Stability of Retained Inferior Vena Cava Filter Fragments after Filter Removal

PurposeTo assess the stability and outcome of fractured inferior vena cava (IVC) filter fragments that are retained in patients after IVC filter removal.Materials and MethodsA retrospective analysis was conducted on all patients at a single tertiary referral center between May 2005 and June 2020 with fractured IVC filters where fragment(s) were retained after removal of the main filter body. IVC filter fragment stability was assessed by a clinician review of computed tomography images, chosen from available radiologic studies, to best visualize the fragments. Data collected included filter type, fragment location, duration of fragment follow-up, fragment stability in location, and further fragment fracture or clinical sequelae.ResultsSeventy-seven patients with retained IVC filter fragment(s) after complex filter removal were identified. Of this, 37 patients (14 men, 23 women) were deemed to have adequate imaging follow-up to assess positional stability of the retained fragments, whereas the remainder were excluded from further analysis. Excluding fractured foot processes, 51 separate filter fragments were retrospectively identified and followed for a median duration of 726 days (interquartile range, 843 days; range, 28–3353 days). Filter designs producing the studied fragments included Celect, G2, Recovery, Günther, OptEase, Meridian, and G2X/Eclipse. In all, 50 of 51 (98%) fragments were found to be unchanged in position during their respective intervals of observation. One fragment displayed a rotational change without migrating from its original location. No further fragment fractures or clinical sequelae were observed among the group.ConclusionsWhen asymptomatic, retained IVC filter fragments are predominantly stable and can be safely followed on an intermediate-term basis.     

Suprarenal Inferior Vena Cava Filter Placement and Retrieval: Safety Analysis

PurposeTo evaluate safety and retrieval success of retrievable suprarenal inferior vena cava (IVC) filters.Materials and MethodsA retrospective chart review of patients who received a retrievable suprarenal IVC filter between January 2008 and December 2017 was conducted. Suprarenal IVC filters were placed in 24 female and 27 male patients. The most common indications for filter placement were IVC thrombus (n = 20; 39.2%) and iliofemoral venous thrombosis with contraindication to anticoagulation (n = 16; 31.3%). The most common indications for suprarenal placement were IVC thrombus (n = 20; 39.2%), anatomic variants (n = 17; 33.3%), and external IVC compression (n = 8; 15.8%). Duplicated IVC was the most common anatomic variant requiring suprarenal placement (n = 7; 13.7%).ResultsGünther Tulip (n = 40; 78.4%), Denali (n = 10; 19.6%), and Celect (n = 1; 2.0%) filters were used. Retrieval was attempted in 27 of the 51 filters placed (52.9%). Of the 27 attempted retrievals, the technical success rate was 100% (27/27). The median dwell time was 87.0 days (95% confidence interval, 28–137 d). One complication involving fractured struts during filter retrieval occurred. No significant change in craniocaudal filter position, lateral filter tilt, or renal function between placement and retrieval was observed (P < .05). There were no instances of indwelling filter fracture.ConclusionsSuprarenal IVC filters, when indicated, can be placed and retrieved with a low complication rate.     

Endobronchial Forceps Retrieval of Embedded Inferior Vena Cava Filters: Retrieval of 535 Filters at a Single Center

