May-Thurner syndrome and thrombosis: A systematic review of antithrombotic use after endovascular stent placement

Interventional Therapy of Pelvic Venous Disorders (PeVD)

BACKGROUND

 Pelvic venous disorders (PeVD) are an underdiagnosed cause of chronic pelvic pain in women. They are caused by venous insufficiency of the pelvic or ovarian veins, leading to the development of mainly periuterine and periovarian varices. It is a progressive disease if left untreated and can cause swelling, dyspareunia, dysmenorrhea, and other symptoms, some non-specific, that affect the patient's quality of life. Interventional therapies are a central component of the treatment of PeVD, with a variety of techniques available for both diagnosis and treatment.

METHOD

 This review provides an overview of the pathophysiologic background, diagnosis, and, most importantly, interventional treatment options for PeVD.

RESULTS

 There is a lack of standardized nomenclature and internationally accepted diagnostic criteria for PeVD as well as randomized controlled trials demonstrating clinical success. However, in clinical trials, endovascular therapy for PeVD has been shown to be safe and effective. This review presents the various interventional techniques for the treatment of PeVD, including embolization, stenting, and sclerotherapy.

CONCLUSION

 The importance of PeVD is receiving growing recognition. Recent advances, such as the development of the Symptoms-Varices-Pathophysiology (SVP) classification, provide an impetus to standardize nomenclature and are the first step toward systematizing disease management. Interventional therapies provide a safe and tailored minimally invasive treatment option for patients with PeVD.

KEY POINTS

  · Pelvic venous disorders are an underdiagnosed condition with frequently delayed diagnosis and debilitating symptoms.. · Until now, the PeVD nomenclature has been imprecise, with terms like May-Thurner syndrome/Nutcracker syndrome.. · Interventional approaches are effective and play a central role in PeVD treatment..

CITATION FORMAT

· Dewald CL, Becker LS, Meyer BC. Interventional Therapy of Pelvic Venous Disorders (PeVD). Fortschr Röntgenstr 2024; 196: 921 - 927.

Comprehensive overview of the venous disorder known as pelvic congestion syndrome

Pelvic venous disorders (PeVD) also known as Pelvic Congestion Syndrome (PCS) affect a great number of women worldwide and often remain undiagnosed. Gynecological symptoms caused by vascular background demand a holistic approach for appropriate diagnosis. This is a relevant cause of chronic pelvic pain and atypical varicose veins. The diagnosis is based on imaging studies and their correlation with clinical presentation. Although the aetiology of PCS still remains unclear, it may result from a combination of factors including genetic predisposition, anatomical abnormalities, hormonal factors, damage to the vein wall, valve dysfunction, reverse blood flow, hypertension and dilatation. The following paper describes an in-depth overview of anatomy, pathophysiology, symptoms, diagnosis and treatment of PCS. In recent years, minimally invasive interventions have become the method of first choice for the treatment of this condition. The efficacy of a percutaneous approach is high and it is rarely associated with serious complications.Key MessagesPelvic venous disorders demand a holistic approach for appropriate diagnosis.This article takes an in-depth look at existing therapies of Pelvic Congestion Syndrome and pathophysiology of this condition.Embolisation is an effective and safe treatment option.

Antithrombotic Therapy After Venous Interventions: AJR Expert Panel Narrative Review

Interventions for thrombotic and nonthrombotic venous disorders have increased with technical advances and more trained venous specialists. Antithrombotic therapy is essential to clinical and procedural success; however, post-procedural therapeutic regimens exhibit significant heterogeneity due to limited prospective randomized data as well as incomplete mechanistic understanding of the critical factors driving long-term patency. Post-interventional antithrombotic therapy for thrombotic venous disorders should adhere to existing venous thromboembolism management guidelines, which include 3-6 months of therapeutic anticoagulation at minimum and consideration of extended therapy in patients with higher risk of thrombosis due to procedural or patient factors. The additive benefit of antiplatelet agents in the acute and intermediate period is unknown, having shown improved long-term stent patency in some retrospective studies. Dual and/or triple agent therapy should be limited based on individual risks of thrombosis and bleeding. The treatment of non-thrombotic disorders is more heterogeneous, though patients with limited flow, extensive stent material, or underlying prothrombotic states such as malignancy or chronic inflammation may benefit from single- or multi-agent antithrombotic therapy. However, the agent, dose, and duration of therapy remain indeterminate. Future prospective studies are warranted to improve patient risk stratification and standardize post-procedural antithrombotic therapy in patients receiving venous interventions.

