Comparison of the Villalta and Ginsberg clinical scales to diagnose the post-thrombotic syndrome: correlation with patient-reported disease burden and venous valvular reflux

Assessment of venous disease with different venous disease specific scales in Behçet's disease patients with deep vein thrombosis

Objectives: Post-thrombotic syndrome (PTS) is a frequent and important consequence of deep vein thrombosis (DVT) for Behcet`s disease (BD) patients. Although various clinical scales are used to diagnose PTS, Villalta scale was accepted as the standard tool to diagnose and grade the severity of PTS. Poor quality of life (Qol) in the general population was defined for patients with PTS, however, studies in BD patients with PTS is limited. Our aim was to compare the performance of different scales to assess venous disease in BD patients with a history of DVT and to assess the relationship with quality of life.Methods: Patients with BD (n = 194, M/F:157/37, age:39.1 ± 9.5 years) with a DVT history were investigated. Villalta, VCSS,CEAP scale and SF 36,Veines scales were used to assess venous disease and QoL respectively.Results: Among BD patients, 120 (61.9 %) patients were classified as having PTS by Villalta and of patients 18% had severe PTS. Half of patients with CEAP score <4 were classified as having PTS. Also, 42% of patients with CEAP>4 and almost two third of VCSS classified severe CVD patients was grouped in severe PTS by Villalta scale. VCSS and Villalta classified PTS patients had decreased disease specific and general Qol scores compared to the patients without PTS. Also, severe PTS group (by VCSS) had decreased veines QoL scores and PCS compared to mild/moderate group.Conclusion: BD patients with DVT have a high risk of PTS. Our results show that both Villalta scale and VCSS should be used to assess venous disease BD patients with DVT. However, VCSS classified severity of PTS can show better correlation with venous disease -specific QoL.

Diagnosis of chronic iliac venous obstruction

Stenting has become the first line of treatment for symptomatic chronic iliofemoral venous obstruction in patients with quality-of-life-impairing clinical manifestations who have failed conservative therapy. Patient selection for such intervention is, however, dependent on clear identification of relevant clinical manifestations and subsequent testing to confirm the diagnosis. In this regard, the physician engaged in management of such patients needs to be well-aware of symptoms and signs of chronic iliofemoral venous obstruction, and instruments used to grade chronic venous insufficiency and determine quality of life, in addition to diagnostic tests available and their individual roles. This review serves to provide an overview of the diagnosis of chronic iliofemoral venous obstruction and patient selection for stenting.

Biomarkers and the post-thrombotic syndrome: A systematic review of biomarkers associated with the occurrence of the post-thrombotic syndrome after lower extremity deep venous thrombosis

INTRODUCTION

Post-thrombotic syndrome (PTS) is a frequent chronic complication of deep venous thrombosis (DVT). Biomarkers are potentially valuable clinical tools for handling PTS. The purpose of this review was to examine which biomarkers are associated with the development of PTS in adults with lower extremity DVT.

METHODS

We performed a systematic review of all English language prospective studies of biomarkers and PTS published in PubMed and EMBASE. Studies were included if diagnosing DVT by diagnostic imaging and assessing PTS by clinical scales, for example, the Villalta scale. Biomarkers of thrombophilia and pathological clot properties were not assessed. Data was reported qualitatively.

RESULTS

15 prospective studies were included. Studies varied widely in study design and methods of data analysis. Forty-six different biomarkers were examined, with seven being measured in two or more studies. The most frequently studied biomarkers were D-dimer, CRP, and IL-6. Associations between PTS and D-dimer were predominantly significant, while results on CRP and IL-6 were inconsistent. ICAM-1 was consistently associated with PTS in all studies and at all timepoints. IL-10 was significantly related to PTS development in the largest study and at all time points. Adiponectin, tPA, HRG and TAFI, MMP-1 and -8, and TIMP-1 and -2 were significantly associated with PTS in single studies.

CONCLUSION

(1) Further research on biomarkers and PTS is clearly warranted. (2) Significant differences in study designs made it difficult to draw reliable conclusions regarding individual biomarkers. We suggest the implementation of a standardized framework for the study of biomarkers and PTS, to make comparison of future studies more feasible. (3) D-dimer, ICAM-1, IL-10, MMP-1 and 8, TIMP-1, TIMP-2, and adiponectin are clinical biomarkers of particular interest to include in future studies of PTS. Large scale systemic quantitative proteomic analyses of DVT patients could help identify novel biomarkers of interest in PTS-patients.

Delphi Consensus on Reporting Standards in Clinical Studies for Endovascular Treatment of Acute Iliofemoral Venous Thrombosis and Chronic Iliofemoral Venous Obstruction

Acute iliofemoral deep vein thrombosis and chronic iliofemoral venous obstruction cause substantial patient harm and are increasingly managed with endovascular venous interventions, including percutaneous mechanical thrombectomy and stent placement. However, studies of these treatment elements have not been designed and reported with sufficient rigor to support confident conclusions about their clinical utility. In this project, the Trustworthy consensus-based statement approach was utilized to develop, via a structured process, consensus-based statements to guide future investigators of venous interventions. Thirty statements were drafted to encompass major topics relevant to venous study description and design, safety outcome assessment, efficacy outcome assessment, and topics specific to evaluating percutaneous venous thrombectomy and stent placement. Using modified Delphi techniques for consensus achievement, a panel of physician experts in vascular disease voted on the statements and succeeded in reaching the predefined threshold of >80% consensus (agreement or strong agreement) on all 30 statements. It is hoped that the guidance from these statements will improve standardization, objectivity, and patient-centered relevance in the reporting of clinical outcomes of endovascular interventions for acute iliofemoral deep venous thrombosis and chronic iliofemoral venous obstruction in clinical studies and thereby enhance venous patient care.

