Iliac vein compression: epidemiology, diagnosis and treatment

A comprehensive study on venous endovascular management and stenting in deep veins occlusion and stenosis: A review study

Background

Patients with deep venous disease can be classified into two distinct categories: those with disease resulting from known deep vein thrombosis (DVT), which may subsequently lead to post-thrombotic syndrome (PTS), and those with disease caused by compressive factors or non-thrombotic iliac vein lesions (NIVL). The major factor causing the symptoms in patients with PTS and NIVL is venous hypertension which happens due to venous stenosis or venous obstruction. Nowadays Venous stenting offers a noninvasive approach for treatment of NIVL and PTS demonstrating high patency rate.

Methods

We comprehensively reviewed relevant published papers from 2008 to 2023 that surveyed various influencing factors including the site of occlusion and etiology of occlusions, proper diagnostic imaging, ideal characteristics of venous stents, different dedicated venous stents, pre-operative, concomitant, and post-operative interventions and factors that challenge stenting in both PTS and NIVL patients. The papers were identified by searching the keywords "venous stenting", "PTS", "NIVL", "occlusion", and "stenosis" in PubMed central library MEDLINE and Google Scholar.

Results

Patency rates, post-stent complications, and relevant data according to the patient's quality of life were included and analyzed from 476 identified studies. There is no validated protocol and guideline for using stents in patients with PTS and NIVL.

Conclusion

As there is no validated protocol and guideline for using stents in patients with PTS and NIVL, our study may provide comprehensive information to assist researchers interested in writing the protocol and give them insight.

Surgical anteriorization of the left common iliac vein results in improved venous outflow and quality of life for May-Thurner syndrome

May-Thurner syndrome or left iliac vein compression occurs when the left common iliac vein is compressed by the right common iliac artery, leading to venous outflow obstruction. This obstruction can cause venous hypertension, resulting in lower extremity swelling, discoloration, pelvic congestion, and venous ulcerations. The standard surgical treatment of May-Thurner syndrome is endovascular venous stent placement. In a small, single-center sample, surgical anteriorization of the left common iliac vein was used to treat symptomatic left common iliac vein compression in younger patients, alleviating their symptoms, and can be considered an alternative treatment.

Venous Stasis Ulceration due to Massive Splenomegaly Causing Iliac Vein Compression From Secondary Myelofibrosis

Venous stasis ulcers are nonhealing lesions due to venous hypertension secondary to valvular dysfunction or deep venous outflow obstruction. We describe a case of a 71-year-old male with a history of polycythemia vera, secondary myelofibrosis, and massive splenomegaly up to 38 cm who presented with chronic, perimalleolar venous stasis ulcers and pain on the left lower extremity. CT showed significant compression of the left common iliac vein due to mass effect from the spleen. He was managed medically while being evaluated for partial splenic artery embolization but expired due to other chronic conditions before any intervention could be performed. Partial splenic artery embolization may be considered as a treatment option for patients with symptomatic iliac vein compression due to massive splenomegaly secondary to myelofibrosis, as long as extramedullary hematopoiesis is not compromised.

Race differences in iliofemoral vein stenting for chronic venous insufficiency

INTRODUCTION

Major disparities in outcomes by race are present throughout vascular surgery, yet little has been published on iliac vein stent outcomes by race. This retrospective study assessed iliac vein stent outcomes by patient race.

METHODS

Patients who underwent iliac vein stenting at a single institution for chronic venous insufficiency (CVI) from 2011 to 2021 were reviewed. Demographic, preoperative, perioperative, and postoperative data were collected. Self-reported race groups included Asian, Black, Hispanic, and White. Univariate differences were analyzed using χ2 tests for categorical variables and 1-way ANOVA for continuous variables. Outcomes included change in Venous Clinical Severity Score (VCSS) at interval timepoints relative to a preoperative baseline and reinterventions. Logistic regression models were used to determine the unadjusted and adjusted odds ratio (OR) of any minor and major reintervention. Multivariate regression models controlled for demographic and comorbidity characteristics.

RESULTS

A total of 827 patients were included. Asian patients were younger and had a greater proportion of male patients, lower Body mass index (BMI), less smoking history, and fewer comorbidities. White patients were more likely to have a history of deep vein thrombosis (DVT). White patients presented with the most severe CVI symptoms as defined by both Clinical-Etiological-Anatomical-Pathophysiological (CEAP) classification and preoperative VCSS composite scores. There were no differences in acute DVT, number of stents deployed, and bilateral versus unilateral stent placement. Black patients had the longest average days of follow-up, followed sequentially by Hispanic, White, and Asian. Black patients had the most reinterventions, while Asian patients had the fewest. Asian patients were less likely to have a major reintervention. No differences in VCSS composite or change in VCSS were observed.

CONCLUSIONS

In patients with CVI, Asian patients presented younger and healthier, while White patients presented with the most severe symptoms. No differences were observed in VCSS outcomes, though Black patients had the most reinterventions.

Intravascular Ultrasound Use in Peripheral Arterial and Deep Venous Interventions: Multidisciplinary Expert Opinion From SCAI/AVF/AVLS/SIR/SVM/SVS

Percutaneous revascularization is the primary strategy for treating lower extremity venous and arterial disease. Angiography is limited by its ability to accurately size vessels, precisely determine the degree of stenosis and length of lesions, characterize lesion morphology, or correctly diagnose postintervention complications. These limitations are overcome with use of intravascular ultrasound (IVUS). IVUS has demonstrated the ability to improve outcomes following percutaneous coronary intervention, and there is increasing evidence to support its benefits in the setting of peripheral vascular intervention. At this stage in its evolution, there remains a need to standardize the use and approach to peripheral vascular IVUS imaging. This manuscript represents considerations and consensus perspectives that emerged from a roundtable discussion including 15 physicians with expertise in interventional cardiology, interventional radiology, and vascular surgery, representing 6 cardiovascular specialty societies, held on February 3, 2023. The roundtable's aims were to assess the current state of lower extremity revascularization, identify knowledge gaps and need for evidence, and determine how IVUS can improve care and outcomes for patients with peripheral arterial and deep venous pathology.