May-Thurner syndrome: an unusual cause of unprovoked deep vein thrombosis of the left lower limb

May-Thurner syndrome, an unprovoked form of deep vein thrombosis (DVT), should be kept in mind in case of DVT with no predisposing factors. We present a case of a 37-year-old male with DVT of left lower limb due to May-Thurner syndrome, treated with anticoagulants with a plan of left common iliac vein (LCIV) stenting and inferior vena cava (IVC) filter later. Venous duplex scan showed features suggestive of May-Thurner syndrome. Hence, we proceeded for CT abdominal aortogram with bilateral lower limb angiogram, which confirmed the above findings. Management of May-Thurner syndrome is a stepwise approach, with initial anticoagulation for dissolution of the thrombus followed by endovenous stenting of the LCIV and concomitant IVC filter.

Current Status and Prospect of Stent Placement for May-Thurner Syndrome

Stent implantation has been proven to be safe and has become the first-line intervention for May-Thurner syndrome (MTS), with satisfactory mid-term patency rates and clinical outcomes. Recent research has demonstrated that catheter-directed thrombolysis is the preferred strategy when MTS is combined with deep vein thrombosis after self-expanding stent placement. However, the stent used for the venous system was developed based on the experience obtained in the treatment of arterial disease. Consequently, relatively common corresponding complications may come along later, which include stent displacement, deformation, and obstruction. Different measures such as adopting a stent with a larger diameter, improving stent flexibility, and increasing stent strength have been employed in order to prevent these complications. The ideal venous stent is presently being evaluated and will be introduced in detail in this review.

May-Thurner syndrome

May-Thurner syndrome (MTS) is a venous compression syndrome in which the left common iliac vein (LCIV) is compressed between the lower lumbar spine and the right common iliac artery (RCIA). Variations are known where in the right lower limb can be affected. While most of the cases are asymptomatic, it can cause severe morbidity in symptomatic individuals, most commonly deep vein thrombosis and post thrombotic sequelae. In this article, we review the key clinical features, multimodality imaging findings and treatment options of this disorder. Our goal is to raise awareness of this under-diagnosed condition among clinicians in order to promote early detection and recognition to enhance positive and expedited outcomes.

May Thurner syndrome: Sixty years later

May-Thurner syndrome (MTS) was described sixty years ago. Once ignored for several years, it is currently a recognized pathology in the vascular surgery community; but not long ago due to several factors, it was underdiagnosed and sub-optimally treated. In the last 20 years, with renewed interest in venous pathology, technical imaging advances and the recent interventional procedures, it has become a better known disease. On the other hand, nowadays the easiness in diagnosis and treatment of the syndrome has lead to overtreatment of such patients. In this article, we do a historical review and describe the significant advances and current management of May-Thurner syndrome.

Comparison of Anticoagulation Regimens Following Stent Placement for Nonthrombotic Lower Extremity Venous Disease

PURPOSE

To determine whether subtherapeutic anticoagulation regimens are noninferior to therapeutic anticoagulation regimens following stent placement for nonthrombotic lower extremity venous disease.

