Quality Improvement Guidelines for the Treatment of Lower Extremity Deep Vein Thrombosis with Use of Endovascular Thrombus Removal

Review of the literature supporting international clinical practice guidelines on iliac venous stenting and their applicability to Australia and New Zealand practice

BACKGROUND

The overall goal of this report is to provide a high-level, practical approach to managing venous outflow obstruction (VOO).

METHODS

A group of vascular surgeons from Australia and New Zealand with specific interest, training, and experience in the management of VOO were surveyed to assess current local practices. The results were analyzed and areas of disagreement identified. After this, the group performed a literature review of consensus guidelines published by leading international organizations focused on the management of chronic venous disease, namely, the Society for Vascular Surgery, American Venous Forum, European Society for Vascular Surgery, American Vein and Lymphatic Society, Cardiovascular and Interventional Radiology Society of Europe, and American Heart Association. These guidelines were compared against the consensus statements obtained through the surveys to determine how they relate to Australian and New Zealand practice. In addition, selected key studies, reviews, and meta-analyses on venous stenting were discussed and added to the document. A selection of statements with >75% agreement was voted on, and barriers to the guideline's applicability were identified. The final recommendations were further reviewed and endorsed by another group of venous experts.

RESULTS

The document addresses two key areas: patient selection and technical aspects of venous stenting. Regarding patient selection, patients with clinically relevant VOO, a Clinical-Etiologic-Anatomic-Physiologic score of ≥3 or a Venous Clinical Severity Score for pain of ≥2, or both, including venous claudication, with evidence of >50% stenosis should be considered for venous stenting (Level of Recommendation Ib). Patients with chronic pelvic pain, deep dyspareunia, postcoital pain affecting their quality of life, when other causes have been ruled out, should also be considered for venous stenting (Level of Recommendation Ic). Asymptomatic patients should not be offered venous stenting (Level of Recommendation IIIc). Patients undergoing thrombus removal for acute iliofemoral deep vein thrombosis, in whom a culprit stenotic lesion of >50% has been uncovered, should be considered for venous stenting (Level of Recommendation Ib).

CONCLUSIONS

Patients with VOO have been underdiagnosed and undertreated for decades; however, in recent years, interest from physicians and industry has grown substantially. International guidelines aimed at developing standards of care to avoid undertreating and overtreating patients are applicable to Australia and New Zealand practice and will serve as an educational platform for future developments.

RETRACTED: Australian and New Zealand Society for Vascular Surgery clinical practice guidelines on venous outflow Obstruction of the femoral-iliocaval veins

BACKGROUND

The overall goal of this report is to provide a high-level, practical approach to managing venous outflow obstruction (VOO) in Australia and New Zealand.

METHODS

A group of vascular surgeons from the Australian and New Zealand Society for Vascular Surgery with specific interest, training, and experience in the management of VOO were surveyed to assess current local practice. The results were analyzed and areas of disagreement identified. Following this, the group performed a literature review of consensus guidelines published by leading international organizations focused on the management of chronic venous disease, namely the Society for Vascular Surgery, American Venous Forum, European Society for Vascular Surgery, American Vein and Lymphatic Society, Cardiovascular and Interventional Radiology Society of Europe, and American Heart Association. These guidelines were compared against the consensus statements obtained through the surveys to determine how they relate to Australian and New Zealand practice. In addition, selected key studies, reviews, and meta-analyses on venous stenting were discussed and added to the document. Finally, a selection of statements with >75% agreement was voted on, and barriers to the guideline's applicability were identified.

RESULTS

The document addresses two key areas: patient selection and technical aspects of venous stenting. Regarding patient selection, patients with a CEAP (Clinical-Etiologic-Anatomic-Physiologic) score of ≥3 or a venous clinical severity score for pain of ≥2, or both, and evidence of >50% stenosis on venography, computed tomography venography, magnetic resonance venography, and/or intravascular ultrasound should be considered for venous stenting (level of recommendation Ib) Patients undergoing thrombus removal for acute iliofemoral deep vein thrombosis, in whom a culprit stenotic lesion has been uncovered, should be considered for venous stenting (level of recommendation Ib). Patients with chronic pelvic pain, deep dyspareunia, postcoital pain affecting their quality of life, when other causes have been ruled out, should be considered for venous stenting (level of recommendation Ic). Asymptomatic patients should not be offered venous stenting (level of recommendation IIIc).

CONCLUSIONS

Patients with deep VOO have been underdiagnosed and undertreated for decades; however, in recent years, interest from physicians and industry has grown substantially. The advent of simpler and safer treatment options has revolutionized its management, but, unfortunately, formal training for venous disease has not grown at the same rate. Simplifying the technology and training required can result in inconsistent outcomes. These guidelines are aimed at developing standards of care and will serve as an educational platform for future developments.

Venous Intervention

Any overview of the treatment of venous disease should begin with a brief examination of its history. From the first rudimentary attempt at venous thrombectomy in the early 1920s to the evolution of percutaneous and mechanical thrombectomy and endovascular stents in the 21st century. It is the aim of this review to provide a comprehensive summary of the state of the art of venous disease treatment at the turn of the new century.