Clinical Outcomes at 3 Years After Stenting for Thrombotic and Non-thrombotic Iliac Vein Compression Syndrome Patients

Iliac vein stenting for the treatment of iliac vein compression syndrome (IVCS) has been gradually developed. This article investigated the long-term patency and improvement of clinical symptoms after endovascular stenting for iliac vein obstruction patients. From 2020 to 2022, 83 patients at a single institution with IVCS underwent venous stent implantation and were divided into two groups: non-thrombotic IVCS (n = 55) and thrombotic IVCS (n = 28). The main stent-related outcomes include technical success, long-term patency, and thrombotic events. The technical success rate of all stent implantation was 100%. The mean length of hospital stay and cost were higher in the thrombotic IVCS group than in the non-thrombotic ICVS group, as well as the length of diseased vessel segment and the number of stents implanted were higher than in the control non-thrombotic group. The 1-, 2-, and 3-year patency rates were 85.4%, 80% and 66.7% in the thrombosis group, which were lower than 93.6%, 88.7%, and 87.5% in the control group (P = .0135, hazard ratio = 2.644). In addition, patients in both groups had a foreign body sensation after stent implantation, which resolved spontaneously within 1 year after surgery. Overall, there were statistically significant differences in long-term patency rate outcome between patients with thrombotic and non-thrombotic IVCS, the 1-, 2-, and 3-year patency rates in non-thrombotic IVCS patients were higher than those in thrombotic IVCS patients.

Ultrasound characteristics of abdominal vascular compression syndromes

Abdominal vascular compression syndrome (AVCS) is caused by the compression of abdominal blood vessels by adjacent structures or the compression of abdominal organs by neighboring blood vessels. Such compressions can result in a variety of clinical symptoms. They are not commonly seen in ultrasound practices, and their presence may have been underrecognized and underdiagnosed. This article reviews the clinical features, ultrasound characteristics, and diagnostic criteria of four types of AVCS, namely, celiac artery compression syndrome, renal vein compression syndrome, iliac vein compression syndrome, and superior mesenteric artery syndrome to increase awareness of these conditions among ultrasound practitioners. The ultrasound criteria for AVCS are primarily based on studies with small sample sizes, and therefore, it is important to exercise caution if these criteria are used.

Obesity, thrombosis, venous disease, lymphatic disease, and lipedema: An obesity medicine association (OMA) clinical practice statement (CPS) 2023

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) is intended to provide clinicians with an overview on obesity, thrombosis, venous disease, lymphatic disease, and lipedema.

Methods

The scientific support for this CPS is based upon published citations, clinical perspectives of OMA authors, and peer review by the Obesity Medicine Association leadership.

Results

Topics in this CPS include obesity, thrombosis, venous disease, lymphatic disease, and lipedema. Obesity increases the risk of thrombosis and cardiovascular disease via fat mass and adiposopathic mechanisms. Treatment of thrombosis or thrombotic risk includes healthful nutrition, physical activity, and the requisite knowledge of how body weight affects anti-thrombotic medications. In addition to obesity-related thrombotic considerations of acute coronary syndrome and ischemic non-hemorrhagic stroke, this Clinical Practice Statement briefly reviews the diagnosis and management of clinically relevant presentations of deep vein thromboses, pulmonary embolism, chronic venous stasis, varicose veins, superficial thrombophlebitis, lipodermatosclerosis, corona phlebectatica, chronic thromboembolic pulmonary hypertension, iliofemoral venous obstruction, pelvic venous disorder, post-thrombotic syndrome, as well as lymphedema and lipedema - which should be included in the differential diagnosis of other edematous or enlargement disorders of the lower extremities.

Conclusions

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) on obesity, thrombosis, and venous/lymphatic disease is one of a series of OMA CPSs designed to assist clinicians in the care of patients with the disease of obesity.

A review of the pathophysiology and evidence-based management of varicoceles and pelvic congestion syndrome

Pelvic congestion syndrome (PCS) in females and varicoceles in males may be regarded as closely related conditions since the main pathophysiological cause for both processes is pelvic venous insufficiency. Varicoceles are more prevalent amongst sub-fertile males, with an approximate incidence of 15% in the general male population. PCS is commonly diagnosed amongst premenopausal multiparous women, representing one of the leading causes of chronic pelvic pain. Both conditions appear to be predominantly left-sided and are associated with oxidative stress and pro-inflammatory cascades with subsequent effects on fertility. Clinical examination and pelvic ultrasonography play an essential role in the assessment of varicoceles, PCS and chronic pelvic pain. Venography is generally considered as a gold-standard procedure for both conditions. There is still much debate on how these conditions should be managed. This review article provides a comparative analysis of the underlying pathophysiological mechanisms of both PCS and varicoceles, their impact on fertility, as well as their clinical management.

Coaxial Placement of Balloon-Expandable and Self-Expanding Stents: Impact on Crush Resistance and Luminal Recovery in a Benchtop Model

During endovascular interventions, coaxial deployment of stents may be required to preserve luminal gain. This study characterized in vitro the effect on crush resistance and postcompression recovery when 316L stainless steel balloon-expandable (BE) and laser-cut nitinol self-expanding (SE) venous stents were deployed coaxially. Various stent configurations were parallel-plate compressed from a fully expanded state to 50% diameter reduction (Criterion, Model 42; MTS, Eden Prairie, Minnesota) in a 37 °C ± 1 water bath. Coaxial deployments of SE stent inside BE stent and BE stent inside SE stent demonstrated higher crush resistances compared with each stent individually or their mathematical summation (analysis of variance P < .0001; pairwise comparison P < .01). The configuration of SE stent inside BE stent showed higher postcompression luminal recovery at 48.7% compared with that of BE stent inside SE stent at 27.5% (P = .0001). Coaxial deployment of SE stent inside BE stent may improve crush resistance and luminal recovery after compression in the appropriate clinical context.

