Recurrent Ipsilateral Deep Vein Thrombosis Research Articles

Use of Magnetic Resonance Direct Thrombus Imaging for the Diagnostic Management of Suspected Thrombosis in Routine Clinical Practice.

Background The noninvasive magnetic resonance direct thrombus imaging (MRDTI) technique can be used to diagnose acute deep vein thrombosis (DVT), without the use of intravenous contrast. MRDTI holds the potential to differentiate between acute and chronic DVT and could be helpful when diagnosing thrombosis is challenging. Objectives Our objective was to evaluate the application of MRDTI in clinical practice, including the frequency and indications of MRDTI scans performed in practice-based conditions, results, impact on treatment decisions, and associated patient outcomes. Methods A retrospective study was performed at the Leiden University Medical Center, the Netherlands. MRDTI scans performed since its implementation in patients aged ≥18 years as part of clinical practice for the diagnostic management of suspected thrombosis were evaluated. Results Between October 2015 and September 2023, 36 patients had undergone MRDTI for the diagnostic evaluation of thrombosis. MRDTI application increased since 2019 (five-eight scans per year). The most common indication was to differentiate between acute and chronic thrombosis, mainly for suspected recurrent ipsilateral DVT after inconclusive compression ultrasonography. In over a third of patients, acute thrombosis was confirmed by MRDTI. MRDTI results determined treatment decisions in all except two patients. One patient had symptomatic thrombosis of the lower extremity within 3 months after an MRDTI of the upper extremity without signs of acute thrombosis (1/23; 4.3%, 95% confidence interval: 0.77-21). Conclusion Over the past 4 years, MRDTI has been used increasingly in our hospital. MRDTI results guided treatment decisions, which confirms the clinical impact and feasibility of its application in daily practice.

Management of Deep Vein Thrombosis: An Update Based on the Revised AWMF S2k Guideline.

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are the most common manifestations of venous thromboembolism (VTE). Most DVTs affect the lower-extremity veins. Since the symptoms of DVT are non-specific, a prompt and standardised diagnostic work-up is essential to minimise the risk of PE in the acute phase and to prevent thrombosis progression, post-thrombotic syndrome and VTE recurrence in the long-term. Only recently, the AWMF S2k guidelines on Diagnostics and Therapy of Venous Thrombosis and Pulmonary Embolism have been revised. In the present article, we summarize current evidence and guideline recommendations focusing on lower-extremity DVT (LEDVT). Depending on whether the diagnostic work-up is performed by a specialist in vascular medicine or by a primary care physician, different diagnostic algorithms are presented that combine clinical probability, D-dimer testing and diagnostic imaging. The diagnosis of ipsilateral recurrent DVT poses a particular challenge and is presented in a separate algorithm. Anticoagulant therapy is an essential part of therapy, with current guidelines clearly favouring regimens based on direct oral anticoagulants over the traditional sequential therapy of parenteral anticoagulants and vitamin K antagonists. For most DVTs, a duration of therapeutic-dose anticoagulation of at least 3 to 6 months is considered sufficient, and this raises the question of the risk of VTE recurrence after discontinuation of anticoagulation and the need for secondary prophylaxis in the long-term. Depending on the circumstances and trigger factors that have contributed to the occurrence of DVT, management strategies are presented that allow decision-making taking into account the individual bleeding risk and patient's preferences.

Cost-Effectiveness of Performing Reference Ultrasonography in Patients with Deep Vein Thrombosis.