PurposeTo report results of 16 years of using the endobronchial forceps technique to remove embedded inferior vena cava (IVC) filters.Materials and MethodsBetween January 2005 and June 2021, 534 patients (310 women and 224 men) with a mean age of 52 years (standard deviation [SD] ± 16 years) presented for complex filter retrieval of 535 tip- or strut-embedded IVC filters. Tip-embedded filters were diagnosed on rotational venography. Filters were considered strut-embedded if they were closed-cell filters with dwell times of >6 months. The filter was dissected from the IVC using rigid bronchoscopy forceps and removed through a vascular sheath.ResultsThe endobronchial forceps technique was successful in 530 of 537 retrieval attempts on an intention-to-treat basis (98.7%); a total of 530 filters were retrieved. There were 7 failures: (a) 5 failed retrieval attempts (2 that were retrieved successfully in subsequent procedures) and (b) 2 for which retrieval was not attempted. The mean filter dwell time was 1,459 days (SD ± 1,617 days). Laser sheaths were not used for any removal. Filters included herein were 137 Celect (94 Celect and 43 Celect Platinum), 99 Günther Tulip, 72 Option (48 Option and 24 Option Elite), 68 G2, 45 G2X/Eclipse, 42 Denali, 30 OptEase, 29 Recovery, 7 Meridian, and 6 ALN with Hook filters. Thirty-four minor (6.3%) and 11 major (2%) adverse events (AEs) occurred, which did not result in permanent sequelae.ConclusionsUse of endobronchial forceps for removal of tip- and strut-embedded retrievable IVC filters is effective and has low AE rates.     

Prevalence and Characterization of Interaction of Retrievable Inferior Vena Cava Filters with the Spine in Patients Undergoing Complex Filter Removal

PurposeTo examine spinal interaction types and prevalence of inferior vena cava (IVC) filters in patients presenting for complex filter removal.Materials and MethodsThe records of 447 patients presenting for complex removal of IVC filters were reviewed, including patient demographics, IVC filter dwell time, filter fracture status, and computed tomography (CT) evidence of filter interaction with the spine. Spinal interaction was defined as a filter strut touching or penetrating into the vertebral body or disc. Patients with evidence of filter penetration and spinal interaction had abdominal CT that preceded filter removal assessed by 2 interventional radiologists to categorize the type of spinal interaction, including bony reaction and osteophyte formation.ResultsCT evidence of spinal interaction by the filter was found in 18% of patients (80/447). Interaction with the spine was more common in single point of fixation filters than filters with rails (P = .007) and was more likely in filters with round wires than flat wires (P = .0007). Patients with interaction had longer dwell times (mean [SD] 5.7 [4.46] y) compared with patients without interaction (mean [SD] 3.2 [3.85] y); this relationship was significant (P < .0001). Women were more likely than men to experience filter/spine interaction (P = .04). Filters with spinal interaction were more likely to be fractured (P = .001). Filter interaction was found in 38% (30/78) of patients with symptoms, including chest and back pain, compared with 14% (50/369) of patients without symptoms (P < .0001, odds ratio 3.99).ConclusionsRetrievable IVC filters may interact with the spine. These interactions are associated with longer filter dwell times, female sex, and round wire filter construction.     

Inferior Vena Cava Filter Litigation Review: An Analysis of Medicolegal Cases Pertaining to Inferior Vena Cava Filters

PurposeTo identify and analyze all medical malpractice and product liability lawsuits pertaining to inferior vena cava (IVC) filters published within a well-recognized legal research database.Materials and MethodsLexisNexis, a legal research database, was used to retrieve cases that mentioned harm from IVC filters, or lack thereof, as the cause for legal action. A total of 672 cases were analyzed for type of case (medical malpractice or product liability), filter model implanted, filter complications, court decisions, and settlement payments if any.ResultsOf 95 analyzed cases, 20 (21.1%) were medical malpractice cases and 75 (78.9%) were product liability cases. C.R. Bard was the manufacturer associated with the most lawsuits (n = 41, 48.8%). The most litigious filters were the G2 filter from C.R. Bard (n = 17, 20.2%) and Greenfield filter from Boston Scientific (n = 17). The most common complications were IVC penetration (n = 26, 29.9%), filter migration (n = 26, 29.9%), filter fracture (n = 23, 26.4%), and tilt (n = 16, 18.4%). The number of product liability cases has increased from accounting for 25.0% (2 of 8) of filter lawsuits between 2000 and 2010 to 83.9% (73 of 87) during 2011–2020. Of the 20 medical malpractice claims, 9 (45%) were filed for failure to place a filter. One physician was found liable for filter-related complications by a state court in 2014.ConclusionsThe majority of recent IVC filter–related lawsuits are filed against manufacturers on the basis of product liability claims, with the main litigious filters being the G2 and Greenfield filters. Most cases resulted in rulings for physicians or manufacturers. Some were filed against physicians for filter-related complications or for failure to place an IVC filter.     