Management of May Thurner Syndrome in Pregnant Patients

May Thurner Syndrome contributes to thromboembolic disease and can cause significant morbidity in pregnant patients secondary to exaggerated anatomic relationships and physiologic changes in the hematologic system favoring thrombogenesis. Because this condition is both underrecognized and underreported, management in pregnant and postpartum patients is based on expert opinion without any formal evidence-based guidance. Herein, we review five pregnancies in four patients with May Thurner Syndrome and general management strategies. Through collaborative and multidisciplinary care, patients with May Thurner Syndrome can be safely and successfully managed during pregnancy and the postpartum period with appropriate anticoagulation.

Endovascular Therapy for the Management of Acute Ilio-femoral Deep Vein Thrombosis

Ilio-femoral deep vein thrombosis (DVT) has a high rate of long-term morbidity in the form of the postthrombotic syndrome (PTS). Therefore, management of acute thrombosis should not only focus on the prevention of acute complications such as propagation or embolisation of the initial clot but also on preventing recurrent thrombosis and PTS. Contemporary catheter-based treatments of deep vein thrombosis have proven to be safe and effective in selected patients. Current guidelines recommend medical therapy with anticoagulation alone for all but the most severe, limb-threatening thrombosis. They additionally allow for consideration of endovascular catheter-based treatment in selected patients with acute proximal ilio-femoral DVT and low risk of bleeding complications to prevent PTS. 

Imaging-guided, catheter-based endovascular therapy has been used in selected patients to alleviate these sequelae, but important questions remain about their optimal use. In this article, we review the available evidence and summarize the rationale for use of catheter-based therapy in specific patient groups with acute iliofemoral DVT.

Endovascular Treatment for Lower Extremity Deep Vein Thrombosis: An Overview

Lower extremity deep vein thrombosis (DVT) is a serious medical condition that can result in local pain and gait disturbance. DVT progression can also lead to death or major disability as a result of pulmonary embolism, postthrombotic syndrome, or limb amputation. However, early thrombus removal can rapidly relieve symptoms and prevent disease progression. Various endovascular procedures have been developed in the recent years to treat DVT, and endovascular treatment has been established as one of the major therapeutic methods to treat lower extremity DVT. However, the treatment of lower extremity DVT varies according to the disease duration, location of affected vessels, and the presence of symptoms. This article reviews and discusses effective endovascular treatment methods for lower extremity DVT.

Single-Session Percutaneous Mechanical Thrombectomy Using the Aspirex®S Device Plus Stenting for Acute Iliofemoral Deep Vein Thrombosis: Safety, Efficacy, and Mid-Term Outcomes

To assess the safety, efficacy and mid-term outcomes of single-session percutaneous mechanical thrombectomy (PMT) for acute symptomatic iliofemoral deep vein thrombosis (DVT) using the Aspirex^®S device. Retrospective review of 30 patients (women, 23; mean age, 45.5 ± 19.9 years; range, 17-76) who underwent PMT with the 10-French Aspirex^®S device (Straub Medical AG, Wangs, Switzerland) for acute DVT between December 2015 and March 2019. Procedures were performed by popliteal (n = 22) or jugular (n = 7) approach, or both (n = 1). Mean time from diagnosis to PMT was 5.5 ± 4.6 days (range, 2-11). Successful thrombus removal and venous patency restoration were achieved in all patients (100%). Fluid removal was 307.8 ± 66.1 mL (range, 190-410). Additional venous stenting rate was 100%. Mean procedural time was 107.3 ± 33.9 min (range, 70-180). No major complication occurred. The patient's postprocedural course was uneventful in all cases, with hospital discharge within 2 days in 83.3%. Early in-stent rethrombosis occurred within 1 week in 3 patients, successfully managed by endovascular approach. Secondary stent patency rate was 86.7% at a mean follow-up of 22.3 ± 14.2 months (range, 6-48), as assessed by Duplex ultrasound. Single-session of PMT using the Aspirex^®S device is a safe and effective therapeutic option in patients presenting with acute symptomatic iliofemoral DVT.

Single-Drug Approach with Edoxaban is Effective for Resolving Non-Acute Cancer-Associated Venous Thrombosis: A Single-Arm Retrospective Analysis

Recently, cancer-related venous thromboembolism (VTE) has been termed "cancer-associated thrombosis (CAT)" and is the focus of current research. We retrospectively investigated the efficacy of a single-drug approach with edoxaban for the treatment of non-acute CAT. Thirty-two non-acute CAT patients who received edoxaban were analyzed. The primary endpoint of this analysis was the thrombus disappearance rate at the first evaluation. Secondary endpoints included progression/recurrence of VTE, major bleeding, and D-dimer levels. The thrombus disappearance rate was 62.5%. Therefore, the null hypothesis for the primary endpoint (thrombus disappearance rate of ≤32.0%) was rejected (p = 0.00038) based on the rate of the previous study as the historical control. Recurrent VTE and major bleeding occurred in two patients each. After the start of treatment with edoxaban, a significant difference in D-dimer levels was observed (p = 0.00655). We demonstrated that a single-drug approach with edoxaban is a potential treatment option for non-acute CAT.