The diagnosis of recurrent ipsilateral deep vein thrombosis (DVT) with compression ultrasonography (CUS) may be hindered by residual intravascular obstruction after previous DVT. A reference CUS, an additional ultrasound performed at anticoagulant discontinuation, may improve the diagnostic work-up of suspected recurrent ipsilateral DVT by providing baseline images for future comparison. To evaluate the cost-effectiveness of routinely performing reference CUS in DVT patients. Patient-level data (n = 96) from a prospective management study (Theia study; NCT02262052) and claims data were used in a decision analytic model to compare 12 scenarios for diagnostic management of suspected recurrent ipsilateral DVT. Estimated health care costs and mortality due to misdiagnosis, recurrent venous thromboembolism, and bleeding during the first year of follow-up after presentation with suspected recurrence were compared. All six scenarios including reference CUS had higher estimated 1-year costs (€1,763-€1,913) than the six without reference CUS (€1,192-€1,474). Costs were higher because reference CUS results often remained unused, as 20% of patients (according to claims data) would return with suspected recurrent DVT. Estimated mortality was comparable in scenarios with (14.8-17.9 per 10,000 patients) and without reference CUS (14.0-18.5 per 10,000). None of the four potentially most desirable scenarios included reference CUS. One-year health care costs of diagnostic strategies for suspected recurrent ipsilateral DVT including reference CUS are higher compared to strategies without reference CUS, without mortality benefit. These results can inform policy-makers regarding use of health care resources during follow-up after DVT. From a cost-effectiveness perspective, the findings do not support the routine application of reference CUS.

Rivaroxaban plus aspirin versus acenocoumarol to manage recurrent venous thromboembolic events despite systemic anticoagulation with rivaroxaban

IntroductionThe evaluation and management of patients who sustain recurrent thromboembolic events while taking therapeutic anticoagulation have not been well characterized; moreover, there has been no systematic review or randomized trial focused on treating patients with recurrent deep vein thrombosis (DVT) and pulmonary embolism (PE) during anticoagulant treatment. Therefore, we developed a pilot trial to compare rivaroxaban plus aspirin versus acenocoumarol in patients with recurrent venous thromboembolism despite ongoing anticoagulation with rivaroxaban. Materials and methodsThe study was a multicenter, randomized clinical trial. We randomly assigned patients with objectively documented recurrent venous thromboembolism to receive rivaroxaban (20 mg once a day) plus aspirin (300 mg once a day) or an adjusted dose of acenocoumarol. The study was designed to evaluate the incidence of recurrent thromboembolic events (recurrent ipsilateral or contralateral DVT, PE, ischemic stroke, and myocardial infarction) and hemorrhagic events. ResultsA total of 58 patients were randomized: 28 were allocated to the rivaroxaban plus aspirin group and 30 to the acenocoumarol group. After 90 days of follow-up, three recurrent thromboembolic events (primary outcome) occurred in the acenocoumarol group – two DVTs and one ischemic stroke – and zero events in the rivaroxaban plus aspirin group (risk ratio [RR] 0.15; 95 % confidence interval [CI] 0.008–2.83; P = 0.20). Minor bleeding occurred in five patients in the acenocoumarol group and zero in the rivaroxaban plus aspirin group (RR 0.09; 95 % CI 0.005–1.68; p = 0.10). There was one non-fatal gastrointestinal major bleed in the rivaroxaban plus aspirin group. ConclusionsIn this pilot study, there were no significant differences in any outcome assessed; however, recurrent thromboembolic events and minor bleeding events occurred numerically less frequently in the rivaroxaban plus aspirin group. These data suggest the need to carry out more extensive randomized studies with sufficient statistical power to clarify these results.

Cost-effectiveness of magnetic resonance imaging for diagnosing recurrent ipsilateral deep vein thrombosis