MATERIALS AND METHODS

Fifty-one consecutive patients (88% women; mean age, 44 years) who underwent stent placement for nonthrombotic lower extremity venous disease between 2002 and 2016 were retrospectively identified. The patients were divided into 2 cohorts: those who received prophylactic enoxaparin or no anticoagulation (subtherapeutic) after the procedure and those who received therapeutic doses of anticoagulation with enoxaparin, warfarin, and/or rivaroxaban (therapeutic) after the procedure. Baseline demographic characteristics, procedure characteristics, and outcomes were compared between the 2 groups using the Student t test, Fisher exact test, and χ² test. The subtherapeutic and therapeutic anticoagulation groups did not differ significantly in the baseline demographic characteristics (eg, sex, race, and age) or procedure characteristics (eg, number of stents placed, stent brand, stent diameter, etc).

RESULTS

The mean clinical follow-up time was 4.4 years (range, 0-16.3 years). There were no thrombotic adverse events or luminal obstructions due to in-stent restenosis in either group. There were 5 minor bleeding adverse effects in the therapeutic group and no bleeding adverse effects in the subtherapeutic group (P = .051). There were no statistically significant differences in subjective symptom improvement (P = .75).

CONCLUSIONS

In this retrospective cohort, the subtherapeutic and therapeutic anticoagulation regimens produced equivalent outcomes in terms of adverse event rates, reintervention rates, and symptomatic improvement, suggesting that therapeutic doses of anticoagulation do not improve outcomes compared with subtherapeutic anticoagulation regimens following nonthrombotic venous stent placement.

May-Thurner Syndrome: A Rare Case of Unilateral Deep Vein Thrombosis in an Elderly Woman

Patient: Female, 78-year-old

Final Diagnosis: May-Thurner syndrome

Symptoms: Lower extremity edema • lower extremity pain

Medication: —

Clinical Procedure: —

Specialty: Critical Care Medicine • Hematology • General and Internal Medicine • Radiology

An Anomalous Cause of Deep Venous Thrombosis: A Case Report

Introduction

Lower extremity deep venous thrombosis (DVT) is a common diagnosis in the emergency department (ED). Deep venous thromboses can be the result of anatomical variation in the vasculature that predisposes the patient to thrombosis. May-Thurner syndrome (MTS) is one such anatomic variant defined by extrinsic compression of the left common iliac vein between the right common iliac artery and lumbar vertebrae.

Case Report

We report such a case of a 39-year-old woman with no risk factors for thromboembolic disease who presented to the ED with extensive unilateral leg swelling and was ultimately diagnosed with MTS.

Conclusion

This diagnosis is an important consideration particularly in patients who are young, female, have scoliosis or spinal abnormalities, or are at low risk for DVT yet who present with extensive lower extremity swelling and are found to have proximal thrombus burden. Often further imaging, anticoagulation, angioplasty, or thrombectomy are indicated to prevent morbidity and post-thrombotic syndrome in these patients.

Pediatric May-Thurner Syndrome-Systematic review and individual patient data meta-analysis

BACKGROUND

The outcomes of deep vein thrombosis (DVT) in children with May-Thurner Syndrome (MTS) remain unclear.

OBJECTIVES

This systematic review and patient-level meta-analysis aims to describe the outcomes of children with MTS presenting with DVT.

METHODS

A systematic review of the published literature was performed. Data related to patients <18 years diagnosed with MTS and DVT was extracted. Risk of bias was assessed using the Murad criteria. Outcomes included vessel patency post-treatment, DVT recurrence, and post-thrombotic syndrome (PTS). Predictive and explanatory models were developed for these outcomes.

RESULTS

In total, 109 cases were identified (age range 4-17 years; 77 females) in 28 studies; 75% of patients had ≥1 additional risk factor for DVT. PTS was seen in 61% of patients, DVT recurrence in 38%, and complete vessel patency post-treatment in 65%. The models developed to predict and explain PTS performed poorly overall. Recurrent thrombosis (adjusted for age and patency) predicted PTS (odds ratio [OR] 3.36, 95% confidence interval [CI] 1.28-8.82). DVT management strategies (adjusted for age and DVT characteristics) predicted vessel patency (OR 2.10, 95% CI 1.43-3.08). Lack of complete vessel patency (adjusted for age and thrombophilia) predicted recurrent DVT (OR 2.70, 95% CI 1.09-6.67). Sensitivity analyses showed the same direction of effects for all outcomes.