A retrospective observational study investigating the factors associated with right heart failure in patients with primary acute pulmonary embolism and deep vein thrombosis

BACKGROUND

The relationship between the risk of right heart failure in primary acute pulmonary embolism after embolization and the residual thrombus sites in the pelvis and lower limbs is not clear.

METHODS

This single-center retrospective observational study examined the results of contrast-enhanced computed tomography and venous ultrasonography of patients with primary acute PE and DVT. We assessed the association between the occurrence of right heart failure and age; gender; pulmonary thrombosis distribution; most proximal site of deep vein thrombosis in the soleal vein, inferior vena cava (IVC), or common iliac vein (CIV); DVT distribution; and malignancy using univariate and multivariate logistic regression.

RESULTS

In all, 77 of 165 patients were male (mean age: 65.1 ± 13.7 years). Right heart failure occurred in 53 patients (32.1%). Multivariate analysis revealed that the odds ratio (OR) for right heart failure was significantly lower in patients with the most proximal site of DVT in the IVC/CIV (OR = 0.07, 95% confidence interval [CI] 0.01-0.62, P = .017), while it was significantly higher in females (OR = 2.51, 95% CI 1.05-6.01, P = .039), and in patients who exhibited the presence of bilateral venous thrombosis (OR = 3.89, 95% CI 1.60-9.48, P = .003).

CONCLUSION

A significant factor involved in PE without right heart failure was the most proximal site of DVT in the IVC/CIV, and significant risk factors associated with PE with right heart failure were more prevalent in females and in patients who exhibited the presence of bilateral venous thrombosis.

Intervention for Iliofemoral Deep Vein Thrombosis and May-Thurner Syndrome

May-Thurner syndrome, also known as iliac vein compression syndrome, may cause symptoms of venous hypertension and is a predisposing factor for the development of iliofemoral deep vein thrombosis (DVT). Iliofemoral DVT is associated with high rates of development of postthrombotic syndrome, a potentially debilitating condition associated with development of symptoms related to venous outflow obstruction and resulting in reduced quality of life. In this Clinics article, we review procedural intervention with catheter-directed thrombolysis and stenting for iliofemoral DVT and iliac vein compression.

Catheter-directed thrombolysis vs. anticoagulation for the prevention and treatment of post-thrombotic syndrome in deep vein thrombosis: An updated systematic review and meta-analysis of randomized trials

Background

Oral anticoagulation therapy was the mainstay of deep vein thrombosis treatment but recently, catheter-directed thrombolysis has emerged as an alternative.

Objective

To compare the efficacy and safety of the two strategies.

Methods

Medline, Embase and Cochrane CENTRAL were reviewed. Outcomes of interest included post-thrombotic syndrome, thromboembolic events, mortality, bleeding risk and iliofemoral patency. A random effects model meta-analysis was performed. Heterogeneity was assessed with I square.

Results

Four randomized controlled trials (RCTs) including 1005 patients met the inclusion criteria. Catheter-directed thrombolysis was more likely to prevent overall post-thrombotic syndrome compared to anticoagulation only (OR: 0.32; 95% CI: 0.12–0.85; I2=87.2%), and to lead to iliofemoral vein patency (OR: 2.7; 95% CI: 1.08–6.75; I2=55.3%) but no difference was noted in thromboembolic events (OR = 0.5; 95% CI: 0.08–3.02, I2=55.1%), bleeding and mortality rates.

Conclusions

Catheter-directed thrombolysis can decrease post-thrombotic syndrome rates and improve iliofemoral vein patency compared to anticoagulation when used for the treatment of deep vein thrombosis.

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.

Long-term results of additional thrombolytic therapy in patients with acute deep vein thrombosis treated with pharmacomechanical thromboaspiration: A comparative study

Background

This study aims to evaluate the clinical and ultrasonographic long-term results of additional thrombolytic therapy to pharmacomechanical thromboaspiration in patients with acute and subacute lower extremity deep vein thrombosis.

Methods

Medical data of a total of 68 patients ( 41 males, 27 females; mean age 38 years; range, 25 to 56 years) who were admitted to our department with the diagnosis of hyperacute or acute deep vein thrombosis between January 2013 and January 2015 were retrospectively analyzed. The patients were divided into two groups: thrombectomy without thrombolytic therapy (Group 1, n=33) and thrombectomy with thrombolytic therapy (Group 2, n=35). All patients were administered Clinical Symptom Scoring and Doppler ultrasonography at one, six, and 12 months.

Results

Clinical symptom scores were higher in Group 1 at one month (p<0.001), while there was no significant difference between the groups at six months (p=0.102). Group 1 had higher scores at 12 months (p=0.043). The complete patency rates for both groups were similar at one month (p=0.181); however, the rates were higher in Group 2 at six and 12 months (p=0.019 and p=0.002, respectively). There was no significant difference in the complete patency rates between the groups at one and six months (p=0.563 and p=0.064, respectively), while these rates were higher in Group 2 at 12 months (p=0.013). In patients with acute deep vein thrombosis, the complete patency rates were found to be higher in all control Doppler ultrasonography examinations.

Conclusion

In the treatment of both hyperacute and acute deep vein thrombosis, the addition of thrombolytic therapy to pharmacomechanical thromboaspiration improves the clinical symptoms and venous patency rates.