The diagnostic workup of recurrent ipsilateral deep vein thrombosis (DVT) using compression ultrasonography (CUS) can be complicated by persistent intravascular abnormalities after a previous DVT. We showed that magnetic resonance direct thrombus imaging (MRDTI) can exclude recurrent ipsilateral DVT. However, it is unknown whether the application of MRDTI in daily clinical practice is cost effective. The aim of this study was to evaluate the cost effectiveness of MRDTI-based diagnosis for suspected recurrent ipsilateral DVT during first year of treatment and follow-up in the Dutch health care setting. Patient-level data of the Theia study (NCT02262052) were analyzed in 10 diagnostic scenarios, including a clinical decision rule and D-dimer test and imaging with CUS and/or MRDTI. The total costs of diagnostic tests and treatment during 1-year follow-up, including costs of false-positive and false-negative diagnoses, were compared and related to the associated mortality. The 1-year health care costs with MRDTI (range, €1219-1296) were generally lower than strategies without MRDTI (range, €1278-1529). This was because of superior specificity, despite higher initial diagnostic costs. Diagnostic strategies including CUS alone and CUS followed by MRDTI in case of an inconclusive CUS were potential optimal cost-effective strategies, with estimated average costs of €1529 and €1263 per patient and predicted mortality of 1 per 737 patients and 1 per 609 patients, respectively. Our model shows that diagnostic strategies with MRDTI for suspected recurrent ipsilateral DVT have generally lower 1-year health care costs than strategies without MRDTI. Therefore, compared with CUS alone, applying MRDTI did not increase health care costs.

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.

Yield of ultrasonography in patients with or without post‐thrombotic syndrome for diagnosis of suspected recurrent ipsilateral deep vein thrombosis

BackgroundThe yield of ultrasonography in patients with or without post‐thrombotic syndrome (PTS) presenting with a suspected recurrent ipsilateral deep vein thrombosis (DVT) is unknown. MethodsPatients with a first unprovoked DVT received standard anticoagulation for 5 to 7 months. Then, they were assessed for PTS using the Villalta scale (score equal or >5) and followed for up to 18 months. Yield of ultrasonography for recurrent ipsilateral DVT was defined as the number of confirmed DVT divided by the number of suspicions. Outcomes were compared between patients without or with PTS. Results and discussionA total of 452 patients with a symptomatic proximal DVT were included. During follow‐up, there were 144 suspicions of recurrent ipsilateral DVT, which were confirmed in 38 patients (26.4%). The confirmation rate of recurrent ipsilateral DVT was 25.6% (23/90) in patients without PTS as compared with 27.8% (15/54) in patients with PTS (P = .84). Our study supports a similar yield of ultrasonography to diagnose recurrent ipsilateral DVT in patients off anticoagulation therapy with or without PTS as defined by 5 or more points on the Villalta scale.

Safety of using the combination of the Wells rule and D‐dimer test for excluding acute recurrent ipsilateral deep vein thrombosis

BackgroundThe diagnostic accuracy of clinical probability assessment and D‐dimer testing for clinically suspected recurrent deep vein thrombosis (DVT) is largely unknown. AimTo evaluate the safety of ruling out acute recurrent DVT based on an unlikely Wells score for DVT and a normal D‐dimer test. MethodsThis was a predefined endpoint of the Theia study in which the diagnostic accuracy of magnetic resonance direct thrombus imaging in acute recurrent ipsilateral DVT was validated. The Wells rule and D‐dimer test, performed as part of the study protocol, were not used for management decisions. The primary outcome of this analysis was the incidence of recurrent DVT at baseline or during 3‐month follow‐up for patients with an unlikely Wells score and a normal D‐dimer test. ResultsResults of both Wells score and D‐dimer tests were available in 231 patients without anticoagulant treatment. The recurrent DVT prevalence was 45% (103/231). Forty‐nine patients had an unlikely Wells score and normal D‐dimer test, of whom 3 (6.1%, 95% confidence interval [CI] 1.3%‐18%) had recurrent DVT at baseline/follow‐up, yielding a sensitivity of 97% (95% CI 92%‐99%) and specificity of 36% (95% CI 28%‐45%). Thus, if clinical probability scoring and D‐dimer testing would have been applied, radiological imaging could have been omitted in 21% of patients with a diagnostic failure rate of 6.1%. ConclusionBy applying clinical probability scoring and D‐dimer testing, radiological imaging could be spared in one fifth of patients with suspected recurrent ipsilateral DVT. However, the high failure rate does not support implementation of this strategy in daily practice.

