Magnetic resonance venography in the diagnosis and management of May-Thurner syndrome

Can cross-sectional imaging replace diagnostic venography in pelvic venous disorder (PeVD)?

OBJECTIVE

The primary etiology of pelvic venous disorder is multifactorial and challengeable in vascular surgery as it mandates multidisciplinary team cooperation for its evaluation and management.

METHODS

All patients investigated for pelvic venous disorder in a high-volume, tertiary referral university hospital were identified and analyzed retrospectively during the period (March 2021 through September 2022). Demographic and medical data were scored. Agreement between the noninvasive modalities (computed tomographic venography [CTV] or magnetic resonance venography [MRV]) and diagnostic venography in detecting the refluxing pelvic veins was analyzed. Sensitivity, specificity, and diagnostic accuracy are also measured. No patients' treatments were reported in this study as the treatment is scheduled in other sessions in some cases and is out of the scope of this article. All patients had a diagnostic venogram regardless of the axial imaging modality. The main goal was to compare cross-sectional imaging with diagnostic venography.

RESULTS

The total number of patients was 120 with a mean age of 34.4 ± 7.1 years; 86.7% were multiparous. All patients presented chronic pelvic pain with vulvoperineal and/or atypical lower limb varicosities. Then patients were divided into two groups: those with CTV and those with MRV. Sensitivity, specificity, and diagnostic accuracy of CTV were 50%, 33%, and 47% for the detection of incompetent ovarian veins, 83%, 33%, and 53% for the detection of incompetent internal iliac veins, and 50%, 40%, and 47% for the detection of incompetent pelvic plexus veins, respectively, whereas time-resolved MRV achieved sensitivity, specificity, and diagnostic accuracy of 73%, 25%, and 60% for the detection of incompetent ovarian veins, 75%, 46%, and 53% for the detection of incompetent internal iliac veins, and 67%, 33% and 60% for detection of incompetent pelvic plexus veins, respectively.

CONCLUSIONS

The desire to avoid the drawbacks of diagnostic venography led to an increase in the use of noninvasive imaging modalities. Our results achieved acceptable sensitivity, specificity, and diagnostic accuracy outcomes for cross-sectional imaging with the superiority of MRV over CTV in diagnosing PCS.

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.

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.

Varicose Veins and Chronic Venous Disease

Chronic venous disease is a worldwide problem associated with significant morbidity and is expected to increase in prevalence as the current population ages. This is a comprehensive review of the anatomy, pathophysiology, genomics, clinical classification, and treatment modalities of chronic venous disease.

Combined high-resolution 3D CUBE T1-weighted imaging and non-contrast-enhanced magnetic resonance venography for evaluation of vein stenosis in May-Thurner syndrome

PURPOSE

To explore the feasibility of high-resolution MRI 3-dimensional (3D) CUBE T1-weighted magnetic resonance imaging (MRI) in combination with non-contrast-enhanced (NCE) magnetic resonance venography (MRV) for the assessment of lumen stenosis in May-Thurner syndrome.

METHODS

Twenty-nine patients underwent computed tomography venography (CTV) and high-resolution MRI-CUBE T1, and NCE MRV acquisitions. ANOVA and LSD tests were used to compare the stenosis rate and narrowest and distal diameters of the vessel lumen.

RESULTS

There were no significant differences in the estimated stenosis rate between CTV, CUBE T1, and NCE MRV (p = 0.768). However, there were significant differences in the measured stenosis diameters of the left common iliac vein (LCIV), with CTV giving the largest mean diameter and CUBE had the smallest mean diameter (p < 0.05). The measured normal LCIV diameters did not significantly differ between MRV and CUBE (p = 0.075) but were significantly larger on CTV than on MRV and CUBE (p < 0.05).

CONCLUSIONS

Compared with CTV, a combination of CUBE and MRV could provide an improved assessment of the degree of lumen stenosis in May-Thurner syndrome and demonstrate acute thrombosis. MRI underestimates the diameter of the vessel in comparison with CTV. MRI can be a substitute tool for Duplex ultrasound and CTV.

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.

Non-enhanced multimodal magnetic resonance imaging in assessment of iliac vein obstruction with or without thrombosis

OBJECTIVE

To evaluate the diagnostic accuracy of a contrast-free multimodal magnetic resonance (MR) protocol (including M2DIPEAR, THRIVE, BTFE-SPAIR, and FLAIR sequences) in the detection of iliac vein obstruction with or without thrombosis.

MATERIALS AND METHODS

From May 1st, 2015, to May 1st, 2016, a total of 73 patients (aged 51.33 ± 4.21 years) who received both digital subtraction angiography (DSA) and the multimodal MR imaging were included. The protocol of the multimodal MR included M2DIPEAR and BTFE-SPAIR for presenting iliac vein obstruction, and THRIVE and FLAIR for revealing the co-existed thrombosis. Three observers who were blinded to clinical and DSA results independently analyzed all multimodal MR datasets. Per-patient evaluations on presence or absence of iliac vein obstruction were performed to calculate the diagnostic performance of MR imaging (DSA regarded as gold reference) in terms of overall accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). Capability to display the co-existing venous thrombus was also evaluated per-MR sequence using a 3-point scale system.