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.

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

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

Performance of two clinical scales to assess quality of life in patients with post-thrombotic syndrome

OBJECTIVE

We directly compared the Villalta scale and the Venous Clinical Severity Score (VCSS) to determine which of the two measures would be better at capturing clinically important cases of post-thrombotic syndrome (PTS) and PTS severity compared with patient-reported quality of life (QOL) scores.

METHODS

We performed a secondary analysis of the ATTRACT (acute venous thrombosis: thrombus removal with adjunctive catheter-directed thrombolysis) trial study population. We calculated the correlations of the Villalta scores and VCSSs with QOL scores (short-form 36-item health survey [SF-36] physical component summary [PCS] and mental component summary [MCS]; and VEINES [venous insufficiency epidemiological and economic study]-QOL/symptom [VEINES-QOL/Sym] questionnaire) at each study visit (6, 12, 18, and 24 months of follow-up). The correlation of the random intercept (mean scores) and random slope (rate of change of the scores) among the Villalta scores, VCSS, and VEINES-QOL/Sym scores was assessed using a multivariate longitudinal model.

RESULTS

The median correlation between Villalta scores and VCSSs was 0.72. The median correlation between the Villalta scores and VEINES-QOL and VEINES-Sym scores at all follow-up visits was -0.68 and -0.71, respectively. The median correlation between the Villalta scores and SF-36 PCS and MCS scores was -0.51 and -0.31, respectively. For the VCSSs, the median correlation with the VEINES-QOL and VEINES-Sym scores at all follow-up visits was -0.39 and -0.41, respectively. The median correlation between the VCSSs and SF-36 PCS and MCS scores was -0.32 and -0.13, respectively. The correlations between the random effects in the multivariate longitudinal models showed a similar pattern. The effect of covariate adjustment by age, sex, and body mass index was minor.

CONCLUSIONS

The Villalta scores and VCSSs correlated strongly. The Villalta scale showed a substantially greater correlation with venous disease-specific and general QOL scores compared with the correlation with the VCSS. Our findings suggest that when a single scale is used to assess for clinically meaningful PTS, the Villalta scale will better capture the effects of PTS on patient-reported QOL.

Can we predict and prevent the postthrombotic syndrome?

Postthrombotic syndrome (PTS) remains one of the major late complications of deep vein thrombosis (DVT) with a reported prevalence from 10 to 50%. Many factors were found to be related with the development and severity of PTS such as ipsilateral recurrent DVT, advanced age, obesity, ilio-femoral DVT and primary chronic venous disease presence. Some PTS prediction models have been proposed based on risk factor weight. However, it is still difficult to predict which patient with DVT will develop PTS and thus, the clinical application of these models remains limited. Among the identified problems the heterogeneity of the DVT patient population together with the variety of PTS clinical presentations and difficulties concerning PTS severity assessment should be mentioned. Difficulties on the implementation of the specific and objective PTS identification method have also the significant influence on the research focusing on PTS prevention modalities including risk factor modification, compression treatment, anticoagulation and invasive DVT treatment. In this review, the current approach and knowledge on PTS prediction and prevention are presented, including the conservative and invasive DVT treatment possibilities.

Predictors of long-term post-thrombotic syndrome following high proximal deep vein thrombosis: a cross-sectional study

Background

Post-thrombotic syndrome (PTS) is a frequent chronic complication of proximal deep vein thrombosis (DVT) of the lower limb, but predictors of PTS are not well established. We aimed to examine predictors of PTS in patients with long-term PTS following proximal DVT.

Methods

During 2006–09, 209 patients with a first time acute upper femoral or iliofemoral DVT were randomized to receive either additional catheter-directed thrombolysis or conventional therapy alone. In 2017, the 170 still-living participants were invited to participate in a cross-sectional follow-up study. In the absence of a gold standard diagnostic test, PTS was defined in line with clinical practice by four mandatory, predefined clinical criteria: 1. An objectively verified DVT; 2. Chronic complaints (> 1 month) in the DVT leg; 3. Complaints appeared after the DVT; and 4. An alternative diagnosis was unlikely. Possible predictors of PTS were identified with multivariate logistic regression.

Results

Eighty-eight patients (52%) were included 8–10 years following the index DVT, and 44 patients (50%) were diagnosed with PTS by the predefined clinical criteria. Younger age and higher baseline Villalta score were found to be independent predictors of PTS, i.e., OR 0.96 (95% CI, 0.93–0.99), and 1.23 (95% CI, 1.02–1.49), respectively. Lack of iliofemoral patency at six months follow-up was significant in the bivariate analysis, but did not prove to be significant after the multivariate adjustments.

Conclusions

In long-term follow up after high proximal DVT, younger age and higher Villalta score at DVT diagnosis were independent predictors of PTS.

