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

Effects of Deep Venous Thrombosis Treatments on Early and Long-term Quality of Life: Medical Therapy vs. Systemic Thrombolysis vs. Pharmacomechanical Thrombolysis

OBJECTIVES

The present study aimed to compare the effects of medical therapy (MT), systemic thrombolysis (ST), and pharmacomechanical thrombolysis (PMT) methods used in our clinic for the treatment of deep venous thrombosis (DVT) on symptom reduction, the incidence of post-thrombotic syndrome (PTS) development, and quality of life.

METHODS

Data from160 patients diagnosed with acute DVT between January 2012 and May 2021 and treated and followed up in our clinic were retrospectively analyzed. The patients were divided into three groups according to treatment method. The patients who received MT treatment were defined as Group 1, anticoagulant treatment after ST as Group 2, and anticoagulant treatment after PMT as Group 3. The patients were called to the outpatient clinic, informed consent was obtained, EuroQol-5D-3 L (EQ-5D-3 L) scoring and Villalta scoring were performed, and anamnesis was taken.

RESULTS

A total of 160 patients were included, with 71 (44.4%) patients in Group 1, 45 (28.1%) in Group 2, and 44 (27.5%) in Group 3. The mean age was 48.9 ± 14.9 years for Group 1, 42.2 ± 10.8 for Group 2, and 29.0 ± 7.2 for Group 3. When the time to return to normal life and the EQ-5D-3 L score index were compared, the differences between Groups 1 and 2 and between Groups 1 and 3 were statistically significant (P = .000 and P = .000, respectively). However, the differences between Groups 2 and 3 were statistically insignificant (P = .213 andp = .074, respectively). When Villalta scores and EQ Visual Analogue Scale (EQ-VAS) scores were compared between groups, the difference between all groups was statistically significant (P = .000).

CONCLUSIONS

The medical treatment alone was observed to be insufficient in terms of symptomatic improvement, development of PTS, quality of life, and long-term complications. When the ST and PMT groups were compared, it was determined that PMT treatment was more advantageous in terms of EQ-VAS score and PTS development, although there was no statistical difference regarding complications, such as return to normal life and long-term quality of life, the incidence of recurrent DVT development, and pulmonary thromboembolism incidence.

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.

Predictors of long-term outcomes after catheter-directed thrombolysis combined with stent implantation in acute deep vein thrombosis secondary to iliac vein compression

The purpose of this study is to analyze predictive factors for long-term clinical outcomes after catheter-directed thrombolysis (CDT) combined with stent implantation for acute deep vein thrombosis (DVT) secondary to iliac vein compression (IVC). A retrospective analysis was performed to review clinical data and follow-up information on 52 patients who underwent CDT combined with stent implantation for acute DVT secondary to IVC from June 2015 to March 2020. Clinical outcomes including stent patency and incidence of postthrombotic syndrome (PTS) were investigated using Kaplan-Meier analysis. All included patients were categorized into 2 groups according to the presence of PTS. Potential risk factors, including age, gender, degree of iliac vein stenosis, time from onset to treatment, dosage of thrombolytic agent, stent extending below the inguinal ligament, and duration of anticoagulation for PTS were evaluated using multivariate logistic regression analysis. Over a median follow-up of 24 months, 4 individuals underwent reintervention due to in-stent stenosis or stent compression. Primary stent patency was 98.1% at 1 month, 94.2% at 6 months, 90.4% at 12 months, and 88.5% at 24 months. Freedom from PTS was 98.1% at 6 months, 84.6% at 12 months, and 75% at 24 months. No treatment-related mortality or morbidity was observed. Based on the development of PTS, 13 patients with PTS were classified into group A and 39 patients without PTS were regarded as group B. Upon multivariate logistic regression analysis, key prognostic factors for PTS were degree of iliac vein stenosis and time from onset to treatment. CDT combined with stent implantation is safe and effective for acute DVT secondary to IVC in the long-term perspective. Severe iliac vein stenosis and longer period from onset to treatment may be associated with a higher risk of PTS.

Mechanical Thrombectomy for Acute and Subacute Blocked Arteries and Veins in the Lower Limbs: A Health Technology Assessment

Background

A blockage to the blood vessels in the lower extremities may cause pain and discomfort. If left unmanaged, it may lead to amputation or chronic disability, such as in the form of post-thrombotic syndrome. We conducted a health technology assessment of mechanical thrombectomy (MT) devices, which are proposed to remove a blood clot, which may form in the arteries or veins of the lower legs. This evaluation considered blockages in the veins and arteries separately, and included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding MT for lower limb blockages, patient preferences and values, and clinical and health system stakeholders' perspectives.

Method

We performed a systematic literature search of the clinical evidence. We assessed the risk of bias of each included study using the Cochrane tool for randomized controlled trials or the risk of bias among non-randomized studies (RoBANS) tool for nonrandomized studies, and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search. We did not conduct a primary economic evaluation since the clinical evidence is highly uncertain. We also analyzed the budget impact of publicly funding MT treatment for inpatients with arterial acute limb ischemia and acute deep vein thrombosis (DVT) in the lower limb in Ontario. To contextualize the potential value of MT, we spoke with people with acute DVT. To understand the barriers and facilitators of accessing MT, we surveyed clinical and health system stakeholders to gain their perspectives.

Results

We included 40 studies (3 randomized controlled trials and 37 observational studies) in the clinical evidence review. For patients who experience arterial acute limb ischemia, compared with catheter-directed thrombolysis (CDT) alone, MT has greater technical success and patency and reduced hospital length of stay, but the evidence for these outcomes is uncertain (GRADE: Very low). Mechanical thrombectomy may reduce the volume of thrombolytic medication required and CDT infusion time (a determinant for intensive care unit [ICU] need) in patients experiencing acute DVT, but it is uncertain if this is to a meaningful degree (GRADE: Moderate to Very low). It may also reduce the proportion of people who experience post-thrombotic syndrome and overall hospital length of stay, but it is uncertain (GRADE: Very low).We estimated that publicly funding MT for people with arterial acute limb ischemia in Ontario would lead to an annual cost savings of $0.17 million in year 1 to $0.14 million in year 5, for a total savings of $0.83 million over 5 years. This cost savings was mainly attributed to reduced ICU stays among people who received MT, but the results had considerable uncertainty. For the population with acute DVT, publicly funding MT would lead to an additional cost of $0.77 million in year 1 to $1.44 million in year 5, for a total additional cost of $5.5 million over 5 years.The people with acute DVT with whom we spoke reported that MT was generally seen as a positive option, and those who had undergone the procedure reported positively on its value as a treatment to quickly remove a clot. Accessing treatment for DVT could be a barrier, especially in more remote areas of Ontario.Clinicians using the technology advised that facilitators to accessing the technology included perceived improvements in patient outcomes, resourcing requirements, addressing unmet needs, and avoidance of ICU stay. The main barrier identified was cost. Clinicians who were not using the technology advised that barriers were low case-use volume, along with costs for the equipment and for health human resources.