RESULTS

Iliac vein obstruction was depicted with DSA in 64 patients. In per-patient evaluation, the multimodal MR imaging yielded accuracy of 95.9% (70/73), sensitivity of 96.9% (62/64), specificity of 88.9% (8/9), positive predictive value of 98.4% (62/63), and negative predictive value of 80% (8/10), respectively. In the multimodal MR sequences, balanced turbo field echo-spectral attenuated inversion recovery (BTFE-SPAIR) sequence was superior to other sequences in depicting the iliac vein configuration, but fluid attenuated inversion recovery (FLAIR) and T1 high-resolution isovolumetric examination (THRIVE) seemed superior in detecting co-existing venous thrombosis.

CONCLUSIONS

M2DIPEAR and BTFE-SPAIR sequence can reveal iliac vein obstruction while THRIVE and FLAIR can detect the co-existed thrombosis. The proposed multimodal MR protocol can accurately depict the iliac vein obstruction and accurately detect the co-existing venous thrombosis comparable with that of DSA.

May-Thurner Syndrome, an Often Overlooked Cause of Deep Vein Thrombosis: A Case Report

Deep vein thrombosis (DVT) is a common medical condition, but the predisposing anatomical factors, which may be amenable to definitive treatment, are usually overlooked. Therefore, a high index of clinical suspicion is the key to early diagnosis. We report here one such case of May-Thurner syndrome (MTS) to raise awareness. MTS (also known as iliac vein compression syndrome) should be suspected in cases of extensive DVT of the leg, particularly involving the iliac vein on the left side. The prognosis is improved with thrombolysis followed by angioplasty and stent to address the venous stenosis.

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.

Imaging of Pelvic Venous Disorders (PeVD); Should Every Patient Get an MRI?

Pelvic venous disease (PeVD) is part of the broad differential diagnosis of chronic pelvic pain with a challenging diagnosis and clinical workup to identify those patients that are most likely to benefit from intervention. Ultrasound, MRI, CT, venography, and intravascular ultrasound can all provide information to aid in the diagnostic algorithm. The purpose of this article is to review imaging as a component of the outpatient workup of patients with chronic pelvic pain to guide appropriate understanding and use of imaging modalities to accurately identify patients suffering from PeVD. A favored approach is to begin with transabdominal sonography with selective use of MRI/MRV in specific patient populations.

Ilio-Femoral Deep Vein Thrombosis Secondary to May-Thurner Syndrome With Ipsilateral Lower Limb Arterio-Venous Graft In-Situ

Ilio-femoral deep vein thrombosis (DVT) is rare in patients with lower limb arterio-venous grafts due to a state of high blood flow. May-Thurner syndrome (MTS) is an anomaly where the left common iliac vein is compressed by the right common iliac artery. We present a rare case of ilio-femoral deep vein thrombosis in a patient with May-Thurner Syndrome and an underlying arteriovenous graft in-situ who presented with acute lower limb swelling. The patient underwent catheter-directed thrombolysis, pharmaco-mechanical thrombectomy, venoplasty and iliac vein stenting. Follow-up surveillance duplex ultrasound showed patency of the iliac vein stent and arteriovenous graft at 1-year postoperatively.

Relaxation-Enhanced Angiography without Contrast and Triggering (REACT) for pelvic MR venography in comparison to balanced gradient-echo and T2-weighted spin-echo techniques

RATIONALE AND OBJECTIVES

To evaluate the imaging capabilities of the REACT pulse sequence in pelvic venous vessels compared to conventional non-contrast pulse sequences.

MATERIALS AND METHODS

In addition to routine MRI venography, non-contrast enhanced REACT pulse sequence was performed in 4 healthy volunteers and 21 patients with suspected or known deep venous thrombosis and post thrombotic syndrome. Acquired images were independently interpreted by two MRI radiologists. The sequence performance was subjectively evaluated on a four-point scale regarding the delineation of small peripheral, midsize and large proximal venous vessels, the imaging of vascular pathologies, and the degradation due to artifacts. To evaluate statistical differences in diagnostic accuracy Friedman's test with Dunn's correction was used.

RESULTS

REACT depicted the peripheral veins superior to bTFE and T2-TSE with an average score of 3.39 compared to 2.33 in bTFE and 1.77 in T2-TSE. In midsize vessels REACT performed significantly better than T2-TSE (1.94) and bTFE (2.68) with a score of 3.64. For the large proximal vessels REACT (3.39), bTFE (3.33) and T2-TSE (3.56) performed equally without statistical difference. Visibility of venous pathologies was found to be equal between REACT (3.62), bTFE (3.51) and T2-TSE (3.52). The image degradation due to artifacts was rated best in T2-TSE (3.56), followed by REACT (3.39) and bTFE (3.33).

CONCLUSIONS

REACT is a promising tool for the visualization of the pelvic venous system using magnetic resonance imaging.