The perplexity of catheter-directed thrombolysis for deep venous thrombosis: the approaches play an important role

The recent adjunctive catheter-directed thrombolysis (ATTRACT) trial rose a controversy about the treatment effect of catheter-directed thrombolysis (CDT) in deep venous thrombosis (DVT). In fact, most studies including the ATTRACT trial did not perform subgroup analysis of catheterization approaches. Different approaches would confound the conclusions. Therefore, a single-center retrospective analysis was performed to compare the differences between the antegrade (AGA) and retrograde (RGA) approaches. Total 217 DVT patients treated with CDT were enrolled from January 2010 to December 2017, with mean age of 55.3 years (67 received antegrade approach, 150 received retrograde approach). The clot burden reduction by segment was evaluated. The mean access establishment time and thrombolytic time were compared. The patency of the iliofemoral vein at 6 months was evaluated. The rate of PTS, quality of life and venous insufficiency were assessed at 1 year. AGA group showed better thrombolytic effect in popliteal and femoral vein than RGA group. The rate of iliofemoral clot burden reduction in RGA group was mostly at Grade II, while most were at Grade III in AGA group. The retrograde approach showed better thrombolysis effect in iliofemoral DVT than popliteal to iliac DVT. The RGA group reported longer mean access establishment time (5.4 ± 1.8 vs 27.0 ± 7.5 min, p < 0.001) and thrombolytic time (6.9 ± 1.5 days vs 6.8 ± 1.5 days, p = 0.586). At 6 months, RGA group had a lower rate of femoral vein patency (52.0% vs 89.6%, p < 0.001) and a higher rate of venous insufficiency (52.0% vs 29.9%, p < 0.001), compared with AGA group. Although there was no difference in the rate of PTS, the RGA group showed higher Villalta scores in the free and mild PTS. The antegrade approach was preferably recommended over the retrograde approach for CDT treatment.

External validation of the SOX-PTS score in a prospective multicenter trial of patients with proximal deep vein thrombosis

BACKGROUND

Using data from the SOX Trial, we recently developed a clinical prediction model for occurrence of the postthrombotic syndrome (PTS) after proximal deep vein thrombosis (DVT), termed the SOX-PTS score. The score includes anatomical extent of DVT; body mass index; and baseline Villalta score.

OBJECTIVE

To externally validate the SOX-PTS score.

METHODS

Logistic regression analysis of data from the ATTRACT Trial that evaluated pharmacomechanical catheter directed thrombolysis in patients with proximal DVT. The primary outcome was the occurrence of PTS (defined as Villalta score ≥ 5) from 6 to 24 months after DVT. Secondary outcomes included moderate-severe PTS (Villalta scale ≥ 10) and severe PTS (Villalta scale ≥ 14). Predictive performance was assessed by discrimination and calibration. An updated score was evaluated in an exploratory analysis.

RESULTS

Six hundred and ninety-one ATTRACT patients were included, of whom 328 (47%) developed PTS. The c-statistic was 0.63; 95% confidence interval (CI) 0.59-0.67 for PTS. The model's performance appeared to be better for the outcomes moderate to severe PTS and severe PTS (c-statistic 0.67; 95% CI 0.62-0.72 for moderate-severe PTS and 0.70; 0.64-0.77 for severe PTS). An updated model with age as an additional variable performed similarly to the original model.

CONCLUSION

We externally validated the SOX-PTS score for estimating the risk of developing PTS, moderate to severe PTS, and severe PTS, in patients with proximal DVT. The score may be useful to predict PTS at the time of DVT diagnosis. Further external validation in different patient cohorts is required.

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.

Development and validation of a tool for patient reporting of symptoms and signs of the post-thrombotic syndrome

Post-thrombotic syndrome (PTS) is a long-term complication of deepvein thrombosis (DVT). The Villalta scale is the recommended tool for diagnosing PTS, but requires a clinician’s assessment in addition to patient self-assessment. In the present study, we validated a self-administered tool for patient reporting of leg symptoms and signs as a mean to assess PTS. We first validated a form for patient self-reported Villalta (PRV1), then developed and validated a visually assisted form (PRV2). The validity of PRV1 and PRV2 was assessed in patients diagnosed with DVT between 2004 and 2012. Median time from DVT to inclusion was 5.1 and 3.5 years for PRV1 (n=162) and PRV2 (n=94), respectively. Patients were requested to complete the PRV form before a scheduled visit. PTS diagnosed by the original Villalta scale during the visit served as the reference method. PRV1 showed only moderate agreement for diagnosing PTS compared with the original Villalta scale (kappa agreement 0.60, 95 % CI 0.48–0.72), whereas PRV2 showed very good agreement (0.82, 95 % CI 0.71–0.94). In the validation of PRV2, PTS was diagnosed in 54 (57 %) patients according to the original Villalta scale and in 60 (64 %) by PRV2. The sensitivity of PRV2 to detect PTS was 98 % and the specificity was 83 %. We conclude that the visually assisted form for PRV is a valid and sensitive tool for diagnosing PTS. Such a tool could be applied in further clinical studies of PTS, making studies less resource demanding by reducing the need for in-person clinic visits.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Compression therapy for prevention of post-thrombotic syndrome

BACKGROUND

Post-thrombotic syndrome (PTS) is a long-term complication of deep vein thrombosis (DVT) that is characterised by chronic pain, swelling, and skin changes in the affected limb. One of every three people with DVT will develop post-thrombotic complications within five years. Several non-pharmaceutical measures are used for prevention of post-thrombotic syndrome during the acute phase of DVT. These include elevation of the legs and compression therapy. Clinicians and guidelines differ in their assessment of the utility of compression therapy for treatment of DVT. This is an update of a review first published in 2003.

OBJECTIVES

To determine relative effectiveness and rate of complications when compression therapy is used in people with deep vein thrombosis (DVT) for prevention of post-thrombotic syndrome (PTS).

