May-Thurner syndrome and other obstructive iliac vein lesions: meaning, myth, and mystery

Acute left iliofemoral vein thrombosis: Comparison between simple and bony May-Thurner syndrome in CT venography

OBJECTIVES

To explore the etiology of May-Thurner syndrome (MTS) with acute iliofemoral deep vein thrombosis (DVT) regarding imaging findings and clinical features.

METHODS

We retrospectively analyzed 57 patients with acute left iliofemoral DVT from 2015 to 2020. The diameter of left common iliac vein (LCIV) at the maximal compression site and its percent compression regarding the average diameter of the uncompressed iliac vein were recorded in central and distal portions of the LCIV according to the location in the quadrant of lumbar vertebral body. Compression was categorized into simple and bony MTS; Simple MTS as LCIV compressed by the right common iliac artery (RCIA) versus Bony MTS as LCIV by lower lumbar degenerative changes regardless of RCIA compression. Initial computed tomographic venography (CTV) regarding chronic change of LCIV such as fibrotic atrophy or cordlike obliteration, extent of thrombus, and lumbar degenerative changes were evaluated. Therapeutic effect after initial therapy was assessed in follow-up CTVs after 3-6 months.

RESULTS

All patients showed LCIV compression with 19 simple MTS (mean age, 42.8 ± 14.1 years [23-67 years]; 12 females; symptom for 4.4 ± 5.5 days) and 38 bony MTS (mean age, 73.0 ± 10.2 years [49-85 years]; 26 females; symptom for 5.5 ± 4.8 days). There was significant difference in age (p < .001) and no significant difference in sex or symptom duration between two groups (p = .691 and 0.415, respectively). All simple MTS showed compression only in the central LCIV and half of bony MTS showed compression in both central and distal LCIV (p < .001). Among the lumbar degenerative changes, symmetric anterolateral osteophyte (p < .001) and asymmetric osteophyte (p < .001) were significantly associated with bony MTS, but not scoliosis (p = .799), compared to simple MTS. Although there was no significant difference in chronic change of LCIV, thrombosis extent, and therapeutic effect between two groups (p > .05), chronic change of LCIV showed significant difference between single and dual compression (23.7% vs. 57.9%, p = .024) and residual thrombus after initial therapy was occurred in 21.1% of single compression and 47.4% in dual compression with non-significant trend (p = .082).

CONCLUSION

Bony MTS related to lumbar degenerative changes with acute iliofemoral DVT occurs in older patients, presenting more than one stenosis at LCIV, inducing more chronic change with possibly weaker therapeutic effect than simple MTS.

May-Thurner Syndrome in a Case of Left Iliofemoral Vein Thrombosis With Contralateral Tubo-Ovarian Abscess in the Post-postpartum Period

May-Thurner syndrome (MTS) is a rare, yet important, differential diagnosis in reproductive-age women with deep vein thrombosis (DVT). It is characterized by the compression of the left common iliac vein by the right common artery against the lumbar vertebra. The condition is complicated by recurrent DVT with pulmonary thromboembolism (PTE). Here is a case of multiparous women in early puerperium with right tubo-ovarian abscess and left lower limb DVT likely due to MTS. The diagnosis was further complicated by the presence of persistent thrombocytosis but a myeloproliferative neoplasm was ruled out by genetic mutation testing. She was given anticoagulants, and laparotomy was done for the excision of the tubo-ovarian mass in view of the persistent fever not responding to injectable antibiotics. PTE in the postoperative period was managed by anticoagulants followed by an inferior vena cava (IVC) filter for the risk of recurrent DVT and/or PTE in an MTS case.

Iliac vein compression syndrome by lumbar degenerative changes is associated with deep vein thrombosis after total knee arthroplasty

INTRODUCTION

This study aimed to identify whether iliac vein compression syndrome(IVCS) is associated with deep vein thrombosis(DVT) after total knee arthroplasty(TKA) and whether lower lumbar degenerative changes were risk factors for IVCS.

MATERIALS AND METHODS

A total of 259 consecutive patients who underwent TKA from January 2019 to March 2022 was retrospectively reviewed. Preoperative plain radiographs of lumbar spines and CT venography (CTV) for DVT diagnosis at postoperative 7 days were performed in all patients. Imaging findings of lower lumbar degenerative changes were analyzed on plain radiograph including lateral osteophytes, scoliosis, lateralolisthesis, retrolisthesis, anterolisthesis, and lower lumbar lordosis angle (LLLA). Percent compression at the left common iliac vein (LCIV) and right common iliac vein (RCIV) as well as DVT were evaluated on CTV. Moreover, IVCS was defined as greater than 50% of compression of the iliac vein on CTV.

RESULTS

DVT occurred in 79 patients (30.5%) after TKA. The overall occurrence of DVT was significantly higher in patients with IVCS of LCIV (52.8%) than those without (18.8%, P < 0.001). When DVT was further subdivided, compared to non-IVCS, IVCS of LCIV was significantly associated with bilateral DVT (P < 0.001, both), especially distal DVT (P < 0.001, both), and IVCS of RCIV was significantly associated with right-side DVT (P = 0.031), especially popliteal (P = 0.008) and distal DVT(P = 0.011). Female patients (OR: 3.945, P = 0.039), presence of left osteophyte (OR: 2.348, P = 0.006), and higher LLLA (OR: 1.082, P < 0.001) were significantly associated with IVCS of LCIV, and presence of right osteophyte (OR: 3.494, P = 0.017) was significantly associated with IVCS of RCIV.

CONCLUSION

IVCS was significantly associated with DVT after TKA and lumbar degenerative changes with lateral osteophytes and hyperlordosis were significant risk factors for IVCS.

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

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

Catheter Directed Thrombectomy and Other Deep Venous Interventions in Cancer Patients

Treating cancer patients with deep venous thrombosis/venous thromboembolism (DVT/VTE) can be challenging as patients are frequently unable to receive the standard therapy of anticoagulation due to the increased risk of bleeding complications seen in this population. Similarly, the hesitation of interventionalists to use thrombolytic agents due to bleeding risks limits percutaneous intervention options as well. Further, outcome data and guidelines do not exist for oncologic patients and often treatment is tailored to patient-specific factors after multidisciplinary discussion. This article reviews specific factors to consider when planning percutaneous treatment of cancer patients with DVT/VTE, focusing on the iliocaval system.