Correlation of venous symptoms with iliac vein stenosis on magnetic resonance imaging

OBJECTIVE

Magnetic resonance imaging (MRI) is used in patients with lower extremity venous disease to screen for iliac vein stenosis. The objective of the present study was to determine the prevalence of iliac vein stenosis and associated lower extremity venous symptoms in consecutive patients undergoing MRI of the pelvis.

METHODS

A retrospective study of all consecutive adult patients who had undergone MRI of the pelvis for various indications from March 2012 to June 2016 was performed. The electronic medical records (EMRs) were reviewed for patient characteristics and, specifically, for the presence and laterality of venous symptoms. All MRI scans were reviewed, and the maximal degree of iliac vein stenosis was recorded. All the patients also responded to a brief telephone survey inquiring about the presence of venous symptoms. Two thresholds of venous stenosis, ≥50% and ≥70%, were used to correlate its presence with the presence of venous symptoms determined from the EMR review and telephone survey results.

RESULTS

A total of 120 patients were included, with a mean age of 53 ± 14 years; 79% were women and 79% were white. The prevalence of iliac vein stenosis ≥50% was significantly greater on the left than on the right (34.2% vs 16.7%; P < .001). The survey demonstrated that 44 of the 120 patients (36.7%) had had venous symptoms compared with only 30 patients (25%) according to the EMR review (P = .001). No differences were found between patients with positive vs negative survey results for venous symptoms and the occurrence of iliac vein stenosis ≥50% on the right (17.2% vs 15.2%; P = .78) or the left (38% vs 26.8%; P = .22). We also found no differences when the occurrence of iliac vein stenosis ≥70% was used as threshold between the right (2.3% vs 3%; P = .99) and the left (10.1% vs 2.4%; P = .16). Analysis of the venous symptoms from the EMR review yielded similar results.

CONCLUSIONS

In our study, iliac vein stenosis was more common on the left and was encountered in up to one third of patients who had undergone MRI of the pelvis. No correlation was found in our study between the presence of iliac vein stenosis and the occurrence of ipsilateral venous symptoms. Venous symptoms were underreported in the EMRs. Further studies are necessary to identify the predictors of pathologic iliac vein stenosis.

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.

May-Thurner Syndrome: A Neglected Cause of Unilateral Leg Swelling

May-Thurner syndrome (MTS) is a clinical condition characterized by the compression of the left iliac vein by the right iliac artery. This condition predisposes the patient to deep venous thrombosis (DVT). We present the case of a 30-year-old female who arrived at the emergency department of our facility with progressive left leg swelling for four weeks, with low-risk probability for DVT. Examination revealed left leg swelling with pitting edema extending up to the knee. Her calf muscle was tender to palpation. Dorsalis pedis, anterior tibial, and posterior tibial pulsations were fairly palpable due to the edema; however, the rest of her pulsations were appropriately felt. Therefore, the provisional diagnosis of possible DVT was made, and further investigations were requested. We present this case intending to highlight the clinical presentation of May-Thurner syndrome, its diagnosis, and treatment.

Magnetic Resonance Imaging Evaluation of Left Common Iliac Vein Compression in Patients With and Without Symptoms of Venous Disease

BACKGROUND

The goal of this study was to assess the degree of the left common iliac vein (LCIV) compression by the right common iliac artery (RCIA) on magnetic resonance imaging (MRI), and verify differences in compression measurements in end-inspiration, end-expiration, supine, and prone decubitus between patients with and without symptoms in the lower limbs.Methods and Results:A total of 82 consecutive participants provided informed consent and underwent pelvic MRI for different clinical indications other than vascular-related disorders. The participants answered a questionnaire about venous disease in the lower limbs and history of previous deep vein thrombosis. This study measured the area and diameter of the LCIV at the site of the crossing with the RCIA and in the uncompressed caudal LCIV segment. Statistical analysis was performed to compare the degree of LCIV compression by the RCIA and verify differences in compression measurements. A total of 71 participants were included; 46.6% were in group A and did not experience signs and symptoms in lower limbs and 53.6% were in group B and answered at least one question with a positive answer. It was observed that there was a statistically significant difference between groups for end-expiration. No statistically significant differences were observed for all other measurements.

CONCLUSIONS

A substantial percentage of the asymptomatic and symptomatic population showed compression of the LCIV, suggesting there are no clear relationships between stenosis and non-specific symptomatology in the general population.

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.

May-Thurner syndrome: History of understanding and need for defining population prevalence

Patients with May-Thurner syndrome (MTS) are at elevated risk of developing an extensive left iliofemoral deep vein thrombosis (DVT; localized blood clot) due to an anatomical variant where the right common iliac artery compresses the left common iliac vein against the lumbar spine. While MTS was initially presumed to be rare when it was first anatomically defined in 1957, case reports of this syndrome have recently become more frequent, perhaps due to improved imaging techniques allowing for enhanced visualization of the iliac veins. Still, the population burden of this condition is unknown, and there is speculation it may be higher than generally perceived. In the present review, we (a) review history of how MTS became recognized, (b) describe practical challenges of studying MTS in population-based settings due to the specialized imaging required for diagnosis, (c) discuss why the contribution of MTS to DVT may be underestimated, (d) describe uncertainty regarding the degree of venous compression which leads to DVT, and (e) outline future research needs. Our goal is to raise awareness of MTS and spark additional research into the epidemiology of this condition, which may be an underappreciated causative venous thromboembolism risk factor.