Effectiveness of iliac vein stenting combined with endovenous laser treatment of recurrent varicose veins associated with iliac vein compression

Background

Iliac vein compression syndrome (IVCS) is an underlying cause of varicose vein (VV) recurrence after venous surgery. However, the management of recurrent varicose veins (RVVs) combined with IVCS has rarely been reported. This study aimed to investigate the outcomes of a one-stop procedure to correct outflow obstruction and superficial reflux for patients with RVVs and IVCS.

Methods

A retrospective analysis was conducted of 102 consecutive patients diagnosed with RVVs. Computed tomography venography (CTV) was performed to confirm IVCS. The cases were divided into 2 groups: the IRVVs group, including patients with RVVs and IVCS (n=48), and the RVVs group, including patients with RVVs only (n=54). The characteristics, vein reflux, and clinical, etiological, anatomical, and pathophysiological (CEAP) distribution were investigated. Then, the IRVVs group patients who underwent endovenous laser ablation (EVLA) (n=39) were divided into a further 2 groups: the EVLA + S group (n=19), who received EVLA and stenting of iliac vein, and the EVLA group (n=20), who received EVLA treatment alone. The great/small saphenous vein (GSV/SSV) trunk occlusion, VV recurrence, visual analogue scale (VAS), and venous clinical severity score (VCSS) were investigated.

Results

The prevalence rate of femoral vein reflux was 81.2% in IRVVs group and 50% in RVVs group (P<0.05). In the IRVVs group, 72.9% of patients manifested as CEAP clinical class >3, which was higher than that in RVVs group (48.1%) (P<0.05). The 12-month GSV/SSV occlusion rate in the EVLA + S and EVLA groups were 94.7% and 90.0%, respectively. Totals of 9 patients in EVLA + S group and 6 patients in EVLA group had active venous ulcers, and the ulcer healing time in EVLA + S group was significantly shorter (27.22±7.12 vs. 46.67±9.83 days, P<0.05). The reductions in the VAS and VCSS values between baseline, 1 month, and 12 months in the EVLA + S group were more obvious than those in EVLA group (P<0.05).

Conclusions

The one-stop combination treatment of iliac venous stenting and EVLA in patients with RVVs and IVCS is safe and effective and provides prominent symptom relief, improved quality of life, and a more satisfactory ulcer healing than EVLA alone.

CFD Study of the Effect of the Angle Pattern on Iliac Vein Compression Syndrome

Iliac vein compression syndrome (IVCS, or May-Thurner syndrome) occurs due to the compression of the left common iliac vein between the lumbar spine and right common iliac artery. Because most patients with compression are asymptomatic, the syndrome is difficult to diagnose based on the degree of anatomical compression. In this study, we investigated how the tilt angle of the left common iliac vein affects the flow patterns in the compressed blood vessel using three-dimensional computational fluid dynamic (CFD) simulations to determine the flow fields generated after compression sites. A patient-specific iliac venous CFD model was created to verify the boundary conditions and hemodynamic parameter set in this study. Thirty-one patient-specific CFD models with various iliac venous angles were developed using computed tomography (CT) angiograms. The angles between the right or left common iliac vein and inferior vena cava at the confluence level of the common iliac vein were defined as α1 and α2. Flow fields and vortex locations after compression were calculated and compared according to the tilt angle of the veins. Our results showed that α2 affected the incidence of flow field disturbance. At α2 angles greater than 60 degrees, the incidence rate of blood flow disturbance was 90%. In addition, when α2 and α1 + α2 angles were used as indicators, significant differences in tilt angle were found between veins with laminar, transitional, and turbulent flow (p < 0.05). Using this mathematical simulation, we concluded that the tilt angle of the left common iliac vein can be used as an auxiliary indicator to determine IVCS and its severity, and as a reference for clinical decision making.

Intravascular Ultrasound in Treating Iliac Vein Compression With Endovascular Stenting: A Necessary Tool for Optimal Outcomes

Symptomatic compression of the left common iliac vein between the right common iliac artery and spinal vertebrae is referred to as May-Thurner Syndrome (MTS). Atypical cases of MTS including compression of the left external iliac vein, right iliac vein or the inferior vena cava can also coexist and cause double vein compression. Current literature suggests that endovascular treatment including thrombolysis, thrombectomy, venoplasty and stent placement to correct the mechanical obstruction together with anticoagulation therapy is safe and a reasonable management for patients with MTS. Intravascular ultrasound (IVUS) can aid in the diagnosis and the operative planning of MTS, especially regarding sizing and precise deployment of venous stents. Here we present 2 unique atypical cases of MTS with double left iliac vein compression treated endovascularly with stent placement along the common and external iliac vein with the assistance of IVUS.

Symptomatic Chronic Severe Stenosis of the Iliac Vein Successfully Treated Endovascularly Using an Interventional Radiology Computed Tomography System

We report a woman with chronic severe stenosis of the left common and external iliac veins and severe post-thrombotic syndrome symptoms. We successfully recanalized the stenotic segment via interventional radiology, which immediately relieved the symptoms. The interventional radiology computed tomography system was helpful for the safe and precise performance of endovascular treatments.

Complex pathologies in a patient referred for varicose veins

Varicose veins are commonly due to saphenous vein reflux, but they can manifest more complex venous pathologies. A 45-year-old woman presented with painful leg varicosities and pelvic pain. Duplex examination showed bilateral superficial venous reflux, and, on further interrogation, cross-sectional imaging demonstrated enlarged ovarian veins and nonthrombotic iliac vein compression. Ovarian vein embolization followed by iliac vein stenting and bilateral lower extremity venous ablations and sclerotherapy was performed. After 5 years, she reports no pelvic symptoms and minimal leg symptoms. This case highlights the complex interplay of these venous pathologies and their successful treatment.

High fibrinogen and mixed proximal and distal thrombosis are associated with the risk of residual venous thrombosis in patients with posttraumatic deep vein thrombosis

Background

The risk factors for residual venous thrombosis (RVT) in patients with post-trauma deep vein thrombosis (DVT) are unknown.

