Final 3-Year Study Outcomes from the Evaluation of the Zilver Vena Venous Stent for the Treatment of Symptomatic Iliofemoral Venous Outflow Obstruction (VIVO Clinical Study)

PURPOSE

To report 3-year outcomes from a prospective, multicenter, nonrandomized, single-arm study designed to assess the safety and effectiveness of the Zilver Vena Venous Stent for the treatment of symptomatic iliofemoral venous outflow obstruction.

MATERIALS AND METHODS

The VIVO study included patients with symptomatic obstruction of 1 iliofemoral venous segment (ie, 1 limb), characterized by a Clinical, Etiological, Anatomic, Pathophysiology (CEAP) clinical classification of ≥3 or a Venous Clinical Severity Score (VCSS) for pain of ≥2. Patients were retrospectively grouped based on baseline clinical presentation as postthrombotic syndrome (PTS), nonthrombotic iliac vein (NIVL) obstruction, or acute deep vein thrombosis (aDVT). Clinical improvement was assessed by change in VCSS, Venous Disability Score, Chronic Venous Disease Quality of Life Questionnaire (CIVIQ-20) scores, and CEAP C classification. Stent performance was evaluated by rates of patency by ultrasound (US), freedom from clinically driven reintervention, and freedom from stent fracture.

RESULTS

The 3-year results for the 243 patients in the VIVO cohort included a 90.3% rate of patency by US and a 92.6% rate of freedom from clinically driven reintervention. The 3-year rates of patency by US for the NIVL, aDVT, and PTS groups were 100%, 84.0%, and 86.1%, respectively. Sustained clinical improvement through 3 years was demonstrated by changes in VCSS, Venous Disability Score, CIVIQ-20, and CEAP C classification. No stent fractures were observed.

CONCLUSIONS

The VIVO study demonstrated sustained high rates of patency and freedom from clinically driven reintervention and improvements in venous clinical symptoms through 3 years. Each patient group (NIVL, aDVT, and PTS) showed clinical improvement and sustained patency through 3 years; some variation existed among groups (eg, only the NIVL group had a 100% patency rate).

Editor's Choice - Management of Lower Extremity Venous Outflow Obstruction: Results of an International Delphi Consensus

OBJECTIVE

The endovascular treatment of venous obstruction has expanded significantly in recent years. Best practices for optimal patient outcomes are not well established and the evidence base is poor. The purpose of this study was to obtain consensus on management criteria for patients with lower extremity venous outflow obstruction.

METHODS

The study was conducted as a two round Delphi consensus. Statements addressed imaging, symptoms and other baseline measures, differential diagnosis, treatment algorithm, indications for stenting, inflow and outflow assessment, successful procedural outcomes, post-procedure therapies and stent surveillance, and clinical success factors. Statements were prepared by six expert physicians (round 1, 40 statements) and an expanded panel of 24 physicians (round 2, 80 statements) and sent to a pre-identified group of venous experts who met qualifying criteria. A 9 point Likert scale was used and consensus was defined as ≥ 70% of respondents rating a statement between 7 and 9 (agreement) or between 1 and 3 (disagreement). Round 1 results were used to guide rewording and splitting compound statements for greater clarity in round 2.

RESULTS

In round 1, 75 of 110 (68%) experts responded, and 91 of 121 (75%) experts responded in round 2. Round 1 achieved consensus in 32/40 (80%) statements. Consensus was not reached in the treatment algorithm section. Round 2 achieved consensus in 50/80 (62.5%). Statements reaching consensus were imaging (2/3, 66%), symptoms and other baseline measures (12/24, 50%), differential diagnosis (2/8, 25%), treatment algorithm (10/17, 59%), indications for stenting (10/10, 100%), inflow and outflow assessment (2/2, 100%), procedural outcomes (2/2, 100%), post-procedure therapies and stent surveillance, (5/7, 71%), and clinical success factors (5/7, 71%).

CONCLUSION

This study demonstrated that considerable consensus was achieved between venous experts on the optimal management of lower extremity venous outflow obstruction. There were multiple domains where consensus is lacking, highlighting important areas for further investigation and research.

Current State of Private Practice and Academic Interventional Radiology: Differences in Practice Structure, Case Mix, and Productivity

PURPOSE

To investigate whether private practice interventional radiology (IR) groups self-report higher overall productivity given differing case mix and more diagnostic radiology interpretation.

MATERIALS AND METHODS

A 60-question survey was distributed to 3,159 self-identified US IR physicians via the Society of Interventional Radiologists member search engine, with 357 responses (11.3% response rate). Of these responses, there were 258 unique practices from 34 US states.

RESULTS

Out of 84 IR group responses, private practice IR (PPIR) physicians reported a minimal trend for higher annual work relative value units (wRVUs) per clinical full-time equivalent compared with academic IR physicians (8,000 versus 7,140, P = .202), but this did not reach statistical significance. PPIR groups reported fewer median weekly hours (50 versus 52), more frequent call (every 6 versus every 5 days), and significantly higher median tenured compensation ($573,000 versus $451,000, P = .000). Out of 179 responses, academic practices reported significantly higher case percentages of interventional oncology and complex hepatobiliary intervention (P <.001), and private practices reported significantly higher percentages of musculoskeletal intervention (P < .001) with a nonsignificant trend for stroke or neurologic intervention (P = .010). Private practices reported more wRVUs from the interpretation of diagnostic imaging, at 26% of total wRVU production compared with 7% of total wRVU production for academic practices (P < .001; n = 131).

CONCLUSIONS

Self-reported data from private and academic IR groups suggest minimally higher wRVUs per clinical full-time equivalent among PPIRs with lower weekly work hours, more frequent call, differing case mix, and significantly higher tenured compensation among PPIR groups.

Reimagining the IR Workflow for a Better Work-Life Balance

Several workflow changes were implemented in a large academic interventional radiology practice, including separation of inpatient and outpatient services, early start times, and using an adaptive learning system to predict case length tailored to individual physicians. Metrics including procedural volume, on-time start, accuracy at predicting case length, and room shutdown time were assessed before and after the intervention. Considerable improvements were seen in accuracy of first case start times, predicting block times, and last case encounter ending times. It is proposed that with improved role clarity, interventional radiologists can regain control over their schedules, utilize work hours more efficiently, and improve work-life balance.

