Five-year outcome study of deep vein thrombosis in the lower limbs

Acute phase determinant of post-thrombotic syndrome: A review of the literature

BACKGROUND

Post-thrombotic syndrome (PTS) is the main long-term complication of deep vein thrombosis (DVT). Several therapies are being evaluated to prevent or to treat PTS. Identifying the patients most likely to benefit from these therapies presents a significant challenge.

OBJECTIVES

The objective of this review was to identify risk factors for PTS during the acute phase of DVT.

ELIGIBILITY CRITERIA

We searched the PubMed and Cochrane databases for studies published between January 2000 and January 2021, including randomized clinical trials, meta-analyses, systematic reviews and observational studies.

RESULTS

Risk factors for PTS such as proximal location of DVT, obesity, chronic venous disease, history of DVT are associated with higher risk of PTS. On the initial ultrasound-Doppler, a high thrombotic burden appears to be a predictor of PTS. Among the evaluated biomarkers, some inflammatory markers such as ICAM-1, MMP-1 and MMP-8 appear to be associated with a higher risk of developing PTS. Coagulation disorders are not associated with risk of developing PTS. Role of endothelial biomarkers in predicting PTS has been poorly explored. Lastly, vitamin K antagonist was associated with a higher risk of developing PTS when compared to direct oral anticoagulants and low molecular weight heparin.

CONCLUSIONS

Several risk factors during the acute phase of VTE are associated with an increased risk of developing PTS. There is a high-unmet medical need to identify potential biomarkers for early detection of patients at risk of developing PTS after VTE. Inflammatory and endothelial biomarkers should be explored in larger prospective studies to identify populations that could benefit from new therapies.

Acute and chronic venous occlusion

This review article provides an overview of acute and chronic venous occlusion, a condition that can cause significant morbidity and mortality if not diagnosed and treated promptly. The article begins with an introduction to the anatomy of the venous system, followed by a discussion of the causes and clinical features of venous occlusion. The diagnostic tools available for the assessment of venous occlusion, including imaging modalities such as ultrasound, CT, and MRI, are then discussed, along with their respective advantages and limitations. The article also covers the treatment options for acute and chronic venous occlusion, including anticoagulant therapy and endovascular interventions. This review aims to provide radiologists with an updated understanding of the pathophysiology, diagnosis, and management of acute and chronic venous occlusion.

The risk for post-thrombotic syndrome of subjects with deep vein thrombosis in an Indonesian referral hospital: a retrospective cohort study

BACKGROUND

Post-thrombotic syndrome (PTS) is a complication of deep vein thrombosis (DVT) and affects 20-40% of DVT subjects. The risk factor of PTS after DVT is difficult to determine. We aimed to evaluate the incidence of PTS after 3 months of DVT diagnosis and to determine the risk of PTS.

METHODS

A retrospective cohort study of subjects who developed DVT confirmed by Doppler ultrasound in Cipto Mangunkusumo Hospital from April 2014 until June 2015. The presence of PTS was assessed after 3 months of completed DVT treatment using the Villalta score. Risk factors for PTS were evaluated from medical records.

RESULTS

There were 91 subjects with DVT with mean age of 58 years. 56% were female. It was dominated by subjects aged ≥ 60 years (45.1%). Hypertension (30.8%) and diabetes mellitus (26.4%) were the major comorbidities in this study. Deep vein thrombosis occurred commonly in unilateral side (79.1%), proximal localization (87.9%), and unprovoked DVT (47.3%). The cumulative incidence of PTS after DVT was 53.8%, 69% of subjects had mild PTS. Heaviness of the leg (63.2%) and edema (77.5%) were the most common symptoms.

RESULTS

There were 91 subjects with DVT with mean age of 58 years. 56% were female. It was dominated by subjects aged ≥ 60 years (45.1%). Hypertension (30.8%) and diabetes mellitus (26.4%) were the major comorbidities in this study. Deep vein thrombosis occurred commonly in unilateral side (79.1%), proximal localization (87.9%), and unprovoked DVT (47.3%). The cumulative incidence of PTS after DVT was 53.8%, 69% of subjects had mild PTS. Heaviness of the leg (63.2%) and edema (77.5%) were the most common symptoms. Significant risk factors for PTS were unprovoked DVT (adjusted RR 1.67; 95%CI: 1.17-2.04; p = 0.01) and female gender (adjusted RR 1.55; 95%CI: 1.03-1.94; p = 0.04). Age, body mass index, thrombus location, immobilization, malignancy and surgery was not associated with PTS.

