hundred forty BNFs were placed in 140 patients from January 1992 through June 1997. There were 56 females and 84 males. Ages ranged from 11 to 91 years, with a mean age of 53.5 years. The indications for BNF placement are reviewed in the Table. Thirty-six of the 140 patients (26%) had BNFs inserted prophylactically in clinical scenarios with documented increased risk of venous thromboembolism. Twenty of these patients had sustained multi-
he bird’s nest filter (BNF) can be repositioned during deployment into the inferior vena cava (IVC) providing a distinct advantage when compared with other inferior vena caval filters (IVCF) currently available. For this reason the BNF has become the IVCF preferred by many interventional radiologists. There are a number of nonfatal complications associated with IVCF placement, including (1) technical difficulties during placement, (2) deep vein thrombosis (DVT) at the insertion site, (3) filter migration, (4) erosion of the filter into the IVC wall, and (5) IVC obstruction from filter thrombosis. Technical difficulties, erosion of the filter into the IVC wall and filter
PATIENTS AND METHODS The medical records of all patients who underwent insertion of a BNF from January 1992 through June 1997 were reviewed. Data recorded included age, gender, risk factors for thromboembolism, indications for placement of the IVCF, and technical aspects of filter placement including location of deployment and complications. Follow-up data were obtained from medical records, and telephone or personal interviews with patients. Information documented included (1) anticoagulation status, (2) presence of lower extremity edema, (3) radiographic documentation of IVC thrombosis or pulmonary embolism (PE), and (4) cause of death. All living patients were requested to return for real-time gray scale and color and duplex Doppler scans to assess the IVC for thrombosis.
RESULTS
TABLE Indications for Bird’s Nest Filter Placement Number of Patients
From the Departments of Surgery and Radiology, the University of Kansas Medical Center, Kansas City, Kansas. Requests for reprints should be addressed to James H. Thomas, MD, Department of Surgery, University of Kansas Medical Center, 3901 Rainbow Boulevard, 4002 Murphy Building, Kansas City, Kansas 66160-7308. Presented at the 50th Annual Meeting of the Southwestern Surgical Congress, San Antonio, Texas, April 19 –22, 1998.
598
© 1998 by Excerpta Medica, Inc. All rights reserved.
Contraindications to anticoagulation Venous thromboembolism while on anticoagulation Location and/or characteristics of thrombus Prophylactic insertion
72
Total patients
140
24 8 36
0002-9610/98/$19.00 PII S0002-9610(98)00285-2
VENA CAVAL OCCLUSION AFTER BIRD’S NEST FILTER PLACEMENT/THOMAS ET AL
system trauma. In the remaining 104 patients, BNFs were placed for documented thromboembolism. Seventy-two of these 104 (69%) BNFs were inserted because of contraindications to IV anticoagulation in the presence of thromboembolism. These contraindications included (1) central nervous system abnormalities in 19 patients (13%); (2) gastrointestinal bleeding on anticoagulation in 20 patients (14%); (3) early (,48 hours) postoperative thromboembolism in 20 patients (14%); (4) bleeding from other sites in 8 patients (6%); (5) heparin-induced thrombocytopenia in 3 patients (2%); and (6) existing coagulopathy secondary to liver disease in 2 patients (1%). BNFs were inserted in 12 patients (9%) who experienced PE and 12 patients (9%) who developed DVT while on anticoagulation. An IVC barrier was considered necessary in 8 patients in addition to IV anticoagulation because of the location and extension of documented venous thrombosis. Thromboembolic conditions for which BNFs were placed included deep vein thrombosis (DVT) in 56 patients (40%), pulmonary embolism (PE) in 25 patients (18%), iliac vein thrombosis in 5 patients (4%), and combined DVT/PE in 35 patients (25%). Underlying clinical risk factors for thromboembolism included malignancy (51 patients, 36%), trauma (32 patients, 23%), recent operation (22 patients, 16%), morbid obesity (11 patients, 8%), and other miscellaneous conditions (24 patients, 18%) with 1 patient having a documented protein S deficiency. BNF Placement IVCFs were deployed in the suprarenal vena cava in 4 patients because of the extent of IVC thrombosis. In the remaining 136 patients, the BNF was placed in the infrarenal vena cava. Complications at the time of insertion of the BNF included prolapse of wires beyond the superior struts into the cava adjacent to or above the renal vein in 5 patients. Struts were located in either the renal vein, in 1 patient, or the right iliac vein, in 4 patients. One filter was found to have migrated 7 days following placement and two filters perforated the IVC. Clinical Follow-up Forty-seven of the 140 patients (34%) were lost to followup. Ninety-three patients had clinical evaluations by either telephone interview alone (33 patients, 35%), clinic/office visits (23 patients, 25%), or duplex scans (37 patients, 40%). Thirty-three of the 93 patients (37%) were placed on warfarin sodium (Coumadin) and adequately anticoagulated following placement of the IVCF. Two patients developed recurrent PE and 2 patients were noted to have significant bilateral lower extremity edema. The 2 patients with PE underwent duplex scanning of the IVC and one was found to have IVC thrombosis. Thirty-five other patients agreed to return for duplex studies of the IVC at a mean of 12.4 months (range 2 to 38) after BNF insertion. Four patients were found to have IVC thrombosis at a mean of 7.8 months (range 2 to 8) after BNF placement. Thus, 5 of the 93 patients (5%) had documented evidence of caval thrombosis by duplex scanning and an additional 2 patients (2%) who did not undergo a duplex evaluation of the IVC had bilateral lower extremity edema, a clinical
sign consistent with caval thrombosis.5 Three of these 4 patients who developed inferior vena caval filter thrombosis and 1 of the 2 patients who developed a PE were on warfarin sodium at the time of recurrent thromboembolism. Forty-two (45%) of the 93 patients died at a mean of 4.2 months (range 4 days to 39 months) after BNF insertions. Thirty of these patients died secondary to underlying malignancies (71%). Other causes of death included cardiac disease in 6 patients (14%).