Magnetic resonance imaging for diagnosis of recurrent ipsilateral deep vein thrombosis

AbstractThe diagnosis of recurrent ipsilateral deep vein thrombosis (DVT) is challenging, because persistent intravascular abnormalities after previous DVT often hinder a diagnosis by compression ultrasonography. Magnetic resonance direct thrombus imaging (MRDTI), a technique without intravenous contrast and with a 10-minute acquisition time, has been shown to accurately distinguish acute recurrent DVT from chronic thrombotic remains. We have evaluated the safety of MRDTI as the sole test for excluding recurrent ipsilateral DVT. The Theia Study was a prospective, international, multicenter, diagnostic management study involving patients with clinically suspected acute recurrent ipsilateral DVT. Treatment of the patients was managed according to the result of the MRDTI, performed within 24 hours of study inclusion. The primary outcome was the 3-month incidence of venous thromboembolism (VTE) after a MRDTI negative for DVT. The secondary outcome was the interobserver agreement on the MRDTI readings. An independent committee adjudicated all end points. Three hundred five patients were included. The baseline prevalence of recurrent DVT was 38%; superficial thrombophlebitis was diagnosed in 4.6%. The primary outcome occurred in 2 of 119 (1.7%; 95% confidence interval [CI], 0.20-5.9) patients with MRDTI negative for DVT and thrombophlebitis, who were not treated with any anticoagulant during follow-up; neither of these recurrences was fatal. The incidence of recurrent VTE in all patients with MRDTI negative for DVT was 1.1% (95% CI, 0.13%-3.8%). The agreement between initial local and post hoc central reading of the MRDTI images was excellent (κ statistic, 0.91). The incidence of VTE recurrence after negative MRDTI was low, and MRDTI proved to be a feasible and reproducible diagnostic test. This trial was registered at www.clinicaltrials.gov as #NCT02262052.

Factors Affecting Recurrent Deep Vein Thrombosis after Pharmacomechanical Thrombolysis and Left Iliac Vein Stent Placement in Patients with Iliac Vein Compression Syndrome

PurposeThis study evaluated the factors affecting contralateral and ipsilateral recurrent deep vein thrombosis (DVT) after iliac vein stent placement in patients with iliac vein compression syndrome (IVCS). Materials and MethodsData from 130 patients (95 female patients) who underwent catheter-directed thrombolysis and stent placement for IVCS with left lower leg thrombosis at a single institution were retrospectively analyzed. Mean patient age was 69.0 ± 14.0 years old. Median follow-up was 14 months (range, 3–164 months). Anticoagulation therapy was prescribed for 6 months, followed by lifelong antiplatelet therapy. Multivariate logistic regression analysis was performed to evaluate the factors affecting the development of contralateral and ipsilateral recurrent DVT. ResultsSeven patients (5.4%) developed contralateral DVT (median, 26 months; range, 2–61 months), and 11 patients (8.5%) developed ipsilateral DVT (median, 1 month; range, 0–53 months). Stent location (odds ratio [OR], 11.564; 95% confidence interval [CI], 1.159–115.417) and in-stent thrombosis during follow-up (OR, 15.142; 95% CI, 1.406–163.119) were predictors of recurrent contralateral DVT. Thrombophilia (OR, 47.560; 95% CI, 2.369–954.711), remaining inferior vena cava filter (OR, 30.552; 95% CI, 3.495–267.122), and in-stent thrombosis during follow-up (OR, 82.057; 95% CI, 2.915–2309.848) were predictors of ipsilateral DVT. ConclusionsContralateral DVT occurs late and is associated with extension of the iliac vein stent to the inferior vena cava and in-stent thrombosis. Ipsilateral DVT occurs relatively early and is associated with thrombophilia, remaining inferior vena cava filter, and in-stent thrombosis.

Diagnosing Recurrent DVT of the Leg by Two Different Non-Contrast-Enhanced Magnetic Resonance Direct Thrombus Imaging Techniques: A Pilot Study.