CONCLUSION

We conclude that 53.8% of subjects suffered PTS after 3 months of DVT. Unprovoked DVT and female gender were significant risk factors for PTS.

Ultrasound screening for asymptomatic deep vein thrombosis in critically ill patients: a pilot trial

Deep vein thrombosis (DVT) in critically ill patients still represents a clinical challenge. The aim of the study was to investigate whether a systematic ultrasound (US) screening might improve the management of the antithrombotic therapy in intensive care unit (ICU). In this non-randomized diagnostic clinical trial, 100 patients consecutively admitted to ICU of the University Hospital of Perugia were allocated either in the screening group or in the control group. Subjects in the screening group underwent US examination of lower limbs 48 h after admission, and again after 5 days. Subjects in the control group underwent US examination according to the standard of care (SOC) of the enrolling institution. Retrospectively registered at ClinicalTrials.gov (NCT05019092) on 24.08.2021. Lower limb DVT was significantly more frequent in the screening group (p < 0.001), as well as the subsequent extension of a pre-existing DVT (p = 0.027). In the control group, DVT of large veins was more frequent (p = 0.038). Major bleedings were reported in 5 patients, 4 in the non-screening group and in 1 in the screening group. Patients in the screening group started the antithrombotic treatment later (p = 0.038), although the frequency, dose and duration of the treatment were not different between the two groups. The duration of stay in ICU was longer in the screening group (p = 0.007). Active screening for DVT is associated with an increased diagnosis of DVT. The screening could be associated with a reduced incidence of proximal DVT and a reduction in the bleeding risk.

Patterns and Distribution of Deep Vein Thrombosis and Its Effects on Clinical Outcomes After Opening-Wedge High Tibial Osteotomy

Background:

Although a few studies have reported the incidence of deep vein thrombosis (DVT) after opening-wedge high tibial osteotomy (OWHTO), previous studies focused only on symptomatic DVT. Information is lacking regarding the overall incidence of DVT after OWHTO, thrombus location, and the relationship between DVT and clinical outcome.

Purpose:

To determine the overall incidence of DVT and classify the location of DVT after OWHTO. We also determined whether significant differences in clinical improvement exist in patients with and without DVT at 6 months and at 2 years after OWHTO.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

This study included 46 patients (47 knees) who underwent OWHTO. All patients were instructed to perform knee range of motion exercises and partial weightbearing after drain removal. None of the patients received a chemoprophylaxis for DVT except intermittent pneumatic compression. DVT was diagnosed using 128-row multidetector computed tomography performed before discharge on the fourth postoperative day. The location was classified into 6 segments in the distal portion (muscular and axial veins) and proximal portion (popliteal, femoral, and common femoral veins and veins located above the iliac vein). International Knee Documentation Committee (IKDC) score was assessed preoperatively and postoperatively at 6 months, 1 year, and 2 years using a linear mixed model.

Results:

Although the incidence of symptomatic DVT was 8.5% (n = 4), the overall incidence of early DVT was 44.7% (n = 21). All DVTs were located in the distal portion of the lower extremity vein, and 76.2% of the DVTs were located in an axial vein. The IKDC scores were 33.6 ± 7.2 and 35.3 ± 9.1 (P = .910) preoperatively, 38.1 ± 5.6 and 40.6 ± 8.4 (P = .531) at 6 months after surgery, and 44.8 ± 6.9 and 45.9 ± 11.4 (P = .786) at 2 years after surgery in patients without and those with DVT, respectively.

Conclusion:

The overall incidence of early DVT after OWHTO was 44.7%. DVT after OWHTO was found particularly around the osteotomy site (76.2%). Patients with DVT did not have inferior short-term clinical outcomes after surgery.