Conclusions

Mechanical thrombectomy may have greater technical success and patency and reduce hospital length of stay for patients experiencing an arterial acute limb ischemia and, for patients with an acute DVT, it may reduce CDT volume and infusion time, the proportion of people who experience post-thrombotic syndrome, and hospital length of stay. Mechanical thrombectomy may reduce the associated ICU costs, but it has higher equipment costs compared with usual care. Publicly funding MT in Ontario for populations with arterial acute limb ischemia may not lead to a substantial budget increase to the province. Publicly funding MT for acute DVT would lead to an additional cost of $5.5 million over 5 years. For people with acute DVT, MT was seen as a potential positive treatment option to remove the clot quickly. Overall, the majority of clinical stakeholders we engaged with (including both those with and without experience with MT) were supportive of the use of the technology.

Exploring the Villalta scale to capture postthrombotic syndrome using alternative approaches: A subanalysis of the ATTRACT trial

Background

Clinical trials that evaluated interventions to prevent postthrombotic syndrome (PTS) used the Villalta scale (VS) to define PTS, but there is a lack of consistency in its use.

Objectives

This study aimed to improve the ability to identify patients with clinically meaningful PTS after DVT in participants of the ATTRACT trial.

Methods

We conducted a post hoc exploratory analysis of 691 patients from the ATTRACT study, a randomized trial evaluating the effectiveness of pharmacomechanical thrombolysis to prevent PTS in proximal deep vein thrombosis. We compared 8 VS approaches to classify patients with or without PTS in terms of their ability to discriminate between those with poorer vs better venous disease-specific quality of life (Venous Insufficiency Epidemiological and Economic Study Quality of Life [VEINES-QOL]) between 6- and 24-months follow-up. The difference in the average area under the fitted curve of VEINES-QOL scores between PTS and no PTS ( Δ A U C ¯ ) were compared among approaches.

Results

For any PTS (a single VS score ≥5), approaches 1 to 3 had similar Δ A U C ¯ (-21.2, -23.7, -22.0, respectively). Adjusting the VS for contralateral chronic venous insufficiency (CVI) or restricting to patients without baseline CVI (approaches 7 and 8) did not improve Δ A U C ¯ (-13.6, -19.9, respectively; P >.01). For moderate-to-severe PTS (a single VS score ≥10), approaches 5 and 6 requiring 2 positive assessments had greater but not statistically significant Δ A U C ¯ than approach 4, using one single positive assessment (-31.7, -31.0, -25.5, respectively; P >.01).

Conclusion

A single VS score of ≥ 5 reliably distinguishes patients with clinically meaningful PTS as assessed by impact on QOL and is preferred because of greater convenience (only one assessment needed). Alternative methods to define PTS (ie, adjusting for CVI) do not improve the scale's ability to identify clinically meaningful PTS.

Closing the Gaps in Racial Disparities in Critical Limb Ischemia Outcome and Amputation Rates: Proceedings from a Society of Interventional Radiology Foundation Research Consensus Panel

Minority patients such as Blacks, Hispanics, and Native Americans are disproportionately impacted by critical limb ischemia and amputation due to multiple factors such as socioeconomic status, type or lack of insurance, lack of access to health care, capacity and expertise of local hospitals, prevalence of diabetes, and unconscious bias. The Society of Interventional Radiology Foundation recognizes that it is imperative to close the disparity gaps and funded a Research Consensus Panel to prioritize a research agenda. The following research priorities were ultimately prioritized: (a) randomized controlled trial with peripheral arterial disease screening of at-risk patients with oversampling of high-risk racial groups, (b) prospective trial with the introduction of an intervention to alter a social determinant of health, and (c) a prospective trial with the implementation of an algorithm that requires criteria be met prior to an amputation. This article presents the proceedings and recommendations from the panel.

Invasive and Pharmacological Treatment of Deep Vein Thrombosis: a Scoping Review

The annual occurrence of venous thromboembolism (VTE) is 300,000-600,000 cases in the United States and 700,000 in Europe. VTE includes deep venous thrombosis (DVT) of upper or lower extremities, superior and inferior vena cava thrombosis, and pulmonary embolism (PE) as well. The primary treatment of DVT includes oral anticoagulation to prevent the progression of the thrombus and decrease the risk of pulmonary embolism. Depending on the symptoms, more invasive treatments can be applied to target the iliofemoral thrombus and its removal. However, less emphasis is given to acute symptomatology, early recovery of function, quality of life improvement, and the individualized likelihood of developing post-thrombotic syndrome. While invasive therapy has been used to enhance the acute management of iliofemoral DVT, our knowledge about the overall outcomes associated with the invasive treatment of VTE is still limited. In this review, we illustrate the available data on pharmacological and endovascular management of iliofemoral VTE, including therapies such as catheter-directed thrombolysis (CDT), mechanical thrombectomy (PMT), and pharmacomechanical catheter-directed thrombolysis (PCDT).

The shifting care and outcomes for patients with endangered limbs - Critical limb ischemia (SCOPE-CLI) registry overview of study design and rationale

BACKGROUND

Critical limb ischemia (CLI), the most severe form of peripheral artery disease, is associated with pain, poor wound healing, high rates of amputation, and mortality (>20% at 1 year). Little is known about the processes of care, patients' preferences, or outcomes, as seen from patients' perspectives. The SCOPE-CLI study was co-designed with patients to holistically document patient characteristics, treatment preferences, patterns of care, and patient-centered outcomes for CLI.

