Compression of the left common iliac vein in asymptomatic subjects and patients with left iliofemoral deep vein thrombosis

Indications, technical aspects, and outcomes of stent placement in chronic iliofemoral venous obstruction

BACKGROUND

Iliofemoral venous stent placement (IVS) has evolved to a well-established endovascular treatment modality for chronic iliofemoral venous obstruction (CIVO). Dedicated venous stents gained approval from the US Food and Drug Administration in 2019 and solidified IVS as a defined intervention with clear indications, contraindications, risks, benefits, and procedural management principles. This review focuses on the indications, technical aspects and outcomes of stenting for CIVO. Other aspects pertaining to IVS are covered in other articles that are a part of this series.

METHODS

This study conducted a literature search limited to English articles. Three search strategies were used, and references were managed in Covidence software. Four investigators screened and evaluated articles independently, excluding meta-analyses, clinical trial protocols, and nonrelevant studies. Eligible studies, focused on clinical outcomes and stent patencies, underwent thorough review.

RESULTS

The literature search yielded 1704 studies, with 147 meeting eligibility criteria after screening and evaluation. Exclusions were based on duplicates, irrelevant content, and noniliac vein stent placement.

CONCLUSIONS

Successful IVS for CIVO relies on meticulous patient selection, consistent use of intravascular ultrasound examination during procedures and attention to the technical details of IVS.

Left common iliac vein diameter in patients referred for lower limb venous duplex ultrasound

INTRODUCTION

Evidence regarding ultrasound assessment of left common iliac vein diameter (LCIV) is limited. Extensive work is currently being undertaken worldwide on non-thrombotic iliac vein lesions to identify patients who may benefit from intervention to alleviate symptoms of chronic venous obstruction. Interventions include long-term stent implantation to improve vein diameter stenosis. This study aimed to assess a cohort of symptomatic venous patients and the diameter of the LCIV in these patients.

METHODS

: Retrospective medical records review of all patients attending a tertiary vascular surgery centre who underwent a venous duplex ultrasound assessment between April 2017 and February 2018 were analysed for assessment of LCIV. Medical records of those patients with documented LCIV diameter were assessed over 18 months of follow-up.

RESULTS

: A total of 672 (271 males, 401 females) LCIV diameter measurements were collected. The age of the patients ranged from 21 to 95 years (mean = 56.38). Median LCIV diameter overall was 7.64 mm (IQR 5.80mm-9.00 mm). 40 patients (6%) were reported to have a LCIV diameter measurement of < 4 mm, 8 (20%) male and 32 female (80%). 17 of these 40 patients (47.5%) were treated conservatively. Median LCIV diameter was 3.4 mm (IQR 2.5-3.7). 21 of these 40 patients (52.5%) underwent superficial venous intervention only, with a median LCIV diameter of 3.5 mm (IQR 3.2-3.7) and 2 out of these 40 patients (5%) underwent deep venous stenting (2/2 female - 100%), with a median LCIV diameter of 2.9 (IQR 2.9-2.9). No patients underwent both superficial and deep venous treatment in this 40 patient cohort. In those undergoing superficial venous intervention, 4 (19%) underwent repeat treatment. The two deep venous stenting patients underwent magnetic resonance venogram and venogram with intravascular ultrasound to allow stent placement, which confirmed a narrowed left common iliac vein. Primary stent patency at 18 months was 100%.

CONCLUSION

In this large study cohort of venous duplex assessments the median vein diameter was 7.64 mm and 40 patients out of 672 had a vein diameter smaller than 4 mm. 2 patients underwent deep venous stenting with primary patency of 100%.

Appropriateness of care: Deep venous procedures

In the past decade, technologies to treat venous pathologies have increased dramatically, to the benefit of an often underserved and overlooked population of patients with venous disease. However, given the rapid release of various technologies, including venous-dedicated stents and thrombectomy devices across varied venous pathologies, evidence-based guidelines have been slow to develop. When discussing appropriateness of care, one needs to consider optimal patient selection, technical approach, medical management, and surveillance protocols, to name a few. All of which, in the venous space, are currently widely varied in practice. The future of deep venous work is limitless, but multicenter, randomized controlled trials are needed to optimally treat patients with venous disease.