Optimal Medical Therapy Following Deep Venous Interventions: Proceedings from the Society of Interventional Radiology Foundation Research Consensus Panel

The optimal medical management of patients following endovascular deep venous interventions remains ill-defined. As such, the Society of Interventional Radiology Foundation (SIRF) convened a multidisciplinary group of experts in a virtual Research Consensus Panel (RCP) to develop a prioritized research agenda regarding antithrombotic therapy following deep venous interventions. The panelists presented the gaps in knowledge followed by discussion and ranking of research priorities based on clinical relevance, overall impact, and technical feasibility. The following research topics were identified as high priority: 1) characterization of biological processes leading to in-stent stenosis/rethrombosis; 2) identification and validation of methods to assess venous flow dynamics and their effect on stent failure; 3) elucidation of the role of inflammation and anti-inflammatory therapies; and 4) clinical studies to compare antithrombotic strategies and improve venous outcome assessment. Collaborative, multicenter research is necessary to answer these questions and thereby enhance the care of patients with venous disease.

Comparison of Anticoagulation Regimens Following Stent Placement for Nonthrombotic Lower Extremity Venous Disease

PURPOSE

To determine whether subtherapeutic anticoagulation regimens are noninferior to therapeutic anticoagulation regimens following stent placement for nonthrombotic lower extremity venous disease.

MATERIALS AND METHODS

Fifty-one consecutive patients (88% women; mean age, 44 years) who underwent stent placement for nonthrombotic lower extremity venous disease between 2002 and 2016 were retrospectively identified. The patients were divided into 2 cohorts: those who received prophylactic enoxaparin or no anticoagulation (subtherapeutic) after the procedure and those who received therapeutic doses of anticoagulation with enoxaparin, warfarin, and/or rivaroxaban (therapeutic) after the procedure. Baseline demographic characteristics, procedure characteristics, and outcomes were compared between the 2 groups using the Student t test, Fisher exact test, and χ² test. The subtherapeutic and therapeutic anticoagulation groups did not differ significantly in the baseline demographic characteristics (eg, sex, race, and age) or procedure characteristics (eg, number of stents placed, stent brand, stent diameter, etc).

RESULTS

The mean clinical follow-up time was 4.4 years (range, 0-16.3 years). There were no thrombotic adverse events or luminal obstructions due to in-stent restenosis in either group. There were 5 minor bleeding adverse effects in the therapeutic group and no bleeding adverse effects in the subtherapeutic group (P = .051). There were no statistically significant differences in subjective symptom improvement (P = .75).

CONCLUSIONS

In this retrospective cohort, the subtherapeutic and therapeutic anticoagulation regimens produced equivalent outcomes in terms of adverse event rates, reintervention rates, and symptomatic improvement, suggesting that therapeutic doses of anticoagulation do not improve outcomes compared with subtherapeutic anticoagulation regimens following nonthrombotic venous stent placement.

Laser-Assisted Removal of Embedded Vena Cava Filters: A First-In-Human Escalation Trial in 500 Patients Refractory to High-Force Retrieval

Background

Many patients are subject to potential risks and filter‐related morbidity when standard retrieval methods fail. We evaluated the safety and efficacy of the laser sheath technique for removing embedded inferior vena cava filters.

Methods and Results

Over an 8.5‐year period, 500 patients were prospectively enrolled in an institutional review board–approved study. There were 225 men and 275 women (mean age, 49 years; range, 15–90 years). Indications for retrieval included symptomatic acute inferior vena cava thrombosis, chronic inferior vena cava occlusion, and/or pain from filter penetration. Retrieval was also offered to prevent risks from prolonged implantation and potentially to eliminate need for lifelong anticoagulation. After retrieval failed using 3X standard retrieval force (6–7 lb via digital gauge), treatment escalation was attempted using laser sheath powered by 308‐nm XeCl excimer laser system (CVX‐300; Spectranetics). We hypothesized that the laser‐assisted technique would allow retrieval of >95% of embedded filters with <5% risk of major complications and with lower force. Primary outcome was successful retrieval. Primary safety outcome was any major procedure‐related complication. Laser‐assisted retrieval was successful in 99.4% of cases (497/500) (95% CI, 98.3%–99.9%) and significantly >95% (P<0.0001). The mean filter dwell time was 1528 days (range, 37–10 047; >27.5 years]), among retrievable‐type (n=414) and permanent‐type (n=86) filters. The average force during failed attempts without laser was 6.4 versus 3.6 lb during laser‐assisted retrievals (P<0.0001). The major complication rate was 2.0% (10/500) (95% CI, 1.0%–3.6%), significantly <5% (P<0.0005), 0.6% (3/500) (95% CI, 0%–1.3%) from laser, and all were successfully treated. Successful retrieval allowed cessation of anticoagulation in 98.7% (77/78) (95% CI, 93.1%–100.0%) and alleviated filter‐related morbidity in 98.5% (138/140) (95% CI, 96.5%–100.0%).

Conclusions

The excimer laser sheath technique is safe and effective for removing embedded inferior vena cava filters refractory to high‐force retrieval. This technique may allow cessation of filter‐related anticoagulation and can be used to prevent and alleviate filter‐related morbidity.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01158482.

Analysis of patent, unstented lower extremity vein segment diameters in 266 patients with venous disease

OBJECTIVE

The objective of this study was to characterize the average maximum diameters of widely patent lower extremity vein segments in patients with underlying venous disease and the demographic factors that affect these diameters.

METHODS

Maximum axial diameters of each deep vein segment from the diaphragm to the knee were measured from computed tomography venography studies for all patients who underwent venous stent placement during a 20-year period at a single quaternary venous referral institution. Limbs containing only widely patent, unstented vein segments without variant anatomy were identified for inclusion. The final analysis involved diameter measurements from 870 imaging studies of 266 patients. Multivariate linear regression was used to identify factors associated with vein segment diameters.

RESULTS

Average vein segment diameters ranged from 7.8 mm for the left and right femoral veins to 27.9 mm for the long axis of the suprarenal inferior vena cava. Multivariate linear regression demonstrated that women had larger IVC, common iliac vein, and external iliac vein diameters, whereas men had larger common femoral veins. Laterality, height, weight, and sex also had statistically significant associations with the diameters of select vein segments.

CONCLUSIONS

This study provides an estimate of the average diameters of widely patent deep vein segments in the lower extremities from the diaphragm to the knees in patients with underlying venous disease and characterizes covariates that significantly affect vein diameter. These findings may help interventionalists better select devices for endovascular intervention.

Bronchial Artery Embolization for Hemoptysis in Cystic Fibrosis Patients: A 17-Year Review

PURPOSE

To review safety and efficacy of bronchial artery embolization (BAE) for treatment of hemoptysis in adult patients with cystic fibrosis (CF) and to report 30-day, 1-year, and 3-year outcomes.