METHODS

This 11-center prospective observational registry will enroll and interview 816 patients from multispecialty, interdisciplinary vascular centers in the United States and Australia. Patients will be followed up at 1, 2, 6, and 12 months regarding their psychosocial factors and health status. Hospitalizations, interventions, and outcomes will be captured for 12 months with vital status extending to 5 years. Pilot data were collected between January and July of 2021 from 3 centers.

RESULTS

A total of 70 patients have been enrolled. The mean age was 68.4 ± 11.3 years, 31.4% were female, and 20.0% were African American.

CONCLUSIONS

SCOPE-CLI is uniquely co-designed with patients who have CLI to capture the care experiences, treatment preferences, and health status outcomes of this vulnerable population and will provide much needed information to understand and address gaps in the quality of CLI care and outcomes.ClinicalTrials.gov identifier (NCT Number): NCT04710563 https://clinicaltrials.gov/ct2/show/NCT04710563.

Does ATTRACT change our DVT management practice?

In 2017, the long awaited results of the ATTRACT trial were published in the New England Journal of Medicine leaving the scientific community with disappointment as the study did not show the expected results. Producing not the expected outcome is not uncommon in science - furthermore, it is important to disapprove common beliefs. But has the ATTRACT trial really the power to change our practice? Are the results correct in terms of evidence based on the methods used?

A Retrospective Comparison of Catheter-Directed Thrombolysis versus Pharmacomechanical Thrombolysis for Treatment of Acute Lower Extremity Deep Venous Thrombosis

BACKGROUND

Pharmacomechanical thrombolysis (PMT) and catheter-directed thrombolysis (CDT) are frequently employed for treating deep venous thrombosis (DVT). However, there have been relatively few studies comparing PMT outcomes to those associated with CDT. The present study was thus designed to compare short- and mid-term PMT and CDT patient outcomes following the treatment of DVT of the lower extremities.

METHODS

This study was a retrospective analysis of 98 patients treated at the 3rd Affiliated Hospital of Shenzhen University (Shenzhen, China) and Beijing Chao Yang Hospital (Beijing, China). All patients had undergone treatment for symptomatic DVT of the lower legs via either CDT or PMT. Clinical records and outcome data between the patients in these 2 treatment groups were compared.

RESULTS

Of the 98 patients analyzed in this retrospective study, 50 had been treated via CDT while 48 had undergone PMT. These PMT and CDT operations were associated with mean treatment durations of 0.97 ± 0.20 hr and 32.48 ± 7.46 hr, respectively (P < 0.0001). Complete lysis was achieved in 78 patients (42 and 36 in the PMT and CDT groups, respectively P = 0.057), while effective lysis was achieved in 96 patients (48 and 48 in the PMT and CDT groups, respectively P = 0.162), with lysis being ineffective in the 2 remaining patients. PMT was associated with a significantly decreased length of hospital stay, usage of UK dose, and treatment duration relative to CDT(P < 0.0001). No major complications or MACE incidence were noted in either group, although 18 patients in the PMT group suffered from bradyarrhythmia (P = 0.007). Clinical efficacy was achieved in 96 patients (48 in each treatment group) at time of discharge (P = 0.162). A Kaplan-Meier analysis revealed that 2-year primary patency rates did not differ significantly between these 2 groups (P = 0.442).

CONCLUSION

PMT is an effective treatment modality in patients with symptomatic DVT. Relative to CDT it is associated with high treatment success rates, reduced treatment duration, and reduced hospitalization duration, although it is also associated with higher rates of systemic complications.

Thrombolytic strategies versus standard anticoagulation for acute deep vein thrombosis of the lower limb

BACKGROUND

Standard treatment for deep vein thrombosis (DVT) aims to reduce immediate complications. Use of thrombolytic clot removal strategies (i.e. thrombolysis (clot dissolving drugs), with or without additional endovascular techniques), could reduce the long-term complications of post-thrombotic syndrome (PTS) including pain, swelling, skin discolouration, or venous ulceration in the affected leg. This is the fourth update of a Cochrane Review first published in 2004.

OBJECTIVES

To assess the effects of thrombolytic clot removal strategies and anticoagulation compared to anticoagulation alone for the management of people with acute deep vein thrombosis (DVT) of the lower limb.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and AMED and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registries to 21 April 2020. We also checked the references of relevant articles to identify additional studies.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) examining thrombolysis (with or without adjunctive clot removal strategies) and anticoagulation versus anticoagulation alone for acute DVT.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as recommended by Cochrane. We assessed the risk of bias in included trials with the Cochrane 'Risk of bias' tool. Certainty of the evidence was evaluated using GRADE. For dichotomous outcomes, we calculated the risk ratio (RR) with the corresponding 95% confidence interval (CI). We pooled data using a fixed-effect model, unless we identified heterogeneity, in which case we used a random-effects model. The primary outcomes of interest were clot lysis, bleeding and post thrombotic syndrome.

MAIN RESULTS

Two new studies were added for this update. Therefore, the review now includes a total of 19 RCTs, with 1943 participants. These studies differed with respect to the thrombolytic agent, the doses of the agent and the techniques used to deliver the agent. Systemic, loco-regional and catheter-directed thrombolysis (CDT) strategies were all included. For this update, CDT interventions also included those involving pharmacomechanical thrombolysis. Three of the 19 included studies reported one or more domain at high risk of bias. We combined the results as any (all) thrombolysis interventions compared to standard anticoagulation. Complete clot lysis occurred more frequently in the thrombolysis group at early follow-up (RR 4.75; 95% CI 1.83 to 12.33; 592 participants; eight studies) and at intermediate follow-up (RR 2.42; 95% CI 1.42 to 4.12; 654 participants; seven studies; moderate-certainty evidence). Two studies reported on clot lysis at late follow-up with no clear benefit from thrombolysis seen at this time point (RR 3.25, 95% CI 0.17 to 62.63; two studies). No differences between strategies (e.g. systemic, loco-regional and CDT) were detected by subgroup analysis at any of these time points (tests for subgroup differences: P = 0.41, P = 0.37 and P = 0.06 respectively). Those receiving thrombolysis had increased bleeding complications (6.7% versus 2.2%) (RR 2.45, 95% CI 1.58 to 3.78; 1943 participants, 19 studies; moderate-certainty evidence). No differences between strategies were detected by subgroup analysis (P = 0.25). Up to five years after treatment, slightly fewer cases of PTS occurred in those receiving thrombolysis; 50% compared with 53% in the standard anticoagulation (RR 0.78, 95% CI 0.66 to 0.93; 1393 participants, six studies; moderate-certainty evidence). This was still observed at late follow-up (beyond five years) in two studies (RR 0.56, 95% CI 0.43 to 0.73; 211 participants; moderate-certainty evidence). We used subgroup analysis to investigate if the level of DVT (iliofemoral, femoropopliteal or non-specified) had an effect on the incidence of PTS. No benefit of thrombolysis was seen for either iliofemoral or femoropopliteal DVT (six studies; test for subgroup differences: P = 0.29). Systemic thrombolysis and CDT had similar levels of effectiveness. Studies of CDT included four trials in femoral and iliofemoral DVT, and results from these are consistent with those from trials of systemic thrombolysis in DVT at other levels of occlusion.

