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FEATURED ABSTRACT, Does prolonged implantation predict IVC filter retrieval failure? A single center experience in 610 retrieval procedures
MONDAY: Scientific Sessions
S62
’
Monday
Scientific Session
Materials and Methods: 245 patients (250 consecutive encounters) in whom inferior vena cavography was performed before and after IVC filter retrieval were reviewed from a 12year period ending 3/2014. Retrieval was considered complex if it required forceps or other adjuncts. The cavograms were assessed for abnormalities including stenosis, filling defects, dissection, and extravasation of contrast. Stenosis was measured with electronic calipers and graded by quartiles. Change in stenosis in a given location greater than or equal to one quartile after removal was considered spasm. Results: Of the original 250 encounters, 2 were excluded because they were removed immediately after being placed, 16 due to missing records, and 4 due to extensive baseline caval thrombosis precluding analysis. Dwell time could not be determined for 15 encounters due to missing records. Filling defects and stenosis were significantly more frequent after retrieval, p o 0.05, but they did not change patient management (Table). The only major abnormality after retrieval was extravasation, which occurred only in the complex group and was treated with balloon tamponade and observation. No dissection was observed. There were no cases of 76% or greater stenosis. Dwell time was not correlated with the presence of abnormalities after retrieval (r ¼ 0.002, p ¼ 0.977). Conclusion: Caval stenosis is the primary abnormality found by cavography after IVC filter retrieval. The lack of cavographic abnormalities requiring treatment following routine IVC filter retrieval may justify omitting the post-retrieval cavogram irrespective of dwell time. While uncommon, extravasation requiring treatment may be seen after complex retrieval, thus cavography remains warranted in this setting.
3:39 PM
Abstract No. 127
Conductive IVC filter retrieval following optimized radiofrequency ablation in an ex vivo model V.P. Krishnasamy1, L. Jiang1,2, A.H. Negussie1, T. Tse3, M. Mathew1, R. Seifabadi1, S. Xu1, Y. Chen3, H. Amalou1, B.J. Wood1; 1Interventional Radiology, National Institutes of Health, Arlington, VA; 2Johns Hopkins University, Baltimore, MD; 3University of Georgia, Athens, GA Purpose: To assess in a novel ex vivo model the retrievability of a custom conductive inferior vena cava (IVC) filter and snare following deposition of radiofrequency (RF) energy with optimization of RF current and duration. Materials and Methods: Porcine IVC was affixed to a radiofrequency ablation (RFA) patient return electrode. Two legs of a custom conductive IVC filter were manually hooked into the IVC wall. A commercial 200 W, 480 kHz RFA generator was electrically coupled to the filter apex and varied electrical currents were applied for varied durations (100, 200, and 300 mA of current for 0, 3, 5, 10, 20, and 30 seconds). Following each RFA duration, filter removal force was measured via a motorized pull wire connecting the leg of the filter to a custom force gauge. Tissue samples were subsequently sent for histology and microscopy to assess mechanical and thermal damage. Results: At 100 mA of RFA current, the minimum force required to dislodge the filter was 64.4⫾22.9 g force after 5 seconds of RFA, compared to 110.2⫾25.7 g force in the control group (no RFA). With increases in current beyond 100 mA or RFA duration beyond 5 seconds, mean dislodging
’
JVIR
force increased, presumably due to adhesive charring. One-way ANOVA found no difference in force with different RFA times while holding current at either 200 or 300 mA. In the 100 mA group, two sample t-tests comparing each of the RFA times versus control demonstrated statistical significance at the 3, 5, and 30 second time points. On histologic examination of the 100 mA samples, minimal thermal damage of the IVC wall was identified at 5 second time point. However, near transmural thermal injury and tissue coagulation was found at the 30 second time point, but limited to less than 5 mm in diameter. Conclusion: RFA with 100 mA for 5 seconds required the lowest retrieval force, compared to control, longer RFA durations, or higher currents. RF energy to a conductive IVC filter was optimized to potentially facilitate difficult filter retrieval with a conductive snare.