CONCLUSIONS

PTS and DVT recurrence occur frequently in pediatric MTS. PTS prediction is complex and it was not possible to identify early predictors to guide clinical practice. Use of imaging-guided therapy and thrombus burden predicted venous patency, and lack of patency predicted DVT recurrence.

Diagnosis, Clinical Characteristics, and Treatment Modalities of Adolescent May-Thurner Syndrome-associated Deep Venous Thrombosis

May-Thurner syndrome (MTS) predisposes individuals to develop lower extremity deep venous thrombosis (DVT) because of compression of the left common iliac vein. Diagnosis of the anatomic obstruction is critical for effective therapy, as treatment by interventional radiology is often required in addition to anticoagulation to prevent thrombus progression and recurrence. The authors performed a retrospective review of adolescent patients who presented with MTS-associated DVT at a pediatric tertiary care center from 2009 to 2018 to assess for delays in MTS diagnosis after the presentation. Fourteen patients (median age 16.5 y, range, 13.8 to 17.9 y) were included, no DVTs were provoked by a central venous catheter. The median time from DVT to MTS diagnosis was 0.65 months (range, 0 to 21.5 mo). The initial imaging modalities used for DVT diagnosis were not able to diagnosis MTS. All patients were treated with anticoagulation and 13 underwent interventional therapy. Four patients had thrombus progression or recurrence, whereas 6 had complete thrombus resolution on follow-up imaging. Three patients who had a delayed MTS diagnosis had clinical worsening despite therapeutic anticoagulation requiring rehospitalization. Adolescent patients with "unprovoked" left lower extremity DVT should undergo appropriate imaging to diagnose MTS to allow for adequate medical and interventional therapy.

Antithrombotic Therapy after Venous Stent Placement

Chronic deep venous disease (CVD) affects millions of Americans and can result in significant morbidity, such as debilitating lower extremity oedema, venous claudication, and in severe cases, venous ulcers. CVD can be caused by thrombotic and non-thrombotic disease processes, such as deep venous thrombosis and iliac compression syndrome. Recently, endovascular intervention with percutaneous transluminal angioplasty and venous stent placement has become the mainstay therapy for these patients, with several studies demonstrating its safety and efficacy. However, anticoagulation management following venous stent placement is largely unstudied, and there are no large randomised controlled trials or official guidelines establishing an optimal regimen. Most published studies are plagued with data heterogeneity and incomplete reporting. This is further complicated by rapidly evolving improvements in technique and dedicated devices in endovenous intervention. In this article, the authors discuss the current literature to date and offer an approach to anticoagulation and antiplatelet management following venous stent placement in CVD.

Outcomes of endovascular venous stenting in patients on direct oral anticoagulants and antiplatelet therapy at a tertiary referral center

BACKGROUND

Endovenous revascularization is the standard in the management of acute thrombotic, chronic post-thrombotic iliocaval or iliofemoral obstruction, and nonthrombotic iliac vein lesions. The purpose of this study is to describe our single-center experience of postprocedure anticoagulation and antiplatelet regimens used after endovenous revascularization for a variety of venous occlusive conditions.

METHODS

We conducted a retrospective analysis of 100 consecutive patients who underwent endovenous stenting for iliocaval or iliofemoral obstruction from January 1, 2014, to April 30, 2018. Patients treated with direct oral anticoagulants, warfarin, or low-molecular-weight heparin (LMWH) with or without antiplatelet therapy were identified. Demographic, procedural, patency, and follow-up data were collected. Stent patency was evaluated using duplex Doppler ultrasound examination or contrast venography.