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.

Surgical aspects of venous pelvic pain treatment

This review presents modern information on the anatomy of pelvic veins, mechanisms of development of pelvic congestion syndrome (PCS) and venous pelvic pain (VPP), methods for verifying the venous nature of pelvic pain, as well as opportunities of various surgical interventions on the gonadal veins in treatment of PCS and relief of its most severe symptom, VPP. A comparative analysis of resection and embolization treatment methods and their effects on VPP, as well as rates of postprocedural complications, was carried out. The issues of elimination of specific compression syndromes causing occurrence of VPP, by using open, endoscopic and endovascular techniques are addressed.

Automated Quantitative Imaging Measurements of Disease Severity in Patients with Nonthrombotic Iliac Vein Compression

PURPOSE

An automated segmentation technique (AST) for computed tomography (CT) venography was developed to quantify measures of disease severity before and after stent placement in patients with left-sided nonthrombotic iliac vein compression.

MATERIALS AND METHODS

Twenty-one patients with left-sided nonthrombotic iliac vein compression who underwent venous stent placement were retrospectively identified. Pre- and poststent CT venography studies were quantitatively analyzed using an AST to determine leg volume, skin thickness, and water content of fat. These measures were compared between diseased and nondiseased limbs and between pre- and poststent images, using patients as their own controls. Additionally, patients with and without postthrombotic lesions were compared.

RESULTS

The AST detected significantly increased leg volume (12,437 cm³ vs 10,748 cm³, P < .0001), skin thickness (0.531 cm vs 0.508 cm, P < .0001), and water content of fat (8.2% vs 5.0%, P < .0001) in diseased left limbs compared with the contralateral nondiseased limbs, on prestent imaging. After stent placement in the left leg, there was a significant decrease in the water content of fat in the right (4.9% vs 2.7%, P < .0001) and left (8.2% vs 3.2%, P < .0001) legs. There were no significant changes in leg volume or skin thickness in either leg after stent placement. There were no significant differences between patients with or without postthrombotic lesions in their poststent improvement across the 3 measures of disease severity.

CONCLUSIONS

ASTs can be used to quantify measures of disease severity and postintervention changes on CT venography for patients with lower extremity venous disease. Further investigation may clarify the clinical benefit of such technologies.

The influence of May-Thurner syndrome on post-thrombotic syndrome in young women

Summary. Background: The mechanism for post-thrombotic syndrome (PTS), the most important long-term sequelae of deep venous thrombosis, is not entirely known. It is probably caused by venous hypertension due to venous insufficiency and venous obstruction. Venous hypertension could also be a consequence of the May-Thurner syndrome (MTS), i.e. the obstruction of the common iliac vein. The aim of the present study was to explore if women with untreated MTS and a history of proximal DVT develop PTS more frequently. Patients and methods: A cohort of 68 female patients with a history of proximal left-sided DVT in the past were evaluated. According to Villalta score, they were segregated in two groups – with and without PTS (Villalta score ≥ 5 or < 5 points, respectively). For the diagnosis of MTS, magnetic resonance venography was performed. Results: Out of 68 patients, 25 developed PTS (36.8 %). Recurrent DVT, older age, pre-existent chronic venous insufficiency, and shorter compression stockings wearing time were statistically related to PTS. Deep and superficial valve incompetence was also significantly related to PTS, while incomplete thrombus removal showed only a trend towards PTS development. On the other hand, MTS per se turned out not to be linked to PTS. Conclusions: Our study suggests that women with MTS might not develop PTS more often, which puts aggressive treatment of MTS under question. More clinical trials are warranted to further examine this yet not fully explained field.

May-Thurner Syndrome with Large Abdominal Varicosity, Treated Successfully Using Multiple Approaches

May-Thurner syndrome (MTS) is a venous outflow obstruction disorder characterized by compression of the left common iliac vein by an overriding right common iliac artery. MTS primarily affects young to middle-aged women, although many patients remain entirely asymptomatic. Anatomic variations of MTS, while uncommon, have been described. Treatment usually involves endovascular management, including thrombolysis and/or thrombectomy with or without inferior vena cava filter placement, followed by angioplasty and stenting of the left common iliac vein. We report a unique case of a 31-year-old woman who presented with MTS-related deep vein thrombosis accompanied by symptomatic abdominal and pelvic varicosities. The varicosities were treated successfully using multiple procedures, resulting in complete resolution of all symptoms. Our case discusses a treatment approach for an unusual presentation of MTS-related postthrombotic syndrome, and provides a brief literature review of MTS complications and management.

Occult Left Common Iliac Vein Compression Increases Postoperative Venous Thromboembolism Risk Following Total Hip Arthroplasty

BACKGROUND

Left common iliac vein (LCIV) compression by the right or left common iliac artery (RCIA, LCIA) is known to cause venous thromboembolism (VTE), but the extent to which occult LCIV compression synergizes with lower extremity orthopedic surgery is unknown. We hypothesize that occult LCIV compression is associated with increased VTE risk following total hip or knee arthroplasty (THA, TKA).