3:48 PM
Abstract No. 128
’ FEATURED ABSTRACT Does prolonged implantation predict IVC filter retrieval failure? A single center experience in 610 retrieval procedures K.R. Desai1, J. Karp1, S. Mouli1, R.J. Lewandowski1, R. Ryu2; 1Department of Radiology, Section of Interventional Radiology, Northwestern University, Chicago, IL; 2Department of Radiology, Section of Interventional Radiology, University of Colorado, Denver, CO Purpose: Studies have demonstrated decreased technical success when removing retrievable inferior vena cava filters (rIVCF) that have prolonged dwell time. However, the adoption of adjunctive techniques appears to have positively impacted overall retrieval rates of these devices. We aim to compare the technical success rate of removing rIVCFs with prolonged dwell time, defined as 46 months. We hypothesize that with adjunctive techniques, the technical success rate of rIVCF retrieval is maintained despite prolonged implantation. Materials and Methods: With IRB approval, all rIVCF retrieval procedures from 1/2009-9/2014 were identified from a prospectively acquired database. We assessed the technical success of rIVCF retrieval; we recorded filter dwell time as o6 months or 46 months for all cases. The necessity of adjunctive techniques to remove these devices was also recorded. The adjunctive techniques employed include loop wire, directional sheath use, balloon disruption, endobronchial forceps, and Excimer laser sheath assistance. Statistics were analyzed using the Chi square test, with statistical significance accepted at po0.05. Results: During the study period, 610 rIVCF retrieval procedures were performed. The technical success rate for retrieval procedures performed with rIVCFs in place o6 months was 97.5% (n¼561); retrieval technical success rate for rIVCFs in place 46 months was 93.9% (n¼49) (p¼0.12). Adjunctive techniques were necessary to remove rIVCFs with o6 months dwell time 9.6% of the time (n¼53), and 65% of the time (n¼30) for rIVCFs with 46 months dwell time (po0.0001). Conclusion: There is no significant difference in the technical success rate for removal of rIVCFs that were
JVIR
’
Scientific Session
Monday
implanted 46 months vs. o6 months ago. Retrieval rates for both cohorts exceeded 93%. In patients with prolonged IVC filter dwell time, adjunctive techniques are often necessary to achieve these results.
3:57 PM
Abstract No. 129
Retrospective review of 507 implantations of Option inferior vena cava filter at a single healthcare system B.Q. Tsui1, T. An2,3, E. Moon1, W. Wang2; 1Case Western Reserve Medical School, Cleveland, OH; 2Radiology, The Cleveland Clinic, Cleveland, OH; 3Interventional Radiology, Guiyang Medical School, Guiyang, China
4:06 PM
Abstract No. 130
Improving IVC filter retrieval rates: the impact of adjunctive retrieval techniques in 589 patients S. Mouli1, K.R. Desai1, J. Karp1, R. Ryu2, R. J. Lewandowski1; 1Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL; 2Radiology, University of Colorado, Denver, CO
S63
Purpose: The FDA encourages the retrieval of all inferior vena cava (IVC) filters once their utility is complete. With increased IVC filter dwell time, retrievals have become increasingly technically challenging. In this study, we aim to evaluate the impact of adjunctive measures to remove IVC filters. We hypothesize that these methods can significantly improve the technical success rate of these procedures with minimal added morbidity. Materials and Methods: With IRB approval, all patients undergoing IVC filter removal between 01/2009-09/2014 were identified from a prospectively acquired database. The technical success rate of IVC filter retrieval was calculated when either a) standard retrieval techniques (snare/sheath only) or b) adjunctive techniques (loop-wire, directional sheath use, balloon disruption, endobronchial forceps, and excimer laserassistance (Spectranetics Inc, Colorado Springs, CO)) were used. Pre/post-retrieval venography and 30-day clinical/imaging follow-up were analyzed. ANOVA was used for statistical analysis (po0.05 statistically significant). Results: The technical success rate for standard technique IVC filter retrieval was 86% (509/589); adjunctive techniques allowed IVC filter retrieval in 74/80 patients. This increased the technical success rate to 99% (583/589), po0.01. Of note, laser-assistance was successful in 48/50 patients. Cases requiring laser-assistance had significantly longer dwell time (111, 87, 643 days, for standard, non-laser adjunctive, and laser-assisted techniques, respectively; po0.01). The overall complication rate was 1.7%, with no significant difference between the retrieval groups (p¼0.69). Two major complications occurred following laser-assisted retrieval of OptEase filters (Cordis, Warren, NJ); patients were observed for 48 hours secondary to an inguinal hematomas. Conclusion: The use of adjunctive techniques significantly increases IVC filter retrieval rates, with minimal impact on complication rates. Adjunctive IVC filter retrieval techniques should be considered in efforts to comply with FDA recommendations.