Introduction Magnetic resonance direct thrombus imaging (MRDTI) is a promising technique to improve the diagnostic management of patients with a suspected ipsilateral recurrent deep vein thrombosis (DVT) by direct visualization of a thrombus. Another magnetic resonance imaging (MRI) technique, T1-weighted turbo spin-echo spectral attenuated inversion recovery (TSE-SPAIR), has the potential to image a thrombus directly with a high spatial resolution as well. The main aim of this pilot study was to investigate if adding the TSE-SPAIR sequence to an MRDTI sequence performed in patients with suspected recurrent DVT may increase the diagnostic confidence of expert MRDTI readers. Methods Fifteen patients with suspected acute recurrent DVT were included in this study. The TSE-SPAIR sequence was scanned directly after the MRDTI scan but not used to guide clinical decision making, and both scans were adjudicated post hoc two times separately by three independent expert MRDTI readers. Diagnostic confidence was scored on a 4-point Likert scale: (1) poor (definite diagnosis impossible), (2) fair (evaluation of major findings possible), (3) good (definite diagnosis possible), and (4) excellent (exact diagnosis possible). Results The diagnostic confidence of expert readers increased when adding the TSE-SPAIR sequence on top of the MRDTI sequence from “good” (median, 3.0; interquartile range [IQR], 2.66–3.0) to “excellent” (median, 3.67; IQR 3.33–3.67; p = 0.001). Evaluation of the scans in the reversed order 5 months after initial reading showed similar results. Diagnostic accuracy for proximal DVT of both scan techniques was good. Conclusion The extra TSE-SPAIR sequence may help increase diagnostic confidence of radiologists in cases of uncertain diagnosis in patients with suspected ipsilateral recurrent DVT.

The post-thrombotic syndrome

SummaryPost-thrombotic syndrome (PTS) is a common complication of deep vein thrombosis (DVT) in the legs. Risk factors include recurrent ipsilateral DVT, proximal vein involvement, persistent occlusion of the deep venous system, obesity, and pre-existing chronic venous disease. Compression therapy, exercise, and weight loss, as well as effective anticoagulation of the initial DVT and secondary thromboprophylaxis, are all important aspects in the prevention and treatment of post-thrombotic syndrome.

Post-thrombotic syndrome in patients treated with rivaroxaban or enoxaparin/vitamin K antagonists for acute deep-vein thrombosis. A post-hoc analysis.

Post-thrombotic syndrome (PTS) is a common complication of deep-vein thrombosis (DVT). Poor quality treatment with vitamin K antagonists (VKA) is a risk factor for PTS. We hypothesised that treatment with the direct oral anticoagulant (DOAC) rivaroxaban may lower PTS incidence as compared to enoxaparin/VKA, as DOACs have a more stable pharmacologic profile than VKA. We performed a post-hoc subgroup analysis of the Einstein DVT trial (n=3449). Kaplan-Meier survival analysis was performed to compare the cumulative incidence of PTS between the rivaroxaban and enoxaparin/VKA groups. Hazard ratios (HR) and 95 % confidence intervals (CI) were calculated using Cox proportional hazards models. We included 336 patients with a mean age of 58 ± 16 years and a median follow-up after index DVT of 57 months (interquartile range 48-64). Of these, 162 (48 %) had been treated with rivaroxaban and 174 (52 %) with enoxaparin/VKA. The cumulative PTS incidence at 60 months follow-up was 29 % in the rivaroxaban group and 40 % in the enoxaparin/VKA group. After adjusting for age, gender, body mass index, previous VTE, ipsilateral recurrent DVT, extent of DVT, idiopathic DVT, duration of anticoagulant treatment, compliance to assigned study medication, elastic compression stocking use and active malignancy, the HR of PTS development for rivaroxaban was 0.76 (95 % CI: 0.51-1.13). In conclusion, treatment of acute DVT with rivaroxaban was associated with a numerically lower but statistically non-significant risk of PTS compared to enoxaparin/VKA treatment. The potential effect on reducing PTS deserves evaluation in a large randomised trial.