METHODS

This case-control study involves all patients at our institution who underwent primary or revision THA or TKA from 2009 to 2017 who had computed tomography or magnetic resonance imaging of the abdomen or pelvis available preoperatively. VTE cases (pulmonary embolism or left-sided deep vein thrombosis) within 30 days of surgery were matched to a control by age, gender, body mass index, Charlson Comorbidity Index, surgical site, and hypercoagulable risk factors. LCIV compression by the right common iliac artery and/or the left common iliac artery was measured in a blinded fashion and was considered present at 50% diameter reduction.

RESULTS

One hundred twelve patients (22 cases, 90 controls) were included for analysis. Nineteen (86.4%) cases and 46 (51.1%) controls demonstrated LCIV compression. The overall sample odds ratio of postoperative VTE in the presence of LCIV compression was 5.97 (95% confidence interval 1.59-33.67, P = .003). In patients who underwent THA (n = 75), LCIV compression was highly predictive of VTE (odds ratio ∞, 95% confidence interval 2.83-∞, P < .001). Compression in the TKA patients did not significantly predict VTE.

CONCLUSION

Compression of the LCIV significantly increases odds of developing postoperative VTE following THA. This effect may suggest a new method of stratifying VTE risk in the orthopedic population to reduce VTE-associated morbidity and mortality.

May-Thurner Syndrome: A Rare Cause of Deep Venous Thrombosis

May-Thurner syndrome (MTS) is a medical condition where the left iliac vein is compressed by the right iliac artery, which in turn predisposes patients to deep venous thrombosis (DVT). We present a case of a 67-year-old female who had pain and swelling of the left leg. Ultrasound of the deep veins of the leg revealed DVT of the distal external iliac vein. She was treated with catheter-directed thrombolysis and stent placement. Finally, she was discharged on long-term anticoagulation with warfarin. The purpose of presenting this case is to highlight the clinical presentation, diagnosis, and treatment of MTS.

Iliac Vein Compression Syndrome in an Asymptomatic Patient Population: A Prospective Study

BACKGROUND

Iliac vein compression syndrome (IVCS) is an important cause of deep vein thrombosis, but the incidence of IVCS is still unclear. The purpose of this prospective study was to determine the incidence of IVCS in an asymptomatic patient population and to evaluate the risk factors in patients with and without IVCS.

METHODS

From October 2011 to November 2012, a total of 500 patients (228 women and 272 men; mean age of 55.4 ± 14.7 years) with no vascular-related symptoms were enrolled in this study. Computed tomography was performed to evaluate all patients. The degree of venous compression was calculated as the diameter of the common iliac vein at the site of maximal compression divided by the mean diameter of the uncompressed proximal and caudal left common iliac vein (LCIV). We compared the stenosis rate of the common iliac vein in women and men according to age and followed up patients to evaluate outcomes.

RESULTS

The mean compression degree of the LCIV was 16% (4%, 36%); 37.8% of patients had a compression degree ≥25% and 9.8% had a compression degree ≥50%. There was a significant difference between men and women in the LCIV compression degree (9% [3%, 30%] vs. 24% [8%, 42%]; U = 4.66, P< 0.01). In addition, the LCIV compression degree among younger women (≤40 years) was significantly different compared with that in older women (>40 years) (42% [31%, 50%] vs. 19% [5%, 39%]; U = 5.14, P< 0.001). Follow-up was completed in 367 patients with a mean follow-up of 39.5 months (range, 6-56 months). The incidence of IVCS in the follow-up period was 1.6%. Stenosis rate and the diameter of the site of maximal compression correlated with the incidence of IVCS. Multivariable Cox regression analysis showed that the stenosis rate was an independent risk factor of IVCS (Wald χ2 = 8.84, hazard ratio = 1.13, P< 0.001).

CONCLUSIONS

The incidence of IVCS was low and correlated with the stenosis rate of iliac vein. Preventative therapy may be warranted for common iliac vein compression in patients at an increased risk of venous thromboembolism, especially patients with a higher iliac vein compression degree.

Variant May-Thurner syndrome: Compression of the left common iliac vein by the ipsilateral internal iliac artery

May Thurner syndrome (MTS) is an anatomic variant that can present as acute or chronic deep vein thrombosis. Although it is classically reported in young and middle-aged women, it is also seen in both young and older men. Multiple cases of anatomic variations of MTS have been described. We present an uncommon case of variant MTS, including diagnostic imaging and approach to treatment.

Midterm Results of Endovascular Treatment for Iliac Vein Compression Syndrome from a Single Center

BACKGROUND

The efficacy of endovascular interventional treatment for iliac vein compression syndrome (IVCS) is not well studied. The purpose of our study was to investigate the clinical outcome of endovascular interventional treatment for IVCS.