Venous anomalies and thromboembolism

Patients with venous anomalies are at increased risk of developing venous thromboembolism (VTE) and subsequent complications, but they are often under-recognised. While unprovoked VTE may trigger testing for inherited thrombophilias and malignancy screening, anatomic variants are considered less often. Venous anomalies increase the risk due to venous flow disturbance, resulting in hypertension, reduced flow velocity and turbulence. Recognition is important as endovascular or surgical intervention may be appropriate, these patients have a high rate of VTE recurrence if anticoagulation is ceased, and the anomalies can predispose to extensive VTE and severe post-thrombotic syndrome (PTS). In this case series, we present representative cases and radiological images of May-Thurner syndrome (MTS), inferior vena cava (IVC) variants and venous aneurysms, and review the available literature regarding optimal diagnosis and management in each condition.

Multi-factor analysis of failure for modified single-session Angiojet rheolytic thrombectomy in treatment of acute iliofemoral venous thrombosis from iliac vein compression syndrome

PURPOSE

To explore the risk factors of failure for modified single-session Angiojet rheolytic thrombectomy combined with directed iliac vein stenting, directed filter retrieval in the treatment of iliac vein compression with iliofemoral vein thrombosis.

METHODS

During September 2017 to September 2021, 278 patients with DVT were retrospectively analyzed and 203 were eligible for inclusion. All patients were tried to take modified single-session Angiojet rheolytic thrombectomy combined with directed iliac vein stenting, directed filter retrieval treatment. The perioperative factors were analyzed between groups: group 1-modified single-session therapy succeed, and group 2-modified single-session therapy failed. The high risk factors of failure group were evaluated by logistic regression analysis.

RESULTS

48 patients failed in modified single-session therapy, up to 23.64%. Single factor analysis indicated that there were five independent risk factors related with the failure (p < 0.05), including course of disease longer than 7 days, lumbar degeneration-related iliac vein compression syndrome (dIVCS), antegrade vein access, balloon-assisted cracking thrombus, and suction time. Logistic regression analysis indicated that course of disease longer than 7 days (OR = 19.642.95%CI:6.776∼56.933), dIVCS (OR = 11.586.95%CI:4.016∼33.427) were high risk factors for modified single-session therapy failed, antegrade vein access (OR = 0.171.95%CI:0.047∼0.614) and balloon-assisted cracking thrombus (OR = 0.157.95%CI:0.045∼0.542) were protective factors for therapy failure (p < 0.05).

CONCLUSIONS

Long course of disease and dIVCS are the high risk factors for failure of modified single-session Angiojet rheolytic thrombectomy combined with directed iliac vein stenting, directed filter retrieval in the treatment of iliac vein compression syndrome (IVCS). But, antegrade vein access and balloon-assisted cracking thrombus intraoperatively may improve the success rate of modified single-session treatment.

Pathologic characteristics of human venous in-stent stenosis and stent occlusion

OBJECTIVE

The objective of this study was to determine the pathologic features of venous in-stent stenosis over time occurring in bare metal stents.

METHODS

Endovascular biopsy samples were obtained prospectively from venous bare metal stents implanted in 2009 through 2018. All samples were formalin-fixed, paraffin-embedded and stained with hematoxylin and eosin. Samples were examined by a cardiovascular pathologist to estimate the amount of its constituent components, which included fresh thrombus, organizing thrombus, old thrombus, or diffuse intimal thickening (DIT), and pathologic features including calcification, neovascularization, and hemosiderin deposition. This pathologic characterization was correlated with time following stent implantation to discern time-dependence of pathologic evolution of in-stent stenosis using both descriptive statistics and binary logistic regression.

RESULTS

A total of 254 post-stent venograms with biopsies of in-stent contents from 148 unique patients were studied. Fresh thrombus and organizing thrombus were both present across all studied time intervals. Old thrombus was seen beginning at approximately 2 weeks and DIT at approximately 4 weeks. Calcification was a rare finding encountered at later time intervals. The prevalence of each component varied with time: the probability of encountering fresh thrombus (P = .010) and organizing thrombus (P = .008) decreased over time. By contrast, the probability of finding DIT (P = .002) and calcifications (P < .001) increased over time. The presence of old thrombus, neovascularization, or hemosiderin did not demonstrate time dependence. Diffuse intimal thickening was frequently seen along with organizing thrombus as well as independently, and in many instances, these two features were directly merged.

CONCLUSIONS

The evolution of human venous in-stent restenosis appears to follow a time-dependent course, suggesting a possible progressive evolution from fresh and organizing thrombus to DIT. Contrasted with the literature on arterial in-stent restenosis, vein in-stent restenosis may have an increased thrombus prevalence (both organizing and old thrombus). DIT is a primary feature of late in-stent stenosis and may explain in part why many of these lesions may not respond to thrombolytic or anticoagulant treatment alone.

Venous Intervention

Any overview of the treatment of venous disease should begin with a brief examination of its history. From the first rudimentary attempt at venous thrombectomy in the early 1920s to the evolution of percutaneous and mechanical thrombectomy and endovascular stents in the 21st century. It is the aim of this review to provide a comprehensive summary of the state of the art of venous disease treatment at the turn of the new century.

Management of May Thurner Syndrome in Pregnant Patients

May Thurner Syndrome contributes to thromboembolic disease and can cause significant morbidity in pregnant patients secondary to exaggerated anatomic relationships and physiologic changes in the hematologic system favoring thrombogenesis. Because this condition is both underrecognized and underreported, management in pregnant and postpartum patients is based on expert opinion without any formal evidence-based guidance. Herein, we review five pregnancies in four patients with May Thurner Syndrome and general management strategies. Through collaborative and multidisciplinary care, patients with May Thurner Syndrome can be safely and successfully managed during pregnancy and the postpartum period with appropriate anticoagulation.

Morphometric and Hemodynamic Analysis of the Compressed Iliac Vein

PURPOSE

To investigate the relationship between the morphological structure and hemodynamic properties of the compressed iliac vein and explore the reason for the formation of thrombosis in the compressed iliac vein.

MATERIALS AND METHODS

A total of 11 patients with iliac vein compression syndrome (IVCS) were included in this study, and their iliac veins were reconstructed in 3 dimensions (3D). The morphological structures of the iliac veins (confluence angle, degree of stenosis) were analyzed based on the 3D model. Variations in the hemodynamic properties of the iliac vein were investigated at 4 typical moments in one cardiac cycle, and the relationship between the different morphological configurations and the pressure difference was investigated.

RESULTS

In the region of the compressed iliac vein, the blood flow velocity is accelerated and the pressure changes abruptly accompanied by the increase in pressure difference. Higher time averaged wall shear stress (TAWSS) and lower relative residence time (RRT) appeared in stenosis regions of compressed iliac vein, while TAWSS was low and RRT was large near the stenosis position. There was a strong positive correlation between the degree of stenosis and the pressure difference (r=0.894), and a positive correlation between the confluence angle of the iliac vein and the pressure difference (r=0.638).