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist (CIS) searched the Cochrane Vascular Specialised Register (20 March 2017) and CENTRAL (2017, Issue 2). The CIS also searched trial registries for details of ongoing or unpublished studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and controlled clinical trials (CCTs) of compression therapy, such as bandaging and elastic stockings, in people with clinically confirmed DVT. The primary outcome was the occurrence of PTS.

DATA COLLECTION AND ANALYSIS

Two review authors (DK and EvL) identified and assessed titles and abstracts for relevance, and a third review author (DA) verified this assessment independently. Review authors imposed no restrictions on date or language of publications. Three review authors (DA, DK, EvL) used data extraction sheets to independently extract study data. We resolved disagreements by discussion.

MAIN RESULTS

We identified 10 RCTs with a total of 2361 participants that evaluated compression therapy. The overall methodological quality of these trials was low. We used only five studies in meta-analysis owing to differences in intervention types and lack of data. Three studies compared elastic compression stockings (pressure of 30 to 40 mmHg at the ankle) versus no intervention. Two studies compared elastic compression stockings (pressure 20 to 40 mmHg) versus placebo stockings. Overall, use of elastic compression stockings led to a clinically significant reduction in the incidence of PTS (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.38 to 1.01; P = 0.05; 1393 participants; 5 studies; low-quality evidence); no reduction in the incidence of severe PTS (RR 0.78, 95% CI 0.53 to 1.15; P = 0.21; 1224 participants; 4 studies; low-quality evidence); and no clear difference in DVT recurrence (RR 0.94, 95% CI 0.69 to 1.28; 1212 participants; 4 studies; P = 0.69; low-quality evidence). We did not pool data on the incidence of pulmonary embolism because this information was poorly reported, but we observed no differences between groups included in individual studies (low-quality evidence).Two studies evaluated effects of compression in the acute phase versus no compression treatment and found no differences in the incidence of PTS (RR 0.76, 95% CI 0.49 to 1.16; P = 0.2; 101 participants). One study reported that thigh-length stockings did not provide better protection against development of PTS than knee-length stockings (RR 0.92, 95% CI 0.66 to 1.28; P = 0.6; 267 participants). Another trial reported that wearing compression stockings for two years seemed to be superior to wearing them for one year in terms of PTS incidence.Two of the 10 included studies described patient satisfaction and quality of life (moderate-quality evidence), using different measurement systems. The first study showed significant improvement in well-being and DVT-related quality of life with compression treatment (P < 0.05) compared with bed rest, and the second study showed no differences in quality of life scores between compression and placebo groups. Four studies poorly reported side effects (low-quality evidence) that included itching, erythema, and other forms of allergic reaction and described no serious adverse events. Compliance with wearing of compression stockings was generally high but varied across studies.

AUTHORS' CONCLUSIONS

Low-quality evidence suggests that elastic compression stockings may reduce the occurrence of PTS after DVT. We downgraded the quality of evidence owing to considerable heterogeneity between studies and lack of or unclear risk of blinding due to clinical assessment scores. No serious adverse effects occurred in these studies. Large randomised controlled trials are needed to confirm these findings because of current lack of high-quality evidence and considerable heterogeneity.

Medical Treatment for Postthrombotic Syndrome

Deep vein thrombosis (DVT) is a prevalent disease. About 20 to 30% of patients with DVT will develop postthrombotic syndrome (PTS) within months after the initial diagnosis of DVT. There is no gold standard for diagnosis of PTS, but clinical signs include pitting edema, hyperpigmentation, phlebectatic crown, venous eczema, and varicose veins. Several scoring systems have been developed for diagnostic evaluation. Conservative treatment includes compression therapy, medications, lifestyle modification, and exercise. Compression therapy, the mainstay and most proven noninvasive therapy for patients with PTS, can be prescribed as compression stockings, bandaging, adjustable compression wrap devices, and intermittent pneumatic compression. Medications may be used to both prevent and treat PTS and include anticoagulation, anti-inflammatories, vasoactive drugs, antibiotics, and diuretics. Exercise, weight loss, smoking cessation, and leg elevation are also recommended. Areas of further research include the duration, compliance, and strength of compression stockings in the prevention of PTS after DVT; the use of intermittent compression devices; the optimal medical anticoagulant regimen after endovascular therapy; and the role of newer anticoagulants as anti-inflammatory agents.

The postthrombotic syndrome: current evidence and future challenges

Postthrombotic syndrome (PTS) is a chronic complication of deep vein thrombosis (DVT) that develops in 20-50% of patients. PTS manifests as a spectrum of symptoms and signs of chronic venous insufficiency that can impose significant morbidity and have a negative impact on quality of life. Chronic venous hypertension caused by a combination of residual venous obstruction and valvular reflux is believed to play a major role in the pathophysiology of PTS. The Villalta scale is the most widely applied clinical scale used to diagnose and define PTS. Proximal DVT and recurrent ipsilateral DVT are the two principal established risk factors for PTS, and efforts in recent years have been focused on identifying a combination of clinical and biomarker predictors that will define high-risk patients and possibly new therapeutic targets. The best way to prevent PTS is to prevent the occurrence of DVT, and to provide optimal anticoagulation for the acute phase of DVT once it occurs. Recent years have brought progress in our understanding of the role of endovascular techniques in the prevention and treatment of PTS and the subgroups of patients that may benefit from these modalities. Pharmacomechanical catheter-directed thrombolysis is the most promising interventional modality for prevention of PTS. This review summarizes the current state of evidence on PTS of the lower limbs, and highlights areas where uncertainty still exists that require further research.