Deep Venous Thrombosis in a Patient with a Moderate Pretest Probability and a Negative D-Dimer Test: A Review of the Diagnostic Algorithms

Modern diagnostic strategies of venous thromboembolism (VTE) have been developed. In this review, the diagnostic algorithms for deep-vein thrombosis (DVT) and their parameters are discussed individually in the context of reporting a case of DVT in a 43-year-old Caucasian female with a moderate pretest probability stratified by Wells’ score and a negative high quality D-dimer test. The patient was on treatment with Xarelto (rivaroxaban), 20 mg PO daily at the time of presentation. The diagnosis was verified through a complete lower limb ultrasound (US). This case highlights the diagnostic challenges and pitfalls of the current algorithms, especially those seen in a subgroup of patients such as patients with cancer, pregnancy, recurrent VTE or are on anticoagulation therapy at the time of presentation. The diagnosis of DVT is less plausible in a patient who is on anticoagulation therapy, but physicians should be aware of such a possibility. Physicians should also know in advance the numerous clinically relevant limitations of D-dimer testing before interpreting the results. Unifying the current diagnostic strategies, modifying the current Wells’ score and using the protocol of a whole-leg compression US instead of the limited US protocol are among the several cautious suggestions that have been proposed based on this review to possibly decrease the incidence of missed DVT.

Aspiration thrombectomy for acute iliofemoral or central deep venous thrombosis

OBJECTIVE

The use of catheter-directed thrombolysis (CDT) may provide clinical benefit in patients with acute deep venous thrombosis (DVT), but significant doubt remains about its indications and risks. We assessed technical success in resolution of acute iliofemoral or central DVT after single-session treatment with a novel mechanical aspiration thrombectomy device as an alternative to initiation of CDT.

METHODS

This was a single-center retrospective review of patients with acute iliofemoral or central DVT treated with the Indigo continuous aspiration mechanical thrombectomy 8 system (Penumbra, Inc, Alameda, Calif) from 2016 to 2017. The primary outcome was technical success, defined as resolution of >70% of thrombus without need for postaspiration CDT, as an initial or adjunctive treatment. Secondary end points included DVT recurrence and treatment complications.

RESULTS

There were 10 patients (50% male) with a median age of 44 years (range, 19-68 years). Indication for treatment was DVT (n = 4), recurrent DVT (n = 1), stent thrombosis (n = 3), high-grade extrinsic narrowing of the inferior vena cava (IVC) due to immunoglobulin G4-related disease (n = 1), and IVC obstruction from liver tumor invasion (n = 1). Five patients had underlying May-Thurner syndrome. Five patients had iliofemoral involvement, two iliocaval, and one iliac vein alone. Two patients had central DVT, one of them involving the IVC and one involving the superior vena cava with brachiocephalic extension. Aspiration thrombectomy was technically successful in a total of six patients. Success was achieved in five of eight patients as the initial or main treatment modality and as an adjunctive treatment in one of two patients. Of the four patients in whom aspiration thrombectomy was not successful, three underwent successful further treatment with CDT. Recurrence after successful aspiration was seen in two patients. One patient developed pulmonary embolism that required no additional treatment. One patient experienced severe headaches treated with oral analgesics.

CONCLUSIONS

We observed a technical success of 60% for acute iliofemoral and central DVT with an aspiration thrombectomy system that allowed definitive treatment in one setting. As a novel therapy, this avoided the need for thrombolysis in the majority of selected cases with no bleeding complications and is a promising technique for acute DVT management.

Iliac Vein Stent Placement: Acute Venographic Changes and Relevance to Venous Biomechanics

PURPOSE

To describe acute venographic changes of external iliac vein (EIV) after ipsilateral common iliac vein (CIV) stent placement.

MATERIALS AND METHODS

Retrospective review was performed of 17 cases with placement of a single CIV stent. Central CIV stent diameter and minimal ipsilateral EIV diameter were measured on venogram; vein diameter was measured at the same 2 anatomic locations on venogram obtained before intervention. Relative CIV diameter increase was defined as the ratio of change in central CIV diameter after stent placement to CIV diameter before intervention. Relative EIV diameter reduction was defined as the ratio of change in diameter of EIV after stent deployment in CIV to EIV diameter before intervention. Diameters before and after intervention were compared using a 2-tailed, paired sample t test. Pearson coefficient was calculated for correlations.

RESULTS

There was a significant reduction of EIV diameter after ipsilateral CIV stent placement compared with before stent placement (mean 9.3 mm ± 3.1 vs 11.9 mm ± 3.8; P < .01); mean decrease in EIV diameter was 21.7% ± 15.8. There was a correlation between relative CIV diameter increase and relative EIV diameter reduction (r = .8917).

CONCLUSIONS

Significant venographic narrowing of the EIV occurs after placement of an adjacent CIV stent, and the degree of narrowing is associated with the relative increase in CIV diameter. These findings may be explained by the inherent anisotropic elasticity of veins. Further study is warranted to guide future venous interventions.