CONCLUSION

The morphological structure of the compressed iliac vein has an obvious influence on the hemodynamic surroundings; the pressure difference becomes larger when the degree of stenosis and the confluence angle increase. The iliac vein luminal areas with low TAWSS and high RRT near the compressed location can impede blood flow and lead to accumulation of blood components, which may increase the risk of thrombosis formation and should be fully considered in the treatment of IVCS.

Seizures, deep vein thrombosis, and pulmonary emboli in a severe case of May–Thurner syndrome: a case report

Background

May–Thurner syndrome is a vascular disorder caused by the right common iliac artery compressing the left common iliac vein against the lumbar spine, causing distal venous stasis and potentially leading to fibrous change in the venous wall structure. Although May–Thurner syndrome is most commonly discovered in females upon investigation of new-onset deep vein thrombosis, we present the case of an otherwise healthy 29-year-old male with severe May–Thurner syndrome who presented with seizures, bilateral deep vein thrombosis, and diffuse pulmonary emboli. Seizures constituted the earliest presenting symptoms for the patient. Although it is difficult to prove that the patient’s seizures were related to the May–Thurner syndrome, this possible association renders this case extraordinary.

Case presentation

This report describes the case of a 29-year-old previously healthy white male with a severe case of left-sided May–Thurner syndrome that required extensive medical and interventional treatment. The patient experienced two seizures, one month apart, both of which occurred while residing at high altitude. The patient had no prior history of seizures, and epilepsy was ruled out. Three weeks after the second seizure, he presented to the emergency room with hemoptysis, dyspnea, and severe leg pain. Sites of thrombus were confirmed in both legs and diffusely in the lungs. Etiological work-up after treatment with intravenous tissue plasminogen activator revealed May–Thurner syndrome. Hematology workup including genetic testing showed no evidence of coagulopathy. Bilateral common iliac venous stents were placed to attempt definitive treatment. Despite stenting, the patient had another thrombotic event with associated sequelae after discontinuation of anticoagulation. The patient has not had another seizure since the stents were placed. Despite the negative testing, the patient remains on lifelong chemoprophylaxis in the event of an undiscovered hypercoagulopathy.

Conclusions

The care team theorizes that the seizures resulted from hypoxia due to May–Thurner syndrome-induced hemostasis and associated thrombotic events, the high-altitude location of his residence at the time he experienced the seizures, and shallow breathing during sleep. For patients with lower limb venous thrombosis, May–Thurner syndrome should be considered in the differential diagnosis. Endovascular treatment followed by extended prophylactic anticoagulation therapy until the patient is determined to be no longer at risk for thrombosis is recommended. Post-venoplasty thrombosis is a common complication of endovascular treatment of May–Thurner syndrome and should be carefully monitored.

An Unusual Case of May-Thurner Syndrome in a Middle-Aged IV Drug Abuser

May-Thurner syndrome (MTS) is an extrinsic venous compression of the iliocaval venous territory by the arterial system. MTS is common in middle-aged women. Despite its importance, it is uncommonly considered in the differential diagnosis of deep vein thrombosis (DVT), especially in males with other risk factors. Due to the perianal abscess, a 35-year-old male health care worker was abusing IV opioids through his left leg veins. His symptoms included signs and symptoms of cellulitis around the catheter site, followed by recurrent DVTs due to poor response to anticoagulation therapy alone. A comprehensive workup revealed the diagnosis of MTS. The patient eventually required endovenous treatment with stent placement, after which his condition improved dramatically.

Efficacy Analysis of Endovascular Therapy for Nonthrombotic Iliac Vein Compression Syndrome Combined with Chronic Venous Insufficiency

Purpose

This research is aimed at elucidating the clinical efficacy of balloon dilatation (BD) plus stent implantation for nonthrombotic iliac vein compression syndrome (NIVCS) combined with chronic venous insufficiency (CVI) in different compression positions.

Methods

Sixty-five NIVCS patients comorbid with CVI admitted between December 2015 and April 2020 were selected and assigned to two groups according to different iliac vein compression positions. Both groups of patients received iliac vein BD + stent implantation, with the difference lying in that the tip of the stent was inserted 0.5-1 cm into the inferior vena cava (IVC) in the experimental group versus 2-3 cm in the control group. The technical success rate, the postoperative venous clinical severity score (VCSS), and the incidence of complications were compared.

Results

The technical success rate of both groups was 100%. Patients were followed up for 12-36 months (average: 25.5 ± 6.2). Decreases in VCSS were observed in both cohorts at 3, 6, 12, 24, and 36 months postoperatively compared with the preoperative scores, but with no statistical difference. There was no death, nor related complications such as restenosis and lower limb deep vein thrombosis during the follow-up period, with no statistical difference in the incidence of complications between groups.

Conclusions

BD + stent implantation is a safe and effective treatment for NIVCS with few complications and remarkable short-term and medium-term effects.

The Clinical Problem of Pelvic Venous Disorders

Pelvic venous disorders are inter-related pathologic conditions caused by reflux and obstruction in the pelvic veins. It can present a spectrum of clinical features based on the route of transmission of venous hypertension to either distal or caudal venous reservoirs. Imaging can help to visualize pelvic vascular and visceral structures to rule out other gynecologic, gastrointestinal, and urologic diseases. Endovascular treatment, owing to its low invasive nature and high success rate, has become the mainstay in the management of pelvic venous disorders. This article reviews the pathophysiology, clinical presentations, and diagnostic and therapeutic approaches to pelvic venous disorders.

Treatment of Non-thrombotic Iliac Vein Stenosis: Where is the Evidence?

Non-thrombotic iliac vein lesions (NIVLs) refer to iliac vein lumen stenosis, usually secondary to extrinsic compression, without associated thrombosis. Clinical presentation varies; patients may be asymptomatic, have symptoms of lower extremity venous hypertension, or in women, may be associated with chronic pelvic pain. Given the significant variability in symptomatology, thorough history and physical examination are mandatory in excluding other causes of symptoms. Non-invasive imaging, such as venous duplex/insufficiency ultrasound examinations, and axial imaging aid in the diagnosis of a NIVL in the appropriate clinical context. Catheter venography and intravascular ultrasound remain the primary modalities for definitive diagnosis, treatment planning, and ultimately placement of self-expanding venous stents to resolve the causative iliofemoral venous obstruction. In appropriately selected patients, stent placement can lead to marked improvements in symptoms, heal stasis ulceration when present, and improve disease-specific and overall quality of life. Stents placed in patients with NIVL demonstrate high long-term primary patency. In this article, the authors discuss clinical presentation, diagnostic workup, endovascular interventions and outcomes of NIVL treatment.