Endovascular and Open Surgery for Deep Vein Thrombosis

The surgical treatment of deep venous thrombosis (DVT) has significantly evolved and is focused on different strategies of early thrombus removal in the acute phase and deep venous recanalization or bypass in the chronic phase. Along with the use of anticoagulation agents, endovascular techniques based on catheter-directed thrombolysis and pharmacomechanical thrombectomy have been increasingly used in patients with acute extensive DVT. Patient selection is crucial to provide optimal outcomes and minimize complications.

The Role of May-Thurner Syndrome in Recurrent Thrombosis after Catheter-Directed Thrombolysis of Deep Vein Thrombosis

BACKGROUND

May-Thurner syndrome (MTS) leads to an increased incidence of deep vein thrombosis (DVT). Early thrombus removal decreases the post-thrombotic morbidities. Our aim was to better elucidate the relationship between MTS and venous patency after catheter-directed thrombolysis (CDT).

METHODS

The medical records of all patients who underwent CDT from January 2005 to December 2011 due to acute DVT were reviewed retrospectively. Patient characteristics and clinical variables were evaluated to determine association with vein patency.

RESULTS

A total of 51 male and 31 female with a mean age of 34.9 years were treated with CDT. During a median follow-up of 91.7 months, primary patency and secondary patency of all patients were 79.3% and 87.3%, respectively. The presence of MTS was the only significant predictor factor of patency.

CONCLUSIONS

The residual stenosis caused by MTS is a risk for recurrent DVT and should be treated with stenting to improve the outcome.

Safety and Efficacy of Catheter Direct Thrombolysis in Management of Acute Iliofemoral Deep Vein Thrombosis: A Systematic Review

Purpose

Catheter direct thrombolysis (CDT) has been shown to be an effective treatment for deep venous thrombosis. The objective of the review is to improve safety and efficacy of the CDT by using ward based protocol, better able to predict complications and treatment outcome through monitoring of haemostatic parameters and clinical observation during thrombolysis procedure.

Materials and Methods

MEDLINE, EMBASE, CENTRAL and Web of Science were searched for all articles on deep venous thrombosis, thrombolysis and correlations of clinical events (bleeding, successful thrombolysis) during thrombolysis with hemostatic parameters to March 2016. The risk of bias in included studies was assessed by Cochrane Collaboration’s tool and Cochrane Risk of Bias Assessment Tool: for Non-Randomized Studies of Interventions.

Results

Twenty-four studies were included in the review and we found that improving safety and efficacy of CDT by using ward based protocol depending on eight factors; strict patient selection criteria, types of fibrinolytic drugs, mode of fibrinolytic drug injection, biochemical markers monitoring (fibrinogen, D-dimer, activated partial thromboplastin time, plasminogen activator inhibitor-1), timing of intervention, usage of intermittent pneumatic calf, ward monitoring and thrombolysis imaging assessment (intravascular ultrasound). These factors may help to improve safety and efficacy by reducing total thrombolytic drug dosage and at the same time ensure successful lysis. There is a marked lack of randomized controlled trials discussing the safety and efficacy of catheter direct thrombolysis.

Conclusion

CDT can be performed safely and efficiently in clinical ward, providing that careful nursing, biochemical monitoring, proper selection and mode of infusion of fibrinolytic drugs, usage of Intermittent pneumatic calf and adequate thrombolysis imaging assessment are ensured.

Pharmacomechanical Catheter-Directed Thrombolysis for Deep-Vein Thrombosis

BACKGROUND

The post-thrombotic syndrome frequently develops in patients with proximal deep-vein thrombosis despite treatment with anticoagulant therapy. Pharmacomechanical catheter-directed thrombolysis (hereafter "pharmacomechanical thrombolysis") rapidly removes thrombus and is hypothesized to reduce the risk of the post-thrombotic syndrome.

METHODS

We randomly assigned 692 patients with acute proximal deep-vein thrombosis to receive either anticoagulation alone (control group) or anticoagulation plus pharmacomechanical thrombolysis (catheter-mediated or device-mediated intrathrombus delivery of recombinant tissue plasminogen activator and thrombus aspiration or maceration, with or without stenting). The primary outcome was development of the post-thrombotic syndrome between 6 and 24 months of follow-up.

RESULTS

Between 6 and 24 months, there was no significant between-group difference in the percentage of patients with the post-thrombotic syndrome (47% in the pharmacomechanical-thrombolysis group and 48% in the control group; risk ratio, 0.96; 95% confidence interval [CI], 0.82 to 1.11; P=0.56). Pharmacomechanical thrombolysis led to more major bleeding events within 10 days (1.7% vs. 0.3% of patients, P=0.049), but no significant difference in recurrent venous thromboembolism was seen over the 24-month follow-up period (12% in the pharmacomechanical-thrombolysis group and 8% in the control group, P=0.09). Moderate-to-severe post-thrombotic syndrome occurred in 18% of patients in the pharmacomechanical-thrombolysis group versus 24% of those in the control group (risk ratio, 0.73; 95% CI, 0.54 to 0.98; P=0.04). Severity scores for the post-thrombotic syndrome were lower in the pharmacomechanical-thrombolysis group than in the control group at 6, 12, 18, and 24 months of follow-up (P<0.01 for the comparison of the Villalta scores at each time point), but the improvement in quality of life from baseline to 24 months did not differ significantly between the treatment groups.