MATERIALS AND METHODS

Between January 2001 and April 2018, 242 patients with CF were evaluated for hemoptysis. Thirty-eight BAEs were performed in 28 patients with hemoptysis. Technical success was defined as freedom from repeat embolization and hemoptysis-related mortality. Clinical success was defined as freedom from repeat embolization and mortality from any cause. Technical and clinical success were examined at 30 days, 1 year, and 3 years after initial BAE. Mean patient age was 32 years, and median follow-up was 4.8 years (range, 10 mo to 16.7 y).

RESULTS

Technical and clinical success rates at 30 days were 89% (25/28) and 82% (23/28), respectively. Success rates at 1 year were 86% (24/28) and 79% (22/28), respectively, and at 3 years were 82% (23/28) and 75% (21/28), respectively. The 30-day overall complication rate was 7.9% (3/38) with 2.6% (1/38) major complication rate and 5.2% (2/38) minor complication rate. Overall 3-year mortality rate was 25% (7/28).

CONCLUSIONS

BAE is safe and effective in patients with CF presenting with life-threatening hemoptysis. BAE results in high rates of long-term technical and clinical success in this patient population despite progressive chronic disease. Repeat embolization is necessary only in a minority of patients.

Endovascular Thrombus Removal for Acute Iliofemoral Deep Vein Thrombosis

BACKGROUND

The ATTRACT trial (Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis) previously reported that pharmacomechanical catheter-directed thrombolysis (PCDT) did not prevent postthrombotic syndrome (PTS) in patients with acute proximal deep vein thrombosis. In the current analysis, we examine the effect of PCDT in ATTRACT patients with iliofemoral deep vein thrombosis.

METHODS

Within a large multicenter randomized trial, 391 patients with acute deep vein thrombosis involving the iliac or common femoral veins were randomized to PCDT with anticoagulation versus anticoagulation alone (No-PCDT) and were followed for 24 months to compare short-term and long-term outcomes.

RESULTS

Between 6 and 24 months, there was no difference in the occurrence of PTS (Villalta scale ≥5 or ulcer: 49% PCDT versus 51% No-PCDT; risk ratio, 0.95; 95% CI, 0.78-1.15; P=0.59). PCDT led to reduced PTS severity as shown by lower mean Villalta and Venous Clinical Severity Scores ( P<0.01 for comparisons at 6, 12, 18, and 24 months), and fewer patients with moderate-or-severe PTS (Villalta scale ≥10 or ulcer: 18% versus 28%; risk ratio, 0.65; 95% CI, 0.45-0.94; P=0.021) or severe PTS (Villalta scale ≥15 or ulcer: 8.7% versus 15%; risk ratio, 0.57; 95% CI, 0.32-1.01; P=0.048; and Venous Clinical Severity Score ≥8: 6.6% versus 14%; risk ratio, 0.46; 95% CI, 0.24-0.87; P=0.013). From baseline, PCDT led to greater reduction in leg pain and swelling ( P<0.01 for comparisons at 10 and 30 days) and greater improvement in venous disease-specific quality of life (Venous Insufficiency Epidemiological and Economic Study Quality of Life unit difference 5.6 through 24 months, P=0.029), but no difference in generic quality of life ( P>0.2 for comparisons of SF-36 mental and physical component summary scores through 24 months). In patients having PCDT versus No-PCDT, major bleeding within 10 days occurred in 1.5% versus 0.5% ( P=0.32), and recurrent venous thromboembolism over 24 months was observed in 13% versus 9.2% ( P=0.21).

CONCLUSIONS

In patients with acute iliofemoral deep vein thrombosis, PCDT did not influence the occurrence of PTS or recurrent venous thromboembolism. However, PCDT significantly reduced early leg symptoms and, over 24 months, reduced PTS severity scores, reduced the proportion of patients who developed moderate-or-severe PTS, and resulted in greater improvement in venous disease-specific quality of life.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT00790335.

Inferior Vena Cava Atresia: Characterisation of Risk Factors, Treatment, and Outcomes

PURPOSE

To characterise (1) the risk factors associated with inferior vena cava (IVC) atresia, (2) the radiographic and clinical presentations of deep vein thrombosis (DVT) in patients with IVC atresia, and (3) the treatment and outcome of DVT in patients with IVC atresia.

METHODS

The electronic medical record was systematically reviewed for thrombotic risk factors in patients who presented with lower-extremity DVT (n = 409) at a single centre between 1996 and 2017. Patients with IVC atresia were identified based on imaging and chart review. Differences in demographics and thrombotic risk factors between patients with and without IVC atresia were statistically assessed. Extent and chronicity of DVT on imaging, clinical presentation, treatment, and outcomes were evaluated for all patients with IVC atresia.

RESULTS

4.2% of DVT patients (17/409) were found to have IVC atresia; mean age at diagnosis was 25.5 ± 9.4 years. The rate of heritable thrombophilia was significantly higher in patients with IVC atresia compared to patients without IVC atresia (52.9% vs. 17.9%, p < 0.0001). There were bilateral DVT in 70.6% of IVC atresia patients; DVT was chronic in 41.2% and acute on chronic in 58.8%. Pre-intervention Villalta scores were 13.9 ± 9.8 in the left limb and 8.5 ± 7.0 in the right limb. DVT in IVC atresia patients was typically treated with catheter-directed thrombolysis followed by stent placement, achieving complete or partial symptom resolution in 78.6% of cases.

CONCLUSION

Thrombotic risk factors such as heritable thrombophilia are associated with IVC atresia. IVC atresia patients can experience high burdens of lower-extremity thrombotic disease at a young age which benefit from endovascular treatment.

LEVEL OF EVIDENCE

Level 4.

Toward Data-Driven Learning Healthcare Systems in Interventional Radiology: Implementation to Evaluate Venous Stent Patency

We developed a code and data-driven system (learning healthcare system) for gleaning actionable clinical insight from interventional radiology (IR) data. To this end, we constructed a workflow for the collection, processing and analysis of electronic health record (EHR), imaging, and cancer registry data for a cohort of interventional radiology patients seen in the IR Clinic at our institution over a more than 20-year period. As part of this pipeline, we created a database in REDCap (VITAL) to store raw data, as collected by a team of clinical investigators and the Data Coordinating Center at our university. We developed a single, universal pre-processing codebank for our VITAL data in R; in addition, we also wrote widely extendable and easily modifiable analysis code in R that presents results from summary statistics, statistical tests, visualizations, Kaplan-Meier analyses, and Cox proportional hazard modeling, among other analysis techniques. We present our findings for a test case of supra versus infra-inguinal ligament stenting. The developed pre-processing and analysis pipelines were memory and speed-efficient, with both pipelines running in less than 2 min. Three different supra-inguinal ligament veins had a statistically significant improvement in vein diameters post-stenting versus pre-stenting, while no infra-inguinal ligament veins had a statistically significant improvement (due either to an insufficient sample size or a non-significant p value). However, infra-inguinal ligament stenting was not associated with worse restenosis or patency outcomes in either a univariate (summary-statistics and Kaplan-Meier based) or multivariate (Cox proportional hazard model based) analysis.