May-Thurner syndrome in patients with postural orthostatic tachycardia syndrome and Ehlers-Danlos syndrome: a case series

Background

Postural orthostatic tachycardia syndrome (POTS), Ehlers-Danlos syndrome (EDS), and May-Thurner syndrome (MTS) are three syndromes that are often misdiagnosed or underdiagnosed. The true prevalence of these syndromes may be higher than currently reported. The following case series is the first to report a three-way association between POTS, EDS, and MTS.

Case summary

We describe three patients with concomitant POTS, EDS, and MTS. Although abdominopelvic vasculature evaluation can be difficult via conventional imaging techniques, we present the use of novel dynamic contrast-enhanced magnetic resonance angiography with Differential Subsampling with Cartesian Ordering (DISCO) and four-dimensional flow magnetic resonance imaging to aid vasculature evaluation and the diagnosis of MTS. Two patients underwent left common iliac vein stenting to treat MTS, experiencing significant improvement in their POTS symptoms and quality of life.

Discussion

Ehlers-Danlos syndrome, POTS, and MTS may interact synergistically to exacerbate symptoms. Patients with EDS should be evaluated for possible POTS and pelvic venous complications. Left common iliac vein stenting for MTS can mitigate POTS symptoms by decreasing lower extremity venous pooling and should be considered in this patient population. Further research is needed to understand the exact mechanism and intricacies of this syndrome triad.

Combined Oral Contraceptives Bringing to Light May-Thurner Syndrome

May-Thurner syndrome (MTS) is a relatively uncommon clinical condition characterized by venous blockage in the left lower leg. Compression of the left common iliac vein by the right common iliac artery and the underlying vertebral body causes obstruction. We report a case of MTS with extensive venous thrombosis in a 44-year-old female who remained clinically silent until she used combined oral contraceptive pills (OCPs) for more than three years.

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.

Sonographic Evaluation of Pelvic Venous Disorders

ABSTRACT

Pelvic venous disorders are a group of interrelated conditions characterized by venous incompetence. These conditions often manifest with nonspecific symptoms that overlap with many gynecological, gastrointestinal, and urologic diseases. Clinical diagnosis can be difficult, and imaging can play a vital role in differentiating etiology. Sonographic evaluation is often the first step in evaluating these symptoms. Special attention to possible underlying pelvic venous disorders can reveal characteristic findings, support diagnosis, and guide treatment. Here we review pelvic congestion syndrome, nutcracker syndrome, May-Thurner syndrome, and other venous disorders, with a specific focus on sonographic findings and considerations.

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.

Treatment of May-Thurner's Syndrome and Associated Complications: A Multicenter Experience

OBJECTIVE

To assess the treatment options and associated complications in patients with May-Thurner's syndrome (MTS).

METHODS

We retrospectively reviewed the charts of patients diagnosed with MTS. Thorough review was completed and data relevant to methods of diagnosis, treatment, complications, hospital readmission, and mortality were extracted from patient charts. The patients were followed for two years after diagnosis.

RESULTS

Of the 47 patients identified as having "MTS", 32 (70%) were diagnosed formally with either magnetic resonance venography, computed tomography venography, or ultrasound. Two patients were excluded for insufficient availability of follow-up records. Mean age of the population included (N = 30) was 50.24 ±15.33 years and 83% (N = 25) had female gender. The majority (40%) of patients were treated with anticoagulation, thrombolysis, and stent placement, and 13.3% received a combination of anticoagulation, antiplatelet agent, thrombolysis, and stent placement. Overall, we found 28 patients (93%) who underwent endovascular stenting. However, 39.3% (11/28) had stent-related complications that included stent thrombosis, stenosis, and migration. One patient underwent open heart surgery for stent retrieval. Duration of anticoagulation therapy ranged from 6 months to lifelong. Two patients (6.7%) suffered major bleeds requiring transfusion. Fourteen patients (46.6%) developed post-thrombotic syndrome. Seven (23.3%) patients required MTS-related readmission within 30 days. No mortality was noted at two-year follow-up.

CONCLUSION

Although our study only included 30 patients, it was evident to us that there is no consensus in the management of MTS. Furthermore, endovascular stenting, which has a major role in the management of MTS, has complication rates that hover close to 40%. Further research is needed to help develop a standardized evidence-based approach in the management of MTS that ensures a decreased risk of immediate and long-term complications.

Left common iliac vein compression identified by vascular ultrasonography in asymptomatic women: does standing position influence diagnosis?

Background

Vascular ultrasonography is the imaging exam of choice for initial screening for left common iliac vein compression, which is an asymptomatic finding that can be detected in up to 25% of some patient samples.

Objective

To determine, using vascular ultrasonography, whether findings of left common iliac vein compression in asymptomatic women are different when assessed in the prone and standing positions.

Methods

This is a cross-sectional observational study of 50 adult female volunteers with no symptoms of pelvic venous compression. The parameters assessed with vascular ultrasonography in the prone and standing positions were diameters and maximum velocities of the left common iliac vein at the point at which it crosses behind the right common iliac artery and before this point, in addition to left common iliac vein velocity indices at the crossing.

Results

Eight cases of significant compression of the left common iliac vein were identified when assessed in prone position (16%) and just two cases (4%) were identified in the standing position. Left common iliac vein diameters were statistically larger (p = 0.002) at the point where it crosses behind the right common iliac artery in the standing position and velocities and velocity indices were statistically higher (p < 0.001) in the prone position. No significant compression of the left common iliac vein was identified in the standing position when velocity indices were normal in the prone position.

Conclusions

There was no difference in detection of significant compression of the left common iliac vein when assessed in the standing position in comparison with assessment in the prone position. However, the study showed that anatomic compression of the left common iliac vein may be reduced in the standing position.

Treatment of Nonthrombotic Iliac Vein Lesions

Nonthrombotic iliac vein lesions (NIVLs) most frequently result from extrinsic compression of various segments of the common or external iliac vein. Patients develop symptoms associated with chronic venous insufficiency (CVI); female patients may develop symptoms of pelvic venous disease. Given that iliac vein compression can be clinically silent, a thorough history and physical examination is mandatory to exclude other causes of a patient's symptoms. Venous duplex ultrasound, insufficiency examinations, and axial imaging are most commonly used to assess for the presence of a NIVL. Catheter venography and intravascular ultrasound (IVUS) are the mainstay for invasive assessment of NIVLs and planning prior to stent placement. IVUS in particular has become the primary modality by which NIVLs are evaluated; recent evidence has clarified the lesion threshold for stent placement, which is indicated in patients with moderate to severe symptoms. In appropriately selected patients, stent placement results in improved pain, swelling, quality of life, and, when present, healing of venous stasis ulcers. Stent patency is well preserved in the majority of cases, with a low incidence of clinically driven need for reintervention. In this article, we will discuss the clinical features, workup, endovascular management, and treatment outcomes of NIVL.