AUTHORS' CONCLUSIONS

Complete clot lysis occurred more frequently after thrombolysis (with or without additional clot removal strategies) and PTS incidence was slightly reduced. Bleeding complications also increased with thrombolysis, but this risk has decreased over time with the use of stricter exclusion criteria of studies. Evidence suggests that systemic administration of thrombolytics and CDT have similar effectiveness. Using GRADE, we judged the evidence to be of moderate-certainty, due to many trials having small numbers of participants or events, or both. Future studies are needed to investigate treatment regimes in terms of agent, dose and adjunctive clot removal methods; prioritising patient-important outcomes, including PTS and quality of life, to aid clinical decision making.

Diagnosis and treatment of iliac vein stenosis

Stenosis of the iliac veins is common in patients with chronic venous insufficiency. The article describes the methods for the diagnosis and treatment of iliac vein stenosis. The causes of iliac vein stenosis include extravasal compression or the consequences of ileofemoral thrombosis. Stenosis of the iliac veins exists in 1/4 of the entire adult population, but clinical manifestations do not occur in all patients. Stenosis of the iliac veins should be considered in case of an unknown edema, more often in the left lower extremity, since venous duplex ultrasound of lower extremities is not sensitive and specific enough when examining the veins above the inguinal ligament. The most accurate diagnostic method is intravascular ultrasound (IVUS) but the appeared computed tomography angiography (CTA) and magnetic resonance angiography (MRA) with high-quality images have become a good replacement for IVUS. The main method of treatment of iliac vein stenosis, besides stenting, isindispensable drug therapy consisting of antithrombotic and phlebotonic drugs.

Trans-jugular AngioJet rheolytic thrombectomy for acute deep vein thrombosis: Alternative to overcome the limitation of patient's position

BACKGROUND

To introduce a transjugular retrograde approach for AngioJet rheolytic thrombectomy (RT) just after transjugular placement of inferior vena cava filter (IVCF) to treat acute deep vein thrombosis (DVT).

METHODS

From September 2018 to April 2019, transjugular Angiojet RT using pulse spray method was performed just after transjugular placement of IVCF in five patients (M:F = 3:2, mean age 70 years). Patients less than 165 cm in height with acute (<14 days) iliofemoral DVT were unable to assume a prone position. All patients underwent pre- and postprocedural venography to estimate thrombus reduction grade. Computed tomography angiograms at 3 and 6 months postoperative were compared with baseline scans. Post-thrombotic syndrome (PTS) symptoms were evaluated according to Villalta score during 12-month follow-up.

RESULTS

Mean procedure time for all procedures was 1.4 h. Thrombus was completely reduced in three patients and 50% to 99% reduction was noted in the other two. No patients had major complications during the hospital stay and follow-up period. Distal migration of IVCF occurred in one patient during the procedure and immediate IVCF repositioning was performed. No DVT remained in follow-up computed tomography scans of all patients. PTS did not develop in any patients during the follow-up period.

CONCLUSION

In patients who are unable to assume a prone position, a transjugular retrograde approach with AngioJet RT just after transjugular placement of IVCF to treat acute lower extremity DVT was a time-saving and easy alternative. During the procedure, attention to the guiding catheter position and AngioJet device movement was required to avoid affecting the IVCF.

Acute Deep Vein Thrombosis and Pulmonary Embolism: is the Thromboaspiration Device an Appropriate Choice?

Nowadays patients affected by deep vein thrombosis (DVT) and pulmonary embolism (PE) are studied widely but the challenge for physicians is when and how they are to be treated. Most patients present serious comorbidities that can potentially make treatment difficult. An increasing cohort of patients cannot be treated with systemic fibrinolysis but fortunately today, physicians can utilize a number of different instruments to resolve acute DVT and PE.

Quality of life after pharmacomechanical catheter-directed thrombolysis for proximal deep venous thrombosis

BACKGROUND

After deep venous thrombosis (DVT), many patients have impaired quality of life (QOL). We aimed to assess whether pharmacomechanical catheter-directed thrombolysis (PCDT) improves short-term or long-term QOL in patients with proximal DVT and whether QOL is related to extent of DVT.

METHODS

The Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) trial was an assessor-blinded randomized trial that compared PCDT with no PCDT in patients with DVT of the femoral, common femoral, or iliac veins. QOL was assessed at baseline and 1 month, 6 months, 12 months, 18 months, and 24 months using the Venous Insufficiency Epidemiological and Economic Study on Quality of Life/Symptoms (VEINES-QOL/Sym) disease-specific QOL measure and the 36-Item Short Form Health Survey (SF-36) physical component summary (PCS) and mental component summary general QOL measures. Change in QOL scores from baseline to assessment time were compared in the PCDT and no PCDT treatment groups overall and in the iliofemoral DVT and femoral-popliteal DVT subgroups.

RESULTS

Of 692 ATTRACT patients, 691 were analyzed (mean age, 53 years; 62% male; 57% iliofemoral DVT). VEINES-QOL change scores were greater (ie, better) in PCDT vs no PCDT from baseline to 1 month (difference, 5.7; P = .0006) and from baseline to 6 months (5.1; P = .0029) but not for other intervals. SF-36 PCS change scores were greater in PCDT vs no PCDT from baseline to 1 month (difference, 2.4; P = .01) but not for other intervals. Among iliofemoral DVT patients, VEINES-QOL change scores from baseline to all assessments were greater in the PCDT vs no PCDT group; this was statistically significant in the intention-to-treat analysis at 1 month (difference, 10.0; P < .0001) and 6 months (8.8; P < .0001) and in the per-protocol analysis at 18 months (difference, 5.8; P = .0086) and 24 months (difference, 6.6; P = .0067). SF-36 PCS change scores were greater in PCDT vs no PCDT from baseline to 1 month (difference, 3.2; P = .0010) but not for other intervals. In contrast, in femoral-popliteal DVT patients, change scores from baseline to all assessments were similar in the PCDT and no PCDT groups.