CONCLUSIONS

Among patients with acute proximal deep-vein thrombosis, the addition of pharmacomechanical catheter-directed thrombolysis to anticoagulation did not result in a lower risk of the post-thrombotic syndrome but did result in a higher risk of major bleeding. (Funded by the National Heart, Lung, and Blood Institute and others; ATTRACT ClinicalTrials.gov number, NCT00790335 .).

Catheter-directed thrombolysis to avoid late consequences of acute deep vein thrombosis

The application of catheter-based methods to treat acute deep vein thrombosis (DVT) has increased in recent years. Catheter-directed thrombolysis (CDT), introduced during the early 1990s, has shown the ability to rapidly eliminate thrombus and is used in many centers as a salvage therapy for DVT patients who exhibit a poor initial response to anticoagulant therapy. However, CDT has disadvantages in terms of safety and resource use. Although CDT methods have evolved substantially to try to address these issues, for most of the last 25years there was little high-quality data on CDT outcomes upon which to base patient care decisions. The paucity of evidence was particularly problematic for long-term outcomes such as recurrent venous thromboembolism (VTE) and the post-thrombotic syndrome (PTS). Fortunately, rigorous studies of CDT are now being completed. Accordingly, the purpose of this article is to: 1) state the known and unknown factors influencing risk and benefit with use of CDT and related methods to treat acute DVT; 2) summarize emerging evidence showing the patient outcomes that occur when CDT is used for first-line management of DVT; and 3) suggest clinical parameters for CDT utilization in light of the available evidence.

Acute Venous Iliofemoral Thrombosis: Early Surgical Thrombectomy Is Effective and Durable

BACKGROUND

The first-line recommendation for the treatment of acute iliofemoral deep vein thrombosis (IFDVT) is catheter-directed thrombolysis or pharmacomechanical thrombolysis. Recent analysis of surgical thrombectomy has shown comparable results. However, this procedure is not commonly given as much importance as interventional techniques. We analyzed the patient outcome of surgical thrombectomy using modern endovascular techniques in both the short and long term.

METHODS

All consecutive patients who underwent surgical thrombectomy at our institution between April 2008 and April 2017 were included. Only patients with iliofemoral thrombosis, and only those with the first onset of symptoms <10 days, were analyzed. All patients received preoperative duplex ultrasound and contrast-enhanced computed tomography scans for thrombus extension and detection of pulmonary embolism. All operations were performed by vascular surgeons with open and endovascular skills in a C-arm-equipped operating room. During follow-up (FU), all patients received clinical examination for symptoms of postthrombotic syndrome (PTS), as well as duplex ultrasound.

RESULTS

Within a 9-year period, 21 patients underwent surgical thrombectomy for IFDVT (17 females/4 males). Primary technical success was 100%; 10 (47.6%) patients received additional primary stenting. 30-day mortality was 0%, 3 patients (14.3%) needed reoperation for early rethrombosis, while secondary 30-day patency was 100%. During FU (median, 6 years; range, 1-104 months), 1 patient received additional stenting for stenosis of the common iliac vein. Nineteen patients (90.5%) presented patent iliofemoral veins without signs of rethrombosis. Two patients (9.5%) died during FU of cancer without signs for recurrent IFDVT. All patients with patent veins were free of symptoms for PTS.

CONCLUSIONS

Surgical thrombectomy for acute IFDVT is a successful, safe, and durable procedure and provides alternative treatment options for acute IFDVT in selected cases.

Catheter directed interventions for acute deep vein thrombosis

Venous thromboembolism (VTE) is an extremely common form of vascular disease and impacts a great number of patients worldwide. Acute deep vein thrombosis (DVT) is a subset of VTE and is traditionally been treated with anticoagulation. There is good quality data which suggests the use of catheter directed interventions for the treatment of acute DVT with the aim of reducing post-thrombotic syndrome (PTS). The present review will discuss the various therapies available for acute DVT, focusing on catheter directed interventions, ranging from traditional anticoagulation to the most novel forms of aspiration thrombectomy.

Postthrombotic syndrome and other outcomes of lower extremity deep vein thrombosis in children

The frequency of PTS, PE, and DVT recurrence was higher in children with Non-LR DVT than in children with LR DVT. Thrombus resolution, DVT triggering event, and sex were predictors of LE PTS in children.

Diagnosis and Treatment of Lower Extremity Deep Vein Thrombosis: Korean Practice Guidelines

Lower extremity deep vein thrombosis is a serious medical condition that can result in death or major disability due to pulmonary embolism or post-thrombotic syndrome. Appropriate diagnosis and treatment are required to improve symptoms and salvage the affected limb. Early thrombus clearance rapidly resolves symptoms related to venous obstruction, restores valve function and reduces the incidence of post-thrombotic syndrome. Recently, endovascular treatment has been established as a standard method for early thrombus removal. However, there are a variety of views regarding the indications and procedures among medical institutions and operators. Therefore, we intend to provide evidence-based guidelines for diagnosis and treatment of lower extremity deep vein thrombosis by multidisciplinary consensus. These guidelines are the result of a close collaboration between interventional radiologists and vascular surgeons. The goals of these guidelines are to improve treatment, to serve as a guide to the clinician, and consequently to contribute to public health care.