COMMENTS Currently, 30,000 to 40,000 caval filters are placed each year in the United States.6 The use of IVC filters has expanded in spite of inadequate evaluation of the classical contraindications to anticoagulation and the lack of studies comparing the safety and efficacy of caval filters and anticoagulation. IVC filters are now placed prophylactically, particularly in trauma patients.7 Decousus et al8 have recently demonstrated in a prospective study comparing IVC filters with anticoagulation for the treatment of DVT, an increase in recurrence of DVT in patients with IVCF, and no difference in mortality rates in nontrauma patients. Thrombosis at the filter site was found in 16 of 37 patients with symptomatic recurrent thromboembolism, 12 with recurrent DVT, and 4 with concomitant PE and recurrent DVT. Fifteen percent of the 196 patients in this randomized study received a BNF. However, no data were provided for this subset of patients. As previously noted the incidence of caval thrombosis ranged from a low of zero in Lord and Benn’s report3 of 37 patients with BNF, to a high of 19% described by Roehm et al.2 It is unlikely that the low incidence described by Lord and Benn3 is accurate. It is also probable that the inordinately high incidence of 19% reported by Roehm et al2 in 1988 reflects an early experience with this filter. Our study was designed to provide additional information about the frequency of filter thrombosis in unselected symptomatic and asymptomatic patients. Thirty-seven patients underwent duplex evaluation of the IVC and an additional 56 patients were followed up by either telephone interview or clinic visits. Clinical symptoms and signs developed in 4 of the 93 patients, consistent with recurrent thromboembolization, and thrombosis of the IVC was confirmed by duplex scanning in 5 patients, 4 asymptomatic patients, and 1 of the 2 symptomatic patients studied. Three of these 5 patients (60%) were adequately anticoagulated at the time of IVC thrombosis. It is probable that the study reported herein, and all such studies, underestimate the frequency of IVC thrombosis owing to the high early mortality rate of patients in whom IVCFs are placed and because clinical symptoms are unreliable in predicting the presence of IVC thrombosis. However, the results of this study suggest that the incidence of caval thrombosis in patients with BNF is comparable with that of Greenfield filters, which was reported by Becker et al1 to be 6.5%. Since only 40% of our patients agreed to return for follow-up duplex evaluation, these conclusions are limited by the small number of patients who underwent direct objective evaluation of the IVC filter site. Filter thrombosis, in spite of the low risk documented for most IVCFs, can be catastrophic. The occurrence of a
THE AMERICAN JOURNAL OF SURGERY® VOLUME 176 DECEMBER 1998
599
VENA CAVAL OCCLUSION AFTER BIRD’S NEST FILTER PLACEMENT/THOMAS ET AL
disabling IVC thrombosis with compromise of renal function in a 20-year-old man in whom a BNF had been placed prophylactically has convinced the authors that well-designed clinical studies are mandatory if these devices are to be appropriately used in the management of patients with thromboembolism.
REFERENCES 1. Becker DM, Philbrick JT, Selby JB. Inferior vena cava filters. Arch Intern Med. 1992;152:1985–1993. 2. Roehm JOF Jr, Johnsrude IS, Barth MH, Gianturco C. The bird’s nest inferior vena cava filter: progress report. Radiology. 1988;168:745–749. 3. Lord RSA, Benn I. Early and late results after bird’s nest filter
600
placement in the inferior vena cava: clinical and duplex ultrasound follow up. Aust NZ J Surg. 1994;64:106 –114. 4. Mohan CR, Hoballah JJ, Sharp WJ, et al. Comparative efficacy and complications of vena caval filters. J Vasc Surg. 1995;21:235– 245. 5. Tardy B, Mismetti P, Page Y, et al. Symptomatic inferior vena cava filter thrombosis: clinical study of 30 consecutive cases. Eur Respir J. 1996;9:2012–2016. 6. Magnant JG, Walsh DB, Juravsky LI, Cronenwett JL. Current use of inferior vena cava filters. J Vasc Surg. 1992;16:701–706. 7. Rohrer MJ, Scheidler MG, Wheeler HB, Cutler BS. Extended indications for placement of an inferior vena cava filter. J Vasc Surg. 1989;10:44 –50. 8. Decousus H, Leizorovicz A, Parent F. A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. NEJM. 1998;338:409 – 415.
THE AMERICAN JOURNAL OF SURGERY® VOLUME 176 DECEMBER 1998