The role of iliac vein stent placement in pelvic venous disorder management

Pelvic venous disease (PeVD) has historically been challenging to diagnose and treat. This paper describes a comprehensive approach to the diagnosis of PeVD and reviews the role of iliac vein stent placement in treatment. Patient selection is vital for non-thrombotic iliac vein lesions (NIVLs) as only a small subset of patients with an NIVL will benefit from stent placement. There is limited, inconclusive data on optimal treatment for patients with both primary ovarian vein reflux and an NIVL. Patients with chronic post-thrombotic outflow obstruction typically have a more favorable risk/benefit ratio for intervention but require anticoagulation and close follow-up due to poorer long-term stent patency. Intravascular ultrasound is a useful tool for identifying obstructive lesions, sizing stents, and planning landing zones. More research is needed to characterize underlying pathophysiology, validate thresholds for intervention, develop reliable methods for outcomes assessment, and determine treatment response. Until this data is produced, an individualized treatment approach is warranted.

The background and role of catheter-directed thrombolysis evolving procedures for acute iliofemoral deep venous thrombosis

Minimal invasive treatment such as early endovenous thrombus removal for iliofemoral deep venous thrombosis (DVT) emerged in the end of last century. The principle is catheter-directed thrombolysis (CDT) using either plasminogen activating agents alone, as ultrasound-assisted CDT, or in combination with mechanical devices as pharmaco-mechanical CDT. The interest for this treatment modality is the high rate of post-thrombotic syndrome (PTS) with anticoagulation (AC) alone, especially after iliofemoral DVT. Recently published randomized controlled trials (RCTs) comparing early thrombus removal with AC alone, as well as non-randomized studies, have demonstrated favorable rates, or at least a decrease of moderate and severe PTS, in favor of these procedures. This article will summarize the background and evolution of the procedures in the last three decades and discuss fundamental criteria for inclusion and exclusion, focusing on the procedures regarding thrombus age and location, technical issues, complications and results including different outcome measures for PTS, for which iliac DVT involvement is a massive risk factor to be prevented.

Three-Year Outcomes, Risk Factors for Restenosis After Stenting for DVT Combined with Iliac Vein Compression Syndrome

This study aimed to evaluate the safety and efficacy of pharmacomechanical catheter-directed thrombolysis (PCDT) and stenting for treating acute iliofemoral deep venous thrombosis (DVT) combined with iliac vein compression syndrome (IVCS), and to identify the predictors of stent restenosis. Patients with acute proximal DVT combined with IVCS underwent PCDT and stenting from January 2017 to December 2022 were enrolled. Primary and secondary patency were assessed by duplex ultrasound (DUS). The morbidity of postthrombotic syndrome (PTS) was assessed by the Villalta score. Risk factors for stent restenosis were assessed using univariate and multivariate Cox regression models. Total of 254 patients were included. The mean follow-up time was 36.06 ± 17.66 months. The primary patency rates at 1 year, 3 years, and 5 years were 92.5%±1.7%, 85.4%±2.4%, and 82.4%±2.9%, respectively. The incidence of stent restenosis was 14.2%. Discontinuation of anticoagulants within one year [hazard ratio (HR) = 5.03; P = .048] was the factor associated with acute in-stent thrombosis. Previous DVT history (HR =2.29; P = .037) and stent placement across the inguinal ligament (HR =6.70; P < .001) were identified as independent risk factors significantly associated with stent restenosis. The overall PTS rate was 19.3%. PCDT with stenting is safe and effective for patients with iliofemoral DVT secondary to IVCS, leading to low rates of PTS. Previous DVT history and stents placed across the inguinal ligament may be predictors of stent restenosis. Furthermore, stent restenosis typically occurs within one year and is mainly caused by acute thrombosis due to discontinuation of anticoagulants.

Prevalence and predictors of radiological left common iliac vein compression in asymptomatic patients

OBJECTIVE

The aim of this study was to investigate the prevalence of radiological left common iliac vein (LCIV) compression among the asymptomatic population and identify possible predictors.

METHODS

Contrast-enhanced abdominal and/or pelvic computed tomography scans of eligible asymptomatic patients were examined. The LCIV diameter was measured from different horizontal planes in the venous phase using PACSView. Degree of LCIV compression (Dc) was calculated by a predefined formula and graded as insignificant (Dc < 25%), mild (≥25% Dc < 50%), moderate (≥50% Dc <75%), and severe (Dc ≥ 75%). Venous stenosis was defined as a Dc of ≥50%. Comparison of variables, including gender, age, body mass index (BMI), and comorbidities was performed between the different grades of LCIV compression.