Methods

We evaluated 127 patients with DVT after trauma, all of whom were treated with conventional anticoagulation and assessed for the presence of RVT with venous compression ultrasound (CUS), using an internal diameter of the venous lumen ≥ 4 mm after compression as the criterion.

Results

RVT was present in 59 (46%) patients, and complete thrombus dissolution was present in 68 (54%) patients. Among them, mixed proximal and distal thrombosis (OR, 4.292; 95% CI, 1.253-14.707), diabetes (OR, 6.345; 95% CI, 1.125-35.786), fibrinogen > 4.145 g/L (OR, 2.858; 95% CI, 1.034-7.897), the time between detection of thrombus and initiation of antithrombotic therapy > 2.5 days (OR, 3.470; 95% CI, 1.085-11.094) was an independent risk factor for RVT in patients with posttraumatic DVT.

Conclusion

A mixed proximal and distal thrombosis, diabetes mellitus, late initiation of antithrombotic therapy, and high fibrinogen levels increase the risk of RVT in patients with posttraumatic DVT. Therefore, treatment regimens for patients with posttraumatic DVT can be adjusted according to the site of thrombosis, the presence of diabetes mellitus, and the level of fibrinogen, and antithrombotic therapy can be started as early as possible after the detection of thrombosis to prevent the development of RVT and its serious complications.

Case report: Non-thrombotic iliac vein lesion: an unusual cause of unilateral leg swelling in a patient with endometrial carcinoma

81-year-old female presented with subacute right lower extremity edema due to iliac vein compression by a markedly enlarged external iliac lymph node later identified as newly relapsed metastatic endometrial carcinoma. The patient underwent a full evaluation of the iliac vein lesion and cancer and had an intravenous stent placed with complete resolution of symptoms post-procedure.

Utilization of and Outcomes Associated with Intravascular Ultrasound during Deep Venous Stent Placement among Medicare Beneficiaries

PURPOSE

To evaluate temporal trends, practice variation, and associated outcomes with the use of intravascular ultrasound (US) during deep venous stent placement among Medicare beneficiaries.

MATERIALS AND METHODS

All lower extremity deep venous stent placement procedures performed between January 1, 2017, and December 31, 2019 among Medicare beneficiaries were included. Temporal trends in intravascular US use were stratified by procedural setting and physician specialty. The primary outcome was a composite of 12-month all-cause mortality, all-cause hospitalization, or repeat target vessel intervention. The secondary outcome was a composite of 12-month stent thrombosis, embolization, or restenosis.

RESULTS

Among the 20,984 deep venous interventions performed during the study period, 15,184 (72.4%) utilized intravascular US. Moderate growth in intravascular US use was observed during the study period in all clinical settings. There was a variation in the use of intravascular US among all operators (median, 77.3% of cases; interquartile range, 20.0%-99.2%). In weighted analyses, intravascular US use during deep venous stent placement was associated with a lower risk of both the primary (adjusted hazard ratio, 0.72; 95% confidence interval [CI], 0.69-0.76; P < .001) and secondary (adjusted hazard ratio, 0.32; 95% CI, 0.27-0.39; P < .001) composite end points.

CONCLUSIONS

Intravascular US is frequently used during deep venous stent placement among Medicare beneficiaries, with further increase in use from 2017 to 2019. The utilization of intravascular US as part of a procedural strategy was associated with a lower cumulative incidence of adverse outcomes after the procedure, including venous stent thrombosis and embolization.

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.

Iliac vein stenting outcomes for patients with superficial venous insufficiency concurrent with deep venous disease

OBJECTIVE

Many patients will present with chronic proximal venous outflow obstruction (PVOO) and superficial venous insufficiency (SVI) at the time of iliac vein stenting. In the present study, we aimed to determine whether differences in outcomes were present for patients receiving an iliac vein stent according to whether concurrent SVI was present.

METHODS

A registry of 553 patients who had undergone iliac vein stent placement for chronic PVOO from 2011 to 2021 was retrospectively analyzed. Two groups of patients were followed for ≤6 years after initial vein stent placement: group 1 (n = 178; 32.2%) had not had SVI before or after stent placement and group 2 (n = 375; 67.8%) had had SVI at initial iliac vein stent procedure. The patients' symptoms were evaluated using the venous clinical severity score (VCSS). Postoperative procedures after initial stent placement were recorded. Postoperative procedures included any operation performed after the index iliac vein stent procedure. Endovenous thermal ablation was classified as a minor postoperative procedure, and any intervention with venography was classified as a major postoperative reintervention. Multivariate regression models were used to determine the odds of a major reintervention or minor procedure postoperatively.

RESULTS

Across the two groups, the mean age (group 1, 65.3 years; group 2, 59.9 years; P < .001), body mass index (27.6 vs 26.1 kg/m²; P = .004), diabetes (32.6% vs 17.6%; P < .001), arterial hypertension (68.5% vs 42.1%; P < .001), and coronary artery disease (16.9% vs 9.6%; P = .048) differed significantly. The time to follow-up was similar between the two groups (P = .915). Longitudinally, both groups had had similar improvements in the composite VCSSs. After multivariable adjustment, group 2 was more likely than group 1 (odds ratio, 5.26; 95% confidence interval, 3.33-8.59; P < .001) to have required a postoperative minor procedure, but not a major reintervention. Group 2 had also averaged a shorter interval from the index procedure to a postoperative procedure than group 1 (525.7 days vs 258.1 days; P < .001).

CONCLUSIONS

Compared with patients without SVI, those with SVI and chronic PVOO were younger, had had fewer comorbidities, and fared similarly in the change in the composite VCSSs but were more likely to have required a minor procedure and less likely to have required a major reintervention after the index iliac vein stent procedure.

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.