Compression Stockings for Prevention of Postthrombotic Syndrome: A Systematic Review and Meta-Analysis

OBJECTIVE

The present meta-analysis aimed to evaluate the efficacy and safety of compression stockings for postthrombotic syndrome (PTS) prevention in patients with deep venous thrombosis (DVT).

METHODS

Randomized controlled trials (RCTs) regarding the use of compression stockings for prevention of PTS were identified from the Medline, PubMed, and Embase databases as well as the Cochrane library. The resulting manuscripts were analyzed according to the criteria in the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

Six RCTs involving 1465 patients with DVT were included. The meta-analysis indicated no statistical differences between the compression stocking and the control groups in PTS incidence, using either the Villalta scale (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.23-1.74) or the Ginsberg scale (OR, 1.13; 95% CI, 0.72-1.77). Based on the Villalta scale categorization, there were no differences in the incidence of mild-moderate PTS (OR, 0.71; 95% CI, 0.36-1.41) or incidence of severe PTS (OR, 0.68; 95% CI, 0.15-3.11). The difference in the recurrence of venous thromboembolism (OR, 0.89; 95% CI, 0.61-1.30) was also not significant. In the 3 RCTs that reported side effects of compression stockings, they were primarily related to discomfort, including itching, erythema, and rash.

CONCLUSION

The present meta-analysis has indicated that compression stockings may not prevent PTS, as determined by either the Villalta or the Ginsberg scale, in patients with DVT. However, owing to the limited number of trials, the evidence is not strong enough to draw a reliable conclusion. Further larger, randomized, double-blind, placebo-controlled, multicenter trials are needed.

The post thrombotic syndrome: Ignore it and it will come back to bite you

Post thrombotic syndrome (PTS) is a very common chronic complication of deep venous thrombosis (DVT), as three out of ten patients with lower extremity DVT will develop PTS. The possibility to identify patients at risk is limited. Diagnosis is challenging, because there is no gold standard diagnostic method. Progress in diagnostic options may therefore change future diagnostic strategies. The better understanding of pathophysiologic processes that underlie PTS may stimulate the development of treatment modalities and improve and diversify management options. The quest for adequate preventive strategies and treatment is important because PTS has a detrimental effect on patients' quality of life and is associated with increased healthcare as well as societal costs. The problem of PTS prevention is therefore clearly relevant to patients, doctors as well as policy makers.

Compression Therapy in the Prevention of Postthrombotic Syndrome: A Systematic Review and Meta-Analysis

Although compression therapy has been widely used after deep vein thrombosis (DVT), its efficacy in prevention of postthrombotic syndrome (PTS) remains disputable. We aimed to update the meta-analysis to comprehensively evaluate the effect of compression therapy on the prevention of PTS in adult patients after DVT.PubMed, Embase, and Cochrane library databases were systematically searched. Randomized controlled trials (RCTs) evaluating the preventive effect of compression therapy on PTS in adult patients after DVT were included. The primary outcome was the incidence of PTS. All meta-analyses were performed using random-effects models regardless of the heterogeneity. Subgroup and sensitivity analysis were also performed to examine the robustness of the pooled effects according to our predesigned plan. Potential publication bias was assessed.Eight RCTs with 1598 patients were included. Overall, compression therapy could significantly reduce the incidence of PTS (estimate 0.68, 95% confidence interval [CI] 0.52-0.90; P = 0.007). However, it was only associated with a reduction in the incidence of mild/moderate PTS (relative risk [RR] 0.66, 95% CI 0.46-0.93; P = 0.019) but not in the incidence of severe PTS (RR 0.64, 95% CI 0.27-1.50; P = 0.31). Additionally, compression therapy failed to reduce the incidence of recurrent venous thromboembolism (RR 0.91, 95% CI 0.65-1.27; P = 0.58), the incidence of ulceration (RR 0.74, 95% CI 0.36-1.53; P = 0.42), or mortality (RR 0.99, 95% CI 0.72-1.37; P = 0.96). No publication bias was observed.Current evidence still supports compression therapy to be a clinical practice for prophylaxis of PTS in adult patients after DVT. However, our findings should be cautiously interpreted because of heterogeneity and hence more large-scale and well-designed RCTs are still warranted.

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.

Inflammation markers and their trajectories after deep vein thrombosis in relation to risk of post-thrombotic syndrome

BACKGROUND

Post-thrombotic syndrome (PTS) is a frequent chronic complication of deep vein thrombosis (DVT).

OBJECTIVE

In the BioSOX study, we investigated whether inflammation markers predict the risk of PTS after DVT.

METHODS

We measured C-reactive protein (CRP), ICAM-1, interleukin (IL)-6, and IL-10, at baseline, and 1 month and 6 months after a first proximal DVT, among 803 participants in the SOX trial. Participants were prospectively followed for 24 months for development of PTS.

RESULTS

Median CRP levels at 1 month, ICAM-1 levels at baseline, 1 month and 6 months, IL-6 levels at 1 month and 6 months and IL-10 levels at 6 months were higher in patients who developed PTS than in those who did not. Multivariable regression with the median as a cutoff showed risk ratios (RRs) for PTS of 1.23 (95% confidence interval [CI] 1.05-1.45) and 1.25 (95% CI 1.05-1.48) for ICAM-1 at 1 month and 6 months, respectively, and 1.27 (95% CI 1.07-1.51) for IL-10 at 6 months. Quartile-based analysis demonstrated a dose-response association between ICAM-1 and PTS. ICAM-1 and IL-10 were also associated with PTS severity. Analysis of biomarker trajectories after DVT demonstrated an association between the highest-trajectory group of ICAM-1 and PTS.