4:15 PM
Abstract No. 131
Inferior vena cava filters: placement and retrievals - an audit M. Naeem, G.E. McEnteggart, S.H. Ahn, G.M. Soares, T. Murphy; Brown University/ Rhode Island Hospital, Providence, RI Purpose: To identify differences in the approach and practices of inferior vena cava (IVC) filter placement and retrieval procedures between two vascular specialties - interventional radiology (IR) and vascular surgery (VS). Materials and Methods: We completed a retrospective analysis of all IVC filter insertion and corresponding retrieval procedures completed by IR and VS at a University Hospital for the year 2012. The variables assessed were patient demographics, radiation dose, contrast dose, fluoroscopy time, indication for placement, duration of filter stay, and retrieval success rates. Data were analyzed using survival curves and t-test with SAS 9.4. Results: Out of 166 patients who underwent IVC filter placement in 2012, 29 were excluded due to incomplete procedure data. Of the 137 placements, 43 (31%) were retrieved
MONDAY: Scientific Sessions
Purpose: To retrospectively evaluate the safety, efficacy, and retrievability of the Option inferior vena cava (IVC) filter. Materials and Methods: All cases of patients who received an Option filter at a single healthcare system between August 2009 and August 2014 were identified, and outcomes were reviewed through the hospital electronic medical chart. Results: A total of 507 patients (262 men, 245 women) underwent filter placement (mean age at filter placement, 67.24⫾15.18 years; range, 19.48-101.69 years). A total of 357 patients had Z1 follow-up imaging study available and were included in this study. Images demonstrated no filter fractures or en bloc distant migrations. Limb penetration was seen in 41 patients with available imaging studies (abdomen CT, fluoroscopy) (21.47%; 41/191), with 106 total penetrated limbs (3 cases involving the duodenum, 3 involving the aorta, 100 involving the IVC only). Tilt 4101 was seen in 14 filters (6.7%; 14/288) among available images (abdomen CT, X-ray, fluoroscopy). Among 60 patients who returned for filter removal, 49 (81.67%) filters were successfully retrieved. Retrieval failures were attributed to endothelialization of the leg hooks into the IVC wall (n¼3), failure of filter collapse during retrieval (n¼3), filter tip embedment (n¼2), residual thrombi in the filter (n¼2), and tilt 4151 (n¼1). Breakthrough pulmonary embolism was seen in 14 cases (14/507, 2.8%). Trapped clot within the filter was seen in 16 patients with contrast-enhanced computed tomography imaging available (26.2%; 16/61). A total of 111 out of 507 patients (21.89%) patients died as a result of underlying diseases. Twelve patients (12/507, 2.4%) had recurrent deep venous thrombosis; 10 had filters in situ (1 had completely occluded IVC), and 2 underwent filter retrieval. Conclusion: Option filters were placed for both permanent and temporary indications in our institute; most filters were converted to permanent use. Rates of device-related complications, pulmonary embolism breakthrough, and successful retrieval were similar to the rates seen with other retrievable filters.