RESULTS

Between November 2019 and July 2022, 1698 eligible asymptomatic patients (53.1% females; mean age, 39.3 ± 11.8 years; mean BMI, 22.9 ± 3.6 kg/m2) were reviewed. The mean Dc was 46.2% (range, 0.29%-90.4%). Insignificant, mild, moderate, and severe compression were distributed in 14.5%, 38.0%, 42.2%, and 5.2% of the cohort population, respectively. Prevalence of venous stenosis was higher in females than males (58.1% vs 42.2%; χ2 = 15.52; P < .001). Females aged ≥25 and <35 years accounted for the highest proportion of venous stenosis than other age groups and was a significant predictor (odds ratio [OR], 3.18; 95% confidence interval [CI], 1.74-7.79; P < .001). In the Asian BMI classification group, being underweight is associated with venous stenosis (OR, 4.69; 95% CI, 2.70-8.14; P < .001) and obesity may be a protective factor (OR, 0.38; 95% CI, 0.23-0.64; P < .001). There is an inverse relationship between Dc and age and BMI.

CONCLUSIONS

The prevalence of radiological LCIV compression on computed tomography scans was high, but all patients were asymptomatic. Female gender, especially those aged ≥25 and <35 years, and underweight were possible predictors for venous stenosis.

The utility of computed tomography venography in the routine evaluation of patients who present to a lymphedema center with lower extremity edema

OBJECTIVE

Computed tomography venography (CTV) is not routinely used to screen patients presenting with a presumed lower extremity lymphedema diagnosis for left iliac vein obstruction (IVO) or May-Thurner syndrome (MTS). The objective of this study is to determine the utility of routine CTV screening for these patients by evaluating the proportion presenting with clinically significant CTV-identified left IVO.

METHODS

We retrospectively reviewed 121 patients who had presented to our lymphedema center with lower extremity edema between November 2020 and May 2022. Information regarding demographics, comorbidities, lymphedema characteristics, and imaging reports was collected. Cases of IVO present on CTV were reviewed by a multidisciplinary team to determine the clinical significance of the CTV findings.

RESULTS

Of the patients with complete imaging studies, 49% (n = 25) had abnormal lymphoscintigraphy findings, 45% (n = 46) had reflux on ultrasound, and 11.4% (n = 9) had IVO on CTV. Seven patients (6%) had CTV findings of IVO and edema of either the isolated left (n = 4) or bilateral (n = 3) lower extremities. Cases of IVO on CTV were determined by the multidisciplinary team to be the predominant cause of lower extremity edema for three of these seven cases (43%; or 2.5% of all 121 patients).

CONCLUSIONS

Six percent of patients presenting to a lymphedema center with lower extremity edema had left-sided IVO on CTV suggestive of MTS. However, the cases of IVO were determined to be clinically significant <50% of the time or for 2.5% of all patients. CTV should be reserved for patients with isolated left-sided or bilateral lower extremity edema with a greater left-sided component and a history of findings that raise clinical suspicion for MTS.

Impact of Common Iliac Vein Compression on the Incidence of Pulmonary Embolism in Patients with Acute Deep Vein Thrombosis

OBJECTIVE

This study aimed to investigate the association between common iliac vein (CIV) compression and pulmonary embolism (PE) in lower extremity deep vein thrombosis (DVT).

METHODS

This was a single centre retrospective study. Between January 2016 and December 2021, DVT patients with enhanced computed tomography of the iliac vein and pulmonary artery were included. Patient demographics, comorbidities, risk factors, and degree of CIV compression were collected and analysed. Logistic regression was performed to evaluate the odds ratio (OR) with a 95% confidence interval (CI) of PE in relation to compression severity groups. The association between PE and compression degree was evaluated with restricted cubic splines (RCS) based on an adjusted logistic regression model.

RESULTS

Two hundred and twenty-six DVT patients (left side, n = 153; right side, n = 73) were included. Univariable analyses suggested that symptomatic or asymptomatic PE (54.4%, 123/226) was more common in men (p = .048) and right side DVT (p = .046) patients. Compared with no CIV compression, multivariable analyses suggested that mild compression did not statistically significantly reduce the PE risk, whereas moderate (adjusted OR 0.36; 95% CI 0.15 - 0.88; p = .025) and severe (adjusted OR 0.18; 95% CI 0.06 - 0.54; p = .002) compression statistically significantly reduced the risk. RCS showed that a smaller minimum diameter or greater compression percentage was correlated with continuously decreasing PE risk at a minimum diameter of < 6.77 mm or compression > 42.9%.