Prevalence of left iliac vein compression in an asymptomatic population and patients with left iliofemoral deep vein thrombosis: A multicenter cross-sectional study in southern China

OBJECTIVE

Population-based epidemiological data on left common iliac vein (LCIV) compression is scarce. This study aimed to investigate the prevalence of LCIV compression in an asymptomatic population and patients with left iliofemoral deep vein thrombosis (IF-DVT).

MATERIALS AND METHODS

Nonprobability sampling method was used in this multicenter cross-sectional study. The minimum diameter of LCIV and right common iliac vein minimum were measured. The percentage of LCIV compression (LCIV-CP) was calculated. Compression severity (CS) was classified as mild (CP ≤ 50%), moderate (50% < CP ≤ 70%), and severe (CP > 70%).

RESULTS

In all, 896 subjects constituted the asymptomatic population and 93 patients constituted the IF-DVT population. In the asymptomatic population, LCIV-CP ranged from 1.1% to 89.9% (mean 44.0%), and people with mild, moderate, and severe CS accounted for 62.3%, 28.2%, and 9.5%, respectively. In the IF-DVT population, the mean LCIV-CP was 71.1% (range 42.2%-95.2%), and patients with severe CS accounted for 75.3%. Gender and age differences in LCIV-CP and CS distribution were observed in the asymptomatic population. Females, the young- and middle-aged group had higher LCIV-CPs. In the population with moderate-severe CS, the middle-aged group accounted for a larger proportion. Middle-aged females comprised the highest percentage of patients with moderate or severe CS. Sex and age affected the LCIV-CP and CS distribution. No gender and age differences were observed in the IF-DVT population.

CONCLUSIONS

LCIV compression is common in population. Middle-aged females are the predominant population with moderate-severe compression. Overlapping of LCIV-CP in the asymptomatic and IF-DVT population is significant and other risk factors should be integrated into the consideration when assessing the risk of IF-DVT secondary to LCIV compression.

May-Thurner Syndrome and Lymphedema Reconstruction

May-Thurner syndrome (MTS) is an anatomical variant that results in compression of the left common iliac vein by the right common iliac artery. Although often asymptomatic, lower extremity swelling/edema, deep venous thrombosis, post-thrombotic syndrome, and eventual lymphedema (due to long-standing venous obstruction) can develop. The clinical management of patients presenting for lymphedema surgery with concomitant or undiagnosed MTS is not well described.

Methods

This review investigates two patients who were evaluated for unilateral lower extremity lymphedema, both of whom were subsequently diagnosed with MTS. Standard imaging (including lymphoscintigraphy, indocyanine green lymphangiography, and magnetic resonance venography) were performed to identify proximal venous obstruction. Treatment was accomplished using vascular surgical management, including stenting of the iliac vein before lymphedema reconstruction with vascularized lymph node transfer and multiple lymphovenous bypass.

Results

Both patients we examined in this review had improvement of lymphedema with vascular surgical management. Literature review reveals that MTS has an incidence as high as 20% in the population, although commonly unidentified due to lack of symptomatology.

Conclusions

There are no studies documenting the incidence of MTS in patients referred for lymphedema surgical management. Routine studies should be obtained to screen for proximal venous obstruction in patients presenting for surgical management of lower extremity lymphedema. Additional research is needed regarding the approach to managing patients with both MTS and lymphedema. Careful observational and prospective studies may elucidate the appropriate time interval between venous stenting and lymphedema microsurgical reconstruction.

Comparison of intravascular ultrasound and magnetic resonance venography in the diagnosis of chronic iliac venous disease

BACKGROUND

The diagnosis of chronic iliofemoral venous obstruction (CIVO) can be made with several different modalities. Intravascular ultrasound (IVUS) is the gold standard in the diagnosis of CIVO. However, being invasive, it should not be the initial examination to screen patients with CIVO. The aim of this report is to compare the performance of magnetic resonance venography (MRV) to IVUS in the diagnosis of CIVO.

METHODS

From January, 2016 to December, 2020, records of all patients who underwent pre-operative MRV and then IVUS in the evaluation of CIVO were retrospectively analyzed.

RESULTS

505 patients were evaluated by any modality for CIVO. 15% (78) of these patients were evaluated by MRV. Patients who had failed a trial of conservative therapy for at least 3 - 6 months and who had disabling and life-style limiting symptoms of CIVO were selected to undergo further evaluation with MRV at the treating physician's discretion. For inclusion in analysis, technically satisfactory IVUS and MRV data was mandatory. Data was available for 60 common iliac vein (CIV) segments and 61 external iliac vein (EIV) segments for comparative analysis after appropriate exclusions. The mean age of the patients was 56 ± 15 years. Male to female ratio was 1:2. The distribution of patients across different CEAP classes was as follows: CEAP 3: 28%, CEAP 4: 62%, CEAP 5: 2% and CEAP 6: 8%. Bland-Altman plots of mean difference in area between IVUS and MRI were 74.1% for CIV and 56.9% for EIV. The sensitivity of MRV was 93% and 100% while the specificity was 0 and 50% for CIV and EIV respectively. The positive predictive value was 93% and 86% while the negative predictive value was 0 and 50% for CIV and EIV respectively. Improvement was noted in clinical parameters (Venous Clinical Severity score; VCSS, visual analogue pain scale and grade of swelling) after IVUS and stenting following MRV investigation. For VCSS, the score improved from 6 ± 2.7 (pre-procedure) to 4 ± 2.7 (post-procedure), p=0.0001.

CONCLUSION

There is dimensional disparity between MRV and IVUS in the diagnosis of symptomatic CIVO. MRV has a high sensitivity but low specificity when compared to IVUS and overestimates the severity of the stenosis in both the EIV and CIV. MRV is not a reliable diagnostic tool for iliac vein stenosis and should not be used for the definitive disposition of CIVO patients.