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.

The predictive value of markers of fibrinolysis and endothelial dysfunction in the post thrombotic syndrome

The post thrombotic syndrome (PTS) develops in 20–40% of deep venous thrombosis (DVT) patients. Risk factors for PTS have not been well elucidated. Identification of risk factors would facilitate individualised risk assessment for PTS. We conducted a systematic review to determine whether biomarkers of fibrinolysis or endothelial dysfunction can predict the risk for PTS among DVT patients. Studies were identified by searching the electronic databases PubMed, EMBASE, Scopus and Web of science. We included studies published between 1990 and 2013, measured biomarker levels in adult DVT patients, and reported rates of PTS development. Fourteen studies were included: 11 investigated the association between D-dimer and PTS; three examined fibrinogen; two measured von Willebrand factor; one measured plasminogen activator inhibitor-1; one assessed ADAMTS-13 (A Disintegrin and Metalloprotease with Thrombospondin type 1 repeats) and one measured factor XIII activity. Studies varied with regards to inclusion criteria, definition of PTS, time point and method of biomarker measurement. We were unable to meta-analyse results due to marked clinical heterogeneity. Descriptively, a significant association with PTS was found for D-dimer in four studies and factor XIII in one study. Further prospective research is needed to elucidate whether these markers might be useful to predict PTS development.

Epidemiology of the post-thrombotic syndrome

The post thrombotic syndrome (PTS) refers to clinical manifestations of chronic venous insufficiency (CVI) following a deep-vein thrombosis (DVT). PTS is the most frequent complication of DVT, which develops in 20 to 50% of cases after proximal DVT and is severe in 5-10% of cases. The reported prevalence of PTS differs widely among studies because of differences in study populations, tools used to assess PTS, and time interval between acute DVT and PTS assessment. The two most important predictors of PTS are extensive proximal character of DVT and previous ipsilateral DVT. Other reported risk factors include pre-existing CVI, obesity, quality of anticoagulant treatment, older age and residual venous obstruction. Standardization of PTS assessment tools combined with the development of patient self-reported PTS scales are likely to constitute a breakthrough in research of the epidemiology of PTS, by allowing comparison between studies, meta-analyses and increasing the feasibility of longer follow-up of DVT patients. This should enable identification of patient populations at high risk of severe PTS, new predictors of PTS and targets for potential new treatments. In this perspective, identification of biomarkers that are predictive of PTS such as markers of inflammation is crucial in ongoing research.

Clinical implications of the anatomical variation of deep venous thrombosis

Introduction

Little is known about the anatomic variation and its implication in patients with lower limb deep venous thrombosis (DVT). We studied the clinical presentation, site of thrombosis and risk factors based on the anatomic distribution of lower limb DVT.

Methods

A retrospective analysis of clinically suspected DVT cases was conducted between 2008 and 2012. DVT was categorized by the location of the thrombosed segment and limb involved. The DVT anatomic segments were assessed according to left-to-right ratio, predisposing factors and clinical presentations.

Results

A total of 637 patients with DVT were included with a mean age of 50 ± 17 years (51%; females). The most frequently thrombosed segments were popliteal, posterior tibial and profunda femoris veins. DVT was more common at the left side, with a left-to-right ratio of 1.5:1. Bilateral DVT cases (38.5%) had more prior history of DVT as compared to left- (20.3%) and right-sided DVTs (22.6%); p = 0.01. Bilateral DVT was complicated more with post-thrombotic syndrome (leg ulcer) ( p = 0.02). The rates of pulmonary embolism (25%) and mortality (23.1%) were significantly higher for bilateral DVT in comparison to left- and right-sided DVT. Abnormal coagulation profile was significantly associated with posterior tibial DVT (81% vs. 71.4%; p = 0.01) as compared to patients with normal coagulation profile.

Conclusion

Lower limb DVTs are more common at the left side; however, patients with bilateral DVT have higher frequency of recurrence, post-thrombotic syndrome, pulmonary embolism and mortality. The anatomic segments of DVT show specific distribution depending on the predisposing factors. These findings could improve our understanding of the pathophysiology and management of DVT patients.

Short-Term Anticoagulant Therapy and Thrombus Location Are Independent Risk Factors for Delayed Recanalization of Deep Vein Thrombosis

Background

Prompt recanalization of the vein containing the thrombus is an important goal during the initial treatment of DVT, and risk factors for delayed recanalization in patients with deep vein thrombosis (DVT) in the lower extremities need to be determined.