Fracture and Migration of Celect Inferior Vena Cava Filters: A Retrospective Review of 741 Consecutive Implantations

PurposeTo determine the incidence of fracture and migration of the Celect inferior vena cava (IVC) filter at a single tertiary-care center.Materials and MethodsImages obtained after placement of Celect IVC filters between August 2007 and January 2013 were retrospectively reviewed for evidence of device fracture and migration. The probability of filter fracture at 6 and 12 months after filter placement was estimated, and a 95% upper confidence bound was constructed.ResultsA total of 741 consecutive Celect filters were placed, and the following studies were subsequently evaluated: 301 abdominal radiographs, 282 abdominal computed tomography (CT) scans, 154 cavagrams, 19 lumbar spine radiographs, 462 chest radiographs, 108 chest CT scans, and 31 pelvic radiographs. The mean imaging follow-up interval was 5.78 months ± 8.80 (range, 0.01–56.03 mo). There was no filter fracture or en-bloc migration outside the IVC. Upper 95% confidence bounds for the probability of fracture were 1.8% at 6 months and 4.3% at 12 months. Intracaval filter migration of more than 2 cm (mean, 2.43 ± 0.12 cm; range, –2.54 to 2.99 cm) was seen in 3.9% of patients (21 of 534; 12 cranial and nine caudal).ConclusionsNo fracture of a Celect filter was observed in this large cohort over a relatively short follow-up interval. The results also suggest that the Celect filter has an adequate securing mechanism to prevent distant en-bloc or significant intracaval migration.     

Final Two-Year Outcomes for the Sentry Bioconvertible Inferior Vena Cava Filter in Patients Requiring Temporary Protection from Pulmonary Embolism

PurposeTo report final 2-year outcomes with the Sentry bioconvertible inferior vena cava (IVC) filter in patients requiring temporary protection against pulmonary embolism (PE).Materials and MethodsIn a prospective multicenter trial, the Sentry filter was implanted in 129 patients with documented deep vein thrombosis (DVT) and/or PE (67.5%) or who were at temporary risk of developing DVT/PE (32.6%). Patients were monitored and bioconversion status ascertained by radiography, computed tomography (CT), and CT venography through 2 years.ResultsThe composite primary 6-month endpoint of clinical success was achieved in 97.4% (111/114) of patients. The rate of new symptomatic PE was 0% (n = 126) through 1 year and 2.4% (n = 85) through the second year of follow-up, with 2 new nonfatal cases at 581 and 624 days that were adjudicated as not related to the procedure or device. Two patients (1.6%) developed symptomatic caval thrombosis during the first month and underwent successful interventions without recurrence. No other filter-related symptomatic complications occurred through 2 years. There was no filter tilting, migration, embolization, fracture, or caval perforation and no filter-related deaths through 2 years. Filter bioconversion was successful for 95.7% (110/115) of patients at 6 months, 96.4% (106/110) of patients at 12 months, and 96.5% (82/85) of patients at 24 months. Through 24 months of follow-up, there was no evidence of late-stage IVC obstruction or thrombosis after filter bioconversion or of thrombogenicity associated with retracted filter arms.ConclusionsThe Sentry IVC filter provided safe and effective protection against PE, with a high rate of intended bioconversion and a low rate of device-related complications, through 2 years of follow-up.     