Automated Quantitative Imaging Measurements of Disease Severity in Patients with Nonthrombotic Iliac Vein Compression

PURPOSE

An automated segmentation technique (AST) for computed tomography (CT) venography was developed to quantify measures of disease severity before and after stent placement in patients with left-sided nonthrombotic iliac vein compression.

MATERIALS AND METHODS

Twenty-one patients with left-sided nonthrombotic iliac vein compression who underwent venous stent placement were retrospectively identified. Pre- and poststent CT venography studies were quantitatively analyzed using an AST to determine leg volume, skin thickness, and water content of fat. These measures were compared between diseased and nondiseased limbs and between pre- and poststent images, using patients as their own controls. Additionally, patients with and without postthrombotic lesions were compared.

RESULTS

The AST detected significantly increased leg volume (12,437 cm³ vs 10,748 cm³, P < .0001), skin thickness (0.531 cm vs 0.508 cm, P < .0001), and water content of fat (8.2% vs 5.0%, P < .0001) in diseased left limbs compared with the contralateral nondiseased limbs, on prestent imaging. After stent placement in the left leg, there was a significant decrease in the water content of fat in the right (4.9% vs 2.7%, P < .0001) and left (8.2% vs 3.2%, P < .0001) legs. There were no significant changes in leg volume or skin thickness in either leg after stent placement. There were no significant differences between patients with or without postthrombotic lesions in their poststent improvement across the 3 measures of disease severity.

CONCLUSIONS

ASTs can be used to quantify measures of disease severity and postintervention changes on CT venography for patients with lower extremity venous disease. Further investigation may clarify the clinical benefit of such technologies.

Electronic Patient-Reported Outcomes: Semi-Automated Data Collection in the Interventional Radiology Clinic

INTRODUCTION

Patient-reported outcomes are important for clinical research and will likely be used in the near future as a metric for physician reimbursement. This study aims to evaluate the implementation of an electronic data collection system for deep vein thrombosis and lymphedema quality-of-life (QOL) questionnaires in a tertiary care interventional radiology practice.

METHODS

A single provider's clinic patients were automatically e-mailed validated questionnaires 1 week before their appointments. If not completed via e-mail, the questionnaire was administered on an electronic tablet in clinic by a research coordinator. Patients were also sent postprocedure questionnaires.

RESULTS

In all, 106 patients visited the clinic for a pre-intervention venous consultation. Of them, 96% (n = 102 of 106) completed the pre-intervention questionnaire: 48% (n = 47 of 98) via e-mail and 52% (n = 51 of 98) via tablet. Of the patients who had procedures and were sent questionnaires, 49% (n = 26 of 53) were seen in person. Of the postprocedure in-person clinic patients, 76% (n = 20 of 26) completed the questionnaire via e-mail, and the remainder with the tablet in clinic. Twenty-seven of the 53 (51%) patients did not return for follow-up and instead were sent an electronic questionnaire as their only source of follow-up, of which 74% (n = 20 of 27) complied.

CONCLUSION

After an initial introduction to electronic QOL reporting, patients were more likely to complete the questionnaires remotely for their follow-up appointment. A semi-automated electronic QOL system allows physicians to collect patient outcome data even in the absence of a clinic visit.

Venous disease patient registries available in the United States

Patient registries are beneficial in that they allow the collection of prospective data focused on a specific medical issue. These registries give providers a "real-world" view of patient outcomes. Many medical disciplines have a long history of developing and using patient registries; the first patient registry for chronic venous disease in the United States was launched in 2011, fairly recently in comparison. Registries included in this review were identified by surveying members of major academic societies that focus on the care of chronic venous disease and by searching MEDLINE and Embase databases using Ovid interface. Medical directors of four of the five databases available in the United States completed a standard questionnaire, and the answers served as the basis for this review. This review is not a comparison of registries; it does, however, describe the common and unique features of four venous registries currently available in the United States with the purpose of increasing awareness of and fostering participation in these registries.

Endovascular Management of May-Thurner Syndrome in Adolescents: A Single-Center Experience

PURPOSE

To report a single-center experience in regard to the technique, safety, and clinical outcomes of endovascular therapy for treatment of May-Thurner syndrome (MTS) in adolescent patients.

MATERIALS AND METHODS

A retrospective review identified 10 patients (6 female; mean age, 16 y; range, 12-18 y; mean weight, 73 kg; range, 50-116 kg) treated by endovascular therapy for MTS from 1998 to 2015. Clinical presentations consisted of acute thrombotic MTS (n = 6) and nonthrombotic MTS (n = 4). Catheter-directed thrombolysis was performed in all cases of thrombosis. Venoplasty and stent placement were performed in all cases. Self-expanding stents 12-16 mm in diameter and 4-9 cm in length were deployed.

RESULTS

No major periprocedural complications were observed. Median follow-up was 32 months (range, 6-109 mo). Primary and secondary patency rates were 79% and 100% at 12 months and 79% and 89% at 36 months, respectively. In a single patient with permanent loss of flow in the treated segment, multiple risk factors for thrombosis were identified. Rates of posttreatment symptoms were 0% by Villalta score and 60% (n = 6; mild symptoms) by modified Villalta score at the last clinical follow-up.

CONCLUSIONS

Endovascular therapy for the treatment of MTS in our adolescent cohort was safe and effective in relieving venous obstruction. Stent placement in patients with underlying thrombophilic disorders is associated with loss of secondary patency, suggesting the need for further consideration in this population.

Assessing the Risk of Hemorrhagic Complication following Transjugular Liver Biopsy in Bone Marrow Transplantation Recipients

PURPOSE

To determine if recipients of bone marrow transplants (BMTs) are at increased risk of hemorrhagic complications following transjugular liver biopsy (TJLB).

MATERIALS AND METHODS

TJLBs in BMT and non-BMT patients between January 2007 and July 2014 were reviewed. Patient demographic and pre- and postprocedural laboratory data were reviewed. Mean platelet count and International Normalized Ratio were 174,300 × 10(3)/µL ± 107.3 (standard deviation) and 1.2 ± 0.4, respectively, for BMT recipients, compared with 88,100 × 10(3)/µL ± 70.9 and 1.2 ± 0.5, respectively, for non-BMT. Patients in whom hemoglobin level decreased by > 1 g/dL and/or required transfusion within 15 days of TJLB were reviewed to determine the presence of a biopsy-related hemorrhagic complication.