CONCLUSIONS

In this prospective study, ICAM-1 over time was most consistently associated with the risk of PTS. Further study is required to confirm these findings and assess their potential clinical relevance.

Impact of graduated compression stockings on the prevention of post-thrombotic syndrome - results of a randomized controlled trial

OBJECTIVE

Post-thrombotic syndrome is a chronic complication of acute deep venous thrombosis in the lower extremity. The role of graduated compression stockings in the prevention of post-thrombotic syndrome has been studied with opinion being divided on the beneficial effects. We aim to answer this question with a randomized controlled study that uses multiple scoring instruments to assess post-thrombotic syndrome.

METHODS

Sixty-nine consecutive patients with acute deep venous thrombosis diagnosed by duplex ultrasonography were randomized to treatment with graduated compression stockings or no graduated compression stockings. Venous Clinical Severity Score and Villalta-Prandoni Score, commonly used scoring systems, were used to appraise post-thrombotic syndrome at 3, 6, 12, 18, and 24 months following diagnosis of deep venous thrombosis. In both scoring systems, the individual either had post-thrombotic syndrome or no post-thrombotic syndrome. Cumulative incidence was computed using Kaplan-Meier analysis. Relative risk was assessed for age, obesity, varicose veins, and iliofemoral deep venous thrombosis.

RESULTS

As measured by both Villalta-Prandoni Score and Venous Clinical Severity Score instruments, the graduated compression stockings group had a lower incidence of post-thrombotic syndrome compared to the control group, but only when one month was used as cut off time for the first diagnosis of post-thrombotic syndrome. When 6 or 12 months were used, there was no difference in the incidence of post-thrombotic syndrome between the two groups. The burden of post-thrombotic syndrome was significantly more when the Villalta-Prandoni Score instrument (∼75%) was used as compared to the Venous Clinical Severity Score instrument (∼30%) at 24 months' follow-up. Obesity was the only statistically significant predictor for the development of post-thrombotic syndrome.

CONCLUSION

As assessed by both Villalta-Prandoni Score and Venous Clinical Severity Score instruments, use of graduated compression stockings does not reduce the incidence of post-thrombotic syndrome. There is a significant difference in the incidence post-thrombotic syndrome as detected by Villalta-Prandoni Score and Venous Clinical Severity Score instruments with incidence of post-thrombotic syndrome dependent on instrument and cut off time interval used to assess post-thrombotic syndrome. However, larger prospective studies are required to confirm these differences.

Compression stockings to prevent post-thrombotic syndrome: a randomised placebo-controlled trial

BACKGROUND

Post-thrombotic syndrome (PTS) is a common and burdensome complication of deep venous thrombosis (DVT). Previous trials suggesting benefit of elastic compression stockings (ECS) to prevent PTS were small, single-centre studies without placebo control. We aimed to assess the efficacy of ECS, compared with placebo stockings, for the prevention of PTS.

METHODS

We did a multicentre randomised placebo-controlled trial of active versus placebo ECS used for 2 years to prevent PTS after a first proximal DVT in centres in Canada and the USA. Patients were randomly assigned to study groups with a web-based randomisation system. Patients presenting with a first symptomatic, proximal DVT were potentially eligible to participate. They were excluded if the use of compression stockings was contraindicated, they had an expected lifespan of less than 6 months, geographical inaccessibility precluded return for follow-up visits, they were unable to apply stockings, or they received thrombolytic therapy for the initial treatment of acute DVT. The primary outcome was PTS diagnosed at 6 months or later using Ginsberg's criteria (leg pain and swelling of ≥1 month duration). We used a modified intention to treat Cox regression analysis, supplemented by a prespecified per-protocol analysis of patients who reported frequent use of their allocated treatment. This study is registered with ClinicalTrials.gov, number NCT00143598, and Current Controlled Trials, number ISRCTN71334751.

FINDINGS

From 2004 to 2010, 410 patients were randomly assigned to receive active ECS and 396 placebo ECS. The cumulative incidence of PTS was 14·2% in active ECS versus 12·7% in placebo ECS (hazard ratio adjusted for centre 1·13, 95% CI 0·73-1·76; p=0·58). Results were similar in a prespecified per-protocol analysis of patients who reported frequent use of stockings.

INTERPRETATION

ECS did not prevent PTS after a first proximal DVT, hence our findings do not support routine wearing of ECS after DVT.

FUNDING

Canadian Institutes of Health Research.

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.

Multifaceted management of the postthrombotic syndrome

The postthrombotic syndrome (PTS) is a frequent cause of chronic pain, swelling, ulceration, and disability in patients with lower extremity deep vein thrombosis (DVT). As interventional radiologists are consulted on more patients with chronic DVT and PTS, their management strategies must be informed by a balanced understanding of the different facets of chronic DVT care and the available treatment options. This article provides an overview of the important elements of a multifaceted approach to the management of patients with PTS that includes pharmacological, physiological, and endovascular aspects of care.