VenaTech Convertible Vena Cava Filter 6 Months after Conversion Follow-up

PurposeTo report device-related adverse events 6 months after placement or conversion of the VenaTech convertible vena cava filter (VTCF).Materials and MethodsA review of 6-month follow-up data of an investigational device exemption multicenter, prospective, single-arm study was performed. The VTCF was implanted in 149 patients. Conversion was attempted in 64.4% of those patients (n = 96) and successfully in 96.9% of the patients (n = 93). A total of 76 patients completed imaging evaluation at 6 months after filter conversion. Patients who required continued venous thromboembolism prophylaxis at 6 months did not undergo a conversion attempt and were designated as nonconverted filter subjects. A total of 28 nonconverted filter subjects completed imaging evaluation at 6 months after implantation.ResultsEvaluation of patients at 6 months after conversion demonstrated 1 of 76 (1.3%) inferior vena cava (IVC) perforations with a filter strut greater than 3 mm outside of the caval lumen. No cases of recurrent PE, clinically significant filter migration, filter fracture, or IVC thrombosis were reported in the converted subjects. In the nonconverted filter subjects, there was a 14.3% (4 of 28) complete or nearly complete rate of IVC thromboses. There were no cases of recurrent pulmonary embolism, penetration, fracture, or spontaneous conversion in the nonconverted filter subjects. There was a significant reduction in the rate of IVC thrombosis and migration in the converted cohort compared to that in the nonconverted cohort.ConclusionsAt 6 months, the VTCF demonstrated low adverse event rates in the converted configuration, whereas a minority of patients with the nonconverted configuration demonstrated a high risk of IVC thrombosis.     

First-in-Human Study with Eight Patients Using an Absorbable Vena Cava Filter for the Prevention of Pulmonary Embolism

PurposeTo prospectively evaluate the initial human experience with an absorbable vena cava filter designed for transient protection from pulmonary embolism (PE).Materials and MethodsThis was a prospective, single-arm, first-in-human study of 8 patients with elevated risk of venous thromboembolism (VTE). Seven absorbable IVC filters (made of polydioxanone that breaks down into H₂O and CO₂ in 6 mo) were placed prophylactically before orthopedic (n = 5) and gynecologic (n = 2) surgeries, and 1 was placed in a case of deep vein thrombosis. Subjects underwent CT cavography and abdominal radiography before and 5, 11, and 36 weeks after filter placement to assess filter migration, embolization, perforation, and caval thrombosis and/or stenosis. Potential PE was assessed immediately before and 5 weeks after filter placement by pulmonary CT angiography.ResultsNo symptomatic PE was reported throughout the study or detected at the planned 5-week follow-up. No filter migration was detected based on the fixed location of the radiopaque markers (attached to the stent section of the filter) relative to the vertebral bodies. No filter embolization or caval perforation was detected, and no caval stenosis was observed. Throughout the study, no filter-related adverse events were reported.ConclusionsImplantation of an absorbable vena cava filter in a limited number of human subjects resulted in 100% clinical success. One planned deployment was aborted as a result of stenotic pelvic veins, resulting in 89% technical success. No PE or filter-related adverse events were observed.     

Complications of Celect,Günther Tulip,and Greenfield Inferior Vena Cava Filters on CT Follow-up: A Single-Institution Experience

PurposeTo evaluate and compare the rates of complications on follow-up computed tomography (CT) studies of patients with Celect, Günther Tulip, and Greenfield inferior vena cava (IVC) filters.Materials and MethodsRetrospective review of CT studies obtained 0–1,987 days after infrarenal placement of an IVC filter identified 255 Celect, 160 Tulip, and 50 Greenfield filters. Follow-up CT studies were independently evaluated by two observers for IVC perforation, contact with adjacent organs, and filter fracture. Multivariate analysis was performed to identify factors associated with higher rates of IVC perforation, including age, IVC diameter, sex, and history of malignancy.ResultsIVC perforation was observed in 126 of 255 Celect filters (49%) with a mean follow-up of 277 days, 69 of 160 Tulip filters (43%) with a mean follow-up of 437 days, and one of 50 Greenfield filters (2%) with a mean follow-up of 286 days. A significantly higher IVC perforation rate was observed in women (45.5%) compared with men (30.8%; P = .002) and in patients with a history of malignancy (43.7%) compared with patients with no history of malignancy (29.9%; P < .001). Filter fracture was rare, observed in two of 255 Celect filters (0.8%), one of 160 Tulip filters (0.6%), and none of 50 Greenfield filters.ConclusionsNo significant difference was observed in IVC perforation rate between Celect and Tulip filters. Greenfield filters had a significantly lower rate of IVC perforation than Celect and Tulip filters. Higher IVC perforation rates were observed in women and patients with a history of malignancy.     