’
S62
’
Monday
Scientific Session
Materials and Methods: 245 patients (250 consecutive encounters) in whom inferior vena cavography was performed before and after IVC filter retrieval were reviewed from a 12year period ending 3/2014. Retrieval was considered complex if it required forceps or other adjuncts. The cavograms were assessed for abnormalities including stenosis, filling defects, dissection, and extravasation of contrast. Stenosis was measured with electronic calipers and graded by quartiles. Change in stenosis in a given location greater than or equal to one quartile after removal was considered spasm. Results: Of the original 250 encounters, 2 were excluded because they were removed immediately after being placed, 16 due to missing records, and 4 due to extensive baseline caval thrombosis precluding analysis. Dwell time could not be determined for 15 encounters due to missing records. Filling defects and stenosis were significantly more frequent after retrieval, p o 0.05, but they did not change patient management (Table). The only major abnormality after retrieval was extravasation, which occurred only in the complex group and was treated with balloon tamponade and observation. No dissection was observed. There were no cases of 76% or greater stenosis. Dwell time was not correlated with the presence of abnormalities after retrieval (r ¼ 0.002, p ¼ 0.977). Conclusion: Caval stenosis is the primary abnormality found by cavography after IVC filter retrieval. The lack of cavographic abnormalities requiring treatment following routine IVC filter retrieval may justify omitting the post-retrieval cavogram irrespective of dwell time. While uncommon, extravasation requiring treatment may be seen after complex retrieval, thus cavography remains warranted in this setting.
3:39 PM
Abstract No. 127
Conductive IVC filter retrieval following optimized radiofrequency ablation in an ex vivo model V.P. Krishnasamy1, L. Jiang1,2, A.H. Negussie1, T. Tse3, M. Mathew1, R. Seifabadi1, S. Xu1, Y. Chen3, H. Amalou1, B.J. Wood1; 1Interventional Radiology, National Institutes of Health, Arlington, VA; 2Johns Hopkins University, Baltimore, MD; 3University of Georgia, Athens, GA Purpose: To assess in a novel ex vivo model the retrievability of a custom conductive inferior vena cava (IVC) filter and snare following deposition of radiofrequency (RF) energy with optimization of RF current and duration. Materials and Methods: Porcine IVC was affixed to a radiofrequency ablation (RFA) patient return electrode. Two legs of a custom conductive IVC filter were manually hooked into the IVC wall. A commercial 200 W, 480 kHz RFA generator was electrically coupled to the filter apex and varied electrical currents were applied for varied durations (100, 200, and 300 mA of current for 0, 3, 5, 10, 20, and 30 seconds). Following each RFA duration, filter removal force was measured via a motorized pull wire connecting the leg of the filter to a custom force gauge. Tissue samples were subsequently sent for histology and microscopy to assess mechanical and thermal damage. Results: At 100 mA of RFA current, the minimum force required to dislodge the filter was 64.4⫾22.9 g force after 5 seconds of RFA, compared to 110.2⫾25.7 g force in the control group (no RFA). With increases in current beyond 100 mA or RFA duration beyond 5 seconds, mean dislodging
’
JVIR
force increased, presumably due to adhesive charring. One-way ANOVA found no difference in force with different RFA times while holding current at either 200 or 300 mA. In the 100 mA group, two sample t-tests comparing each of the RFA times versus control demonstrated statistical significance at the 3, 5, and 30 second time points. On histologic examination of the 100 mA samples, minimal thermal damage of the IVC wall was identified at 5 second time point. However, near transmural thermal injury and tissue coagulation was found at the 30 second time point, but limited to less than 5 mm in diameter. Conclusion: RFA with 100 mA for 5 seconds required the lowest retrieval force, compared to control, longer RFA durations, or higher currents. RF energy to a conductive IVC filter was optimized to potentially facilitate difficult filter retrieval with a conductive snare.