RESULTS

A total of 1,600 TJLBs in 1,120 patients were analyzed. Of these, 183 TJLBs in 159 BMT recipients and 1,417 TJLBs in 961 patients non-BMT patients were performed. Thirteen TJLBs were complicated by hemorrhage: five in BMT (2.9%) and eight in the non-BMT cohorts (0.6%; P < .01). Preprocedural platelet counts were within normal range (57-268 × 10(3)/µL) in all but one patient (8 × 10(3)/µL). BMT recipients had an odds ratio of 4.9 (95% confidence interval, 1.25-17.3) for post-TJLB bleeding/hemorrhage compared with those without BMTs (P < .01).

CONCLUSIONS

TJLB continues to be a safe procedure in the vast majority of patients. However, hemorrhagic complications occurred at a rate of 2.9% in BMT recipients, compared with 0.6% in patients without BMTs, and therefore caution should be exercised when performing TJLB in this group.

Novel protocol including liver biopsy to identify and treat CD8+ T-cell predominant acute hepatitis and liver failure

In the majority of children with ALF, the etiology is unknown and liver transplantation is often needed for survival. A patient case prompted us to consider that immune dysregulation may be the cause of indeterminate acute hepatitis and liver failure in children. Our study includes nine pediatric patients treated under a multidisciplinary clinical protocol to identify and treat immune-mediated acute liver injury. Patients with evidence of inflammation and no active infection on biopsy received treatment with intravenous immune globulin and methylprednisolone. Seven patients had at least one positive immune marker before or after treatment. All patients had a CD8+ T-cell predominant liver injury that completely or partially responded to immune therapy. Five of the nine patients recovered liver function and did not require liver transplantation. Three of these patients subsequently developed bone marrow failure and were treated with either immunosuppression or stem cell transplant. This series highlights the importance of this tissue-based approach to diagnosis and treatment that may improve transplant-free survival. Further research is necessary to better characterize the immune injury and to predict the subset of patients at risk for bone marrow failure who may benefit from earlier and stronger immunosuppressive therapy.

Excimer Laser–Assisted Removal of Embedded Inferior Vena Cava Filters

Background—

Although chronically implanted inferior vena cava filters may result in filter-related morbidity, there is currently no routine option for removing such filters when they become firmly embedded along the vena cava endothelium.

Methods and Results—

During a 3-year period, 100 consecutive patients were prospectively enrolled in a single-center study. There were 42 men and 58 women (mean age, 46 years; limits, 18–76 years). Retrieval indications included filter-related acute inferior vena cava thrombosis, chronic inferior vena cava occlusion, and pain from retroperitoneal or bowel penetration. Filter retrieval was also performed to prevent risks from prolonged implantation and to potentially eliminate the need for lifelong anticoagulation. After standard methods failed, photothermal tissue ablation was attempted with a laser sheath powered by a 308-nm xenon chloride excimer laser. Applied forces were recorded with a digital tension meter before and during laser activation. Laser-assisted retrieval was successful in 98.0% (95% confidence interval [CI], 93.0%–99.8%) with mean implantation of 855 days (limits, 37–6663 days; >18 years). The following filter types were encountered in this study: Günther-Tulip (n=34), Celect (n=12), Option (n=17), Optease (n=20, 1 failure), TrapEase (n=6, 1 failure), Simon-Nitinol (n=1), 12F Stainless Steel Greenfield (n=4), and Titanium Greenfield (n=6). The average force during failed standard retrievals was 7.2 versus 4.6 pounds during laser-assisted retrievals ( P <0.0001). The major complication rate was 3.0% (95% CI, 0.6%–8.5%), the minor complication rate was 7.0% (95% CI, 0.3%–13.9%), and there were 4 adverse events (2 coagulopathic hemorrhages, 1 renal infarction, and 1 cholecystitis; 4.0%; 95% CI, 1.1%–9.9%) at mean follow-up of 500 days (limits, 84–1079 days). Scar tissue ablation was histologically confirmed in 96.0% (95% CI, 89.9%–98.9%). Successful retrieval allowed cessation of anticoagulation in 30 of 30 (100%) patients and alleviated morbidity in 23 of 24 patients (96%).

Conclusions—

Excimer laser–assisted removal is effective in removing embedded inferior vena cava filters refractory to standard retrieval and high force. This method can be safely used to prevent and alleviate filter-related morbidity.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01158482.

MicroRNA-regulated non-viral vectors with improved tumor specificity in an orthotopic rat model of hepatocellular carcinoma

In hepatocellular carcinoma (HCC), tumor specificity of gene therapy is of utmost importance to preserve liver function. MicroRNAs (miRNAs) are powerful negative regulators of gene expression and many are downregulated in human HCC. We identified seven miRNAs that are also downregulated in tumors in a rat hepatoma model (P<0.05) and attempted to improve tumor specificity by constructing a panel of luciferase-expressing vectors containing binding sites for these miRNAs. Attenuation of luciferase expression by the corresponding miRNAs was confirmed across various cell lines and in mouse liver. We then tested our vectors in tumor-bearing rats and identified two miRNAs, miR-26a and miR-122, that significantly decreased expression in liver compared with the control vector (6.40 and 0.26%, respectively; P<0.05). In tumor, miR-122 had a nonsignificant trend towards decreased (∼50%) expression, whereas miR-26 had no significant effect on tumor expression. To our knowledge, this is the first work using differentially expressed miRNAs to de-target transgene expression in an orthotopic hepatoma model and to identify miR-26a, in addition to miR-122, for de-targeting liver. Considering the heterogeneity of miRNA expression in human HCC, this information will be important in guiding development of more personalized vectors for the treatment of this devastating disease.

X-ray-visible microcapsules containing mesenchymal stem cells improve hind limb perfusion in a rabbit model of peripheral arterial disease

The therapeutic goal in peripheral arterial disease (PAD) patients is to restore blood flow to ischemic tissue. Stem cell transplantation offers a new avenue to enhance arteriogenesis and angiogenesis. Two major problems with cell therapies are poor cell survival and the lack of visualization of cell delivery and distribution. To address these therapeutic barriers, allogeneic bone marrow-derived mesenchymal stem cells (MSCs) were encapsulated in alginate impregnated with a radiopaque contrast agent (MSC-Xcaps). In vitro MSC-Xcap viability by a fluorometric assay was high (96.9% ± 2.7% at 30 days postencapsulation) and as few as 10 Xcaps were visible on clinical x-ray fluoroscopic systems. Using an endovascular PAD model, rabbits (n = 21) were randomized to receive MSC-Xcaps (n = 6), empty Xcaps (n = 5), unencapsulated MSCs (n = 5), or sham intramuscular injections (n = 5) in the ischemic thigh 24 hours postocclusion. Immediately after MSC transplantation and 14 days later, digital radiographs acquired on a clinical angiographic system demonstrated persistent visualization of the Xcap injection sites with retained contrast-to-noise. Using a modified TIMI frame count, quantitative angiography demonstrated a 65% improvement in hind limb perfusion or arteriogenesis in MSC-Xcap-treated animals versus empty Xcaps. Post-mortem immunohistopathology of vessel density by anti-CD31 staining demonstrated an 87% enhancement in angiogenesis in Xcap-MSC-treated animals versus empty Xcaps. MSC-Xcaps represent the first x-ray-visible cellular therapeutic with enhanced efficacy for PAD treatment.