CONCLUSION

PE is more common in men and right side DVT patients. An increasing severity of CIV compression is consistently associated with a decreasing risk of PE when the minimum diameter is < 6.77 mm or the compression is > 42.9%, indicating that it is a protective factor against PE.

Clinical implications of hemodynamic analysis for the three-dimension iliac vein model with different stenosis

Background

The aim of this study was to perform hemodynamic simulations of a three-dimension ideal inferior vena cava-iliac vein model with artificial stenosis to determine the degree of stenosis that requires clinical intervention.

Methods

Four three-dimension stenosis models (30%, 50%, 70%, and 90% stenosis) were constructed using commercial software (Solidworks). The inlet flow rates were acquired from previous literatures to perform the hemodynamic simulations. Changes in the old blood volume fraction, as well conventional hemodynamic parameters including pressure, differential pressure, wall shear stress, and flow patterns, over time were recorded. The pressure at the telecentric region of the stenosis increased with increasing degree of stenosis.

Results

For the 70% stenosis model, the pressure at the telecentric region of the stenosis reached 341 Pa, and the differential pressure between the two ends of the stenosis was 363 Pa (approximately 2.7 mmHg). Moreover, in the 70% and 90% stenosis models, there was a marked change in wall shear stress in the stenosis and the proximal end region, and the flow patterns began to show the phenomenon of flow separation. Blood stasis analysis showed that the 70% stenosis model had the slowest decrease in old blood volume fraction, while the proximal end region had the largest blood residue (15%).

Conclusion

Iliac vein stenosis of approximately 70% is associated with clinically relevant hemodynamic changes, and is more closely related to DVT than other degrees of stenosis.

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

Background

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

Case presentation

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

Conclusions

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

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.

Diagnostic Value of the Iliac Vein Stenosis Percentage Combined With Indicators of Venous Reflux for Iliac Vein Compression Syndrome With Computed Tomography Venography

OBJECTIVES

To identify a cutoff value of iliac vein stenosis in computed tomography venography (CTV) for assisting in the diagnosis of iliac vein compression syndrome (IVCS). Meanwhile, determining whether the inclusion of venous return and collateral imaging findings could further enhance the diagnostic performance.

METHODS

We conducted a retrospective study on 264 patients suspected of IVCS who underwent both CTV and digital subtraction venography (DSV) from January 2016 to December 2020; they were assigned to either a control group (n = 101) or an IVCS group (n = 163) based on the DSV results. The narrowest anteroposterior diameter of the common iliac vein and the anteroposterior diameter of the distal end were measured to calculate the percentage of iliac vein stenosis. Receiver operating characteristic curve analysis was performed to determine the predictive accuracy of the percentage of iliac vein stenosis for IVCS and whether the inclusion of venous reflux indicators can further improve the diagnostic accuracy.

RESULTS

With respect to the DSV results, the area under the curve was 0.797 (P < 0.001). The best cutoff value was 46.67%, corresponding to a sensitivity of 83.44% and a specificity of 69.31% for predicting IVCS. Moreover, the combination diagnostic method had higher sensitivity and accuracy (94.48% vs 83.44% [P = 0.01] and 84.85% vs 78.03% [P = 0.04], respectively).

CONCLUSIONS

The best cutoff percentage of iliac vein stenosis to diagnose IVCS was 46.67% with CTV. The sensitivity and accuracy of the combined diagnostic method were higher than those of the iliac vein stenosis ratio diagnostic method.

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

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

[Endovascular Therapy of Chronic Iliofemoral Venous Outflow Obstructions]

Deep vein thrombosis (DVT) is associated with a high cost burden for health care systems because of secondary cost intensive complications like pulmonary embolism and especially the post thrombotic syndrome (PTS). Current standard therapy of anticoagulation for DVT therapy has not changed through the years leaving patients especially with iliofemoral vein thrombus on a high-risk situation for developing PTS. For patients with chronic venous outflow obstruction of the iliac vein system dedicated venous stents and recanalization techniques are today available.

Neue Therapien akuter und chronischer Beckenvenenobstruktionen

Die Inzidenz der tiefen Venenthrombose (TVT) beträgt in Westeuropa 1/1000 Einwohner pro Jahr. Je nach Lokalisation und Ausdehnung der TVT entwickeln 20–83% der Patienten ein postthrombotisches Syndrom trotz einer optimalen Antikoagulation und Kompressionstherapie. Endovaskuläre Thrombektomieverfahren mit Wiedereröffnung der iliofemoralen venösen Strombahn haben das Ziel, mittel- und langfristig ein postthrombotisches Syndrom zu vermeiden. Bei Patienten mit chronischen V.-cava- und Beckenvenenverschlüssen stehen heutzutage spezielle Rekanalisationstechniken mit Einsatz von speziellen venösen Stents zur Verfügung.