Deep Learning for Automated Classification of Inferior Vena Cava Filter Types on Radiographs

PurposeTo demonstrate the feasibility and evaluate the performance of a deep-learning convolutional neural network (CNN) classification model for automated identification of different types of inferior vena cava (IVC) filters on radiographs.Materials and MethodsIn total, 1,375 cropped radiographic images of 14 types of IVC filters were collected from patients enrolled in a single-center IVC filter registry, with 139 images withheld as a test set and the remainder used to train and validate the classification model. Image brightness, contrast, intensity, and rotation were varied to augment the training set. A 50-layer ResNet architecture with fixed pre-trained weights was trained using a soft margin loss over 50 epochs. The final model was evaluated on the test set.ResultsThe CNN classification model achieved a F1 score of 0.97 (0.92–0.99) for the test set overall and of 1.00 for 10 of 14 individual filter types. Of the 139 test set images, 4 (2.9%) were misidentified, all mistaken for other filter types that appear highly similar. Heat maps elucidated salient features for each filter type that the model used for class prediction.ConclusionsA CNN classification model was successfully developed to identify 14 types of IVC filters on radiographs and demonstrated high performance. Further refinement and testing of the model is necessary before potential real-world application.     

Randomized Controlled Study of an Absorbable Vena Cava Filter in a Porcine Model

PurposeTo compare the safety and efficacy of an absorbable inferior vena cava (IVC) filter and a benchmark IVC filter in a porcine model.Materials and MethodsA randomized controlled Good Laboratory Practice study was performed in Domestic Yorkshire cross swine. Sixteen swine were implanted with an absorbable IVC filter (test device; Adient Medical, Pearland, Texas); 8 were implanted with a benchmark metal IVC filter (control device; Cook Medical, Bloomington, Indiana). All animals underwent rotational digital subtraction pulmonary angiography and cavography (anteroposterior and lateral) before filter deployment and 5 and 32 weeks after deployment. Terminal procedures and necropsy were performed at 32 weeks. The IVC, heart, lungs, liver, and kidneys were harvested at necropsy. The reported randomized controlled GLP animal study was conducted at Synchrony Labs, Durham, North Carolina.ResultsOne animal died early in the test cohort of a recurring hemorrhage at the femoral access site resulting from a filter placement complication. All other animals remained clinically healthy throughout the study. No pulmonary embolism was detected at the 5- and 32-week follow-up visits. The absorbable filter subjects experienced less caval wall perforation (0% vs 100%) and thrombosis (0% vs 75%). The control device routinely perforated the IVC and occasionally produced collateral trauma to adjacent tissues (psoas muscle and aorta). The veins implanted with the absorbable filter were macroscopically indistinguishable from normal adjacent veins at 32 weeks except for the presence of radiopaque markers. Nontarget tissues showed no device-related changes.ConclusionsImplantation of the absorbable IVC filter in swine proved safe with no pulmonary emboli detected. There was complete to near-complete resorption of the filter polymer by 32 weeks with restoration of the normal appearance and structure of the IVC.     

Safety and Efficacy of Peripheral Embolization with EASYX Liquid Embolic Agent: A Multicenter Prospective Study