METHODS

Data of 68 patients with IVCS, who underwent interventional treatment in our hospital, were analyzed retrospectively. Among these patients, 46 had lower extremity varicose veins. Sixty-five patients underwent stent implantation, and 3 patients underwent simple balloon angioplasty. Fourteen patients had post-thrombotic syndrome (PTS) and 11 patients had acute deep venous thrombosis (DVT). Among these 14 patients with PTS, 12 underwent stent implantation and 2 underwent iliac venous simple balloon angioplasty. On the other hand, 9 of the 11 patients with DVT underwent catheter-directed thrombolysis (CDT) and then stent implantation. Of the remaining 2 patients, one underwent Angiojet Rheolytic thrombectomy (ART) before CDT and the other underwent CDT with simple balloon angioplasty. The stenosis rate of iliac vein and the circumference differences between the affected limb and healthy one were measured before and after operation. These patients were followed up with duplex ultrasound postoperatively.

RESULTS

A total of 75 stents were placed in 65 patients. The diameter and the length of stent were 6 to 14 mm (mean 12.5 ± 2.0 mm) and 40 to 260 mm (mean 82.5 ± 36.9 mm), respectively. CDT with/without ART was performed, using urokinase and/or alteplase, after inferior vena cava filtration in all of 11 patients with DVT, without the recurrence of pulmonary embolism. The difference in iliac venous stenosis was statistically significant ([91.2% ± 8.4%] [70.0% ∼ 100.0%] vs. 3.9% ± 13.0% [0 ∼ 70.0%], P < 0.01). The patency rates at 1-, 3-, 6- months, 1 year, and 2 years were 98.5%, 95.6%, 94.1%, 92.4%, and 90.7%, respectively. Four patients (5.9%) suffered from minor bleeding at puncture point and were successfully treated with compression. However, 1 (1.5%) patient underwent stent implantation of right iliac vein that became complicated due to migration of stent to the right ventricle which was successfully arrested by Amplatz Goose Neck Snare Kit. The incidence of PTS was 10.3% (7/68) during the follow-up at 1 to 24 (mean 18.2 ± 7.7) months.

CONCLUSIONS

Interventional therapy for patients of IVCS is safe and effective. Satisfactory outcomes were obtained for stent placement for IVCS.

Incidence and Risk Factors of Deep Venous Thrombosis in Asymptomatic Iliac Vein Compression: A Prospective Cohort Study

BACKGROUND

Deep vein thrombosis (DVT) may be associated with iliac vein compression. Up to now, the majority of data has come from a retrospective study about the correlation between DVT and iliac vein compression. This prospective study was to determine the incidence of DVT in individuals with iliac vein compression and identify risk factors predictive of DVT.

METHODS

A total of 500 volunteers without symptoms of venous diseases of lower extremities and overt risk factors of deep venous thrombosis between October 2011 and September 2012 in Shijitan Hospital were enrolled in this cohort study. All the participants underwent contrast-enhanced abdominal computed tomography (CT) to evaluate iliac vein compression. Baseline demographic information and degree of iliac vein compression were collected. They were categorized into ≥50% or <50% iliac vein compression group. Ultrasound examination was performed to screen DVT at the time of CT examination and 3, 6, 9, and 12 months after the examination. Primary event was DVT of ipsilateral lower extremity. Correlation between DVT and iliac vein compression was estimated by multivariate Logistic regression after adjusting for age, gender, malignancy, surgery/immobilization, chemotherapy/hormonal therapy, and pregnancy.

RESULTS

In 500 volunteers, 8.8% (44) had ≥50% iliac vein compression and 91.2% (456) had <50% iliac vein compression. Ipsilateral DVT occurred in six volunteers including two in iliofemoral vein, two in popliteal vein, and two in calf vein within 1 year. Univariate analysis showed that the incidence of DVT was 6.8% in ≥50% compression group, significantly higher than that in <50% compression group (0.7%) (χ2 = 12.84, P = 0.01). Patients with malignancy had significantly higher incidence of DVT than those without malignancy (χ2 = 69.60,P< 0.01). Multivariate Logistic regression indicated that iliac vein compression and malignancy were independent risk factors of DVT. After adjustment for malignancy, patients with ≥50% iliac vein compression had 10-fold increased risk of developing DVT (adjusted relative risk [RR] = 10.162, 95% confidence interval [CI]: 1.149-89.865, P = 0.037). In subgroup analysis, patients with malignancy and ≥50% iliac vein compression had 12-fold increased the risk of DVT than those without malignance and ≥50% compression (RR = 12.389, 95% CI: 2.327-65.957, P = 0.003).

CONCLUSIONS

Iliac vein compression is common, but the incidence of DVT is low. Only individuals with ≥50% iliac vein compression or compression combined with other risk factors might have significantly increased the risk of DVT. Further study is recommended to improve prevention strategies for DVT in significant iliac vein compression.

Venous Compression Syndromes: a Review

OPINION STATEMENT

Venous compression syndromes present a diagnostic and therapeutic challenge as the clinical presentation can be vague, diagnostic criteria are often not present, and high quality standardization of when and how to treat is not available in part due to the limited number of cases reported and also due to the limited literature available. Significant venous compression should be considered when clinical symptoms correlate to location of compression and there is evidence of hemodynamic changes including venous hypertension, collateral/variceal formation, and/or thrombus formation. In general, treatment of venous compression should address the etiology of the compression as opposed to just treating symptoms associated with it such as significant varices or anticoagulation for thrombus to avoid recurrence of symptoms.