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.

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.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Treatment of Nonthrombotic Iliac Vein Lesions

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

Braided nitinol stent for chronic iliofemoral venous disease - the real-world BLUEFLOW registry

Background: In patients with iliofemoral chronic venous disease (CVD) secondary to post-thrombotic or non-thrombotic obstruction, venous outflow obstruction after adequate anticoagulation alone is still frequent and post-thrombotic syndrome is a common complication. Thus, we aimed to evaluate mid-term effectiveness and safety of a novel braided venous stent for venous outflow obstruction treatment. Patients and methods: Consecutive patients who underwent venous recanalization with a new braided, closed cell, venous stent for non- or post-thrombotic CVD were eligible for inclusion in our retrospective, observational study. Effectiveness outcomes were primary patency and change in the revised venous clinical severity score (rVCSS) and the clinical score of the comprehensive classification system for chronic venous disease (CEAP) at 6- and 12-month follow-up. Safety outcomes were recurrent DVT, clinically driven target vein revascularization, index limb major amputation, or death. Results: A total of 67 participants (50.7% female, aged 46.7±18.1 years) who underwent blueflow Venous Stent implantation between February 2018 and March 2019 were enrolled. Primary patency of the target segment was present in 91.7% (95%CI: 76.8-97.7) of participants at the 6-month examination and in 79.8% (95%CI: 66.4-93.2) at the 12-month examination. Twelve-month primary patency was 91.7% (95%CI: 76.0-100) in non-thrombotic, and 72.6% (95%CI: 53.9-91.3) in postthrombotic disease (log-rank p=0.14). Median rVCSS improved from 8 (interquartile range [IQR]: 9-7) at baseline to 4 (IQR: 6.3-2.8) at 12 months (p<0.001) with a substantial clinical improvement of ≥2 points in 86.1% (31 of 36 participants). No significant association of rVCSS improvement with thrombotic pathogenesis could be found. Median clinical CEAP score improved from 3 (IQR: 3-3) to 2 (IQR: 3-2), p>0.001. No safety signal occurred. Conclusions: blueflow Venous Stent implantation for the treatment of iliofemoral CVD was associated with promising patency and favorable clinical improvement over the mid-term.

Endovascular and medical therapy of May-Thurner syndrome: Case series and scoping literature review

INTRODUCTION

May-Thurner syndrome has been recognized as a cause of chronic venous insufficiency and a trigger for venous thromboembolism. There is no consensus about the definition, diagnosis, and therapeutic approach. We are aiming to describe its characteristics and a scoping literature review.

METHODS

A retrospective review of patients with May-Thurner syndrome from March 2010 to May 2018 and scoping literature review were made.

RESULTS

Seven patients were identified. All patients were female with a median age of 36 (20-60) years. The median time from the first symptom to diagnosis was 3.41 (0.01-9) years. The primary clinical presentation was post-thrombotic syndrome (4 patients). Six patients had at least one risk factor for deep venous thrombosis. All patients underwent angioplasty with stent; patients with acute deep venous thrombosis, furthermore mechanic thrombectomy with or without catheter-directed thrombolysis were done. There were three complications (one patient, lymphedema, and two venous stent thrombosis). Scoping review results were descriptively summarized.

CONCLUSION

May-Thurner syndrome has a varied spectrum of clinical presentation, and clinical awareness is paramount for diagnosis. Its principal complication is the post-thrombotic syndrome, which is associated with high morbidity. There is no consensus on the antithrombotic treatment approach.

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.

A review into the management of May-Thurner syndrome in adolescents

OBJECTIVE

To investigate the presentation, etiology, management and outcomes of May-Thurner syndrome (MTS) in adolescents aged under 18.

METHODS

We searched electronic bibliographic databases to identify published reports of MTS in patients under 18 years of age. We conducted our review according to the PRISMA statement standards.