RESULTS

Seventy-one of 100 patients were treated with direct oral anticoagulant therapy (DOAC). Sixteen (23%) were lost to follow-up, leaving 55 (77%) available for analysis. The mean follow-up was 14 months (range, 1-43 months) with 32 patients (58%) followed for 12 months or longer. Primary, primary-assisted, and secondary-assisted patency rates were 87%, 97%, and 98%, respectively, at 12 months. In the non-DOAC group (patients treated with warfarin or LMWH), these rates were 87%, 93%, and 95%, respectively, at 12 months. Antiplatelet therapy, including clopidogrel, aspirin, or both, was used in 53 of 55 patients in the DOAC cohort and 18 of 19 patients in the non-DOAC group.

CONCLUSIONS

Our-single center retrospective analysis demonstrates acceptable primary patency rates when using DOAC therapy compared with those treated with warfarin or LMWH.

Venous Thromboembolism Research Priorities: A Scientific Statement From the American Heart Association and the International Society on Thrombosis and Haemostasis

Venous thromboembolism is a major cause of morbidity and mortality. The impact of the US Surgeon General's The Surgeon General's Call to Action to Prevent Deep Vein Thrombosis and Pulmonary Embolism in 2008 has been lower than expected given the public health impact of this disease. This scientific statement highlights future research priorities in venous thromboembolism, developed by experts and a crowdsourcing survey across 16 scientific organizations. At the fundamental research level (T0), researchers need to identify pathobiological causative mechanisms for the 50% of patients with unprovoked venous thromboembolism and to better understand mechanisms that differentiate hemostasis from thrombosis. At the human level (T1), new methods for diagnosing, treating, and preventing venous thromboembolism will allow tailoring of diagnostic and therapeutic approaches to individuals. At the patient level (T2), research efforts are required to understand how foundational evidence impacts care of patients (eg, biomarkers). New treatments, such as catheter-based therapies, require further testing to identify which patients are most likely to experience benefit. At the practice level (T3), translating evidence into practice remains challenging. Areas of overuse and underuse will require evidence-based tools to improve care delivery. At the community and population level (T4), public awareness campaigns need thorough impact assessment. Large population-based cohort studies can elucidate the biological and environmental underpinnings of venous thromboembolism and its complications. To achieve these goals, funding agencies and training programs must support a new generation of scientists and clinicians who work in multidisciplinary teams to solve the pressing public health problem of venous thromboembolism.

Venous thromboembolism research priorities: A scientific statement from the American Heart Association and the International Society on Thrombosis and Haemostasis

Venous thromboembolism (VTE) is a major cause of morbidity and mortality. The impact of the Surgeon General's Call to Action in 2008 has been lower than expected given the public health impact of this disease. This scientific statement highlights future research priorities in VTE, developed by experts and a crowdsourcing survey across 16 scientific organizations. At the fundamental research level (T0), researchers need to identify pathobiologic causative mechanisms for the 50% of patients with unprovoked VTE and better understand mechanisms that differentiate hemostasis from thrombosis. At the human level (T1), new methods for diagnosing, treating, and preventing VTE will allow tailoring of diagnostic and therapeutic approaches to individuals. At the patient level (T2), research efforts are required to understand how foundational evidence impacts care of patients (eg, biomarkers). New treatments, such as catheter-based therapies, require further testing to identify which patients are most likely to experience benefit. At the practice level (T3), translating evidence into practice remains challenging. Areas of overuse and underuse will require evidence-based tools to improve care delivery. At the community and population level (T4), public awareness campaigns need thorough impact assessment. Large population-based cohort studies can elucidate the biologic and environmental underpinings of VTE and its complications. To achieve these goals, funding agencies and training programs must support a new generation of scientists and clinicians who work in multidisciplinary teams to solve the pressing public health problem of VTE.

Deep vein thrombosis due to May-Thurner syndrome: a case report

Background

May-Thurner syndrome (MTS) or Cockett’s syndrome is a rare clinical syndrome, which refers to the compression of the left common iliac vein (LCIV) by right common iliac artery and vertebral body. Complications of MTS include deep vein thrombus formation and even life-threatening pulmonary embolism.