Endovenöse Therapie chronisch venöser Obstruktionen

Bei der chronisch venösen Obstruktion (CVO) liegt ein Abstromhindernis vor, welches eine venöse Hypertension im betroffenen Bein verursacht. Die CVO tritt vornehmlich auf dem Boden eines postthrombotischen Syndroms (PTS) oder eines May-Thurner-Syndroms (MTS) auf. Die CVO kann zu einer deutlichen Einschränkung des täglichen Lebens führen und hat erhebliche sozioökonomische Konsequenzen. Bei der endovenösen Rekanalisation zur Behandlung einer symptomatischen CVO handelt es sich um eine relativ neue therapeutische Option, die mittlerweile generell als Behandlung der ersten Wahl akzeptiert ist. Seit Verwendung spezieller venöser Stents können auch ausgedehntere Befunde, die eine anspruchsvollere Rekonstruktion erforderlich machen, erfolgreich therapiert werden.

Damit nach einer venösen Rekanalisation keine Stase des Blutstroms und ein Primärverschluss auftreten, müssen ein suffizienter Ein- und Ausstrom gewährleistet sein. Zur Verbesserung des Einstroms werden Hybrideingriffe mit Endophlebektomie der Vena femoralis communis und AV-Fistel-Anlage, zur Ausstromverbesserung werden spezielle Rekonstruktionen der Vena-cava-inferior-Konfluenz, z. B. die Skipped-Technik, empfohlen.

Usefulness of triggered non-contrast-enhanced magnetic resonance angiography in assessing lower extremity venous disease

Although venous duplex ultrasonography (USG) is reliable for diagnosing lower extremity venous disease (LEVD), cross-sectional imaging studies were usually required before intervention or surgery. Patients of LEVD with renal insufficiency usually restrict the use of contrast-enhanced imaging modalities. In seeking an alternative imaging solution for these patients, we explore the clinical utility of triggered angiography non-contrast-enhanced magnetic resonance imaging (TRANCE-MRI) in the assessment of LEVD.We collected data from patients presenting to a tertiary wound-care center with symptoms of LEVD from April 2017-November 2019. Each participant underwent baseline USG followed by TRANCE-MRI on a 1.5T MR scanner (Philips Ingenia, Philips Healthcare, Best, The Netherlands). Inter-rater reliability was measured using Cohen's kappa (κ).All 80 participants (mean age, 61.9 ± 14.8 years; 35 males, 45 females) were assessed and were classified into one of five disease groups, deep vein thrombosis (n = 38), venous static ulcer (n = 16), symptomatic varicose veins (n = 18), recurrent varicose veins (n = 3), and lymphoedema (n = 5). The inter-rater reliability between TRANCE-MRI and doppler USG showed substantial agreement (κ, 0.73). The sensitivity, specificity, and accuracy of TRANCE-MRI were 90.5%, 88.1%, and 88.8%, respectively. In 59 (73.8%) USG-negative patients, we were able to diagnose positive findings (deep venous thrombosis, n = 7; varicose veins, n = 15; lymphedema, n = 10; iliac vein compression with thrombosis, n = 6; external venous compression, n = 5; vena cava anomaly, n = 2; occult peripheral artery disease, n = 5; ccluded bypass graft, n = 1) by using TRANCE-MRI. Of these, 9 (15.3%) patients underwent additional vascular surgery based on positive TRANCE-MRI findings.TRANCE technique provides the limb's entire venous drainage in clear images without background contamination by associated arterial imaging. Additionally, simultaneous evaluation of bilateral lower extremities can help determine the lesion's exact site. Although TRANCE-MRI can provide MR arteriography and MR venography, we recommend performing only MR venography in symptomatic LEVD patients because the incidence of occult arterial disease is low.

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.

Contemporary treatment of May-Thurner Syndrome

Compression of the left common iliac vein by the overlying right common iliac artery is a benign anatomic abnormality in most individuals. However, in patients with significant vein compression, outflow obstruction and chronic intraluminal venous damage may lead to May-Thurner Syndrome. This syndrome commonly manifests as unilateral left leg swelling or acute iliofemoral deep venous thrombosis. In addition to clinical findings, diagnosis is made with ultrasound, computed tomography venography, or magnetic resonance venography. The extent of compression of the iliac vein is best determined by venography with intravascular ultrasound. Symptoms and hemodynamic significance of the compression guides the ideal treatment approach. Iliocaval stenting has become the standard treatment for this condition and has promising patency rates and clinical outcomes. This review paper provides an overview of pathophysiology, and utility and limitations of the existing diagnostic modalities and treatment options in the management of May-Thurner Syndrome.

Iliac Vein Stenosis: Is the Data Strong Enough for Stenting in the Young Pelvic Venous Disorders (PeVD) Population?

Iliac vein stenosis is a clinical condition resulting from external compression of the iliocaval venous unit with the consequent remodeling of the vascular wall, hemodynamic alterations, and predisposition to venous thrombosis. As such, the most common indications for percutaneous endovascular iliac vein stenting supported by the literature, include the management of thrombotic and non-thrombotic iliac venous lesions associated with advanced chronic venous disease (CVD). However, its clinical presentation is variable, and it may also include features associated with PeVD such as chronic pelvic pain, perineal heaviness, urinary urgency, postcoital pain, and vulvar or superficial non-saphenous veins varicosities. In this setting, the management revolves around the relieving venous obstruction and restoring normal blood flow through the compressed vein with percutaneous endovascular iliac vein stenting, that can be augmented with ovarian vein embolization (OVE) or direct embolization of the superficial varices. Given the heterogeneity of PeVD presentation and the lack of high-level quality data in outcomes for iliac vein stenosis stenting, this review will discuss the current evidence available for this intervention and clinical issues to consider when evaluating these patients.

May-Thurner syndrome, a diagnosis to consider in young males with no risk factors: a case report and review of the literature

Background

May–Thurner syndrome is an anatomical condition characterized by compression of the left common iliac vein by the right common iliac artery, causing venous outflow obstruction. It is an uncommon cause of deep vein thrombosis and is more prevalent among women. This paper highlights the importance of considering May–Thurner syndrome in young males without risk factors presenting with left lower limb pain, as endovascular treatment may be required.