PurposeTo evaluate the clinical safety and efficacy of EASYX, a new nonadhesive precipitating liquid embolic agent based on a polyvinyl alcohol ether polymer labeled with iodine molecules, for peripheral embolization.Materials and MethodsThis open-label prospective multicenter study was conducted on 50 consecutive patients treated with embolization using EASYX in 3 academic hospitals from April 2018 to July 2019. Indications for embolization were symptomatic varicocele (n = 15), type II endoleak (n = 8), acute hemorrhage (n = 16), portal vein embolization (PVE; n = 9), or angiomyolipoma (AML; n = 2). Patient characteristics, technical and clinical success rates, pain at injection, and satisfaction of the interventional radiologists were assessed. Follow-up imaging was performed using ultrasound for varicoceles (at 1 month) and computed tomography (CT) for the other indications (at 3 or 6 months).ResultsThe immediate technical success rate was 98%. The clinical success rates were 100% for acute hemorrhage and type II endoleaks, 89% for PVE, 86% for varicoceles, and 50% for AMLs. Patients who underwent PVE showed significant hypertrophy of the future liver remnant at follow-up (P < .001), and 55.6% of patients proceeded to hepatectomy. The absence of artifacts on imaging allowed improved monitoring of the aneurysmal sac in patients with type II endoleaks. The satisfaction rate of the interventional radiologists was >90% for 5 of 7 items.ConclusionsEASYX as a novel copolymer liquid embolic agent was safe and efficient for peripheral embolization. The absence of tantalum allowed reduced CT artifacts on imaging follow-up, which was especially useful in patients with type II endoleaks.     

Where Have All the Punctures Gone? An Analysis of Thoracic Duct Embolizations

PurposeTo determine how frequently and how severely intra-abdominal structures are affected by transabdominal thoracic duct embolization (TDE).Materials and MethodsThirty-five TDE procedures in 35 patients (22 male; mean age, 57 y; age range, 10–79 y) with therapy-refractory chylous effusions were evaluated in which radiopaque embolization material outlined the access route on postinterventional CT. CT data were analyzed by 2 TDE-experienced radiologists. Abdominal structures and organs transgressed by the access route were recorded, and findings were correlated with clinical postinterventional course with follow-up of at least 44 days.ResultsIntra-abdominal structures/organs transgressed most often by the access route were the liver (n = 28), crus of the diaphragm (n = 25), pancreas (n = 14), portal vein (n = 10), duodenum (n = 7), inferior vena cava (n = 5), colon (n = 3), left renal vein (n = 2), pleura (n = 2), pericardium (n = 2), and gastric sleeve (n = 2). Pancreatitis was observed in 1 of 14 patients after pancreatic transgression. One case of clinically occult pulmonary glue migration occurred on catheter pullback through the left renal vein. Biliary peritonitis was observed after gallbladder puncture, necessitating cholecystectomy in 1 of 2 transbiliary punctures. No other relevant procedure-related complications such as hemorrhages or infectious complications were observed.ConclusionsDespite transgression of intra-abdominal structures, puncture- and access-related complications of TDE are rare. Transpancreatic manipulations are reasonably well tolerated.     

Benchmark Status of Women Interventional Radiologists in China

PurposeTo evaluate the current status of women interventional radiologists in China and discuss possible measures to boost their representation in this male-dominated field for a more diverse workplace environment in the future.Materials and MethodsThe list of Chinese interventional radiologists obtained from the Chinese College of Interventionalists was retrospectively reviewed. Key information was extracted from the database, including sex, chronologic trends of representation of women interventional radiologists, position, education level, geographic distribution, interventional radiology (IR) practice time, departmental affiliation, and hospital classification.ResultsOf the 13,855 entries, 7,324 (52.9%) were interventional radiologists having valid information. Among them, 684 (9.3%) were identified as women. The number of women interventional radiologists has continued to increase since the first woman registered in 1992. The average age of women interventional radiologists was 39.1 years ± 5.7 (range, 26–50). The majority of them were attending physicians (n = 280; 40.9%) with a bachelor’s degree (n = 363; 53.1%). Most women interventional radiologists (n = 215, 31.4%) joined this specialty 5–9 years after becoming physicians, whereas 128 (18.7%) started practicing IR from the very beginning. A total of 42.4% of women interventional radiologists were from the departments of IR and cardiology.ConclusionsAlthough the total number shows an upward trend, women interventional radiologists are still underrepresented. Education level, geographic areas, and other socioeconomic factors may simultaneously influence the population size of women interventional radiologists in China.     