CONCLUSIONS

Among patients with proximal DVT, PCDT leads to greater improvement in disease-specific QOL than no PCDT at 1 month and 6 months but not later. In patients with iliofemoral DVT, PCDT led to greater improvement in disease-specific QOL during 24 months.

In-hospital outcomes of catheter-directed thrombolysis versus anticoagulation in cancer patients with proximal deep venous thrombosis

OBJECTIVE

The objective of this study was to determine the rate of complications of catheter-directed thrombolysis (CDT) in cancer patients with deep venous thrombosis (DVT) compared with anticoagulation therapy alone.

METHODS

This observational study used the National Inpatient Sample database to screen for any cancer patients who were admitted with a principal discharge diagnosis of proximal lower extremity or caval DVT between January 2005 and December 2013. Patients treated with CDT plus anticoagulation were compared with those treated with anticoagulation alone using propensity score matching for comorbidities and demographic characteristics. The primary end point was in-hospital mortality. Secondary end points were acute intracranial hemorrhage, inferior vena cava filter placement, acute renal failure, blood transfusion rates, length of stay, and hospital charges.

RESULTS

We identified 31,124 cancer patients with lower extremity proximal or caval DVT, and 1290 (4%) patients were treated with CDT. Comparative outcomes as assessed in the two matched groups of 1297 patients showed that there was no significant difference in in-hospital mortality of patients undergoing CDT plus anticoagulation compared with those treated with anticoagulation alone (2.6% vs 1.9%; P = .23). However, CDT was associated with increased risk of intracranial hemorrhage (1.3% vs 0.4%; P = .017), greater blood transfusion rates (18.6% vs 13.1 %; P < .001), and higher rates of procedure-related hematoma (2.4% vs 0.4%; P < .001). The length of stay (6.0 [4.0-10.0] days vs 4.0 [2.0-7.0] days; P < .001) and hospital charges ($81,535 [$50,968-$127,045] vs $22,320 [$11,482-$41,005]; P < .001) were also higher in the CDT group compared with the control group.

CONCLUSIONS

There was no significant difference in in-hospital mortality of cancer patients who underwent CDT plus anticoagulation compared with anticoagulation alone. CDT was associated with increased in-hospital morbidity and resource utilization compared with anticoagulation alone. Further studies are needed to examine the effect of CDT on the development of PTS in this population.

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.

A case-controlled study on AngioJet rheolytic thrombectomy and catheter-directed thrombolysis in the treatment of acute lower extremity deep venous thrombosis

Objective

This study aims to compare the efficacy and safety of AngioJet rheolytic thrombectomy vs. catheter-directed thrombolysis in patients with acute lower extremity deep vein thrombosis.

Methods

Between the period of February 2015 and October 2016, 65 patients with documented acute lower extremity deep vein thrombosis were treated with catheter-directed intervention. These patients were divided into two groups: AngioJet group and catheter-directed thrombolysis group. Comparisons were made with regard to efficacy and safety between these two groups.

Results

In the AngioJet group, complete or partial thrombus removal was accomplished in 23 (72%) and 3 (9%) patients, respectively. In the catheter-directed thrombolysis group, complete or partial thrombus removal was accomplished in 27 (82%) patients and 1 (3%) patient, respectively. In the AngioJet group, the perimeter difference between the suffered limb and healthy one declined from 5.1 ± 2.3 cm to 1.4 ± 1.2 cm ( P <  0.05). In the catheter-directed thrombolysis group, the perimeter difference declined from 4.7 ± 1.6 cm to 1.5 ± 0.9 cm ( P <  0.05). The mean urokinase dose was 0.264 ± 0.135 million units in the AngioJet group and 1.869 ± 0.528 million units in the catheter-directed thrombolysis group ( P <  0.05). The duration of thrombolysis was 4.2 ± 1.7 h in the AngioJet group and 73.6 ± 18.3 h in the catheter-directed thrombolysis group ( P <  0.05). The occurrence of complications in these two groups was 19% and 18%, respectively (not significant).

Conclusion

AngioJet rheolytic thrombectomy is a new, safe and effective approach for treating acute lower extremity deep vein thrombosis. When compared to catheter-directed thrombolysis, this treatment provides similar success with lower urokinase dosage and shorter duration of thrombolysis.

Cost-Effectiveness of Pharmacomechanical Catheter-Directed Thrombolysis Versus Standard Anticoagulation in Patients With Proximal Deep Vein Thrombosis: Results From the ATTRACT Trial

BACKGROUND

In patients with acute deep vein thrombosis (DVT), pharmacomechanical catheter-directed thrombolysis (PCDT) in conjunction with anticoagulation therapy is increasingly used with the goal of preventing postthrombotic syndrome. Long-term costs and cost-effectiveness of these 2 treatment strategies from the perspective of the US healthcare system have not been compared.

METHODS AND RESULTS

Between 2009 and 2014, the ATTRACT trial (Acute Venous Thrombosis: Thrombus Removal With Adjunctive Catheter-Directed Thrombolysis) randomized 692 patients with acute proximal DVT to PCDT plus anticoagulation (n=337) or standard treatment with anticoagulation alone (n=355). Costs (2017 US dollars) were assessed over a 24-month follow-up period using a combination of resource-based costing, hospital bills, Medicare reimbursement rates, and the Drug Topics Red Book. Health state utilities were obtained from the Short Form-36. In-trial results and US life tables were used to develop a Markov cohort model to evaluate lifetime cost-effectiveness. For the PCDT group, mean costs of the initial procedure were $13 600; per-patient costs associated with the index hospitalization were $21 509 for PCDT and $3877 for standard care (difference=$17 632; 95% CI, $16 117-$19 243). The 24-month difference in costs was $20 045 (95% CI, $16 093-$24 120). Utility scores increased significantly between baseline and 6 months for both groups, with no significant differences between groups at any follow-up time point. Projected differences in lifetime costs of $16 740 and quality-adjusted life years (QALYs) of 0.08, yield an incremental cost-effectiveness ratio for PCDT of $222 041/QALY gained. In probabilistic sensitivity analysis, the probability that PCDT would achieve a lifetime incremental cost-effectiveness ratio <$50 000/QALY or <$150 000/QALY was 1% and 25%, respectively. For iliofemoral DVT, QALY gains with PCDT were greater, yielding an incremental cost-effectiveness ratio of $137 526/QALY; for femoral-popliteal DVT, standard therapy was an economically dominant strategy.