Blood pool contrast agents for venous magnetic resonance imaging

Imaging of the venous system plays a vital role in the diagnosis and management of a wide range of clinically significant disorders. There have been great advances in venous imaging techniques, culminating in the use of magnetic resonance venography (MRV). Although MRV has distinct advantages in anatomic and quantitative cross sectional imaging without ionizing radiation, there are well-known challenges in acquisition timing and contrast administration in patients with renal impairment. The latest advancement involves the addition of new contrast media agents, which have emerged as valuable alternatives in these difficult scenarios. In this review, we will focus on a group of specific contrast agents called blood pool agents and discuss their salient features and clinical applications.

Diagnosis and Treatment of Lower Extremity Deep Vein Thrombosis: Korean Practice Guidelines

Lower extremity deep vein thrombosis is a serious medical condition that can result in death or major disability due to pulmonary embolism or post-thrombotic syndrome. Appropriate diagnosis and treatment are required to improve symptoms and salvage the affected limb. Early thrombus clearance rapidly resolves symptoms related to venous obstruction, restores valve function and reduces the incidence of post-thrombotic syndrome. Recently, endovascular treatment has been established as a standard method for early thrombus removal. However, there are a variety of views regarding the indications and procedures among medical institutions and operators. Therefore, we intend to provide evidence-based guidelines for diagnosis and treatment of lower extremity deep vein thrombosis by multidisciplinary consensus. These guidelines are the result of a close collaboration between interventional radiologists and vascular surgeons. The goals of these guidelines are to improve treatment, to serve as a guide to the clinician, and consequently to contribute to public health care.

May-Thurner syndrome and iliac arteriovenous fistula in an elderly woman

May-Thurner syndrome most commonly involves compression of the left common iliac vein by the right common iliac artery and can result in leg pain and swelling as well as potentially precipitate deep venous thrombosis. These symptoms can be exacerbated by additional vascular abnormalities. This is a case report of a 91-year-old woman with intractable massive left lower extremity edema that interfered with walking. She was diagnosed with concurrent May-Thurner syndrome and pelvic arteriovenous fistula. Treatment with embolization of the fistula and stenting of the left common iliac vein relieved her symptoms and allowed her to walk again.

Right-sided Cockett's syndrome

Background Cockett and Thomas described and named Cockett's syndrome in 1965, commonly referred to as iliac vein compression syndrome (IVCS). It is often found as underlying cause in iliofemoral deep venous thrombosis (DVT). They described the syndrome mostly seen on the left side and predominantly in women during the second to the fourth decade of life. In this article, we present a patient with a Cockett's syndrome on the right side. Case presentation Our patient is a 52-year old female with edema of the right leg since 4 months. She had no signs of a DVT and did not benefit from a 3-month compression therapy. She was diagnosed using a CT-scan. Endovascular treatment was performed with a venous stent in the right common iliac vein (CIV). No postoperative complications were seen. After a 6-month follow-up, patient was free of pain and had no residual edema of the right leg. Conclusions Our patient presented with a non-complicated right-sided Cockett's syndrome. She was successfully treated with balloon dilatation and additional stenting of the right common iliac vein. Because of the clinical improvement of the patient together with the excellent long-term results and good patency results of the stenting, guidelines nowadays advise more and more venous stenting to prevent DVT and to relieve symptoms in case of vein compression syndromes.

Optimal diagnostics of residual stenosis after lysis

The treatment of acute deep vein thrombosis has developed significantly over the past few years, and catheter-directed thrombolysis is now widely accepted. Controversy still exists over the decision to treat residual or underlying lesions with a venous stent. Magnetic resonance techniques have evolved considerably, which together with intravenous ultrasound can provide a detailed assessment of the deep venous system. Nevertheless, there is still no single perfect imaging modality that can identify a functional stenosis in the venous system. The decision to proceed to stent placement following lysis is multifactorial, reliant on the use of a number of imaging modalities in combination but most importantly good clinical acumen and experience.

Iliac vein compression syndrome: Clinical, imaging and pathologic findings

May-Thurner syndrome (MTS) is the pathologic compression of the left common iliac vein by the right common iliac artery, resulting in left lower extremity pain, swelling, and deep venous thrombosis. Though this syndrome was first described in 1851, there are currently no standardized criteria to establish the diagnosis of MTS. Since MTS is treated by a wide array of specialties, including interventional radiology, vascular surgery, cardiology, and vascular medicine, the need for an established diagnostic criterion is imperative in order to reduce misdiagnosis and inappropriate treatment. Although MTS has historically been diagnosed by the presence of pathologic features, the use of dynamic imaging techniques has led to a more radiologic based diagnosis. Thus, imaging plays an integral part in screening patients for MTS, and the utility of a wide array of imaging modalities has been evaluated. Here, we summarize the historical aspects of the clinical features of this syndrome. We then provide a comprehensive assessment of the literature on the efficacy of imaging tools available to diagnose MTS. Lastly, we provide clinical pearls and recommendations to aid physicians in diagnosing the syndrome through the use of provocative measures.