Scoring systems for the post-thrombotic syndrome

OBJECTIVE

To assess each of the scoring systems used to diagnose and classify post-thrombotic syndrome, a common chronic complication of deep vein thrombosis. The design of the study was a systematic review of the literature pertaining to post-thrombotic syndrome.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines by a search of PubMed (1948 to September 2011) using the search terms "post-thrombotic syndrome," "postthrombotic syndrome," "post-phlebitic syndrome," and "postphlebitic syndrome." A manual reference list search was also carried out to identify further studies that would be appropriate for inclusion. The various scoring systems in use were identified and assessed against a list of criteria to determine their validity for use. For outcome measures, each scoring system was assessed for specific criteria, including interobserver reliability, association with ambulatory venous pressures, ability to assess severity of post-thrombotic syndrome, ability to assess change in condition over time, and association with patient-reported symptom severity.

RESULTS

The Villalta, Ginsberg, Brandjes, Widmer, CEAP, and Venous Clinical Severity Score systems all were assessed for the stated outcome measures. From their use in the literature, only the Villalta score was able to fulfill all the criteria described. The main criticism of the Villalta score in the literature appears to be its use of subjective measures. To that end, we propose that use of a venous disease-specific quality-of-life questionnaire in combination with the Villalta score may help standardize the subjective criteria.

CONCLUSIONS

The Villalta score, combined with a venous disease-specific quality-of-life questionnaire, should be considered the "gold standard" for the diagnosis and classification of post-thrombotic syndrome.

Pharmacologic and compression therapies for postthrombotic syndrome: a systematic review of randomized controlled trials

BACKGROUND

Postthrombotic syndrome (PTS) is a frequent, chronic complication of DVT. The effectiveness and safety of available treatments are unknown. The objective of this study was to systematically review the literature to assess whether pharmacologic and compression therapies are effective and safe for the treatment of PTS.

METHODS

We sought to identify randomized controlled trials (RCTs) via a search of PubMed, studies referenced in included publications, and studies that cited relevant literature.

RESULTS

A total of 121 titles were reviewed, 12 full-text publications were assessed for inclusion, and seven RCTs, including 703 patients, were selected for inclusion. Four trials assessed the effectiveness of drugs, including rutosides, hidrosmin, and defibrotide, and four trials assessed compression therapies for treatment of PTS. Systems for the diagnosis and classification of PTS severity varied across studies. Three of four drug therapy trials reported moderate improvement in selected PTS symptoms, minor changes in calf and ankle circumference, and some effects on ulcer healing. Two studies of compression stockings did not report benefit. Two studies that assessed compression devices reported improvement in PTS symptoms scores; one of these reported an improvement in quality-of-life score.

CONCLUSIONS

There is limited and low-quality evidence for the effectiveness of rutosides, hidrosmin, defibrotide, and compression stockings, but moderate-quality evidence that supports the use of intermittent compression to provide at least short-term relief from PTS. More rigorous studies are needed to assess the short- and long-term effectiveness and safety of PTS therapies.

Viilaita Scale: Goals and Limitations

The post-thrombotic syndrome (PTS) is a common, debilitating complication following deep venous thrombosis. PTS is a syndrome for which it has been difficult to provide a clear definition. PTS was defined as chronic venous signs/symptoms after a deep venous thrombosis. A number of scales are available to diagnose PTS, but there is a strong need for standardization. The Villalta scale was chosen as the standardized PTS scale. The Villalta scale has been validated in several studies and shows good correlation with generic and disease-specific quality of life scales. The inter-observer rate between study nurses and physicians was shown to be very good. Furthermore, the scale shows good discriminative properties among the different severity groups of PTS. The Villalta scale is useful for use in randomized controlled trials and it allows pooling of data from different studies. The Villalta scale should undergo further validation on intra-rater reliability. Ongoing randomized controlled trials will further validate the Villalta scale for use in PTS.

Healthcare burden associated with the post-thrombotic syndrome and potential impact of the new oral anticoagulants

Deep-vein thrombosis (DVT) can have a significant impact on a patient's life. In particular, the development of post-thrombotic syndrome as a long-term complication of DVT can have devastating consequences for the individual and impose a substantial economic burden on healthcare systems. Anticoagulants are the mainstay of DVT treatment; however, the current standard of care, a parenteral anticoagulant followed by a vitamin K antagonist, is associated with complex patient management, often resulting in suboptimal therapy. New, oral anticoagulants have been developed, and a direct thrombin inhibitor--dabigatran etexilate--and two direct Factor Xa inhibitors--rivaroxaban and apixaban--have completed and/or have ongoing phase III trials in the treatment of venous thromboembolism. These agents do not have the drawbacks of the vitamin K antagonists and hold promise for more effective treatment of DVT, possibly resulting in a reduction in the incidence of post-thrombotic syndrome.

Percutaneous mechanical and pharmacomechanical thrombolysis for occlusive deep vein thrombosis of the proximal limb in adolescent subjects: findings from an institution-based prospective inception cohort study of pediatric venous thromboembolism

PURPOSE

Young individuals with occlusive, proximal-limb deep vein thrombosis (DVT) who have acutely increased plasma levels of factor VIII and D-dimer are at high risk for postthrombotic syndrome (PTS) when treated with conventional anticoagulation alone. The present report is an evaluation of experience with adjunctive percutaneous mechanical thrombolysis (PMT) and/or percutaneous pharmacomechanical thrombolysis (PPMT) in such patients.