Using plasma proteomic analysis for venous thromboembolism risk stratification in patients with advanced gastrointestinal cancers

e21153

Background: Cancer patients represent 15-20% of the estimated 900,000 annual cases of venous thromboembolism (VTE) in the U.S., and thrombotic complications are the second most frequent cause of death in patients with cancer. Currently, no predictors or method exists by which patients with cancer can be accurately risk-stratified for thrombotic risk. Methods: Twenty-four patients with stage III/IV gastrointestinal (GI) cancers were followed for six months for incident VTE in a prospective cohort study. Twenty-nine biomarkers relevant to inflammation and thrombosis were tested for ability to discriminate between age- and sex- matched cancer patients with (n=10) and without incident VTE (n=14). Results: Expression levels of VCAM-1 and MMP-1 were statistically significantly elevated in VTE cases compared with controls in a series of univariate analyses. VCAM-1 remained statistically significant in a multivariate analysis. Conclusions: These findings suggest the role of VCAM-1 as a potential predictor of VTE in patients with GI cancers.

Applying a structured innovation process to interventional radiology: a single-center experience

PURPOSE

To determine the feasibility and efficacy of applying an established innovation process to an active academic interventional radiology (IR) practice.

MATERIALS AND METHODS

The Stanford Biodesign Medical Technology Innovation Process was used as the innovation template. Over a 4-month period, seven IR faculty and four IR fellow physicians recorded observations. These observations were converted into need statements. One particular need relating to gastrostomy tubes was diligently screened and was the subject of a single formal brainstorming session.

RESULTS

Investigators collected 82 observations, 34 by faculty and 48 by fellows. The categories that generated the most observations were enteral feeding (n = 9, 11%), biopsy (n = 8, 10%), chest tubes (n = 6, 7%), chemoembolization and radioembolization (n = 6, 7%), and biliary interventions (n = 5, 6%). The output from the screening on the gastrostomy tube need was a specification sheet that served as a guidance document for the subsequent brainstorming session. The brainstorming session produced 10 concepts under three separate categories.

CONCLUSIONS

This formalized innovation process generated numerous observations and ultimately 10 concepts to potentially to solve a significant clinical need, suggesting that a structured process can help guide an IR practice interested in medical innovation.

Intratumoral versus intravenous gene therapy using a transcriptionally targeted viral vector in an orthotopic hepatocellular carcinoma rat model

PURPOSE

To evaluate the feasibility of intratumoral delivery of adenoviral vector carrying a bidirectional two-step transcriptional amplification (TSTA) system to amplify transcriptional strength of cancer-specific Survivin promoter in a hepatocellular carcinoma model.

MATERIALS AND METHODS

MCA-RH7777 cells were implanted in rat liver, and tumor formation was confirmed with [(18)F]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET). The adenoviral vector studied had Survivin promoter driving a therapeutic gene (tumor necrosis factor-α-related apoptosis-inducing ligand [TRAIL]) and a reporter gene (firefly luciferase [FL]; Ad-pSurvivin-TSTA-TRAIL-FL). Tumor-bearing rats were administered Ad-pSurvivin-TSTA-TRAIL-FL intravenously (n = 7) or intratumorally (n = 8). For control groups, adenovirus FL under cytomegalovirus (CMV) promoter (Ad-pCMV-FL) was administered intravenously (n = 3) or intratumorally (n = 3). One day after delivery, bioluminescence imaging was performed to evaluate transduction. At 4 and 7 days after delivery, 18F-FDG-PET was performed to evaluate therapeutic efficacy.

RESULTS

With intravenous delivery, Ad-pSurvivin-TSTA-TRAIL-FL showed no measurable liver tumor FL signal on day 1 after delivery, but showed better therapeutic efficacy than Ad-pCMV-FL on day 7 (PET tumor/liver ratio, 3.5 ± 0.58 vs 6.0 ± 0.71; P = .02). With intratumoral delivery, Ad-pSurvivin-TSTA-TRAIL-FL showed positive FL signal from all tumors and better therapeutic efficacy than Ad-pCMV-FL on day 7 (2.4 ± 0.50 vs 5.4 ± 0.78; P = .01). In addition, intratumoral delivery of Ad-pSurvivin-TSTA-TRAIL-FL demonstrated significant decrease in tumoral viability compared with intravenous delivery (2.4 ± 0.50 vs 3.5 ± 0.58; P = .03).

CONCLUSIONS

Intratumoral delivery of a transcriptionally targeted therapeutic vector for amplifying tumor-specific effect demonstrated better transduction efficiency and therapeutic efficacy for liver cancer than systemic delivery, and may lead to improved therapeutic outcome for future clinical practice.

Consolidation of hepatic arterial inflow by embolization of variant hepatic arteries in preparation for yttrium-90 radioembolization

PURPOSE

Before yttrium-90 ((90)Y) radioembolization administration, the authors consolidated arterial inflow by embolizing variant hepatic arteries (HAs) to make microsphere delivery simpler and safer. The present study reviews the technical and clinical success of these consolidation procedures.

MATERIALS AND METHODS

Preparatory and treatment angiograms were retrospectively analyzed for 201 patients. Variant HAs were coil-embolized during preparatory angiography to simplify arterial anatomy. Collateral arterial perfusion of territories previously supplied by variant HAs was evaluated by digital subtraction angiography (DSA), C-arm computed tomography (CT), and technetium-99m ((99m)Tc)-macroaggregated albumin (MAA) scintigraphy, and by follow-up evaluation of regional tumor response.

RESULTS

A total of 47 variant HAs were embolized in 43 patients. After embolization of variant HAs, cross-perfusion into the embolized territory was depicted by DSA and by C-arm CT in 100% of patients and by (99m)Tc-MAA scintigraphy in 92.7%. Uniform progressive disease prevented evaluation in 33% of patients, but regional tumor response in patients who responded supported successful delivery of microspheres to the embolized territories in 95.5% of evaluable patients.

CONCLUSIONS

Embolization of variant HAs for consolidation of hepatic supply in preparation for (90)Y radioembolization promotes treatment of affected territories via intrahepatic collateral channels.