May-Thurner Syndrome in an Elderly Man

May-Thurner syndrome (MTS) is a rare cause of deep vein thrombosis (DVT). This diagnosis is seldomly included in the differential diagnosis. The disease is defined as extraluminal iliac vein compression by the arterial system against bony structures in the iliocaval area. This occurs more commonly on the left side due to the unfortunate position of the proximal left iliac vein that runs between the right common iliac artery and spine. MTS is commonly presented in younger female patients with left unilateral proximal DVT. However, MTS is rarely reported in elderly patients. We present a case of a 69-year-old man with a diagnosis of MTS and further management with a venous stent.

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.

Preliminary study of hemodynamics of iliac venous compression syndrome using magnetic resonance imaging

OBJECTIVE

In clinical practice, the degree of iliac vein stenosis has often been inconsistent with the symptoms of chronic venous disease (CVD). To the best of our knowledge, no clinical studies have evaluated the hemodynamic changes associated with iliac vein stenosis. Magnetic resonance imaging (MRI) can noninvasively provide hemodynamic information. In the present study, we assessed the degree of stenosis associated with iliac venous compression syndrome and the relationships between iliac venous compression syndrome-induced, MRI-determined hemodynamic changes and lower limb symptoms.

METHODS

Stenosis severity, the presence of collateral vessels, and flow rate (FR) differences between the common and external iliac veins secondary to iliac vein stenosis were measured using MRI in 69 patients with CVD. Villalta scores were used as a measure of symptom severity for all patients, and the percentage of change in the Villalta score was used as a measure of symptom improvement for the patients who had received iliac vein stents. Symptom severity for all patients, a subgroup of patients with iliac vein compression (affected limbs), and a group of patients with unilateral iliac vein compression treated with stents was correlated with stenosis, differences in the external and common iliac vein FRs (<0-mL/s group, indicating stenosis-induced decreased common iliac vein flow, and ≥0-mL/s group), and stenosis-induced collateral vessel formation.

RESULTS

Iliac vein stenosis severity and FR differences in all affected limbs were correlated with the Villalta scores of the affected limbs (stenosis: r = 0.38, P < .001, n = 95; FR difference: r = -0.44, P < .001). In the unilateral compression subgroup, stenosis severity, FR differences, and the presence of collateral vessels were not associated with significant changes in contralateral symptoms. In the endovascular treatment subgroup, both lower limbs exhibited significant improvement after stent implantation (affected limb symptom remission, 64.6% ± 18.2%, n = 15; contralateral limb symptom remission, 49.1% ± 29.1%, n = 11). The rate of symptom remission was greater for patients with decreased iliac vein flow in the affected limbs (<0-mL/s group: 74.6% ± 16.4%, n = 7; ≥0-mL/s group: 52.2% ± 16.6%, n = 6; P = .032).

CONCLUSIONS

Iliac vein stenosis, the presence of collateral vessels, and decreased FRs due to stenosis correlated significantly with lower limb symptom severity. Endovascular treatment yielded good outcomes in patients with stenosis >50%. A decreased iliac venous FR could indicate a better response to stent implantation and could be used in the diagnosis and guiding decisions to treat iliac venous compression.

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.

Timing of Endovascular Interventions for Iliac Vein Compression Syndrome With Thrombus

The aim of this study is to explore the timing and method of endovascular intervention for iliac vein compression syndrome (IVCS) with thrombus. Data from 111 patients with IVCS, complicated acute deep vein thrombosis (DVT), or post-thrombotic syndrome (PTS) who underwent endovascular interventions were analyzed retrospectively. Patients were divided into Group A (DVT group), including 56 patients with IVCS and iliofemoral DVT, with or without femoropopliteal DVT, with sudden lower limb swelling, and Group B (PTS group) included 55 patients with IVCS and PTS, including 18 with lower extremity wet ulcers and 32 with lower limb infections. Interventional therapies were used to treat the thrombus and eliminate stenosis and occlusion of the iliac vein. In both groups, clinical symptoms in the lower limbs after surgery were reduced significantly, and PTS incidence was low during long-term follow-up. The cumulative patency rate was 75.2% in the DVT group and 88.6% in the PTS group. Comprehensive interventional therapies are safe and effective in patients with IVCS and thrombi. Long-term efficacy in the PTS group tended to be better than that in the DVT group.

Choosing the Most Appropriate Treatment Option for Pelvic Venous Disease: Stenting versus Embolization

Pelvic venous disease (PeVD) in women encompasses a wide variety of entities all resulting in pelvic pain and varices. Successful treatment with percutaneous interventions is dependent on identifying underlying factors contributing to the disease and addressing them with either embolization of incompetent veins or stenting for venous stenoses. There are a multitude of embolization methods with marked practice heterogeneity. Moreover, with the ongoing development of dedicated venous stents in the treatment of chronic venous disease, there are more opportunities to consider this modality for the treatment of PeVD, as many patients present with combined vein reflux and central venous stenosis. The necessity to address both and the order of interventions in these patients is still to be elucidated. Here, we describe when to choose stenting or embolization for PeVD, their limitations, and our practice and identify further areas of research in this field.

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

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

Ilio-femoral venous thrombosis with hereditary antithrombin deficiency: a case report of rare thrombotic disease and successful treatment with catheter directed thrombolysis

Background

Hereditary antithrombin (AT) deficiency is an uncommon autosomal dominant thrombogenic disorder, which can cause venous thromboembolism (VTE). Although conservative treatment options for hereditary AT deficiency-associated VTE such as anticoagulation (warfarin, direct oral anticoagulant, or heparin), intravenous thrombolysis, and recombinant AT are well known, interventional treatment options have not been reported so far.

Case summary

A 19-year-old man with a family history of thrombogenic diseases, referred to our hospital with left leg pain, was diagnosed with AT deficiency-associated VTE. In the absence of symptomatic relief with intravenous thrombolysis and anticoagulation, he received venous intervention and catheter directed thrombolysis (CDT) for 4 days for left iliac venous thrombosis. Following a second venous intervention, venous thrombus disappeared almost entirely on cross-sectional imaging, and his symptoms improved. He was discharged on apixaban and has been recurrence-free for one and a half years.