Endovascular Interventions for Acute and Chronic Lower Extremity Deep Venous Disease: State of the Art

The societal and individual burden caused by acute and chronic lower extremity venous disease is considerable. In the past several decades, minimally invasive endovascular interventions have been developed to reduce thrombus burden in the setting of acute deep venous thrombosis to prevent both short- and long-term morbidity and to recanalize chronically occluded or stenosed postthrombotic or nonthrombotic veins in symptomatic patients. This state-of-the-art review provides an overview of the techniques and challenges, rationale, patient selection criteria, complications, postinterventional care, and outcomes data for endovascular intervention in the setting of acute and chronic lower extremity deep venous disease. Online supplemental material is available for this article.

Long-Term Results of Catheter-Directed Thrombolysis Combined with Iliac Vein Stenting for Iliofemoral Deep Vein Thrombosis

Purpose:

We were going to access the effect of catheter-directed thrombolytic therapy (CDT) on post-thrombotic syndrome (PTS) and the long term effects of iliac vein stenting in acute iliofemoral deep vein thrombosis (IFDVT).

Materials and Methods:

Fifty-six limbs in fifty-one patients (46 unilateral, 5 bilateral) were included from November 2001 through December 2007. Patients were classified based on the method of treatment: with stent implantation (n=37) and without stent implantation (n=19). The Villalta scale was chosen to assess for severity of PTS. The validated outcome measures were compared between the treatment groups. Statistical analysis was estimated according to the Kaplan-Meier test and Pearson chi-square test.

Results:

Mean age was 57±13 years (range, 27–76 years). Mean follow up duration was 56±12 months (range, 24–144 months). Overall 5-year primary patency rate was 66.1% (77.8% in the stenting group and 42.1% in the non-stenting group) and showed statistically significant difference between the two groups (P=0.02). The recurrence rate of deep vein thrombosis was 10/37 (27.1%) in the stenting group and 11/19 (57.9%) in the non-stenting group, respectively, which showed statistically significant difference between the two groups (P=0.024). Overall incidence of mild PTS was 8/30 (26.7%): 4/13 (30.8%) in the stenting group and 4/17 (23.5%) in the non-stenting group. None of the other factors showed statistically significant difference between the groups.

Conclusion:

Long term results of CDT in IFDVT were acceptable, and stent implantation to the iliac segment seems to have a good effect on the long term results. Therefore CDT with simultaneous stenting is recommended to improve long term results of IFDVT, if indicated.

Outcomes in children with deep vein thrombosis managed with percutaneous endovascular thrombolysis

BACKGROUND

Our center has developed a multidisciplinary approach to percutaneous endovascular thrombolysis with the goal of improving outcomes in children with thrombosis. There is little data describing the safety and efficacy of endovascular thrombolysis and the frequency of post-thrombotic syndrome after thrombolysis in children.

OBJECTIVE

Retrospective analysis of children undergoing percutaneous endovascular thrombolysis to determine (1) the safety and efficacy of this procedure and (2) the frequency of the diagnosis of post-thrombotic syndrome after thrombolysis.

MATERIALS AND METHODS

We reviewed the medical and imaging databases for children who underwent percutaneous endovascular thrombolysis for deep venous thrombosis (DVT) between November 2008 and June 2013 at our institution. Demographic data were reviewed for the technical success and complications of thrombolysis and the last assigned post-thrombotic syndrome score using standardized scoring tools.

RESULTS

Forty-one children ages 3 months to 21 years (median age: 15 years; 44% male) underwent percutaneous endovascular thrombolysis between November 2008 and June 2013. Upper extremity DVT occurred in 13 patients (32%); lower extremity DVT occurred in 28 patients (68%). All 41 patients received thrombolysis grading; 90% of those patients achieved greater than 50% thrombus lysis. Twenty-eight patients received formal post-thrombotic syndrome scoring and 4 (14%) met diagnostic criteria for post-thrombotic syndrome. One major bleeding episode and one pulmonary embolism occurred with no long-term sequelae.

CONCLUSION

Endovascular thrombolysis for DVT in children is safe, effective at thrombus removal and may reduce the incidence of post-thrombotic syndrome. Randomized or larger clinical trials would be needed to determine the long-term benefits of endovascular thrombolysis.

Radiological diagnosis of dialysis-associated complications

In daily clinical practice, the radiologist in the context of diagnosis often faces dialysis-associated complications. The complications are numerous and range from infections, catheter dysfunctions, haematomas, cardiovascular diseases, digital ischaemia, and pseudoaneurysms to shunt stenosis. In this pictorial essay, we take a close look at the imaging diagnostics of the most common complications in dialysis patients. Teaching Points • The occurrence of venous stenosis in haemodialysis patients is up to 41 %. • Catheters usually have a fibrin sheath that can be rinsed but not aspirated. • The steal phenomenon occurs in 75-90 % of patients with a shunt system. • Arterial pseudoaneurysms can cause a number of complications.

Mechanical thrombolysis of thrombosed central venous port

PURPOSE

To evaluate the effectiveness of a mechanical thrombolysis for thrombosed central venous port (CVP).