Material/Methods

A total of 174 patients with DVT in lower extremities were recruited from June 2014 to March 2015 at our hospital. Duplex ultrasound scanning was conducted for all patients at 1 and 6 months after baseline evaluation. We divided the patients into recanalization and non-recanalization groups and analyzed risk factors for delayed recanalization.

Results

The univariate analysis revealed that an oral anticoagulant time of less than 3 months and venous thrombus location were risk factors for delayed recanalization (P<0.01). However, age, gender, hypertension, diabetes, pulmonary embolism, incidence factors, the use of catheter-directed thrombolytic (CDT) drugs, and inferior vena cava filter (IVCF) implantation had no influence on the incidence of delayed recanalization in patients with DVT (P>0.05). The multivariate analysis showed that patients with an anticoagulant time of less than 3 months had a lower incidence of recanalization than those with an anticoagulant time of more than 3 months (OR=2.358, P<0.05). The risk of delayed recanalization in patients with proximal DVT was 7 times higher than that in patients with distal DVT.

Conclusions

Duration of anticoagulant treatment of less than 3 months and venous thrombus location are independent risk factors for delayed recanalization of DVT in the lower extremities.

Venous thromboembolism in Croatia - Croatian Cooperative Group for Hematologic Diseases (CROHEM) study

Aim

To analyze the incidence and characteristics of venous thromboembolism (VTE) in Croatia.

Methods

The Croatian Cooperative Group for Hematologic Diseases conducted an observational non-interventional study in 2011. Medical records of patients with newly diagnosed VTE hospitalized in general hospitals in 4 Croatian counties (Šibenik-Knin, Koprivnica-Križevci, Brod-Posavina, and Varaždin County) were reviewed. According to 2011 Census, the population of these counties comprises 13.1% of the Croatian population.

Results

There were 663 patients with VTE; 408 (61.54%) had deep vein thrombosis, 219 (33.03%) had pulmonary embolism, and 36 (5.43%) had both conditions. Median age was 71 years, 290 (43.7%) were men and 373 (56.3%) women. Secondary VTE was found in 57.3% of participants, idiopathic VTE in 42.7%, and recurrent VTE in 11.9%. There were no differences between patients with secondary VTE and patients with idiopathic VTE in disease recurrence and sex. The most frequent causes of secondary VTE were cancer (40.8%), and trauma, surgery, and immobilization (38.2%), while 42.9% patients with secondary VTE had ≥2 causes. There were 8.9% patients ≤45 years; 3.3% with idiopathic or recurrent VTE. Seventy patients (10.6%) died, more of whom had secondary (81.4%) than idiopathic (18.6%) VTE (P < 0.001), and in 50.0% VTE was the main cause of death. Estimated incidence of VTE in Croatia was 1.185 per 1000 people.

Conclusion

Characteristics of VTE in Croatia are similar to those reported in large international studies. Improved thromboprophylaxis during the presence of risk factors for secondary VTE might substantially lower the VTE burden.

How I treat isolated distal deep vein thrombosis (IDDVT)

Thromboses limited to infrapopliteal leg deep veins (isolated distal deep vein thrombosis [IDDVT]) are frequently diagnosed in subjects with suspected pulmonary embolism or DVT and account for one-fourth to one-half of all diagnosed leg DVTs. Despite their frequency, the natural history of IDDVTs and their real risk of thromboembolic complications are still uncertain because of the scarcity of prospective, blind, nonintervention studies. Therefore it is still debated whether they warrant diagnosis and treatment. Diagnosis is based on ultrasonographic examination, which is more operator dependent and less sensitive in distal than in proximal veins. The available data seem to support the view that most IDDVTs are self-limiting and inconsequential for patients, though in some cases they can be associated with complications and warrant diagnosis and treatment. The available guidelines for treatment of IDDVTs give different indications ranging from serial imaging of the deep veins for 2 weeks to detect and treat only in case of proximal extension, to giving oral anticoagulation in all IDDVT patients for 3 months. I review this issue, focusing on possible and suggested treatments in symptomatic IDDVT patients, and describe our current therapeutic approach to these patients.