Common iliac vein stenosis: a risk factor for oral contraceptive-induced deep vein thrombosis

OBJECTIVE

The objective of the study was to determine whether women with significant left common iliac vein stenosis who also use combined oral contraceptives (COCs) have a combined likelihood of deep vein thrombosis (DVT) greater than each independent risk.

STUDY DESIGN

This was a case-control study comparing 35 women with DVT against 35 age-matched controls. Common iliac vein diameters were measured from computed tomography and magnetic resonance imaging. Logistic regression modeling was used with adjustment for risk factors.

RESULTS

DVT was associated with COC use (P = .022) and with increasing degrees of common iliac vein stenosis (P = .004). Compared with women without venous stenosis or COC use, the odds of DVT in women with a 70% venous stenosis who also use COCs was associated with a 17-fold increase (P = .01).

CONCLUSION

Venous stenosis and COC use are independent risk factors for DVT. Women concurrently exposed to both have a multiplicative effect resulting in an increased risk of DVT. We recommend further studies to investigate this effect and its potential clinical implications.

Percutaneous cholecystostomy for acute cholecystitis: ten-year experience

PURPOSE

To review the clinical course of patients with acute cholecystitis treated by percutaneous cholecystostomy, and to identify risk factors retrospectively that predict outcome.

MATERIALS AND METHODS

A total of 106 patients diagnosed with acute cholecystitis were treated by percutaneous cholecystostomy during a 10-year period. Seventy-one (67%) presented to the emergency department (ED) specifically for acute cholecystitis, and 35 (23%) were inpatients previously admitted for other conditions. Outcomes of the two groups were compared with respect to severity of illness, leukocytosis, bile culture, liver function tests, imaging features, time intervals from onset of symptoms to medical and percutaneous intervention, and whether surgical cholecystectomy was later performed.

RESULTS

Overall, 72 patients (68%) showed an improvement clinically, whereas 34 (32%) showed no improvement or a clinically worsened condition after cholecystostomy. Patients who presented to the ED primarily with acute cholecystitis fared better (84% of patients showed improvement) than inpatients (34% showed improvement; P < .0001). Gallstones were identified in 54% of patients who presented to the ED, whereas acalculous cholecystitis was more commonly diagnosed in inpatients (54%). Patients with sepsis had worse outcomes overall (P < .0001). Bacterial bile cultures were analyzed in 95% of patients and showed positive results in 52%, with no overall effect on outcome. There was no correlation between the time of onset of symptoms until antibiotic therapy or cholecystostomy in either group. Long-term outcomes for both groups were better for those who later underwent cholecystectomy (P < .0001).

CONCLUSIONS

Outcomes after percutaneous cholecystostomy for acute cholecystitis are better when the disease is primary and not precipitated by concurrent illness.

In vivo MRSI of hyperpolarized [1-(13)C]pyruvate metabolism in rat hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the primary form of human adult liver malignancy, is a highly aggressive tumor with average survival rates that are currently less than 1 year following diagnosis. Most patients with HCC are diagnosed at an advanced stage, and no efficient marker exists for the prediction of prognosis and/or response(s) to therapy. We have reported previously a high level of [1-(13)C]alanine in an orthotopic HCC using single-voxel hyperpolarized [1-(13)C]pyruvate MRS. In the present study, we implemented a three-dimensional MRSI sequence to investigate this potential hallmark of cellular metabolism in rat livers bearing HCC (n = 7 buffalo rats). In addition, quantitative real-time polymerase chain reaction was used to determine the mRNA levels of lactate dehydrogenase A, nicotinamide adenine (phosphate) dinucleotide dehydrogenase quinone 1 and alanine transaminase. The enzyme levels were significantly higher in tumor than in normal liver tissues within each rat, and were associated with the in vivo MRSI signal of [1-(13)C]alanine and [1-(13)C]lactate after a bolus intravenous injection of [1-(13)C]pyruvate. Histopathological analysis of these tumors confirmed the successful growth of HCC as a nodule in buffalo rat livers, revealing malignancy and hypervascular architecture. More importantly, the results demonstrated that the metabolic fate of [1-(13)C]pyruvate conversion to [1-(13)C]alanine significantly superseded that of [1-(13)C]pyruvate conversion to [1-(13)C]lactate, potentially serving as a marker of HCC tumors.

Computed tomography-guided percutaneous needle biopsy of indeterminate pulmonary pathology: efficacy of obtaining a diagnostic sample in immunocompetent and immunocompromised patients

PURPOSE

We aimed to evaluate the efficacy of computed tomography (CT)-guided percutaneous lung biopsy of pulmonary nodules with indeterminate radiologic characteristics in patients at risk for malignant and nonmalignant processes such as infection or inflammation.

PATIENTS AND METHODS

From January 2003 to September 2008, 262 patients (mean age, 59 years; range, 18-92 years) with pulmonary nodules or a mass of uncertain etiology and with indeterminate radiologic characteristics underwent CT-guided percutaneous lung biopsy. Patients with discordant clinical history and imaging findings or immunocompromised patients at risk for both etiologies were included. Specimens were submitted for both cytology and microbiology.

RESULTS

Of the entire cohort, 166 patients (63.4%) had a nonmalignant process, and 96 patients (36.6%) had a malignancy. CT-guided percutaneous lung biopsy established a diagnosis in 166 patients (63.4%). Of the 166 patients with a nonmalignant etiology and 96 patients with malignancy, it provided a definitive diagnosis in 91 patients (54.8%) and 75 patients (78.1%), respectively, a difference that was statistically significant (P = .0001). Overall diagnostic efficacy between immunocompetent and immunocompromised patients was comparable (P = .2); however, detection of infection or inflammation in individual groups was lower compared with detection of malignancy (P = .002 and P = .06, respectively).

CONCLUSION

CT-guided percutaneous lung biopsy in patients who are clinically at risk for both nonmalignant and malignant processes continues to be a challenge. Although CT-guided percutaneous biopsy can establish an accurate diagnosis in a large majority of patients with malignancy, it is significantly less sensitive for infectious or inflammatory processes.

Development of new hepaticoenteric collateral pathways after hepatic arterial skeletonization in preparation for yttrium-90 radioembolization

PURPOSE

Development of new hepaticoenteric anastomotic vessels may occur after endovascular skeletonization of the hepatic artery. Left untreated, they can serve as pathways for nontarget radioembolization. The authors reviewed the incidence, anatomy, management, and significance of collateral vessel formation in patients undergoing radioembolization.