METHODS

A total of 38 patients (22 women and 16 men, median age of 55 years) were referred to our interventional unit for thrombosed implanted CVPs. The period between CVP implantation and the initial suspicion of mechanical complication varied from 2 to 35 months (mean 11.5 months) and the interval since last use of the CVP averaged 47 days (range 28-324 days). Our mechanical thrombolysis technique was performed to fragment thrombus in the port chamber by whirling the floppy tip of 0.018-inch hair-wire. Only 19-gauge noncoring needle and 0.018-inch hire-wire were used without cut-down. After removing the hair-wire and placing a second needle, the fragmented thrombi was slowly aspirated with a negative pressure and the remnant thrombus was flushed out by pushing a saline fluid. The degree of fragmentation of thrombus was evaluated with posttreatment angiography; incomplete lysis was defined as more than 50 % of thrombus remaining, significant lysis was 10-50 % of initial thrombosis remaining, and near-complete lysis was less than 10 % thrombus remaining.

RESULTS

We observed near-complete lysis in 22 patients (58 %), significant lysis in 14 patients (37 %), and incomplete lysis in two patients (5 %). The technical success rate was 82 % (31 of 38 patients). There were no major or minor complications in the recovery room during a 30-min observation period or late complications at outpatient follow-up.

CONCLUSION

A mechanical thrombolysis technique can be used to dissolve thrombus effectively from thrombosed implanted CVP on an outpatient basis.

Treating infrainguinal deep venous thrombosis

Endovascular DVT therapy has historically been directed at patients with the most extensive DVT. As evidence has been developed to support the use of catheter-directed thrombolysis for iliofemoral DVT, interventional radiologists are increasingly being referred patients with DVT that is anatomically less severe. In this article, we outline the key considerations that should be weighed in determining whether or not to provide aggressive therapy to patients with DVT limited to the femoropopliteal veins.

Pulmonary embolism and stroke associated with mechanical thrombectomy

Mechanical thrombectomy offers the advantage of rapid removal of venous thrombi. It allows venous obstructions to be removed and requires shorter duration of infusion of thrombolytic agents. However, aspiration of thrombi can lead to complications, particularly pulmonary embolism and hemolysis. The validity of using vena cava filters during thrombectomy in order to avoid embolism has not yet been established. The authors report a case of massive pulmonary embolism associated with ischemic stroke in a patient with a hitherto undiagnosed patent foramen ovale. The patient developed respiratory failure and neurological deficit after thrombectomy. This case raise questions about the value of the thrombectomy for the treatment of proximal vein thrombosis due to the risks of this procedure. The authors also discuss the need for vena cava filters and ruling out a patent foramen ovale in patients undergoing thrombectomy.

Rationale and design of the ATTRACT Study: a multicenter randomized trial to evaluate pharmacomechanical catheter-directed thrombolysis for the prevention of postthrombotic syndrome in patients with proximal deep vein thrombosis

BACKGROUND

Current standard therapy for patients with acute proximal deep vein thrombosis (DVT) consists of anticoagulant therapy and graduated elastic compression stockings. Despite use of this strategy, the postthrombotic syndrome (PTS) develops frequently, causes substantial patient disability, and impairs quality of life. Pharmacomechanical catheter-directed thrombolysis (PCDT), which rapidly removes acute venous thrombus, may reduce the frequency of PTS. However, this hypothesis has not been tested in a large multicenter randomized trial.

STUDY DESIGN

The ATTRACT Study is an ongoing National Institutes of Health-sponsored, Phase III, multicenter, randomized, open-label, assessor-blinded, parallel two-arm, controlled clinical trial. Approximately 692 patients with acute proximal DVT involving the femoral, common femoral, and/or iliac vein are being randomized to receive PCDT + standard therapy versus standard therapy alone. The primary study hypothesis is that PCDT will reduce the proportion of patients who develop PTS within 2 years by one-third, assessed using the Villalta Scale. Secondary outcomes include safety, general and venous disease-specific quality of life, relief of early pain and swelling, and cost-effectiveness.

CONCLUSION

ATTRACT will determine if PCDT should be routinely used to prevent PTS in patients with symptomatic proximal DVT above the popliteal vein.

Indications for stenting during thrombolysis

The most important vein segment to thrombolyse after deep venous thrombosis (DVT) is the outflow tract meaning the iliofemoral vein. Iliofemoral DVT is defined as DVT in the iliac vein and the common femoral vein. Spontaneous recanalization is less than 50%, particularly on the left side. The compression from adjacent structures, predominantly on the left side is known as the iliac vein compression syndrome. Therefore, it is essential that supplementary endovenous procedures have to be performed in case of persistent obstructive lesions following catheter-directed thrombolysis. Insertion of a stent in this position is the treatment of choice facilitating the venous flow into an unobstructed outflow tract either from the femoral vein or the deep femoral vein or both. The stent, made of stainless steel or nitinol, has to be self-expandable and flexible with radial force to overcome the challenges in this low-pressure system. The characteristics of the anatomy with external compression and often a curved vein segment with diameter difference make stent placement necessary. Ballooning alone has no place in this area. The proportion of inserted stents varies in the published materials with catheter-directed thrombolysis of iliofemoral deep venous thrombosis.