Post-thrombotic syndrome 3 years after deep venous thrombosis in the Thrombosis and Pulmonary Embolism in Out-Patients (TULIPA) PLUS Registry

BACKGROUND

Reported post-thrombotic syndrome (PTS) rates may be confounded by including patients with a history of deep venous thrombosis (DVT) before the index event, varicose veins, or chronic venous insufficiency independent of PTS. We were interested in assessing PTS incidence rates of patients without these pre-existing disease conditions.

METHODS

A prospective registry with a 3-year follow-up after an initial DVT was assessed. Available for analysis were 135 ambulatory patients without a history of DVT (before the index DVT), signs of varicose veins, or chronic venous insufficiency affecting the ipsilateral or contralateral leg, and Villalta score.

RESULTS

PTS was detected in 24.5% of patients, with 17.0% having mild (Villalta score, 5-9), 6.0% moderate (score, 10-14), and 1.5% severe PTS (score ≥15) after a first DVT. Of these, 52.6% had proximal and 47.4% distal DVT; 63.7% were provoked and 35.6% unprovoked (one patient missing). Patients with proximal DVT (32.4%) significantly more often developed any PTS compared with patients with distal DVT (15.6%; P = .024); however, groups were similar with regard to severity of PTS by the four-level Villalta score (P = .109). In univariate analysis, PTS was more frequent (odds ratio, 95% confidence interval) with higher age (1.06 per year; 1.02-1.09), a body mass index of 25 to 30 kg/m(2) (2.38; 0.71-7.97) and ≥30 kg/m(2) (6.08; 1.75-21.14), proximal vs distal DVT (2.59; 1.12-5.98), and calf swelling ≥3 cm larger than the asymptomatic leg (3.77; 1.66-8.55). In a multivariate analysis, age (1.05; 1.01-1.09) and calf swelling ≥3 cm larger than the asymptomatic leg (2.94; 1.20-7.20) remained predictive for PTS. Compression therapy was used by 78.5% of patients at the 1-year follow-up and by 46.7% at the 3-year follow-up. Both rates were higher in patients with PTS (93.9%) vs no PTS (66.7%).

CONCLUSIONS

This prospective survey demonstrates a low rate of PTS in patients with a first DVT and no pre-existing DVT, varicose veins, or chronic venous insufficiency, and a high adherence rate to compression therapy, within the first 3 years of follow-up. Age and marked calf swelling were independent predictors of PTS.

Incidence and Risk Factors of the Post-thrombotic Syndrome

Annually 1–2 in every 1000 adults will develop a deep venous thrombosis of the lower extremity. A third to half of these patients will develop the post-thrombotic syndrome (PTS). However, predicting which patients will develop the PTS remains elusive. Ipsilateral thrombosis recurrence seems to be the most important risk factor. Moreover, residual venous occlusion and valvular reflux seem to predict PTS incidence to some degree. Laboratory parameters, including D-dimers and inflammatory markers, have shown promise in predicting development of the PTS in patients and are currently under investigation. Creating a model based on all combined risk factors and patient characteristics might aid in risk stratification in individual patients.

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.

Multimodality imaging of the peripheral venous system

The purpose of this article is to review the spectrum of image-based diagnostic tools used in the investigation of suspected deep vein thrombosis (DVT). Summary of the experience gained by the author as well as relevant publications, regarding vein imaging modalities taken from a computerized database, was reviewed. The imaging modalities reviewed include phlebography, color Doppler duplex ultrasonography (CDDUS), computerized tomography angiography (CTA) and venography (CTV), magnetic resonance venography (MRV), and radionuclide venography (RNV). CDDUS is recommended as the modality of choice for the diagnosis of DVT. A strategy combining clinical score and D-dimer test refines the selection of patients. Phlebography is reserved for discrepant noninvasive studies.

New oral anticoagulants for thromboprophylaxis after elective total hip and knee arthroplasty

Anticoagulant drugs reduce the risk of venous thromboembolic events after total hip and knee arthroplasty. However, the use of current drugs, such as low molecular weight heparins, is hampered by their subcutaneous route of administration. The use of vitamin K antagonists is hampered by the requirement for routine coagulation monitoring and dose titration to provide effective anticoagulation without an increased risk of bleeding and numerous food and drug interactions. Clearly, there is a need for new oral, fixed-dose anticoagulant drugs that do not require coagulation monitoring, while demonstrating similar or better efficacy and safety profiles when compared with current agents.

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.