Discussion

This case presents CDT and maintenance therapy with apixaban as possible treatment options for VTE in patients with hereditary AT deficiency, especially following failure of conservative therapy. Individual risks and benefits should be considered when CDT is performed for acute VTE in patients with AT deficiency.

Deformation mechanics of self-expanding venous stents: Modelling and experiments

Deformation properties of venous stents based on braided design, chevron design, Z design, and diamond design are compared using in vitro experiments coupled with analytical and finite element modelling. Their suitability for deployment in different clinical contexts is assessed based on their deformation characteristics. Self-expanding stainless steel stents possess superior collapse resistance compared to Nitinol stents. Consequently, they may be more reliable to treat diseases like May-Thurner syndrome in which resistance against a concentrated (pinching) force applied on the stent is needed to prevent collapse. Braided design applies a larger radial pressure particularly for vessels of diameter smaller than 75% of its nominal diameter, making it suitable for a long lesion with high recoil. Z design has the least foreshortening, which aids in accurate deployment. Nitinol stents are more compliant than their stainless steel counterparts, which indicates their suitability in veins. The semi-analytical method presented can aid in rapid assessment of topology governed deformation characteristics of stents and their design optimization.

The Protégé Nitinol Self-Expanding Stent for the Treatment of Iliofemoral Veno-Occlusive Disease

PURPOSE

To evaluate the safety and effectiveness of the Protégé nitinol self-expanding stent for the treatment of iliofemoral veno-occlusive disease.

MATERIALS AND METHODS

A retrospective review was performed of 376 (284 left, 92 right) Protégé stents in 212 limbs of 183 patients (mean age: 53 ± 17 years, 52% female) treated for iliofemoral veno-occlusive disease between 2011 and 2018. Binary patency was assessed with duplex ultrasound and calculated by Kaplan Meier analysis. Clinical outcomes were evaluated by clinical-etiology-anatomy-pathophysiology (CEAP) classification and Villalta scores. Adverse events were recorded and categorized per Society of Interventional Radiology reporting standards.

RESULTS

Of the 212 limbs, 125 presented with acute thrombosis and 28 with chronic thrombosis requiring thrombectomy (n = 44), catheter directed thrombolysis (n = 32), or both (n = 77). Fifty-nine limbs were non-thrombotic. Mean follow-up time was 11.44 ± 11.37 months. Kaplan Meier analysis revealed a primary limb-level patency of 92.3%, 88.6%, 86.9% and 86.9% at 6, 12, 24 and 36 months, respectively. CEAP and Villalta scores improved from a median of C3 (range: 0-6) to C1 (0-5) (p < 0.001) and from a mean of 13.4 ± 7.5 to 5.3 ± 4.9 (p < 0.001), respectively. Nine minor and 2 major adverse events were recorded.

CONCLUSIONS

Endovascular treatment of iliofemoral veno-occlusive disease with the Protégé self-expanding stent appears to have good mid-term patency.

LEVEL OF EVIDENCE

Level 4, Case Series.

Finite Element Simulations of the ID Venous System to Treat Venous Compression Disorders: From Model Validation to Realistic Implant Prediction

The ID Venous System is an innovative device proposed by ID NEST MEDICAL to treat venous compression disorders that involve bifurcations, such as the May-Thurner syndrome. The system consists of two components, ID Cav and ID Branch, combined through a specific connection that prevents the migration acting locally on the pathological region, thereby preserving the surrounding healthy tissues. Preliminary trials are required to ensure the safety and efficacy of the device, including numerical simulations. In-silico models are intended to corroborate experimental data, providing additional local information not acquirable by other means. The present work outlines the finite element model implementation and illustrates a sequential validation process, involving seven tests of increasing complexity to assess the impact of each numerical uncertainty separately. Following the standard ASME V&V40, the computational results were compared with experimental data in terms of force-displacement curves and deformed configurations, testing the model reliability for the intended context of use (differences < 10%). The deployment in a realistic geometry confirmed the feasibility of the implant procedure, without risk of rupture or plasticity of the components, highlighting the potential of the present technology.

Case Report: Rare Iliac Vein Compression (May-Thurner) Syndrome in a Pediatric Patient

Iliac vein compression syndrome (IVCS) or May-Thurner syndrome occurs predominantly in young to middle-aged women. Here we reported a case of IVCS in a 5-year-old boy. The child was admitted to our vasculocardiology department with left lower extremity that had been swollen for 1 month. Blood tests revealed coagulation routine and platelets in the normal ranges. Computer tomography angiography (CTA) and magnetic resonance imaging (MRI) showed the left common iliac vein had become narrow before it entered the right common iliac vein. To further clarify, we performed angiography, which clearly showed the stenosis and the blood return of the left common iliac vein. So IVCS was diagnosed. What is more, we found the aorta descended to the right of the spine, and this may be the reason for the apparent compression of the left common iliac vein. Given the young age and mild symptoms of the child, the treatment was conservative mainly including elevation of the affected limb, wearing medical elastic socks, and short-term oral aspirin for anticoagulation. Meanwhile, the boy is being followed up closely. If the swelling of the left lower extremity significantly increases, stent placement may need to be considered in the future.

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.

Three-dimensional computed tomography venography reconstruction facilitates identification of atypical radiologic features of May-Thurner syndrome

OBJECTIVE

May-Thurner syndrome (MTS) is typically characterized by compression of the left common iliac vein by the overlying right common iliac artery. The present study evaluated the occurrence of atypical imaging features of MTS using three-dimensional computed tomography venography reconstruction (3D-CTV) and analyzed their correlation with clinical features.

METHODS

We analyzed the data from 268 patients with left lower extremity chronic venous disease (CVD) using 3D-CTV at a single institution from January to June 2019. An area stenosis percentage >50% was defined as significant venous compression. Of the 268 patients, 92 had at least one significant iliac and/or vena cava compression confirmed by 3D-CTV. Of the 92 patients, 89 underwent digital subtraction venography via the left common femoral vein, and the outcomes were compared with their 3D-CTV findings. Different types of venous compression were evaluated using 3D-CTV. The relationship among compression type, sex, age, and CVD symptoms was evaluated.