Magnetic resonance direct thrombus imaging differentiates acute recurrent ipsilateral deep vein thrombosis from residual thrombosis

AbstractAccurate diagnostic assessment of suspected ipsilateral recurrent deep vein thrombosis (DVT) is a major clinical challenge because differentiating between acute recurrent thrombosis and residual thrombosis is difficult with compression ultrasonography (CUS). We evaluated noninvasive magnetic resonance direct thrombus imaging (MRDTI) in a prospective study of 39 patients with symptomatic recurrent ipsilateral DVT (incompressibility of a different proximal venous segment than at the prior DVT) and 42 asymptomatic patients with at least 6-month-old chronic residual thrombi and normal D-dimer levels. All patients were subjected to MRDTI. MRDTI images were judged by 2 independent radiologists blinded for the presence of acute DVT and a third in case of disagreement. The sensitivity, specificity, and interobserver reliability of MRDTI were determined. MRDTI demonstrated acute recurrent ipsilateral DVT in 37 of 39 patients and was normal in all 42 patients without symptomatic recurrent disease for a sensitivity of 95% (95% CI, 83% to 99%) and a specificity of 100% (95% CI, 92% to 100%). Interobserver agreement was excellent (κ = 0.98). MRDTI images were adequate for interpretation in 95% of the cases. MRDTI is a sensitive and reproducible method for distinguishing acute ipsilateral recurrent DVT from 6-month-old chronic residual thrombi in the leg veins.

Prospective Study of Natural History of Deep Vein Thrombosis: Early Predictors of Poor Late Outcomes

A proportion of patients with deep vein thrombosis (DVT) will develop postthrombotic syndrome (PTS). Currently, the only clearly identified risk factors for developing PTS are recurrent ipsilateral DVT and extensive proximal disease. The aim of the study was to assess the natural history of DVT and identify early predictors of poor clinical outcome at 5 years. Patients with suspected acute DVT in the lower limb were assessed prospectively. All patients with a confirmed DVT were asked to participate in this study. Within 7-10 days after diagnosis of DVT, patients underwent a further review, involving clinical, ultrasound, and air plethysmography assessment of both lower limbs. Patients were reassessed at regular intervals for 5 years. One hundred twenty-two limbs in 114 patients were included in this study. Thrombus regression occurred in two phases, with a rapid regression between 10 days and 3 months, and a more gradual regression thereafter. Reflux developed as thrombus regression occurred. Segmental reflux progressed to axial deep reflux and continued to deteriorate in a significant proportion of patients with iliofemoral-popliteal-calf DVT throughout the 5-year study period. Similarly, venous filling index became progressively more abnormal, in this group, over the course of the study. Four risk factors for PTS were identified as best predictors: extensive clot load on presentation; <50% clot regression at 6 months; venous filling index >2.5 mL/sec; and abnormal outflow rate (<0.6). Patients with three or more of these risk factors had a significant risk of developing PTS with sensitivity 100%, specificity 83%, and positive predictive value 67%. Patients scoring 2 or less did not have PTS at 5 years with a negative predictive value of 100%. This is the first study to show that venous assessment at 6 months post-DVT can predict PTS at 5 years. Those who will not develop PTS can be reassured of this at 6 months.

Post-thrombotic syndrome: current prevention and management strategies

The post-thrombotic syndrome (PTS) is the most commonly occurring long-term complication of deep vein thrombosis (DVT) with a cumulative incidence of up to 50% within the first 2 years after the thrombotic event. It is characterized by the development of various symptoms and signs related to chronic venous disease in a limb previously affected by DVT. PTS is a condition that significantly impairs quality of life and results in substantial burden to patients and society. So far, treatment options for PTS are limited, and strategies that prevent PTS occurrence are therefore of pivotal importance. These include compression therapy, prevention of recurrent ipsilateral DVT and possibly endovascular catheter-directed thrombolytic procedures. Clinical predictors of PTS are progressively characterized, but the ability to predict which patient with DVT is likely to develop PTS remains limited.