3:48 PM
Abstract No. 128
’ FEATURED ABSTRACT Does prolonged implantation predict IVC filter retrieval failure? A single center experience in 610 retrieval procedures K.R. Desai1, J. Karp1, S. Mouli1, R.J. Lewandowski1, R. Ryu2; 1Department of Radiology, Section of Interventional Radiology, Northwestern University, Chicago, IL; 2Department of Radiology, Section of Interventional Radiology, University of Colorado, Denver, CO Purpose: Studies have demonstrated decreased technical success when removing retrievable inferior vena cava filters (rIVCF) that have prolonged dwell time. However, the adoption of adjunctive techniques appears to have positively impacted overall retrieval rates of these devices. We aim to compare the technical success rate of removing rIVCFs with prolonged dwell time, defined as 46 months. We hypothesize that with adjunctive techniques, the technical success rate of rIVCF retrieval is maintained despite prolonged implantation. Materials and Methods: With IRB approval, all rIVCF retrieval procedures from 1/2009-9/2014 were identified from a prospectively acquired database. We assessed the technical success of rIVCF retrieval; we recorded filter dwell time as o6 months or 46 months for all cases. The necessity of adjunctive techniques to remove these devices was also recorded. The adjunctive techniques employed include loop wire, directional sheath use, balloon disruption, endobronchial forceps, and Excimer laser sheath assistance. Statistics were analyzed using the Chi square test, with statistical significance accepted at po0.05. Results: During the study period, 610 rIVCF retrieval procedures were performed. The technical success rate for retrieval procedures performed with rIVCFs in place o6 months was 97.5% (n¼561); retrieval technical success rate for rIVCFs in place 46 months was 93.9% (n¼49) (p¼0.12). Adjunctive techniques were necessary to remove rIVCFs with o6 months dwell time 9.6% of the time (n¼53), and 65% of the time (n¼30) for rIVCFs with 46 months dwell time (po0.0001). Conclusion: There is no significant difference in the technical success rate for removal of rIVCFs that were
JVIR
’
Scientific Session
Monday
implanted 46 months vs. o6 months ago. Retrieval rates for both cohorts exceeded 93%. In patients with prolonged IVC filter dwell time, adjunctive techniques are often necessary to achieve these results.
3:57 PM
Abstract No. 129
Retrospective review of 507 implantations of Option inferior vena cava filter at a single healthcare system B.Q. Tsui1, T. An2,3, E. Moon1, W. Wang2; 1Case Western Reserve Medical School, Cleveland, OH; 2Radiology, The Cleveland Clinic, Cleveland, OH; 3Interventional Radiology, Guiyang Medical School, Guiyang, China
4:06 PM
Abstract No. 130
Improving IVC filter retrieval rates: the impact of adjunctive retrieval techniques in 589 patients S. Mouli1, K.R. Desai1, J. Karp1, R. Ryu2, R. J. Lewandowski1; 1Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL; 2Radiology, University of Colorado, Denver, CO
S63
Purpose: The FDA encourages the retrieval of all inferior vena cava (IVC) filters once their utility is complete. With increased IVC filter dwell time, retrievals have become increasingly technically challenging. In this study, we aim to evaluate the impact of adjunctive measures to remove IVC filters. We hypothesize that these methods can significantly improve the technical success rate of these procedures with minimal added morbidity. Materials and Methods: With IRB approval, all patients undergoing IVC filter removal between 01/2009-09/2014 were identified from a prospectively acquired database. The technical success rate of IVC filter retrieval was calculated when either a) standard retrieval techniques (snare/sheath only) or b) adjunctive techniques (loop-wire, directional sheath use, balloon disruption, endobronchial forceps, and excimer laserassistance (Spectranetics Inc, Colorado Springs, CO)) were used. Pre/post-retrieval venography and 30-day clinical/imaging follow-up were analyzed. ANOVA was used for statistical analysis (po0.05 statistically significant). Results: The technical success rate for standard technique IVC filter retrieval was 86% (509/589); adjunctive techniques allowed IVC filter retrieval in 74/80 patients. This increased the technical success rate to 99% (583/589), po0.01. Of note, laser-assistance was successful in 48/50 patients. Cases requiring laser-assistance had significantly longer dwell time (111, 87, 643 days, for standard, non-laser adjunctive, and laser-assisted techniques, respectively; po0.01). The overall complication rate was 1.7%, with no significant difference between the retrieval groups (p¼0.69). Two major complications occurred following laser-assisted retrieval of OptEase filters (Cordis, Warren, NJ); patients were observed for 48 hours secondary to an inguinal hematomas. Conclusion: The use of adjunctive techniques significantly increases IVC filter retrieval rates, with minimal impact on complication rates. Adjunctive IVC filter retrieval techniques should be considered in efforts to comply with FDA recommendations.