MATERIALS AND METHODS

One hundred thirty-eight treatments performed on 122 patients were reviewed. Each patient underwent a preparatory digital subtraction angiogram (DSA) and embolization of all hepaticoenteric vessels in preparation for yttrium-90 ((90)Y) administration. Successful skeletonization was verified by C-arm computed tomography (CACT) and technetium-99m macroaggregated albumin ((99m)TcMAA) scintigraphy. During the subsequent treatment session, DSA and CACT were repeated before administration of (90)Y, and the detection of extrahepatic perfusion prompted additional embolization.

RESULTS

Forty-two patients (34.4%) undergoing 43 treatments (31.2%) required adjunctive embolization of hepaticoenteric vessels immediately before (90)Y administration. Previous scintigraphy findings showed extrahepatic perfusion in only three cases (7.1%). Vessels were identified by DSA in 54.1%, by CACT in 4.9%, or required both in 41.0%. The time interval between angiograms did not correlate with risk of requiring reembolization (P = .297). A total of 19.7% of vessels were new collateral vessels not visible during the initial angiography. Despite reembolization, three patients (7.1%) had gastric or duodenal ulceration, compared with 1.3% who never had visible collateral vessels, all of whom underwent whole-liver treatment with resin microspheres (P = .038).

CONCLUSIONS

Development of collateral hepaticoenteric anastomoses occurs after endovascular skeletonization of the hepatic artery. Identified vessels may be managed by adjunctive embolization, but patients appear to remain at increased risk for gastrointestinal complications.

Computed tomography-guided percutaneous needle biopsy of pulmonary nodules: impact of nodule size on diagnostic accuracy

PURPOSE

This study was undertaken to compare the diagnostic accuracy and complication rate of computed tomography (CT)-guided percutaneous lung biopsies of lung nodules<or=1.5 cm versus >1.5 cm in diameter.

PATIENTS AND METHODS

A total of 139 patients (age range, 18-89 years; mean, 62.5 years) underwent CT-guided percutaneous fine-needle aspiration biopsy or 20-gauge core biopsy using an automated biopsy gun. In 37 patients, the lung nodule measured <or=1.5 cm (mean, 1.1 cm), and in 102 patients, the lung nodule was >1.5 cm (mean, 2.8 cm). Diagnostic accuracy was determined by cytopathology results. Major and minor complications were documented.

RESULTS

Overall diagnostic accuracy, pneumothorax rate, and thoracostomy tube insertion rates were 67.6%, 34.5%, and 5%, respectively. Of the 98 patients with malignancy, 77 patients (78.6%) had a definite diagnostic biopsy. Overall, nodules>1.5 cm were statistically more likely to result in a diagnostic specimen (73.5%) than nodules<or=1.5 cm (51.4%; P=.012). Similarly, diagnostic accuracy for malignancy was higher in nodules>1.5 cm than in those<or=1.5 cm (81.3% vs. 69.6%); however, this was not statistically significant. There was no correlation between nodule size and the incidence of complications.

CONCLUSION

Overall, diagnostic accuracy of CT-guided percutaneous lung biopsy of lung nodules<or=1.5 cm is slightly lower than that of nodules>1.5 cm. However, the diagnostic accuracy for malignancy is high in both groups, with a low risk of complications.

Utility of C-arm CT in patients with hepatocellular carcinoma undergoing transhepatic arterial chemoembolization

PURPOSE

To evaluate the utility of C-arm computed tomography (CT) on treatment algorithms in patients undergoing transhepatic arterial chemoembolization for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

From March 2008 to July 2008, 84 consecutive patients with HCC underwent 100 consecutive transhepatic arterial chemoembolizations with iodized oil. Unenhanced and iodinated contrast medium-enhanced C-arm CT with planar and three-dimensional imaging were performed in addition to conventional digital subtraction angiography (DSA) in all patients. The effect on diagnosis and treatment was determined by testing the hypotheses that C-arm CT, in comparison to DSA, provides (a) improved lesion detection, (b) expedient identification and mapping of arterial supply to a tumor, (c) improved characterization of a lesion to allow confident differentiation of HCC from pseudolesions such as arterioportal shunts, and (d) an improved evaluation of treatment completeness. The effect of C-arm CT was analyzed on the basis of information provided with C-arm CT that was not provided or readily apparent at DSA.

RESULTS

C-arm CT was technically successful in 93 of the 100 procedures (93%). C-arm CT provided information not apparent or discernible at DSA in 30 of the 84 patients (36%) and resulted in a change in diagnosis, treatment planning, or treatment delivery in 24 (28%). The additional information included, amongst others, visualization of additional or angiographically occult tumors in 13 of the 84 patients (15%) and identification of incomplete treatment in six (7.1%).

CONCLUSIONS

C-arm CT is a useful collaborative tool in patients undergoing transhepatic arterial chemoembolization and can affect patient care in more than one-fourth of patients.

Catheter-directed therapy for the treatment of massive pulmonary embolism: systematic review and meta-analysis of modern techniques

PURPOSE

Systemic thrombolysis for the treatment of acute pulmonary embolism (PE) carries an estimated 20% risk of major hemorrhage, including a 3%-5% risk of hemorrhagic stroke. The authors used evidence-based methods to evaluate the safety and effectiveness of modern catheter-directed therapy (CDT) as an alternative treatment for massive PE.

MATERIALS AND METHODS

The systematic review was initiated by electronic literature searches (MEDLINE, EMBASE) for studies published from January 1990 through September 2008. Inclusion criteria were applied to select patients with acute massive PE treated with modern CDT. Modern techniques were defined as the use of low-profile devices (< or =10 F), mechanical fragmentation and/or aspiration of emboli including rheolytic thrombectomy, and intraclot thrombolytic injection if a local drug was infused. Relevant non-English language articles were translated into English. Paired reviewers assessed study quality and abstracted data. Meta-analysis was performed by using random effects models to calculate pooled estimates for complications and clinical success rates across studies. Clinical success was defined as stabilization of hemodynamics, resolution of hypoxia, and survival to hospital discharge.

RESULTS

Five hundred ninety-four patients from 35 studies (six prospective, 29 retrospective) met the criteria for inclusion. The pooled clinical success rate from CDT was 86.5% (95% confidence interval [CI]: 82.1%, 90.2%). Pooled risks of minor and major procedural complications were 7.9% (95% CI: 5.0%, 11.3%) and 2.4% (95% CI: 1.9%, 4.3%), respectively. Data on the use of systemic thrombolysis before CDT were available in 571 patients; 546 of those patients (95%) were treated with CDT as the first adjunct to heparin without previous intravenous thrombolysis.

CONCLUSIONS

Modern CDT is a relatively safe and effective treatment for acute massive PE. At experienced centers, CDT should be considered as a first-line treatment for patients with massive PE.