Case presentation

A 23 year-old Caucasian male presented with a 1-week history of left lower limb pain, edema, and pallor. He was found to have an unprovoked deep vein thrombosis on Doppler ultrasound involving the left fibular, soleus, gastrocnemius, popliteal, femoral, common femoral, and external iliac veins. A heparin infusion was commenced as the initial treatment for deep vein thrombosis. Further investigation with computer tomography pulmonary angiogram and computer tomography venography of the abdomen and pelvis showed bilateral pulmonary emboli and left common iliac vein compression with left common, internal, and external iliac vein thrombosis. He was diagnosed with May–Thurner syndrome despite having no risk factors. A retrievable Cook Celect Platinum inferior vena cava filter was placed, and thrombus of the left common femoral, external, and common iliac veins was treated successfully with AngioJet thrombectomy, thrombolysis using 200,000 units of urokinase, angioplasty and stenting using two Cook Zilver Vena venous self-expanding stents. Therapeutic enoxaparin was commenced on discharge. His filter was removed after 10 weeks. Hematological follow-up 4 months later showed an overall negative thrombophilia screen, and anticoagulation was switched to apixaban. He has had no recurrent thrombosis.

Conclusions

Clinicians should have a low threshold to investigate for May-Thurner syndrome in patients with left lower limb venous thrombotic events regardless of risk factors, as endovascular treatment may be required to minimize the long-term sequelae of deep vein thrombosis. Duplex ultrasound can be used initially for diagnosis, and computer tomography venography used subsequently if the common iliac vein is not visualized on ultrasound. Endovascular treatment is preferred over anticoagulation alone, especially in otherwise fit patients presenting early, the aim being to reduce the chances of chronic venous hypertension in the lower limb.

Novel typing of iliac vein compression in asymptomatic individuals evaluated by contrast enhanced CT

Purpose

Compression of the iliac vein between the iliac artery and lumbosacral vertebra can cause iliac vein compression syndrome (IVCS). The purpose of this study is to assess compression characteristics and establish a new sub-typing in asymptomatic IVCS individuals using contrast-enhanced CT.

Methods

A retrospective analysis of abdomen contrast-enhanced CT images from 195 asymptomatic subjects with iliac vein compressed was investigated. Patients had no history of venous pathology, and images were collected from June 2018 to January 2019. Qualitative and quantitative characteristics of compression were examined including the location, pattern, minor diameter, area, and the percentage compression on an orthogonal section by the post-processing of multiple planar reconstruction and volume rendering.

Results

There were 107 females and 88 males with age range 18–92 years. The most common site of iliac vein compression was localized to the left common iliac vein (LCIV) (178/195, 91.3%). Notably, four compression types (type I–IV) were established according to the compression location, with type II being the most common. The four compression types had differences in the upper limit and fluctuation range of compression. It was found that the average level of iliac vein compression was below 25%. The compression degree of the left common iliac vein in type II was relatively concentrated, and the upper limit of compression was close to 70%.

Conclusion

Asymptomatic iliac vein compression was categorized according to compression location. The proposal of four types might help clinicians to predict which IVCS patients would benefit from interventional therapy.

Percutaneous endovenous intervention without vena cava filter for acute proximal deep vein thrombosis secondary to iliac vein compression syndrome: preliminary outcomes

The aim is to report the preliminary outcomes of percutaneous endovenous intervention (PEVI) for acute proximal deep vein thrombosis (DVT) secondary to iliac vein compression syndrome (IVCS) without inferior vena cava filter (IVCF) placement. Acute DVT patients who underwent PEVI without IVCF were analyzed retrospectively. PEVI consisted of catheter-directed thrombolysis, manual aspiration thrombectomy, balloon angioplasty and stenting. CT was used to evaluate the left common iliac vein (LCIV). Sixty-two consecutive patients (17 men and 45 women, mean age, 59.4 ± 15.2 years) were enrolled. The compression percentage of the LCIV ranged from 51.7% to 95.2% (median 83.2%). Iliac DVT was present in 7 patients; iliofemoral, in 30 patients; and iliofemoropopliteal, in 25 patients. Complete technical success and clinical improvement were obtained in all subjects without the occurrence of symptomatic pulmonary embolism (PE). Five patients experienced recurrent thrombosis. The primary patency rates at 12 and 24 months were 93.8% and 91.4%, respectively, which remained stable at 36, 48 and 60 months. The secondary patency rates at 12 and 24 months were 95.7% and 93.3%, respectively, and there was no change at 60 months. Although limited, our preliminary results suggested that PEVI without IVCF placement seemed to be safe and effective for acute proximal DVT secondary to IVCS without inferior vena cava thrombosis or symptomatic PE.

Diagnosis and treatment of iliac vein stenosis

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

Diagnosis and Treatment of Lower Extremity Venous Thromboembolism: A Review

IMPORTANCE

Incidence rates for lower extremity deep vein thrombosis (DVT) range from 88 to 112 per 100 000 person-years and increase with age. Rates of recurrent VTE range from 20% to 36% during the 10 years after an initial event.

OBSERVATIONS

PubMed and Cochrane databases were searched for English-language studies published from January 2015 through June 2020 for randomized clinical trials, meta-analyses, systematic reviews, and observational studies. Risk factors for venous thromboembolism (VTE), such as older age, malignancy (cumulative incidence of 7.4% after a median of 19 months), inflammatory disorders (VTE risk is 4.7% in patients with rheumatoid arthritis and 2.5% in those without), and inherited thrombophilia (factor V Leiden carriers with a 10-year cumulative incidence of 10.9%), are associated with higher risk of VTE. Patients with signs or symptoms of lower extremity DVT, such as swelling (71%) or a cramping or pulling discomfort in the thigh or calf (53%), should undergo assessment of pretest probability followed by D-dimer testing and imaging with venous ultrasonography. A normal D-dimer level (ie, D-dimer <500 ng/mL) excludes acute VTE when combined with a low pretest probability (ie, Wells DVT score ≤1). In patients with a high pretest probability, the negative predictive value of a D-dimer less than 500 ng/mL is 92%. Consequently, D-dimer cannot be used to exclude DVT without an assessment of pretest probability. Postthrombotic syndrome, defined as persistent symptoms, signs of chronic venous insufficiency, or both, occurs in 25% to 50% of patients 3 to 6 months after DVT diagnosis. Catheter-directed fibrinolysis with or without mechanical thrombectomy is appropriate in those with iliofemoral obstruction, severe symptoms, and a low risk of bleeding. The efficacy of direct oral anticoagulants-rivaroxaban, apixaban, dabigatran, and edoxaban-is noninferior to warfarin (absolute rate of recurrent VTE or VTE-related death, 2.0% vs 2.2%). Major bleeding occurs in 1.1% of patients treated with direct oral anticoagulants vs 1.8% treated with warfarin.