4:15 PM
Abstract No. 131
Inferior vena cava filters: placement and retrievals - an audit M. Naeem, G.E. McEnteggart, S.H. Ahn, G.M. Soares, T. Murphy; Brown University/ Rhode Island Hospital, Providence, RI Purpose: To identify differences in the approach and practices of inferior vena cava (IVC) filter placement and retrieval procedures between two vascular specialties - interventional radiology (IR) and vascular surgery (VS). Materials and Methods: We completed a retrospective analysis of all IVC filter insertion and corresponding retrieval procedures completed by IR and VS at a University Hospital for the year 2012. The variables assessed were patient demographics, radiation dose, contrast dose, fluoroscopy time, indication for placement, duration of filter stay, and retrieval success rates. Data were analyzed using survival curves and t-test with SAS 9.4. Results: Out of 166 patients who underwent IVC filter placement in 2012, 29 were excluded due to incomplete procedure data. Of the 137 placements, 43 (31%) were retrieved
MONDAY: Scientific Sessions
Purpose: To retrospectively evaluate the safety, efficacy, and retrievability of the Option inferior vena cava (IVC) filter. Materials and Methods: All cases of patients who received an Option filter at a single healthcare system between August 2009 and August 2014 were identified, and outcomes were reviewed through the hospital electronic medical chart. Results: A total of 507 patients (262 men, 245 women) underwent filter placement (mean age at filter placement, 67.24⫾15.18 years; range, 19.48-101.69 years). A total of 357 patients had Z1 follow-up imaging study available and were included in this study. Images demonstrated no filter fractures or en bloc distant migrations. Limb penetration was seen in 41 patients with available imaging studies (abdomen CT, fluoroscopy) (21.47%; 41/191), with 106 total penetrated limbs (3 cases involving the duodenum, 3 involving the aorta, 100 involving the IVC only). Tilt 4101 was seen in 14 filters (6.7%; 14/288) among available images (abdomen CT, X-ray, fluoroscopy). Among 60 patients who returned for filter removal, 49 (81.67%) filters were successfully retrieved. Retrieval failures were attributed to endothelialization of the leg hooks into the IVC wall (n¼3), failure of filter collapse during retrieval (n¼3), filter tip embedment (n¼2), residual thrombi in the filter (n¼2), and tilt 4151 (n¼1). Breakthrough pulmonary embolism was seen in 14 cases (14/507, 2.8%). Trapped clot within the filter was seen in 16 patients with contrast-enhanced computed tomography imaging available (26.2%; 16/61). A total of 111 out of 507 patients (21.89%) patients died as a result of underlying diseases. Twelve patients (12/507, 2.4%) had recurrent deep venous thrombosis; 10 had filters in situ (1 had completely occluded IVC), and 2 underwent filter retrieval. Conclusion: Option filters were placed for both permanent and temporary indications in our institute; most filters were converted to permanent use. Rates of device-related complications, pulmonary embolism breakthrough, and successful retrieval were similar to the rates seen with other retrievable filters.
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