CONCLUSIONS

With an incremental cost-effectiveness ratio >$200 000/QALY gained, PCDT is not an economically attractive treatment for proximal DVT. PCDT may be of intermediate value in patients with iliofemoral DVT. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT00790335.

Relationships between the use of pharmacomechanical catheter-directed thrombolysis, sonographic findings, and clinical outcomes in patients with acute proximal DVT: Results from the ATTRACT Multicenter Randomized Trial

Few studies have documented relationships between endovascular therapy, duplex ultrasonography (DUS), post-thrombotic syndrome (PTS), and quality of life (QOL). The Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) trial randomized 692 patients with acute proximal deep vein thrombosis (DVT) to receive anticoagulation or anticoagulation plus pharmacomechanical catheter-directed thrombolysis (PCDT). Compression DUS was obtained at baseline, 1 month and 12 months. Reflux DUS was obtained at 12 months in a subset of 126 patients. Clinical outcomes were collected over 24 months. At 1 month, patients who received PCDT had less residual thrombus compared to Control patients, evidenced by non-compressible common femoral vein (CFV) (21% vs 35%, p < 0.0001), femoral vein (51% vs 70%, p < 0.0001), and popliteal vein (61% vs 74%, p < 0.0001). At 12 months, in the ultrasound substudy, valvular reflux prevalence was similar between groups (85% vs 91%, p = 0.35). CFV non-compressibility at 1 month was associated with higher rates of any PTS (61% vs 46%, p < 0.001), a higher incidence of moderate-or-severe PTS (30% vs 19%, p = 0.003), and worse QOL (difference 8.2 VEINES-QOL (VEnous INsufficiency Epidemiological and Economic Study on Quality of Life) points; p = 0.004) at 24 months. Valvular reflux at 12 months was associated with moderate-or-severe PTS at 24 months (30% vs 0%, p = 0.01). In summary, PCDT results in less residual thrombus but does not reduce venous valvular reflux. CFV non-compressibility at 1 month is associated with more PTS, more severe PTS, and worse QOL at 24 months. Valvular reflux may predispose to moderate-or-severe PTS. ClinicalTrials.gov Identifier NCT00790335.

Does the Villalta scale capture the essence of postthrombotic syndrome? A qualitative study of patient experience and expert opinion

BACKGROUND

The Villalta scale is recommended for diagnosing and grading of postthrombotic syndrome (PTS) in clinical studies, but with limitations in specificity and sensitivity.

OBJECTIVES

To explore the typical complaints of PTS through patients experience and expert opinion and relate this to the items of the Villalta scale.

PATIENTS/METHODS

A qualitative study design with focus group interviews including patients with PTS and health care workers experienced in PTS patient care.

RESULTS

Typical PTS complaints were reflected within four main domains: (a) agonizing discomforts; patients without venous ulcers often described other discomforts than pain; (b) skin changes; these were common and sometimes present before deep vein thrombosis (DVT). Except for venous ulcers, skin changes were considered of less importance; (c) fluctuating heaviness and swelling during the day and with activity; (d) post-DVT concerns; fear of DVT recurrence, health services failing to meet the patients' expectations, and psychological and social restrictions. These findings are not necessarily captured or well reflected in the Villalta scale.

CONCLUSION

Our findings indicate that the Villalta scale does not capture typical PTS complaints or their importance to the patients. A revision of the diagnosis and grading should be considered.

PORTRAIT (Patient-Centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories): Overview of Design and Rationale of an International Prospective Peripheral Arterial Disease Study

BACKGROUND

Health status outcomes, including symptoms, functional status, and quality of life, are critically important outcomes from patients' perspectives. The PORTRAIT study (Patient-Centered Outcomes Related to Treatment Practices in Peripheral Arterial Disease: Investigating Trajectories) was designed to prospectively define health status outcomes and examine associations between patients' characteristics and care to these outcomes among those presenting with new-onset or worsened claudication.

METHODS AND RESULTS

PORTRAIT screened 3637 patients with an abnormal ankle-brachial index and new, or worsened, claudication symptoms from 16 peripheral arterial disease (PAD) specialty clinics in the United States, the Netherlands, and Australia between June 2, 2011, and December 3, 2015. Of the 1608 eligible patients, 1275 (79%) were enrolled. Before treatment, patients were interviewed to obtain their demographics, PAD symptoms and health status, psychosocial characteristics, preferences for shared decision-making, socioeconomic, and cardiovascular risk factors. Patients' medical history, comorbidities, and PAD diagnostic information were abstracted from patients' medical records. Serial information about patients' health status, psychosocial, and lifestyle factors was collected at 3, 6, and 12 months by a core laboratory. Follow-up rates ranged from 84.2% to 91%. Clinical follow-up for PAD-related hospitalizations and major cardiovascular events is ongoing.

CONCLUSIONS

PORTRAIT systematically collected serial PAD-specific health status data as a foundation for risk stratification, comparative effectiveness studies, and clinicians' adherence to quality-based performance measures.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01419080.

Pharmacomechanical catheter thrombolysis for pregnancy-related proximal deep venous thrombosis: prevention of post-thrombotic syndrome

OBJECTIVE

The efficacy of pharmacomechanical catheter-directed thrombolysis (PCDT) in preventing post thrombotic syndrome (PTS) for pregnancy related deep vein thrombosis (DVT) is unknown.

STUDY DESIGN

An observational cross section study of women with pregnancy related proximal (femoral/iliofemoral) DVT who underwent PCDT followed by anticoagulation (study group), and women who were treated with anticoagulation alone (control group). Women were evaluated for PTS using the Villalta scale (primary outcome) and VEINES-QOL/Sym questionnaires.

