Intravascular Ultrasound Use in Peripheral Arterial and Deep Venous Interventions: Multidisciplinary Expert Opinion From SCAI/AVF/AVLS/SIR/SVM/SVS.

Percutaneous revascularization is the primary strategy for treating lower extremity venous and arterial disease. Angiography is limited by its ability to accurately size vessels, precisely determine the degree of stenosis and length of lesions, characterize lesion morphology, or correctly diagnose postintervention complications. These limitations are overcome with use of intravascular ultrasound (IVUS). IVUS has demonstrated the ability to improve outcomes following percutaneous coronary intervention, and there is increasing evidence to support its benefits in the setting of peripheral vascular intervention. At this stage in its evolution, there remains a need to standardize the use and approach to peripheral vascular IVUS imaging. This manuscript represents considerations and consensus perspectives that emerged from a roundtable discussion including 15 physicians with expertise in interventional cardiology, interventional radiology, and vascular surgery, representing 6 cardiovascular specialty societies, held on February 3, 2023. The roundtable's aims were to assess the current state of lower extremity revascularization, identify knowledge gaps and need for evidence, and determine how IVUS can improve care and outcomes for patients with peripheral arterial and deep venous pathology.

Research Consensus Panel Follow-up: 8-Year Update on Submassive Pulmonary Embolism.

The 2015 Research Consensus Panel (RCP) on submassive pulmonary embolism (PE) set priorities for research in submassive PE and identified a rigorous randomized trial of catheter-directed therapy plus anticoagulation versus anticoagulation alone as the highest research priority. This update, written 8 years after the RCP was convened, describes the current state of endovascular PE practice and the Pulmonary Embolism-Thrombus Removal with Catheter-Directed Therapy trial, the main output from the RCP.

Society of Interventional Radiology Position Statement on the Endovascular Management of Acute Iliofemoral Deep Vein Thrombosis.

PURPOSE: To establish the updated position of the Society of Interventional Radiology (SIR) on the endovascular management of acute iliofemoral deep vein thrombosis (DVT). MATERIALS AND METHODS: A multidisciplinary writing group with expertise in treating venous diseases was convened by SIR. A comprehensive literature search was conducted to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements. RESULTS: A total of 84 studies, including randomized trials, systematic reviews and meta-analyses, prospective single-arm studies, and retrospective studies were identified and included in the review. The expert writing group developed 17 recommendations that pertain to the care of patients with acute iliofemoral DVT with the use of endovascular venous interventions. CONCLUSIONS: SIR considers endovascular thrombus removal to be an acceptable treatment option in selected patients with acute iliofemoral DVT. Careful individualized risk assessment, high-quality general DVT care, and close monitoring during and after procedures should be provided.

Society of Interventional Radiology Position Statement on the Management of Chronic Iliofemoral Venous Obstruction with Endovascular Placement of Metallic Stents.

PURPOSE: To state the position of the Society of Interventional Radiology (SIR) on the endovascular management of chronic iliofemoral venous obstruction with metallic stents. MATERIALS AND METHODS: A multidisciplinary writing group with expertise in treating venous disease was convened by SIR. A comprehensive literature search was conducted to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements. RESULTS: A total of 41 studies, including randomized trials, systematic reviews and meta-analyses, prospective single-arm studies, and retrospective studies were identified. The expert writing group developed 15 recommendations on the use of endovascular stent placement. CONCLUSIONS: SIR considers the use of endovascular stent placement for chronic iliofemoral venous obstruction to be likely to help selected patients, but the risks and benefits have not been fully quantified in well-designed randomized studies. SIR recommends urgent completion of such studies. In the meantime, careful patient selection and optimization of conservative therapy are recommended prior to stent placement, with attention to appropriate stent sizing and quality procedural technique. The use of multiplanar venography with intravascular ultrasound is suggested in diagnosing and characterizing obstructive iliac vein lesions and in guiding stent therapy. After stent placement, SIR recommends close patient follow-up to ensure optimal antithrombotic therapy, durable symptom response, and early identification of adverse events.