RESULTS

A total of 106 venous compression sites were found in 92 patients. Atypical compression included inferior vena cava (IVC) compression and partial IVC compression (8.5% and 55.7%, respectively). Multiple compression sites were present in 13 patients (14.1%). The compression sites correlated significantly with clinical symptoms (P = .017) and were related to sex (P = .001). The number of patients with IVC and partial IVC compression but false-negative venography findings was four (33.3%) and six (50%), respectively.

CONCLUSIONS

3D-CTV facilitates the detection of atypical venous compression in patients with MTS with notable chronic symptoms. Patients with multiple compression sites had more severe clinical symptoms and greater false-negative rates with venography. IVC compression was more likely to occur in female patients with MTS.

An efficacy and safety study of rivaroxaban for the prevention of deep vein thrombosis in patients with left iliac vein compression treated with stent implantation (PLICTS): study protocol for a prospective randomized controlled trial

BACKGROUND

Balloon dilatation with stent implantation has been proved to be an effective option for left iliac vein compression syndrome (LIVCS), but thrombosis may still occur after the operation. Currently, warfarin is used for anticoagulant therapy, but long-term monitoring is required, while rivaroxaban does not need laboratory monitoring, which can simplify treatment. Therefore, this study aimed to compare the efficacy and safety of rivaroxaban and warfarin in anticoagulation.

METHODS

This study is a multicenter, randomized controlled trial. We will recruit 224 patients with thrombotic LIVCS from 9 hospitals. Moreover, these patients will be randomized to either the experimental group (rivaroxaban) or the control group (warfarin plus nadroparin). The primary outcome is stent occlusion rate. Secondary outcomes are quality of life scale survey results, all-cause mortality, anticoagulation-related mortality, and the proportion of participants with stent displacement/fracture, thrombosis, hemorrhage, and other vascular events.

DISCUSSION

This study will provide reliable, evidence-based clinical evidence for the efficacy and safety of rivaroxaban antithrombotic therapy after stent implantation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04067505 . Registered on August 26, 2019.

C-arm-based flat-panel detector cone-beam computed tomography venography in the diagnosis of iliac vein compression syndrome

Background:

C-arm-based flat-panel detector cone-beam computed tomography (CBCT) venography has never been used in the management of iliac vein compression syndrome (IVCS). This study aimed to determine the technical feasibility and safety of CBCT venography in the diagnosis of IVCS compared with conventional venography (CV).

Methods:

Twenty patients with clinical manifestations of lower extremity venous insufficiency were prospectively enrolled between May 2018 and December 2018. Each patient underwent both CV and CBCT venography. The feasibility and safety of CBCT venography were assessed by technical success rate and complication rate. The relationships between the clinical indexes and the results of CBCT venography and CV were analyzed with correlation analysis. The consistency of the diagnosis of IVCS using each modality was analyzed by the kappa test.

Results:

The technical success rate was 100% for CBCT venography and for CV, without any complications. Compared with CV, CBCT venography was able to show more details of adjacent tissues which might be helpful for making etiological diagnosis. The stenosis rate under CBCT venography had excellent consistency with that under CV (kappa = 0.78, Chi-square test). The stenosis rate under CBCT venography was positively correlated with the presence of collateral veins (odds ratio 1.12, 95% confidence interval: [1.00, 1.26], P = 0.049), while the stenosis rate under CV was not. Unexpectedly, only one patient had a venous pressure gradient of more than 2 mmHg (1 mmHg = 0.133 kPa).

Conclusions:

For the diagnosis of IVCS, C-arm-based CBCT venography was technically feasible, with good safety. The presence of collateral veins on CBCT was clinically significant. A C-arm fluoroscopy-based technique that combines CV and CBCT might be a promising protocol for the management of IVCS during a single session.

Novel Diagnostic Options without Contrast Media or Radiation: Triggered Angiography Non-Contrast-Enhanced Sequence Magnetic Resonance Imaging in Treating Different Leg Venous Diseases

OBJECTIVES

Venous diseases in the lower extremities long lacked an objective diagnostic tool prior to the advent of the triggered angiography non-contrast-enhanced (TRANCE) technique.

METHODS

An observational study with retrospective data analysis.

MATERIALS

Between April 2017 and June 2019, 66 patients were evaluated for venous diseases through TRANCE-magnetic resonance imaging (MRI) and were grouped according to whether they had occlusive venous (OV) disease, a static venous ulcer (SU), or symptomatic varicose veins (VV). The clinical appliance of TRANCE-MRI was analysed by groups.

RESULTS

In total, 63 patients completed the study. TRANCE-MRI could identify venous thrombosis, including that of the abdominal and pelvic vessels, and it enabled the timely treatment of underlying diseases in patients with OV disease. TRANCE-MRI was statistically compared with the duplex scan, the gold standard to exclude deep vein thrombosis (DVT) in the legs, with regard to their abilities to detect venous thrombosis by using Cohen's kappa coefficient at a compatible value of 0.711. It could provide the occlusion degree of the peripheral artery for treating an SU. Finally, TRANCE-MRI can be used to outline all collateral veins and occult thrombi before treating symptomatic or recurrent VV to ensure a perfect surgical plan and to avoid complications.

CONCLUSIONS

TRANCE-MRI is an innovative tool in the treatment of versatile venous pathology in the lower extremities and is widely used for vascular diseases in our institution.

Intervention for Iliofemoral Deep Vein Thrombosis and May-Thurner Syndrome

May-Thurner syndrome, also known as iliac vein compression syndrome, may cause symptoms of venous hypertension and is a predisposing factor for the development of iliofemoral deep vein thrombosis (DVT). Iliofemoral DVT is associated with high rates of development of postthrombotic syndrome, a potentially debilitating condition associated with development of symptoms related to venous outflow obstruction and resulting in reduced quality of life. In this Clinics article, we review procedural intervention with catheter-directed thrombolysis and stenting for iliofemoral DVT and iliac vein compression.