RESULTS

Eleven women with iliofemoral DVT underwent PCDT, two during their first trimester and nine postpartum; 18 women were treated with anticoagulation only. There were no significant differences in age, number of previous pregnancies, and duration of anticoagulation or thrombophilia between the groups. The time between DVT diagnosis and study inclusion was longer in the study group [median 50.5 (range 16-120) months] compared to the control group [median 27 (range 11-64) months], p = .4. None of the women in the PCDT group developed PTS, compared to six (33.3%, p = .03) in the control group, four of whom developed severe PTS. One patient in each group developed recurrent DVT, and one patient in the study group developed a calf hematoma. A reduced frequency of lower extremity symptoms was observed in the PCDT group (VEINES-Sym questionnaire), but no differences in quality of life (VEINES-QOL questionnaire) were reported.

CONCLUSION

This study suggests that PCDT may reduce the incidence of PTS in women with pregnancy related proximal DVT.Bullet pointsDVT involving the iliofemoral veins and development of post thrombotic syndrome is frequent among pregnant or postpartum womenStudies of pharmacomechanical catheter-directed thrombolysis (PCDT) for deep vein thrombosis did not include pregnant or postpartum womenIn our observational cross section study women who underwent PCDT (mainly in the postpartum period) had reduced frequency of post-thrombotic syndrome compared to women who received anticoagulation onlyLarger studies are required to confirm the use of PCDT for prevention of PTS in this population.

Iliac vein compression: epidemiology, diagnosis and treatment

Iliac vein compression (LIVC) is a prevalent finding in the general population, but a smaller number of patients are symptomatic. ILVC should be considered in symptomatic patients with unexplained unilateral lower leg swelling. Patients typically complain of one or more of the following symptoms: lower leg pain, heaviness, venous claudication, swelling, hyperpigmentation and ulceration. ILVC can be thrombotic, combined with acute or chronic DVT, or non-thrombotic. ILVC is best diagnosed with intravascular ultrasound (IVUS), but computed tomography angiography (CTA) and magnetic resonance angiography (MRA) have emerged as valid screening tests. Venography underestimates the severity of ILVC but may provide insights into the anatomy and the presence of collaterals. Based on current available evidence, endovascular therapy with stenting remains the main treatment strategy for ILVC. Dedicated nitinol venous stents are currently under review by the Food and Drug Administration for potential approval in the United States. These stents have been released outside the US. There is no consensus to the optimal anticoagulation regimen post-ILVC stenting. Oral anticoagulants, however, remain a preferred therapy in patients with history of thrombotic ILVC.

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Initial experience with a new pharmacomechanical thrombectomy device for deep venous thrombosis: Report of 91 cases

Background

To evaluate the efficacy and safety of pharmacomechanical thrombectomy using a new rotational thrombectomy device with additional thrombus-removal methods for deep venous thrombosis.

Methods

A total of 91 patients admitted to our tertiary center with symptomatic iliac, ilio-femoral, femoro-popliteal deep venous thrombosis and who underwent hybrid pharmacomechanical thrombectomy constituted the study group. Postinterventional color Doppler ultrasonography was repeated at 1st, 6th, and 12th months. Villalta scoring system was used to evaluate the patients for the development of post-thrombotic syndrome after deep venous thrombosis. The patient-reported severity of pain in the index leg was measured on a Likert scale.

Results

Of the 91 patients whose charts were reviewed, the location of thrombus was iliofemoral in 60 (65.9%) and femoropopliteal in 31 (34.1%) patients, respectively. Duration of symptoms was 5.62 ± 3.43 (range, 2–15) days. Technical success was observed in 82 patients (90.1%) at 3 months, in 77 patients (84.6%) at 6 months, and in 74 patients (81.3%) at 12 months. Villalta score was over 10 points in 15 of 17 patients whose Doppler US revealed venous occlusions, at 12 months, and in 8 patients with recurrent deep venous thrombosis. Post-thrombotic syndrome was detected in 18 patients in our study. Twelve (13.2%) of these 18 patients had mild, 5 (5.5%) moderate, and 1 (1.1%) severe PTS. In predicting predisposing factors in 18 patients with PTS, 13 patients (72.2%) had a Villalta score ≥10, 10 patients (55.6%) had experienced a delayed endovascular procedure (≥10 days), and 8 patients (44.4%) had recurrent deep venous thrombosis.

Conclusion

The endovenous pharmacomechanical thrombectomy with the Mantis thrombectomy device in the treatment of acute and subacute iliofemoral deep venous thrombosis is a promising approach in terms of efficacy and safety in the early period regarding reasonable and long-term prevention of post-thrombotic syndrome, development of pulmonary thromboembolism, and adequate venous system patency.

Assessment of the Probability of Post-thrombotic Syndrome in Patients with Lower Extremity Deep Venous Thrombosis

This study was performed to assess the probability of post-thrombotic syndrome (PTS) after treatment of lower extremity deep venous thrombosis (LEDVT). Patients with LEDVT undergoing their first treatments in Nanjing First Hospital from January 2013 to December 2014 were enrolled in this study (156 patients were enrolled in the training cohort, and 135 patients were enrolled in the validation cohort). 51 and 45 patients developed PTS in the two cohorts, respectively. Independent risk factors for PTS were investigated in the training cohort, and these independent risk factors were employed to develop the APTSD scoring system with which to predict the probability of PTS. Four independent risk factors for PTS were identified: iliac vein compression syndrome, residual iliac-femoral vein thrombosis, residual femoral-popliteal vein thrombosis and insufficient anticoagulation. Patients in the training cohort were divided into 2 groups according to the APTSD score of ≤7.0 and >7.0 points regarding the probability of PTS (median PTS-free time, 21.82 vs. 18.84 months; P < 0.001). The accuracy of this score system was 81.7% for the training cohort and 82.5% for the validation cohort. Patients with an APTSD score of >7.0 points may have an increased probability of developing PTS.

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 evidence supporting treatment of reflux and obstruction in chronic venous disease

On July 20, 2016, a Medicare Evidence Development and Coverage Advisory Committee panel convened to assess the evidence supporting treatment of chronic venous disease. Several societies addressed the questions posed to the panel. A multidisciplinary coalition, representing nine societies of venous specialists, reviewed the literature and presented a consensus opinion regarding the panel questions. The purpose of this paper is to present our coalition's consensus review of the literature and recommendations for chronic venous disease.