How I treat postthrombotic syndrome

Postthrombotic syndrome (PTS) is a chronic complication of deep venous thrombosis (DVT) that reduces quality of life and has important socioeconomic consequences. More than one-third of patients with DVT will develop PTS, and 5% to 10% of patients will develop severe PTS, which may manifest as venous ulceration. The principal risk factors for PTS are persistent leg symptoms 1 month after the acute episode of DVT, extensive DVT, recurrent ipsilateral DVT, obesity, and older age. Daily use of elastic compression stockings (ECSs) for 2 years after proximal DVT appears to reduce the risk of PTS; however, there is uncertainty about optimal duration of use and compression strength of ECSs and the magnitude of their effect. The cornerstone of managing PTS is compression therapy, primarily using ECSs. Venoactive medications such as aescin and rutoside may provide short-term relief of PTS symptoms. The likelihood of developing PTS after DVT should be discussed with patients, and symptoms and signs of PTS should be monitored during clinical follow-up. Further studies to elucidate the pathophysiology of PTS, to identify clinical and biologic risk factors, and to test new preventive and therapeutic approaches to PTS are needed to ultimately improve the long-term prognosis of patients with DVT.

In vivo and in vitro assessment of human saphenous vein wall changes

Purpose:

To investigate if noradrenaline (NA) and 5-hydroxyptamine (5-HT) drugs induce responses of isolated control and varicose veins are altered by removal of the endothelium.

Subjects & Methods:

Specimens of the great saphenous vein (GSV) were obtained from 12 subjects with primary varicose veins and 12 subjects from donor vessels at cardiac surgery. A total of 10 normal healthy volunteers were selected for comparison. The diameter changes of GSV during the resting phase, at the end of 5 minutes occlusion, and then every 30 seconds post deflation for five minutes were measured using B-mode ultrasound. Post-surgery the vein sample was collected in a tube of Krebs-Henseleit solution.

Results:

The repeated measure ANOVA test for the diameter, percent, and difference changes of GSV diameter from maximum diameter at different time intervals showed significance difference within and between all groups. NA and 5-HT produced concentration-dependent contractions of control and varicose saphenous vein segments. There was no significant difference in the potency of NA and for 5-HT, but the maximum response, normalized for tissue weight, was less in varicose vein segments. Removal of the endothelium had no effect on the potency of NA or 5-HT but significantly (p<0.05) reduced the maximum response to NA and 5-HT in varicose vein segments but not to 5-HT in control veins.

Conclusion:

The venous endothelial damage may cause vascular smooth muscle contractions dysfunction that favours dilatation and secondary valvular insufficiency.

The effect of venous thrombus location and extent on the development of post-thrombotic signs and symptoms

OBJECTIVE

This prospective study determined the incidence of signs and symptoms of chronic venous disease and recurrent venous thrombotic events (VTE) in relation to the location and extent of the initial venous thrombus.

METHODS

A first episode of acute deep vein thrombosis (DVT) occurred in 120 lower extremities of 105 patients (59 men; mean age, 54 years [range, 23-82 years]). Patients who presented with pain, swelling, or signs and symptoms of pulmonary embolism of <10 days were included. The DVT was diagnosed with duplex ultrasound (DUS) imaging. Patients were grouped by those having thrombosis in one venous segment (group A) or multiple levels (group B). Patients were treated with heparin and warfarin. Patients with at least 1-year of follow-up with clinical and DUS were included.

RESULTS

No difference was found in the duration of signs and symptoms at presentation. The median follow-up was 3.4 years (range, 1.2-7 years). More symptomatic limbs were seen in group B (71 of 79) compared with group A (21 of 41; P < .001). Post-thrombotic syndrome (PTS) was more advanced in group B vs group A, including the prevalence of skin damage and ulceration (61 of 79 vs 26 of 41, P < .001; 29 of 79 vs 6 of 41, P = .019, respectively). Limbs with calf DVT that had focal thrombosis were most often asymptomatic. Calf thrombosis in patients with proximal DVT produced the highest prevalence of PTS. Venous claudication was exclusively found in group B and was present only when iliac veins were involved. Recurrent thrombosis had a trend for a higher prevalence in group B (5 of 41 vs 16 of 79, P = .39). Reflux, obstruction, or a combination of the two were more common in group B (61 of 79) vs group A (15 of 41; P < .0001). Limbs with both reflux and obstruction were more likely to develop skin damage (group A, 5 of 6 vs 1 of 35, P < .0001; group B, 24 of 29 vs 5 of 50, P < .0001).