Treatment of high-risk venous thrombosis patients using low-dose intraclot injections of recombinant tissue plasminogen activator and regional anticoagulation

Seven patients with venous thrombosis and contraindications to traditional thrombolytic therapy, consisting of recent intracranial surgery, recent pineal or retroperitoneal hemorrhage, active genitourinary or gastrointestinal bleeding, epidural procedures, and impending surgery, were successfully treated with a modified thrombolytic regimen. To improve safety, prolonged continuous infusions of tissue plasminogen activator (tPA) was eliminated in favor of once-daily low-dose intraclot injections of tPA to minimize the amount and duration of tPA in the systemic circulation, and low-therapeutic or regional anticoagulation was used to reduce anticoagulant risks. These modifications may allow thrombolytic treatment for selected patients with severe venous thrombosis who are deemed to be at high risk.

Interventional approaches to deep vein thrombosis

The last decade has seen increased use of aggressive, catheter-based methods of treating deep vein thrombosis (DVT). In this article, we outline the risks, benefits, and uncertainties surrounding endovascular DVT therapies, describe clinical situations in which endovascular treatment options should reasonably be considered, and update the reader on new outcome data that pertains to catheter-based DVT interventions. Endovascular thrombolytic therapy is reasonable to perform for selected patients with DVT causing acute limb-threatening circulatory compromise, acute inferior vena cava occlusion, or acute iliofemoral DVT for the purposes of limb salvage and relief of presenting DVT symptoms, and appears likely to prevent post-thrombotic syndrome (PTS) in patients with proximal DVT. A multicenter randomized trial, the ATTRACT Study, is currently underway in the United States to determine whether pharmacomechanical catheter-directed thrombolysis (PCDT) is sufficiently safe and effective to be recommended for routine use in proximal DVT patients. Selected patients with established moderate-to-severe PTS in association with an occluded iliac vein or a refluxing saphenous vein may also be amenable to endovascular intervention to reduce venous hypertension, alleviate symptoms, and improve limb function and quality of life. Pending the results of further studies, an individualized approach to patient selection for interventional DVT therapies is recommended.

Rationale and Indications for Aggressive Early Thrombus Removal

Randomized clinical trials have defined anticoagulation with unfractionated or low-molecular-weight heparin followed by warfarin as a standard therapy for acute deep venous thrombosis (DVT). Such treatment is highly effective in preventing recurrent venous thromboembolism with a low risk of bleeding, but provides imperfect protection against development of the post-thrombotic syndrome. Several strategies of early thrombus removal, including surgical venous thrombectomy, catheter-directed thrombolysis and pharmacomechanical thrombectomy have been developed with the goal of reducing the incidence of the post-thrombotic syndrome by restoring venous patency and preserving valvular function. Although clinical judgement and a consideration of the individual patient's medical condition and values are required, early thrombus removal strategies should be considered in selected patients with phlegmasia cerulea dolens and those with a first episode of acute iliofemoral thrombosis of less than 14 days duration.

Long-term outcome after additional catheter-directed thrombolysis versus standard treatment for acute iliofemoral deep vein thrombosis (the CaVenT study): a randomised controlled trial

BACKGROUND

Conventional anticoagulant treatment for acute deep vein thrombosis (DVT) effectively prevents thrombus extension and recurrence, but does not dissolve the clot, and many patients develop post-thrombotic syndrome (PTS). We aimed to examine whether additional treatment with catheter-directed thrombolysis (CDT) using alteplase reduced development of PTS.

METHODS

Participants in this open-label, randomised controlled trial were recruited from 20 hospitals in the Norwegian southeastern health region. Patients aged 18-75 years with a first-time iliofemoral DVT were included within 21 days from symptom onset. Patients were randomly assigned (1:1) by picking lowest number of sealed envelopes to conventional treatment alone or additional CDT. Randomisation was stratified for involvement of the pelvic veins with blocks of six. We assessed two co-primary outcomes: frequency of PTS as assessed by Villalta score at 24 months, and iliofemoral patency after 6 months. Analyses were by intention to treat. This trial is registered at ClinicalTrials.gov, NCT00251771.

FINDINGS

209 patients were randomly assigned to treatment groups (108 control, 101 CDT). At completion of 24 months' follow-up, data for clinical status were available for 189 patients (90%; 99 control, 90 CDT). At 24 months, 37 (41·1%, 95% CI 31·5-51·4) patients allocated additional CDT presented with PTS compared with 55 (55·6%, 95% CI 45·7-65·0) in the control group (p=0·047). The difference in PTS corresponds to an absolute risk reduction of 14·4% (95% CI 0·2-27·9), and the number needed to treat was 7 (95% CI 4-502). Iliofemoral patency after 6 months was reported in 58 patients (65·9%, 95% CI 55·5-75·0) on CDT versus 45 (47·4%, 37·6-57·3) on control (p=0·012). 20 bleeding complications related to CDT included three major and five clinically relevant bleeds.

INTERPRETATION

Additional CDT should be considered in patients with a high proximal DVT and low risk of bleeding.

FUNDING

South-Eastern Norway Regional Health Authority; Research Council of Norway; University of Oslo; Oslo University Hospital.