Antithrombotic Therapy After Venous Interventions: AJR Expert Panel Narrative Review.

Interventions for thrombotic and nonthrombotic venous disorders have increased with technical advances and more trained venous specialists. Antithrombotic therapy is essential to clinical and procedural success; however, postprocedural therapeutic regimens exhibit significant heterogeneity due to limited prospective randomized data and incomplete mechanistic understanding of the critical factors driving long-term patency. Postinterventional antithrombotic therapy for thrombotic venous disorders should adhere to existing venous thromboembolism management guidelines, which include 3-6 months of therapeutic anticoagulation at minimum and consideration of extended therapy in patients with higher risk of thrombosis because of procedural or patient factors. The added benefit of antiplatelet agents in the acute and intermediate period is unknown, having shown improved long-term stent patency in some retrospective studies. Dual- and/or triple-agent therapy should be limited based on individual risks of thrombosis and bleeding. The treatment of nonthrombotic disorders is more heterogeneous, though patients with limited flow, extensive stent material, or underlying prothrombotic states such as malignancy or chronic inflammation may benefit from single-agent or multiagent antithrombotic therapy. However, the agent, dose, and duration of therapy remain indeterminate. Future prospective studies are warranted to improve patient risk stratification and standardize postprocedural anti-thrombotic therapy in patients receiving venous interventions.

Inferior Vena Cava Filter Retrieval: Patient Selection, Procedural Planning, and Postprocedural Complications.

OBJECTIVE. Utilization of retrievable inferior vena cava filters (rIVCFs) has come under increased scrutiny because of historically high rates of placement, generalized lack of retrieval when the inferior vena cava filter (IVCF) is no longer indicated, and reports of device-related complications. These events have led to an increased interest in IVCF retrieval, including the development of advanced endovascular retrieval techniques and the proliferation of specialized clinical practices for rIVCFs. We aim to describe the indications for IVCF retrieval, patient selection, procedural planning, and procedural complications and management. CONCLUSION. IVCFs continue to have a role in the prevention of pulmonary embolism in select patients. Rising awareness of device-related complications paired with historically low retrieval rates has prompted renewed emphasis and interest in filter retrieval. Diligent follow-up and procedural planning permit prompt and safe filter retrieval.

Retrievable IVC Filters: Comprehensive Review of Device-related Complications and Advanced Retrieval Techniques.

Use of retrievable inferior vena cava filters (RIVCFs) has grown exponentially since their introduction into clinical practice, but many of these devices are not retrieved. Some are not retrieved due to poor clinical follow-up, but other devices remain in situ for extended periods because they present significant technical challenges during retrieval. Because of these and other factors, many of these devices were thus left in place permanently. However, recent data have placed a renewed emphasis on device retrieval due to increased risk of RIVCF-related complications, which are positively correlated with filter dwell time. Development of advanced filter retrieval techniques has had a significant impact on the removal of embedded RIVCFs, permitting retrieval of the majority of devices. The purpose of this article is to present an imaging and data review of the dominant device-related factors that complicate RIVCF retrieval and to describe the relevant advanced retrieval techniques to manage these factors. RIVCF imaging is frequently encountered in daily clinical practice via various imaging modalities. Therefore, diagnostic radiologists can play a vital role in identifying filter-related issues. Familiarity with the context for managing these issues in the interventional suite is essential for improving triage and care of patients with RIVCFs. © RSNA, 2017.

Endovascular Management of Massive and Submassive Acute Pulmonary Embolism: Current Trends in Risk Stratification and Catheter-Directed Therapies.