CONCLUSIONS AND RELEVANCE

Greater recognition of VTE risk factors and advances in anticoagulation have facilitated the clinical evaluation and treatment of patients with DVT. Direct oral anticoagulants are noninferior to warfarin with regard to efficacy and are associated with lower rates of bleeding, but costs limit use for some patients.

Deep Vein Thrombosis Secondary to Extrinsic Compression: A Case Report

May-Thurner syndrome (MTS) is defined as extrinsic venous compression by the arteries of the iliocaval system. The most common manifestation of MTS is compression of the left common iliac vein by the right common iliac artery. May-Thurner syndrome is pathologically seen in 2%-5% of patients presenting with symptomatic deep vein thrombosis (DVT). As an anatomic variant, the prevalence is predicted to be much higher as most patients with MTS anatomy are asymptomatic and do not seek evaluation.  Symptomatic clinical presentations can include left lower extremity pain, swelling, skin discoloration, ulceration, and venous claudication. Here we present a patient with symptomatic MTS. A 64-year-old female with no pertinent past medical history presented with complaint of worsening left lower extremity swelling and pain. Clinical picture was concerning for phlegmasia cerulea dolens and ultrasound was bypassed in favor of a CT scan of the lower extremities bilaterally. The CT showed occlusion of the deep veins of the left leg secondary to stenosis of the left common iliac vein just posterior to the right common iliac artery; a finding consistent with MTS. Interventional radiology performed a catheter-directed thrombolysis with stenting of the left common iliac and external iliac veins. The patient clinically improved and was discharged with anticoagulative therapy.  May-Thurner syndrome is a condition that typically manifests due to external anatomic compression of the left common iliac vein. It is our belief that patients (with the appropriate risk factors) presenting with signs and symptoms consistent with proximal lower extremity DVT would benefit from further radiographic studies to fully evaluate for iliocaval venous stenosis and subsequent catheter-directed thrombolysis with endovascular stenting.

ACR Appropriateness Criteria® Radiologic Management of Iliofemoral Venous Thrombosis

Iliofemoral venous thrombosis carries a high risk for pulmonary embolism, recurrent deep vein thrombosis, and post-thrombotic syndrome complicating 30% to 71% of those affected. The clinical scenarios in which iliofemoral venous thrombosis is managed may be diverse, presenting a challenge to identify optimum therapy tailored to each situation. Goals for management include preventing morbidity from venous occlusive disease, and morbidity and mortality from pulmonary embolism. Anticoagulation remains the standard of care for iliofemoral venous thrombosis, although a role for more aggressive therapies with catheter-based interventions or surgery exists in select circumstances. Results from recent prospective trials have improved patient selection guidelines for more aggressive therapies, and have also demonstrated a lack of efficacy for certain conservative therapies. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Review of imaging and endovascular intervention of iliocaval venous compression syndrome

Iliocaval venous compression syndrome (ICS) is the extrinsic compression of the common iliac vein by the overlying iliac artery against the vertebra. Chronic compression can lead to venous stenosis and stasis, which manifests as chronic venous disease and treatment resistance. Therefore, early recognition of ICS and prompt treatment are essential. Clinical presentations of ICS can be ambiguous and diagnosis requires a high index of suspicion with the relevant imaging studies. The initial imaging test is typically a Duplex ultrasound for vessel assessment and pelvic ultrasound to exclude a compressive mass, which is followed by computed tomography (CT) or magnetic resonance (MR) venography. CT and MRI can identify the anatomical causes for venous compression. In patients with high clinical suspicion for ICS, negative findings on CT and MR venography would still warrant further investigations. Definitive diagnosis can be established using catheter-based venography complemented with intravascular ultrasonography but the nature of their invasiveness limits its utility as a routine imaging modality. In this review paper, we will discuss the evidence, utility and limitations of the existing imaging modalities and endovascular intervention used in the management of ICS.

A case of May-Thurner Syndrome: An old anomaly but, a new suggestion: A case report

May-Thurner syndrome (MTS) is an anatomical condition resulting in compression of the left common iliac vein between the right common iliac artery and the underlying spine. MTS is rarely diagnosed because diagnostic workup is seldom continued once the diagnosis of a deep vein thrombosis (DVT) has been established. Furthermore, patients with DVT generally have several well-known confounding risk factors. We report a 16-year-old girl with a history of left leg swelling who was incidentally diagnosed with MTS. We hope that our case report will create awareness of vascular abnormalities in sports medicine and suggest that routine venous Doppler ultrasound screening may help to detect MTS or associated anatomical prior to the formation of early thrombosis.

Analysis of patent, unstented lower extremity vein segment diameters in 266 patients with venous disease

OBJECTIVE

The objective of this study was to characterize the average maximum diameters of widely patent lower extremity vein segments in patients with underlying venous disease and the demographic factors that affect these diameters.

METHODS

Maximum axial diameters of each deep vein segment from the diaphragm to the knee were measured from computed tomography venography studies for all patients who underwent venous stent placement during a 20-year period at a single quaternary venous referral institution. Limbs containing only widely patent, unstented vein segments without variant anatomy were identified for inclusion. The final analysis involved diameter measurements from 870 imaging studies of 266 patients. Multivariate linear regression was used to identify factors associated with vein segment diameters.

RESULTS

Average vein segment diameters ranged from 7.8 mm for the left and right femoral veins to 27.9 mm for the long axis of the suprarenal inferior vena cava. Multivariate linear regression demonstrated that women had larger IVC, common iliac vein, and external iliac vein diameters, whereas men had larger common femoral veins. Laterality, height, weight, and sex also had statistically significant associations with the diameters of select vein segments.

CONCLUSIONS

This study provides an estimate of the average diameters of widely patent deep vein segments in the lower extremities from the diaphragm to the knees in patients with underlying venous disease and characterizes covariates that significantly affect vein diameter. These findings may help interventionalists better select devices for endovascular intervention.

Using non-contrast-enhanced magnetic resonance venography for the evaluation of May-Thurner syndrome in patients with renal insufficiency: A case report

RATIONALE

Contrast-enhanced computed tomographic venography (CTV) or magnetic resonance venography (MRV) are usually used to detect May-Thurner syndrome (MTS). However, both are associated with contrast-induced nephrotoxicity. For patients who cannot receive contrast media, non-contrast-enhanced MRV using three-dimensional (3D) turbo spin-echo (TSE) is considered an alternative. We report a case of MTS to describe its clinical utility and advantages.