Accuracy of Magnetic Resonance Direct Thrombus Imaging (MRDTI) As a Novel Tool in the Diagnosis of Acute Ipsilateral Recurrent Deep Vein Thrombosis

AbstractAbstract 395 BackgroundAccurate diagnostic assessment of suspected acute ipsilateral recurrent deep vein thrombosis (DVT) is of high clinical importance, however discriminating residual thrombosis from acute recurrent DVT may be challenging. It is known that in 32% of the patients with a suspected acute ipsilateral recurrent DVT the ultrasound examination are non-conclusive. Despite this, patients were treated with indefinite anticoagulant therapy, indicating overtreatment in this group of patients (Tan M et al. J Thromb Haemost 2010). A non-invasive MR technique (Magnetic Resonance Direct Thrombus Imaging (MRDTI), without need for intravenous contrast agent, showed high sensitivity and specificity for diagnosing a first acute DVT (Fraser et al Ann Intern Med 2002). Furthermore the high signal associated with acute thrombosis was not detected 6 months after the initial acute thrombosis, making MRDTI potential relevant for distinguishing a recurrent DVT from a residual thrombosis (Westerbeek RE et al J Thromb Haemost 2008). This study evaluated the accuracy of MRDTI in patients with an acute ipsilateral recurrent DVT and patients with residual thrombosis. Patients/MethodsIn total 84 patients were enrolled. Of these, 42 consecutive patients had an acute ipsilateral recurrent DVT according to the current ultrasound examination standards in combination with a positive D-dimer test (≥ 500 μg/L); all patients were treated with anticoagulants. Furthermore, 42 patients were without acute signs and symptoms, however had a residual thrombosis on ultrasound examination in combination with a negative D-dimer test (< 500 μg/L). All patients received a MR examination within 48 hours of presentation. MR images were assessed in a blinded fashion by two radiologists. Sensitivity, specificity and interobserver variability were calculated. ResultsThe images of two patients with ipsilateral recurrent DVT were not interpretable, one patient had a knee prosthesis that gave artifacts and in the other patient not the venous system of interest was imaged. The images of 40 patients with an ipsilateral recurrent DVT and of 42 patients with residual thrombosis were fully interpretable. Sensitivity was 86% (95% CI, 71 –94%) and specificity was 100% (95% CI, 89–100%) for MRDTI by the first observer; sensitivity was 88% (95% CI, 74–96%) and specificity was 100% (89–100%) by the second observer. The interobserver agreement between both observers was excellent, with a kappa statistics of 0.97 (95% CI, 0.92 – 1.0). ConclusionOur study shows reasonable sensitivity and very good specificity figures with an excellent observer agreement for imaging an ipsilateral recurrent DVT and residual thrombosis with MRDTI. The sensitivity is somewhat lower than expected; a reason could be that patients with inconclusive ultrasounds were considered as acute recurrent thrombosis by the attending physician, while in fact they had a residual thrombosis. We conclude that MRDTI has good potential in distinguishing a residual thrombosis from an acute recurrent DVT and could therefore be of high value for the diagnosis of patients with suspected acute ipsilateral recurrent DVT. This should however be further evaluated in a management outcome study in which treatment decisions are based on the results of MR. AcknowledgmentThis study was supported by the Netherlands Heart Foundation (grant no. 2007B146) Disclosures:No relevant conflicts of interest to declare.

The post-thrombotic syndrome.