PATIENTS AND METHODS

Among 95 children 11-21 years of age enrolled in a prospective cohort of venous thromboembolism between March 1, 2006, and November 1, 2009, 16 met eligibility criteria and underwent PMT/PPMT, typically with adjunctive catheter-directed thrombolytic infusion (CDTI) of tissue-type plasminogen activator given after the procedure.

RESULTS

Median age was 16 years (range, 11-19 y). Thirteen cases (81%) involved lower limbs. Underlying stenotic lesions were disclosed in 53%, with endovascular stents deployed in all cases of May-Thurner anomaly. There were no periprocedural major bleeding events and one symptomatic pulmonary embolism. Technical success rate was 94%. Early (< 30 days) locally recurrent DVT developed in 40% of cases, of which 83% were successfully treated with repeat lysis. Late recurrent DVT rate (median follow-up duration, 14 months; range, 1-42 mo) was 27%. Cumulative incidence of physically and functionally significant PTS at 1-2 years was 13%.

CONCLUSIONS

This experience provides preliminary evidence that PMT/PPMT with adjunctive CDTI can be used safely and effectively in adolescent subjects with DVT at high risk for PTS.

Relation between D-dimer level, venous valvular reflux and the development of post-thrombotic syndrome after deep vein thrombosis

BACKGROUND

The pathophysiology of post-thrombotic syndrome (PTS) is postulated to involve persistent venous obstruction and venous valvular reflux.

OBJECTIVE

To study the association between D-dimer level, valvular reflux and the PTS in a well-defined cohort of deep vein thrombosis (DVT) patients.

METHODS

Consecutive patients with acute symptomatic DVT were recruited at eight centers and were followed for 24months. D-dimer was measured at 4months. A standardized ultrasound assessment for popliteal valvular reflux was performed at 12months. Using the Villalta scale, patients were assessed for PTS during follow-up by evaluators who were unaware of D-dimer or reflux results.

RESULTS

Three hundred and eighty-seven patients were recruited; of these, 305 provided blood samples for D-dimer and 233 had a 12-month reflux assessment. PTS developed in 45.1% of subjects. Mean D-dimer was significantly higher in patients with vs. without PTS (712.0 vs. 444.0μgL(-1) ; P=0.02). In logistic regression analyses adjusted for warfarin use at the time of D-dimer determination and risk factors for PTS, D-dimer level significantly predicted PTS (P=0.03); when stratifying for warfarin use at the time of blood draw, adjusted odds ratio (OR) for developing PTS per unit difference in log D-dimer was 2.33 (95% CI 0.89, 6.10) in those not on warfarin vs. 1.25 (95% CI 0.87, 1.79) in those on warfarin. Ipsilateral reflux was more frequent in patients with moderate-to-severe PTS than in patients with mild PTS (65% vs. 40%, respectively; P=0.01) and was independently associated with moderate-to-severe PTS in logistic regression analyses (P=0.01).

CONCLUSION

D-dimer levels, measured 4months after DVT in patients not on warfarin, are associated with subsequent development of PTS. Venous valvular reflux is associated with moderate-to-severe PTS.

Individually tailored duration of elastic compression therapy in relation to incidence of the postthrombotic syndrome

OBJECTIVE

We assessed whether individualized shortened duration of elastic compression stocking (ECS) therapy after acute deep venous thrombosis (DVT) is feasible without increasing the incidence of postthrombotic syndrome (PTS).

METHODS

At the outpatient clinic of the Maastricht University Medical Centre, 125 consecutive patients with confirmed proximal DVT were followed for 2 years. Villalta scores were assessed on four consecutive visits; 3, 6, 12, and 24 months after the acute event. Reflux was assessed once by duplex testing. After 6 months, patients with scores <or=4 on the Villalta clinical score and in the absence of reflux were allowed to discontinue ECS therapy. If reflux was present, two consecutive scores <or=4 were needed to discontinue ECS therapy.

RESULTS

ECS therapy was discontinued in 17% of patients at 6 months, in 48% at 12 months, and in 50% at 24 months. Reflux on duplex testing was present in 74/101 (73.3%) tested patients and was not associated with the onset of PTS. At the 6-month visit, the cumulative incidence of PTS was 13.3%, at 12 months 17.0%, and at 24 months 21.1%. Varicosities/venous insufficiency (present at baseline) was significantly associated with PTS; hazard ratio 3.2 (1.2-9.1).

CONCLUSIONS

Patients with a low probability for developing PTS can be identified as early as 6 months after the thrombotic event, and individualized shortened duration of ECS therapy based on Villalta clinical scores may be a safe management option. These findings need to be confirmed in a randomized clinical trial.

Incidence and cost burden of post-thrombotic syndrome

Post-thrombotic syndrome (PTS) is a long-term complication of deep-vein thrombosis (DVT), manifesting as swelling, pain, edema, venous ectasia, and skin induration of the affected limb. PTS has been estimated to affect 23-60% of individuals with DVT, frequently occurring within 2 years of the DVT episode. Symptomatic DVT, post-operative asymptomatic DVT, and recurrent DVT are all risk factors for the development of PTS. Treatment of PTS is often ineffective and treatment-related costs represent a healthcare burden. Therefore, prevention of DVT is essential to reduce PTS, and thus improve outcomes and reduce overall healthcare costs. Although recommended by guidelines, appropriate DVT prophylaxis remains considerably underused. This review evaluates the incidence, risk factors, and economic impact of PTS. Increasing the awareness of PTS, and the methods to prevent this complication may help reduce its incidence, improve long-term outcomes in patients, and decrease resulting costs associated with treatment.