PATIENT CONCERNS

A 49-year-old male experienced isolated left leg swelling and pain for half a month. He had a history of chronic renal insufficiency that made contrast-enhanced imaging studies inadequate.

DIAGNOSES

A lower extremity venous Duplex scan showed a thrombus extending from the left distal femoral vein to the popliteal vein with valvular reflux, consistent with infrainguinal deep vein thrombosis (DVT). The suprainguinal DVT was evaluated by non-contrast-enhanced MRV. The results showed sandwich external compression of the left common iliac vein between the right common iliac artery and lumbar vertebrae, consistent with DVT of the left common iliac vein caused by MTS.

INTERVENTIONS

The patient received angioplasty with the implantation of a balloon-expandable stent over the left common iliac vein.

OUTCOMES

Excellent recanalization of the left iliac vein was noted postoperatively.

LESSONS

In the evaluation of suprainguinal venous lesions, non-contrast-enhanced MRV presents the venous structure alone at high resolution without the accompanying arterial structure, which makes it an excellent diagnostic imaging tool for MTS. These findings indicate that non-contrast-enhanced MRV could be useful for detecting systemic venous pathologies in patients with renal insufficiency.

Evaluation and Management of Chronic Venous Disease Using the Foundation of CEAP

PURPOSE OF THE REVIEW

Venous disease is common. Depending on the population studied, the prevalence may be as high as 80%. Significant chronic venous disease with venous ulcers or trophic skin changes is reported to affect 1-10% of the population. A systematic assessment of the clinical findings associated with chronic venous disease will facilitate appropriate imaging. Based on imaging and assessment, patients with reflux or obstruction can be recommended proper medical and endovascular or surgical management.

RECENT FINDINGS

Many types of endovascular management are available to treat reflux and eliminate varicose veins and tributaries. More recently adopted non-thermal non-tumescent techniques have been shown to be comparable with more widely performed laser or radiofrequency ablation techniques. A thorough clinical assessment, appropriate duplex ultrasound imaging, and use of advanced imaging when needed will allow clinicians to optimize therapy for patients with chronic venous disease based on the etiology, anatomy involved, and the pathophysiology.

Cessation of anticoagulation therapy following endovascular thrombus removal and stent placement for acute iliofemoral deep vein thrombosis

Summary. Background: The optimal duration of anticoagulation therapy (AT) following catheter-based therapy of acute iliofemoral deep vein thrombosis (IFDVT) with stent placement is unknown. Theoretically, resolving the underlying obstructive iliac vein lesion by a stent may eliminate the main trigger for recurrence, the post-thrombotic syndrome (PTS), and the need for extended-duration AT. Patients and methods: From 113 patients with acute IFDVT who underwent endovascular thrombus removal and stent placement, we compared patency rates and clinical outcomes between 58 patients on limited-duration AT (3–12 month) and 55 patients on extended-duration AT (> 12 months). Results: Mean follow-up duration was 26 ± 18 (range 3–77) months; it was 24 ± 18 (range 3–69) months after cessation of AT in the limited-duration AT group. In comparison to patients with extended-duration AT, patients with limited-duration AT were younger (38 versus 54 years; p < 0.001), more often female (74 % versus 49 %; p = 0.01), and had less often prior venous thromboembolism (VTE) (9 % versus 35 %; p = 0.001). May-Thurner syndrome was more frequent in the limited-duration AT group (66 % versus 38 %; p = 0.004). Overall, primary and secondary patency rates at 24 months were 80 % (95 % CI, 70–87 %) and 95 % (95 % CI, 88–98 %), respectively, with no difference between the groups. Overall, 17 (15 %) patients developed recurrent VTE, of which 14 (82 %) events were thrombotic stent occlusions, and 13 (76 %) events occurred during AT. In the limited-duration AT group, 98 % patients were free from the PTS at two years with a VTE recurrence rate of 3.5 per 100 patient years after cessation of AT. Conclusions: In selected patients with acute IFDVT and patent venous stent, particularly in younger and otherwise healthy patients with May-Thurner syndrome, it appears to be safe to discontinue AT 3–12 months after endovascular treatment. Clinical Trial Registration: The study is registered on the National Institutes of Health website (ClinicalTrials.gov; identifier NCT02433054).

Cauda Equina Syndrome Caused by Epidural Venous Plexus Engorgement in a Patient with May-Thurner Syndrome

The purpose of this article is to present a case of cauda equina syndrome in a patient with incomplete motor and sensory deficits due to epidural venous plexus engorgement, owing to May-Thurner syndrome successfully treated with venous iliac stenting. A 40-year-old woman, with previous history of deep vein thrombosis and miscarriages, gradually developed right leg and back pain, with functional limitation, perineal hypoesthesia, and sphincter incontinence. Magnetic resonance imaging revealed epidural venous plexus engorgement and cauda equina roots involvement. Phlebography showed perimedullary venous enlargement and left common iliac vein stenosis, leading to the diagnosis of May-Thurner syndrome. Stenting of the left common iliac vein was performed resulting in pain improvement and disappearance of neurological symptoms. Thrombophilia study was positive to heterozygous factor V Leiden. Cauda equina syndrome as the first presentation of a May-Thurner syndrome is very rare. In this case, venous iliac stent placement was an effective and safe treatment.

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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Venoplasty and stenting in post-thrombotic syndrome and non-thrombotic iliac vein lesion

Introduction: Venous outflow obstruction is a common condition among patients with chronic venous insufficiency. Endovascular treatment is favourable over open surgery. This study aimed to assess stent patency and clinical outcome in venous outflow obstruction of lower limbs, and also to compare it between post-thrombotic syndrome and non-thrombotic iliac vein lesions.Material and methods: The study was a historical cohort study. Patients with chronic deep venous insufficiency referred to our tertiary referral centre who underwent venoplasty were recruited. Patients were divided into two groups: non-thrombotic-iliac-vein-lesions and post-thrombotic syndrome. Stent patency rate, clinical improvement and risk factors were evaluated during a six-months course after venoplasty.Results: One-hundred-sixty-four patients were included. Six-months primary, assisted primary and secondary patency rates were 98.86%, 100% and100% in the non-thrombotic-iliac-vein-lesions group and 88%, 93% and 96% in the post thrombotic syndrome groups (p-value = .005, p-value = .02, and p-value = .09, respectively). Pain, claudication and edema were the most common symptoms in both groups and significantly improved after six months. Early thrombosis in the PTS group was more common (9 vs. 1, P value = .007).Conclusion: Percutaneous stenting in patients with venous outflow obstruction is safe and effective with a high patency rate and significant decrease in clinical score in both post-thrombotic syndrome and non-thrombotic-iliac-vein lesions groups.