Nonhealing Venous Ulcers and Chronic Venous Outflow Obstruction A Case Report

The etiology of chronic venous insufficiency is typically neglected or misunderstood when treating lower-extremity edema and venous ulcerations. Despite the high prevalence of venous compression syndromes, it is rarely considered when treating venous ulcers and unresolved venous disease. We report a case of bilateral iliac vein outflow obstruction that prohibited venous ulcer healing until properly treated. This case highlights the importance of properly identifying and treating venous compression syndromes to enhance ulcer healing and decrease the risk of venous ulcer recurrence.

Magnetic Resonance Imaging in Proximal Venous Outflow Obstruction

BACKGROUND

Proximal venous outflow obstruction (PVOO) in the abdomen and pelvis is increasingly recognized as an important contributor to venous disease of the lower extremity. There are currently no guidelines regarding a noninvasive screening tool for PVOO, although magnetic resonance venography (MRV) is commonly used in many practices. The objective of this study was to determine the value and utility of MRV in diagnosis and screening for PVOO.

METHODS

This retrospective study consisted of 46 consecutive patients, all of whom presented with signs and/or symptoms of PVOO and were evaluated with MRV followed by intravascular ultrasound (IVUS) and venography. Of these 46 patients suspected to have PVOO based on clinical evaluation, 24 patients had PVOO confirmed with IVUS and venography and PVOO was not observed on IVUS and venography in the remaining 22 patients. The MRV of these 46 patients was retrospectively reviewed in a blinded fashion and then correlated with IVUS and venography by 1 vascular surgeon. A scoring system was developed to define the types of radiography findings that were observed: normal, suspicious, and abnormal.

RESULTS

When compared with IVUS and multiplane venography, the interpretation of MRV had a sensitivity of 100% and a specificity of 22.7%. The positive predictive value of MRV was 58.5%, and the negative predictive value was 100%.

CONCLUSIONS

The high sensitivity (100%) and low specificity (22.7%) of MRV suggest that it can be a screening tool at best, used only to rule out PVOO; it cannot be used to confirm PVOO, given its a 41.5% false positive rate. Thus, the development of a different, noninvasive diagnostic test that can more accurately assess patients with suspected PVOO during the initial evaluation of their lower-extremity venous disease should be explored.

Algorithm-based approach to management of venous leg ulceration

Management of venous ulceration has evolved tremendously during the last 2 decades. There has been considerable progress in our understanding of the pathophysiology, hemodynamics, venous imaging, and therapeutic options for venous ulcers, including endovenous ablation, iliac vein stenting, and vein-valve repair techniques. Details of these procedures are described in this issue of Seminars. With so many permutations and combinations of venous disease, including superficial and deep vein abnormalities, that produce venous ulceration, as well as a plethora of diagnostic and therapeutic tools at our disposal, it is important to have an algorithm for venous ulcer management. Also important is knowledge about risk factors that can influence poor outcomes, despite interventions for venous ulcers. In the end, authors also discuss the gray areas of venous ulcer management, which do not have common consensus and that treatment could be individualized based on patient needs.

Iliac vein compression syndrome: literature review

Iliac vein compression syndrome is a clinical condition in which the right common iliac artery extrinsically compresses the left common iliac vein. The syndrome predominantly affects young women between their 2nd and 4th decades of life. In view of the syndrome's potential complications, it should be recognized/diagnosed and treated in symptomatic patients before it causes irreversible damage to patients' venous systems. Noninvasive methods, such as venous color Doppler US are reasonable screening methods, but angiotomography and magnetic resonance angiography are more reliable diagnostic tools and the method of choice for confirmation of diagnosis remains multi-plane phlebography with measurement of pressure gradients. Endovascular treatment (angioplasty with placement of self-expanding stents) is safe and effective and can replace open surgical reconstruction and/or anticoagulation alone.

Multidetector CT of vascular compression syndromes in the abdomen and pelvis

Certain abdominopelvic vascular structures may be compressed by adjacent anatomic structures or may cause compression of adjacent hollow viscera. Such compressions may be asymptomatic; when symptomatic, however, they can lead to a variety of uncommon syndromes in the abdomen and pelvis, including median arcuate ligament syndrome, May-Thurner syndrome, nutcracker syndrome, superior mesenteric artery syndrome, ureteropelvic junction obstruction, ovarian vein syndrome, and other forms of ureteral compression. These syndromes, the pathogenesis of some of which remains controversial, can result in nonspecific symptoms of epigastric or flank pain, weight loss, nausea and vomiting, hematuria, or urinary tract infection. Direct venography or duplex ultrasonography can provide hemodynamic information in cases of vascular compression. However, multidetector computed tomography is particularly useful in that it allows a comprehensive single-study evaluation of the anatomy and resultant morphologic changes. Anatomic findings that can predispose to these syndromes may be encountered in patients who are undergoing imaging for unrelated reasons. However, the diagnosis of these syndromes should not be made on the basis of imaging findings alone. Severely symptomatic patients require treatment, which is generally surgical, although endovascular techniques are increasingly being used to treat venous compressions.