Transarterial Chemoembolization in a Woodchuck Model of Hepatocellular Carcinoma

PurposeTo assess the feasibility of transarterial chemoembolization with drug-eluting embolic (DEE) microspheres in a woodchuck model of hepatocellular carcinoma (HCC).Materials and MethodsNine woodchucks were studied: 4 normal animals and 5 animals infected with woodchuck hepatitis virus in which HCC had developed. Three animals with HCC underwent multidetector CT. A 3-F sheath was introduced into the femoral artery, and the hepatic arteries were selectively catheterized with 2.0–2.4-F microcatheters. Normal animals underwent diagnostic angiography and bland embolization. Animals with HCC underwent DEE transarterial chemoembolization with 70–150-μm radiopaque microspheres loaded with 37.5 mg doxorubicin per milliliter. Cone-beam CT and multidetector CT were performed. Following euthanasia, explanted livers underwent micro-CT, histopathologic examination, and fluorescence imaging of doxorubicin.ResultsThe tumors were hypervascular and supplied by large-caliber tortuous vessels, with arteriovenous shunts present in 2 animals. There was heterogeneous enhancement on multidetector CT with areas of necrosis. Six tumors were identified. The most common location was the right medial lobe (n = 3). Mean tumor volume was 30.7 cm³ ± 12.3. DEE chemoembolization of tumors was achieved. Excluding the 2 animals with arteriovenous shunts, the mean volume of DEE microspheres injected was 0.49 mL ± 0.17. Fluorescence imaging showed diffusion of doxorubicin from the DEE microspheres into the tumor.ConclusionsWoodchuck HCC shares imaging appearances and biologic characteristics with human HCC. Selective catheterization and DEE chemoembolization may similarly be performed. Woodchucks may be used to model interventional therapies and possibly characterize radiologic–pathologic correlations.     

Retrospective Review of 120 Celect Inferior Vena Cava Filter Retrievals: Experience at a Single Institution

PurposeTo evaluate retrospectively the safety and retrievability of the Celect IVC filter.Materials and MethodsAll patients undergoing Celect filter placement and retrieval during the period 2007–2012 were assessed for complications and retrievability.ResultsOf 620 patients who underwent Celect filter placement, 120 presented for removal. The indwelling time in these patients was 158.1 days±103.0 (range, 2–518 d). There were 106 filters (88.3%) removed; 14 filters were left in situ for the following reasons: filter embedment (n=6), caval occlusion (n=3), retained thrombus (n=2), large floating thrombus in IVC (n=2), or tilt >15° (n=1). With filters in place, five patients developed new pulmonary embolism (PE), and two others presented with severe abdominal pain. The available 115 pairs of placement and removal cavagrams suggested limb penetration in 99 cases (86.1%), intracaval migration >2 cm in 5, secondary tilt >15° in 8, filter deformity in 10, retained thrombus within filters in 12, and IVC occlusion in 3. Among 38 available computed tomography (CT) scans, 9 scans (24%) showed asymptomatic limb penetration to the duodenum (n=6), aortic wall (n=2), or kidney (n=1). No filter fracture was found.ConclusionsThis study showed a high penetration rate for Celect IVC filters, including penetrations that were symptomatic or involved adjacent structures. Penetration appears to correlate with indwelling time, suggesting that the filter should be removed as soon as PE protection is no longer indicated. Although most of the filters were removed, 5.8% of retrievals were unsuccessful because of technical failure.     