Case presentation

Here, we report the case of a 60-year-old female patient with a complaint of swelling in the left lower limb and pain for 5 days. Computed tomography angiography indicated MTS, and thrombus formation of left external iliac vein and femoral vein. The patient was diagnosed with deep venous thrombosis (DVT) and MTS. The patient underwent ascending venography from the lower extremity to inferior vena cava (IVC) and then to the pulmonary artery with IVC filter implantation, left iliac vein balloon plasty, and stent placement. The patient visited the hospital for the removal of IVC filter, 28 days after the operation. After the interventional therapy, the patient had no in-stent restenosis and had remission during the 2-year follow-up.

Conclusions

This case presents a successful management of MTS in presence of DVT. Although clinicians are rarely aware, the presence of unilateral lower limb swelling and thrombosis may be the manifestations of MTS.

Long-term antithrombotic therapy after venous stent placement

OBJECTIVES

To examine the prescribing patterns and outcomes of antithrombotic regimens after venous stent placement.

METHODS

A total of 87 patients who received inferior vena cava or iliofemoral venous stents were included in the study. A retrospective review was performed to determine the antithrombotic regimens and the subsequent rates of in-stent restenosis, stent thrombosis, and bleeding.

RESULTS

The prescribing patterns of specific antithrombotic regimens were highly variable. In-stent restenosis and stent thrombosis events were observed in 13 of 63 patients (21%) with available follow-up imaging, while major bleeding events were noted in 6 of 87 patients (7%). Triple therapy appeared to reduce the odds of in-stent restenosis/ stent thrombosis when compared to dual antiplatelet therapy (OR = 0.07, P = 0.01).

CONCLUSIONS

Substantial variability exists in antithrombotic therapy following venous stenting at our institution. This study demonstrated a reduction of in-stent restenosis/thrombosis events when utilizing triple therapy compared to antiplatelet-only regimens. However, larger prospective trials are needed to more accurately determine the relative risks and benefits of each antithrombotic regimen.

Reciprocal enhancement of thrombosis by endothelial-to-mesenchymal transition induced by iliac vein compression

AIMS

Endothelial-to-mesenchymal transition (EndMT) is a pathophysiological change of vascular endothelium commonly seen in the cardiovascular system. Iliac vein compression syndrome (IVCS) is known to be often associated with intimal hyperplasia and thrombosis. However, whether EndMT exists in IVCS has not yet been reported. The purpose of this study was to investigate the relationship between EndMT and thrombosis in IVCS.

MAIN METHODS

Using IVCS models in pig and mouse, we detected intimal changes and thrombus in stenotic iliac vein by immunofluorescence staining. Primary human umbilical vein endothelial cells (HUVEC) were stimulated by transforming growth factor β1 (TGF-β1) and thrombin, and cell phenotypic transition and antithrombotic function of HUVEC were examined through q-PCR, western blot and ELISA. In the end, by immunofluorescence staining, we observed the effect of anticoagulant on interstitial changes of venous endothelial cells in IVCS models.

KEY FINDINGS

We showed that iliac vein compression induced EndMT, of which its inhibition reduced thrombus formation. Further studies showed that HUVECs undergoing EndMT lost their anticoagulation and thrombolytic function. Interestingly, thrombin aggravated EndMT through TGF-β/Smad3 signaling. Moreover, compared with wild type (WT) mice, EndMT in stenotic iliac vein was reduced in WT mice fed with rivaroxaban or factor VII knockout mice, implying that anticoagulation alleviated EndMT in IVCS models.

SIGNIFICANCE

Our findings indicate that EndMT and thrombosis reinforce reciprocally in IVCS, implying that targeting EndMT could be a potential strategy in prevention and treatment of thrombosis in IVCS.

Iliac vein compression: epidemiology, diagnosis and treatment

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

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