CONCLUSIONS

Recurrent thrombosis and skin damage is more likely to develop in patients with multiple sites of thrombosis than in those with thrombosis in a single vein segment. Patients with reflux and obstruction presented more skin damage than those with reflux or obstruction alone. Involvement of the calf veins in the presence of proximal vein thrombosis increased the likelihood for PTS.

Posttreatment ultrasound-detected residual venous thrombosis: a risk factor for recurrent venous thromboembolism and mortality

PURPOSE OF REVIEW

The cumulative risk of recurrent venous thrombosis may rise to 30% over 8 years. Extended oral anticoagulation is effective but major bleeding is increased. To balance these risks attention has focused on identifying patients with the highest likelihood of recurrence for whom continued therapy is most beneficial. Another issue of interest has been the increased probability of death after venous thrombosis, due primarily to malignancy but also to vascular disease.

RECENT FINDINGS

Unprovoked events and cancer are known to be associated with recurrent thrombosis. Residual posttreatment thrombosis confirmed by compression ultrasound is regarded as another risk for recurrence. Confounders in the published studies are the patient mix and the ultrasound technique employed. Other variables such as gender and D-dimer may also predict risk. Although arterial disease is increased in patients with venous thromboses, the association between idiopathic venous thromboembolism and atherosclerosis remains circumstantial.

SUMMARY

There are no validated approaches for predicting recurrent venous events. Ultrasound interrogation for residual thrombosis after primary therapy may improve treatment stratification by defining patients suitable for extended anticoagulation.

Incidence and distribution of lower extremity deep vein thrombosis in rehabilitation patients: implications for screening

Patients admitted to in-patient rehabilitation programs have an increased risk for developing deep venous thrombosis (DVT). However, the utility of screening for lower extremity DVT using duplex ultrasound in this high-risk population is not well characterized. The purpose of this study is to identify whether or not screening lower-extremity duplex exams are indicated in this high-risk population. Screening lower extremity duplex exams were performed on all patients admitted to the rehabilitation center at Mt. Sinai Hospital over a 3-year period. Charts were reviewed for patient age, gender, diagnosis, date of screening and follow-up duplex exams, presence and location of venous thrombosis at each duplex exam, history of anticoagulation, and medical DVT prophylaxis. The presence of DVT at screening, the location of DVT along the lower extremity, and the outcome of calf DVT were analyzed in terms of gender, underlying diagnosis, and history of DVT prophylaxis. Lower extremity DVT was detected in 34% of patients. Twenty-three percent of patients had isolated calf vein thrombosis. Men were more likely than women to have DVT. Calf DVTs progressed in 3% of patients over an average follow-up of 2 weeks. The presence of DVT, its location along the lower extremity, and the outcome of calf vein DVT had no significant relationship to underlying diagnosis or history of prophylaxis. Screening duplex exams to detect lower extremity DVT in rehabilitation patients is useful. Screening altered management in 26% of patients, prompting either anticoagulation or repeat duplex exam.

Current approaches and controversial issues in the diagnosis of deep vein thrombosis via duplex Doppler ultrasound

Duplex and color Doppler sonography (DUS) is currently the technique of choice for the diagnosis of deep venous thrombosis (DVT) in symptomatic patients, because it has proven safe and cost-effective, with a very high sensitivity and specificity (96% and 98%, respectively) for the diagnosis of proximal DVT. Several issues regarding its method and clinical indications remain controversial, however. Although isolated calf vein thrombosis does not seem to have a significant adverse outcome in the short term, scanning the calf only in patients with localized symptoms or signs is cost-effective. Bilateral examination is indicated in high-risk patients or when screening asymptomatic patients. When negative, a complete DUS examination of the proximal and distal veins, at least down to the level of the popliteal trifurcation, allows withholding anticoagulant therapy without the risk of major complications. This examination may be repeated if signs or symptoms worsen. Some populations of asymptomatic patients at high risk of DVT may benefit from DUS screening. Bilateral DUS examination of lower limb veins should be performed as the initial examination in the workflow of pulmonary embolism only in patients with risk factors for DVT. Recurrent thrombosis is a challenging diagnosis for all imaging modalities. A diagnostic strategy combining clinical probability score and D-dimer test may refine the selection of patients. The pitfalls and limitations of venous DUS are related to vein anatomy, flow changes, technical issues, and operator expertise.