The post-thrombotic syndrome (PTS) is a frequent, sometimes disabling complication of deep vein thrombosis (DVT) that reduces quality of life and is costly. This article discusses risk factors for PTS after DVT and available means to prevent and treat PTS, with a focus on new information in the field. After DVT, PTS will develop in 20% to 50% of patients, and severe PTS, including venous ulcers, will develop in 5% to 10%. The principal risk factors for PTS are anatomically extensive DVT, recurrent ipsilateral DVT, persistent leg symptoms 1 month after acute DVT, obesity, and older age. By preventing the initial DVT and ipsilateral DVT recurrence, primary and secondary prophylaxes of DVT will prevent cases of PTS. Based on recent evidence from a large multicenter trial, routine use of elastic compression stockings (ECS) after DVT to prevent PTS is not advocated, but in patients with DVT-related leg swelling that is bothersome, a trial of ECS is reasonable. Selecting DVT patients for catheter-directed thrombolytic treatment as a means of preventing PTS should be done on a case-by-case basis, with a focus on patients with extensive thrombosis, recent symptoms onset, and low bleeding risk. For patients with established PTS, daily use of ECS may help to relieve symptoms and edema. Intermittent compression devices can be tried in patients with moderate-to-severe PTS whose symptoms are inadequately controlled with ECS alone. A supervised exercise training program may improve PTS symptoms. Management of post-thrombotic ulcers should ideally involve a multidisciplinary approach. Important areas for future research are summarized.

The Post-Thrombotic Syndrome

The post-thrombotic syndrome (PTS) is an important chronic complication of deep vein thrombosis (DVT). The present review focuses on risk determinants of PTS after DVT and available means to prevent and treat PTS. More than one-third of patients with DVT will develop PTS, and 5% to 10% of patients develop severe PTS, which can manifest as venous ulcers. PTS has an adverse impact on quality of life as well as significant socioeconomic consequences. The main risk factors for PTS are persistent leg symptoms 1 month after acute DVT, anatomically extensive DVT, recurrent ipsilateral DVT, obesity, and older age. Subtherapeutic dosing of initial oral anticoagulation therapy for DVT treatment may also be linked to subsequent PTS. By preventing the initial DVT and DVT recurrence, primary and secondary prophylaxis of DVT will prevent cases of PTS. Daily use of elastic compression stockings for 2 years after proximal DVT appears to reduce the risk of PTS; however, uncertainty remains regarding optimal duration of use, optimal compression strength, and usefulness after distal DVT. The cornerstone of managing PTS is compression therapy, primarily using elastic compression stockings. Venoactive medications such as aescin and rutosides may provide short-term relief of PTS symptoms. Further studies to elucidate the pathophysiology of PTS, to identify clinical and biological risk factors, and to test new preventive and therapeutic approaches to PTS are needed.

Contemporary Issues in the Prevention and Management of Postthrombotic Syndrome

To provide an evidence-based review and clinical summary of postthrombotic syndrome (PTS). A literature review was performed via MEDLINE (1950-July 1, 2009) and International Pharmaceutical Abstracts (1970-June 2009) searches using the terms post-thrombotic syndrome, post-phlebitic syndrome, deep vein thrombosis, and compression stockings. PTS is best characterized as a chronic syndrome of clinical signs and symptoms including pain, swelling, parasthesias, and ulceration in the affected limb following deep vein thrombosis (DVT). It occurs in up to half of patients with symptomatic DVT, usually within the first 2 years. Although the pathophysiology of PTS is not well understood, a thrombus may cause venous hypertension and valvular incompetence resulting in edema, tissue hypoxia, and in severe cases, ulceration. Risk factors for PTS include recurrent ipsilateral DVT, obesity, and poor quality of anticoagulant therapy. PTS diagnosis is based on the presence of typical signs and symptoms and may be made using one of several clinical scoring systems. Prevention of PTS should focus on DVT prevention and the use of elastic compression stockings following DVT, while fibrinolysis remains under investigation as an effective method for PTS prevention. The treatment of PTS may include either pharmacologic or mechanical modalities, although none of these regimens has been rigorously tested. Pharmacists have the opportunity to provide more comprehensive antithrombotic management by educating patients and providers on PTS, recommending appropriate preventive therapy, assisting patients in obtaining and adhering to this therapy, and assisting providers with the management of PTS. Providers should be proactive in preventing PTS, with pharmacists taking an active role in optimal DVT prevention, identifying patients at risk for PTS, and counseling and directing preventive therapies.