PURPOSE OF REVIEW: Acute pulmonary embolism (PE) is a common condition associated with high morbidity and mortality. Prior studies have evaluated the role of systemic fibrinolysis and catheter-directed therapy (CDT) in the management of PE. In this review, we examine current data on risk stratification and the appropriate allocation of systemic fibrinolysis and CDT in acute PE patients with elevated risk of adverse outcomes. RECENT FINDINGS: Classification of pulmonary embolism is based on risk of adverse events, and relies on clinical parameters, imaging findings, and biomarkers. The synthesis of this data permits appropriate risk stratification of acute PE patients, and is the foundation upon which treatment decisions are made. While systemic thrombolytics remain the frontline therapy for hemodynamically unstable PE patients, studies have suggested that CDT has a significant promise as the primary modality for treating hemodynamically stable patients at increased risk for clinical decompensation and as an alternative therapy for hemodynamically unstable patients who may not tolerate systemic thrombolytics. The appropriate use of CDT in patients with acute PE is dependent on accurate risk stratification. CDT offers the potential to reduce excessive bleeding while maintaining the efficacy of systemic thrombolytics, but will require data from larger randomized trials to support its use prior to widespread adoption as the frontline therapy for PE in patients at elevated risk of adverse outcomes.

Inferior Vena Cava Filter Retrieval: Simple to Complex.

Retrievable inferior vena cava filters were designed to provide mechanical prophylaxis from pulmonary embolism with the intent for retrieval once no longer indicated, and have been utilized at a high rate since their introduction. Unfortunately, retrieval rates have historically lagged behind, in part due to significant rates of failed standard retrieval techniques for filters with prolonged dwell time. Refinement in advanced retrieval techniques has now allowed (in experienced centers) for safe removal of filters previously considered irretrievable. An individualized approach is necessary for each potential advanced filter retrieval to determine appropriate course of action. This review will emphasize complex filter retrieval techniques amidst a larger discussion of inferior vena cava filters and their management.

The role of iliac vein stent placement in pelvic venous disorder management.

Pelvic venous disease (PeVD) has historically been challenging to diagnose and treat. This paper describes a comprehensive approach to the diagnosis of PeVD and reviews the role of iliac vein stent placement in treatment. Patient selection is vital for non-thrombotic iliac vein lesions (NIVLs) as only a small subset of patients with an NIVL will benefit from stent placement. There is limited, inconclusive data on optimal treatment for patients with both primary ovarian vein reflux and an NIVL. Patients with chronic post-thrombotic outflow obstruction typically have a more favorable risk/benefit ratio for intervention but require anticoagulation and close follow-up due to poorer long-term stent patency. Intravascular ultrasound is a useful tool for identifying obstructive lesions, sizing stents, and planning landing zones. More research is needed to characterize underlying pathophysiology, validate thresholds for intervention, develop reliable methods for outcomes assessment, and determine treatment response. Until this data is produced, an individualized treatment approach is warranted.

Antithrombotic Therapy after Deep Venous Intervention.

Chronic deep venous disease (CVD) can result in significant morbidity and impact on quality of life due to a spectrum of symptoms, including lower extremity edema, venous claudication, and venous ulcers. CVD can be secondary to both thrombotic and nonthrombotic disease processes, including postthrombotic syndrome from prior deep vein thrombosis (DVT) or iliac vein compression syndrome. Endovascular therapy has become a mainstay therapy for CVD patients, with venous stent placement frequently performed. However, the management of anticoagulation following venous stent placement is not well-studied, with no large trials or consensus guidelines establishing an optimal regimen. The current knowledge gap in antithrombotic therapy is magnified by heterogeneity in practice and data collection, along with incomplete reporting in available studies. Furthermore, most published datasets are antiquated in the setting of rapid evolution in technique and technology available for deep venous intervention. Herein, we summarize the current available literature and offer an approach to anticoagulation and antiplatelet management following deep venous intervention for CVD.

Endovascular Management of Acute Iliofemoral Deep Vein Thrombosis.