Analysis of Costs and Payments for Inferior Vena Cava Filter Retrieval in the Medicare Population

Over the past decade, inferior vena cava (IVC) filter retrieval has been increasing, in part due to Food and Drug Administration recommendations and legal pressure. The costs and margin of IVC filter removal are poorly understood. Medicare claims data from 2016 for the 103 highest volume centers for IVC filter retrieval were examined. Pooled mean charges, costs, payments, and margin were calculated by institution. Mean ± SD charges, costs, and payments were $14,138.00 ± $8,400.48, $3,693.28 ± $2,294.27, and $1,949.82 ± $702.91, respectively. Average (range) margin was −$1,706.18 (−$7,509.93 to $362.77). The margin was negative in 99 of the 103 (96%) institutions evaluated. The most significant contributors to the total procedure cost were operating room, supplies, and recovery (44.5%, 23.5%, and 10.4%, respectively). While IVC filter retrieval is often medically indicated, it is typically associated with a financial loss under current reimbursement structure.     

Fully Integrated Laser Guidance for CT-Based Punctures: A Study in Phantoms and Patients

PurposeTo test the hypothesis of equal or even superior applicability and accuracy of a fully integrated, laser-based computed tomography (CT) navigation system compared with conventional CT guidance for percutaneous interventions.Materials and MethodsCT-guided punctures were first performed in phantoms. Four radiologists with different experience levels (2 residents (L.B., C.D.) and 2 board-certified radiologists (B.M., K.R.) performed 48 punctures using both conventional image-guided and laser-guided approaches. Subsequently, 12 punctures were performed in patients during a clinical pilot trial. Phantom targets required an in-plane or a single-/double-angulated, out-of-plane approach. Planning and intervention time, control scan number, radiation exposure, and accuracy of needle placement (measured by deviation of the needle tip to the designated target) were assessed for each guidance technique and compared (Mann-Whitney U test and t test). Patient interventions were additionally analyzed for applicability in a clinical setting.ResultsThe application of laser guidance software in the phantom study and in 12 human patients in a clinical setting was both technically and clinically feasible in all cases. The mean planning time (P = .009), intervention time (P = .005), control scan number (P < .001), and radiation exposure (P = .013) significantly decreased for laser-navigated punctures compared with those for conventional CT guidance and especially in punctures with out-of-plane-trajectories. The accuracy significantly increased for laser-guided interventions compared with that for conventional CT (P < .001).ConclusionsInterventional radiologists with differing levels of experience performed faster and more accurate punctures for out-of-plane trajectories in the phantom models, using a new, fully integrated, laser-guided CT software and demonstrated excellent clinical and technical success in initial clinical experiments.     

Intranodal Lymphangiography and Embolization for the Treatment of Early Postoperative Lymphatic Leaks after Pelvic Surgery

PurposeTo assess outcome and predictors of outcome after lymphatic embolization (LE) for early postoperative lymphatic leak after pelvic surgery.Material and MethodsLymphangiography (LG) procedures performed between May 2015 and February 2020 for postoperative intraperitoneal lymphatic leaks after pelvic surgery were reviewed. Treatment indication was lymphatic drainage of >500 mL/d persisting for >1 week. LE was performed by injecting glue into the iliac lymph node. Fisher exact and Wilcoxon rank-sum tests were used for comparative analysis, and logistic regression was used to assess predictors of outcome.ResultsLG was performed in 71 patients. A leak was demonstrated in 69 patients who underwent LE. The mean drainage was 1,329 mL/d ± 773. Catheters were removed in 49 (69.0%) patients after 1 procedure and in 69 (97.2%) patients after a mean of 1.3 procedures. The mean drainage at the time of catheter removal was 157 mL/d ± 100. Failure occurred in 12 (16.9%) cases, including 2 (2.8%) cases of unsuccessful catheter removal and 10 (14.1%) cases of catheter reinsertion owing to recurrent ascites (n = 3) and lymphoceles (n = 7). Older age and drainage of >1,500 mL/d were associated with failure (P = .004). Drainage of >1,500 mL/d was associated with a post-LE catheter dwell time of longer than 1 week (P = .024). Minor adverse events were noted in 4 (5.6%) patients who presented with transient leg swelling.ConclusionsLE was effective for treating pelvic surgery-related lymphatic leaks. Reintervention may be required. Drainage of >1,500 mL/d was associated with clinical failure and a post-LE catheter dwell time of longer than 1 week.