A systematic review of paediatric deep venous thrombolysis

Objectives

The aim was to assess the effectiveness and safety of catheter-directed thrombolysis in children with deep venous thrombosis and to evaluate its long-term effect.

Method and results

EMBASE, Medline and Cochrane databases were searched to identify studies in which paediatric acute deep venous thrombosis patients received thrombolysis. Following title and abstract screening, seven cohort studies with a total of 183 patients were identified. Technical success was 82% and superior in regional rather than systemic thrombolysis (p < 0.00001). One cohort study identified significant difference in thrombus resolution at one year between thrombolytic and anticoagulant groups (p = 0.01). The complication rate was low, with incidence rates of major bleeding, pulmonary embolism and others at 2.8%, 1.8% and 8.4%, respectively. The overall post-thrombotic syndrome rate was 12.7%. The incidence of re-thrombosis ranged from 12.3% to 27%.

Conclusion

Thrombolysis for paediatric deep venous thrombosis is an effective and relatively safe therapeutic option, lowering the incidence of post-thrombotic syndrome and deep venous thrombosis recurrence.

A systematic review on the use of deep venous stenting for acute venous thrombosis of the lower limb

OBJECTIVES

The aim is to evaluate venous stent patency, the development of post-thrombotic syndrome, recurrence, quality of life and the optimal post-procedural anticoagulation regimen in the treatment of iliofemoral deep venous thrombosis.

METHOD AND RESULTS

EMBASE and Medline databases were interrogated to identify studies in which acute deep venous thrombosis patients were stented. Twenty-seven studies and 542 patients were identified. Primary, assisted primary and secondary patency rates 12 months after stent placement ranged from 74 to 95, 90 to 95 and 84 to 100%, respectively. The observed post-thrombotic syndrome rate was 14.6%. The incidence of stent re-thrombosis was 8%. In 26% of studies, patients received additional antiplatelet therapy. Quality of life questionnaires employed in 11% of studies, demonstrating an improvement in the chronic venous insufficiency questionnaire (22.67 ± 3.01 versus 39.34 ± 6.66).

CONCLUSION

Venous stenting appears to be an effective adjunct to early thrombus removal; however, further studies are needed to identify optimal anticoagulant regimen and effect on quality of life.

Management of Chronic Deep Vein Thrombosis in Women

Chronic deep vein thrombosis (DVT) affects hundreds of thousands of women in the United States. Chronic DVT can lead to pain, edema, venous ulcers, and varicosities. While there are limited data regarding the management of chronic DVT, several interventional radiology groups aggressively treat chronic DVT to aid patient symptom resolution. Recanalization of occluded veins and venous stenting re-establishes deep vein flow and decreases venous hypertension.

Update on the electrolytic IVC model for pre-clinical studies of venous thrombosis

BACKGROUND

The electrolytic inferior vena cava model (EIM) is a murine venous thrombosis (VT) model that produces a non-occlusive thrombus. The thrombus forms in the direction of blood flow, as observed in patients. The EIM is valuable for investigations of therapeutics due to the presence of continuous blood flow. However, the equipment used to induce thrombosis in the original model description was expensive and has since been discontinued. Further, the fibrinolytic system had not been previously studied in the EIM.

OBJECTIVES

We aimed to provide an equipment alternative. Additionally, we further characterized the model through mapping the current and time dependency of thrombus resolution dynamics, and investigated the fibrinolytic system from acute to chronic VT.

RESULTS

A voltage to current converter powered by a direct current power supply was constructed and validated, providing an added benefit of significantly reducing costs. The current and time dependency of thrombus volume dynamics was assessed by MRI, demonstrating the flexibility of the EIM to investigate both pro-thrombotic and anti-thrombotic conditions. Additionally, the fibrinolytic system was characterized in EIM. Centripetal distribution of plasminogen was observed over time, with peak staining at day 6 post thrombus induction. Both active circulating plasminogen activator inhibitor-1 (PAI-1) and vein wall gene expression of PAI-1 peaked at day 2, coinciding with a relative decrease in tissue plasminogen activator and urokinase plasminogen activator.

CONCLUSIONS

The EIM is a valuable model of VT that can now be performed at low cost and may be beneficial in investigations of the fibrinolytic system.

Postthrombotic Syndrome: Long-Term Sequela of Deep Venous Thrombosis

Postthrombotic syndrome is a common long-term complication of proximal lower extremity deep venous thrombosis, which not only significantly affects the quality of life of patients but also imposes a substantial financial burden on our healthcare system. Due to limited awareness and inability of physicians to recognize and treat this condition early, its prevalence is steadily increasing. In this article, we review the pathophysiology, the risk factors involved, diagnostic workup, and the various management options available to treat this condition.

How I use catheter-directed interventional therapy to treat patients with venous thromboembolism

Patients who present with severe manifestations of acute venous thromboembolism (VTE) are at higher risk for premature death and long-term disability. In recent years, catheter-based interventional procedures have shown strong potential to improve clinical outcomes in selected VTE patients. However, physicians continue to be routinely faced with challenging decisions that pertain to the utilization of these risky and costly treatment strategies, and there is a relative paucity of published clinical trials with sufficient rigor and directness to inform clinical practice. In this article, using 3 distinct clinical scenario presentations, we draw from the available published literature describing the natural history, pathophysiology, treatments, and outcomes of VTE to illustrate the key factors that should influence clinical decision making for patients with severe manifestations of deep vein thrombosis and pulmonary embolism. The results of a recently completed pivotal multicenter randomized trial are also discussed.

Thrombectomy and thrombolysis for the prevention and treatment of postthrombotic syndrome

Postthrombotic syndrome (PTS) is a frequent complication of lower-extremity deep vein thrombosis (DVT), occurring in approximately 40% of patients despite the use of anticoagulant therapy. PTS causes significant impairment of patients' health-related quality of life, and no evidence-based therapies have been consistently effective. Catheter-directed thrombolysis and thrombectomy have been shown to remove acute thrombus, and it has been hypothesized they could prevent or reduce PTS. However, because these procedures can be associated with complications, mainly bleeding, randomized trial data are needed to determine when they should be used. In this article, I summarize the current status of thrombus removal procedures for DVT to provide contemporary guidance to clinicians seeking to individualize treatment decisions for their patients.