Lower extremity deep vein thrombosis (DVT) is frequently encountered in clinical practice. Postthrombotic syndrome (PTS) is a common sequela of DVT and encompasses a wide variety of symptoms, including severe pain, edema, and ulceration, all of which may contribute to a negative impact on quality of life. Studies have demonstrated that acute thrombosis of the iliofemoral venous segment is correlated with high rates of PTS, increased severity of symptoms, and high rates of thrombus recurrence, despite patients receiving treatment with standard-of-care anticoagulation therapy. Endovascular interventions, including catheter-directed thrombolysis, pharmacomechanical thrombectomy, and mechanical thrombectomy, have generated significant interest as a method for reduction of short-term symptom severity and potential reduction of downstream PTS severity. While there is high-quality evidence evaluating the role of catheter-directed and pharmacomechanical thrombectomy for acute iliofemoral DVT, newer mechanical-only devices that utilize thrombectomy without fibrinolytic medication are less studied. Currently, there are limited data evaluating the efficacy and safety of these treatment modalities, although investigations are ongoing.

A review of the incidence, outcome, and management of venous stent migration.

BACKGROUND: Percutaneous endovenous stenting has emerged during the past decade as the primary method of treating symptomatic venous outflow obstruction. A recognized complication of venous stenting is stent migration. The aim of the present systematic review was to identify the number of cases of stent migration in reported studies to recognize the risk factors that might be associated with this complication and the outcomes following migration. METHODS: A review was conducted in accordance with the MOOSE (meta-analyses of observational studies in epidemiology) and PRIMSA (preferred reporting items for systematic review and meta-analysis) guidelines and registered in the PROSPERO. MEDLINE, EMBASE, and PubMed databases. Key references were searched using specified keywords. All relevant data for the primary procedure and subsequent presentation with stent migration were retrieved. The data were assessed as too low in quality to allow for statistical analysis. RESULTS: Between 1994 and 2020, 31 studies were identified, including 29 case reports and 2 case series, providing data for 54 events of venous stent migration with some data provided regarding the stent used for 47 of the events. The mean age of the 52 patients with stent migration was 50 years (range, 19-88 years) and 30 were men (57.6%). The stents for most of the reported cases were ≤60 mm in length (38 of 46; 82.6%). Only three of the reports were of stents >14 mm in diameter (3 of 47; 3.6%). None of the studies had reported migration of stents >100 mm long. In 85% of the migrated stent events, retrieval was attempted, with 65.2% via an endovascular approach. The immediate outcome was satisfactory for 100% of the reported attempts, whether by an endovascular or open surgical approach. CONCLUSIONS: The findings from our literature review suggest that the risk of migration is rare but might be underreported. Most of reported cases had occurred with shorter and smaller diameter stents. The paucity of reported data and the short-term follow-up provided suggest that more formal data collection would provide a truer reflection of the incidence. However, clear strategies to avoid migration should be followed to prevent this complication from occurring.

A Brief Review of Thrombolytics for Venous Interventions.

Anticoagulation continues to be the mainstay of therapy for the management of venous thromboembolism. However, anticoagulation does not lead to the breakdown or dissolving of the thrombus. In an acute pulmonary embolism, extensive thrombus burden can be associated with a high risk for early decompensation, and in acute deep venous thrombosis, it can be associated with an increased risk for phlegmasia. In addition, residual thrombosis can be associated with chronic thromboembolic pulmonary hypertension and postthrombotic syndrome in a chronic setting. Thrombolytic therapy is a crucial therapeutic choice in treating venous thromboembolism for thrombus resolution. Historically, it was administered systemically and was associated with high bleeding rates, particularly major bleeding, including intracranial bleeding. In the last two decades, there has been a significant increase in catheter-based therapies with and without ultrasound, where lower doses of thrombolytic agents are utilized, potentially reducing the risk for major bleeding events and improving the odds of reducing the thrombus burden. In this article, we provide an overview of several thrombolytic therapies, including delivery methods, doses, and outcomes.