RESULTS

Ten studies encompassing 22 patients treated for MTS in adolescent cases were identified. The mean age of patients was 15 years (range, 10-18 years). Of the 22 patients, 12 (55%) were confirmed to have proximal deep vein thrombosis as the primary indication for intervention. Treatment methods included catheter-directed thrombolysis and iliac vein stenting (41%), pharmacomechanical thrombolysis and iliac vein stenting (18%), iliac vein stenting alone (27%), open surgery (14%), catheter-directed thrombolysis (5%), and anticoagulation alone (5%). Complications were infrequent. All studies reported subjective improvements in clinical symptoms with only two studies using validate outcome measures. In total, 9 of 22 patients (41%) had addition risk factors that may precipitate thrombosis.

CONCLUSIONS

As in adults, the most common form of treatment seen in the literature is a combination of catheter direct thrombolysis, followed by iliac vein stenting with subsequent anticoagulation. Complications from interventions were low. It is unclear how these interventions affect symptomology and the long-term sequalae associated endovascular surgery and stenting in adolescents. Further research is needed in well-designed studies with adequate follow-up.

Compression of left renal vein and left common iliac vein on CT scans: how often are they detected?

Background

The nutcracker and May-Thurner syndromes are rare and, although often underdiagnosed, they can cause limiting symptoms. They are frequently considered only after exclusion of other diagnoses and there is no consensus in the literature on prevalence, incidence, or diagnostic criteria.

Objectives

To estimate the frequency of compression of the left common iliac vein and left renal vein in CT scans of the abdomen and pelvis.

Methods

Descriptive, quantitative, cross-sectional study. The criteria used to define compression of the left renal vein were a hilar/aortomesenteric diameter ratio > 4 and aortomesenteric angle < 39° and the criterion for compression of the left common iliac vein was a diameter < 4mm.

Results

CT scans of 95 patients were analyzed; 61% were women and 39% were men. Left renal vein compression was observed in 24.2% of the sample, with a mean age of 48.8 years, occurring in 27.6% of the women and 18.9% of the men (p = 0.3366). Compression of the left common iliac vein was detected in 15.7% of the sample, with a mean age of 45.9 years, occurring in 24.1% of the women and 2.7% of the men (p = 0.0024). Both veins were compressed in 7.4% of the patients.

Conclusions

Left renal vein compression was detected in women and men at similar frequencies, whereas left common iliac vein compression was more frequent in women. Both venous compressions were most frequently found in patients aged 41 to 50 years.

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.

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.

The clinical outcome of a one-stop procedure for patients with iliac vein compression combined with varicose veins

BACKGROUND

Primary iliac vein compression syndrome (IVCS) often is manifested with varicose veins (VVs), but the treatment of patients with IVCS combined with VVs remains unclear. The aim of this study was to investigate the outcome of a one-stop procedure for patients with IVCS and VVs.

METHODS

The 32 enrolled patients underwent iliac stenting first and then endovenous laser ablation for VVs. The reflux time of the femoral vein, peak reflux velocity, and mean flow velocity were measured, and the effect on quality of life was also assessed using the Aberdeen Varicose Vein Questionnaire and Venous Clinical Severity Score. All clinical data have been recorded and analyzed.

RESULTS

The success rate of the procedures was 100%. No serious complications occurred. The Aberdeen Varicose Vein Questionnaire score and Venous Clinical Severity Score of patients were significantly lower at 1 month, 6 months, and 12 months after the procedure compared with scores before the procedure (P < .01). The reflux time and peak reflux velocity were lower at 6 and 12 months after the procedure (P < .01), and the mean flow velocity was higher at 6 and 12 months after the procedure (P < .05). The patency rate of the iliac vein stent was 100% during follow-up, and one patient (3.13%) had a restenosis without symptoms.

CONCLUSIONS

The one-stop procedure for patients with IVCS combined with VVs is a safe and effective method that might be a therapy choice for these patients.

Diagnosis and Treatment of Nonthrombotic Right Iliac Vein Compression Syndrome

BACKGROUND

The anatomical etiology of right iliac vein compression syndrome (RIVCS) differs from that of left iliac vein compression syndrome. This study aimed to investigate the clinical features and therapeutic characteristics of RIVCS.

METHODS

Sixteen patients with nonthrombotic RIVCS were admitted to our hospital from May 2013 to July 2017. All patients underwent computed tomography venography (CTV) examinations of the right lower limb, which indicated that the right iliac veins were compressed by extrinsic structures. RIVCS was divided into 3 types according to the CTV findings. Stenting was conducted in patients with the appropriate indications. The superficial varicose veins in the lower limbs were simultaneously treated during endovascular treatment in a compound operating room. Antiplatelet therapy was administered after discharge.

RESULTS

Most RIVCS cases were types II and III, and the most frequently compressed segments were the middle and distal parts of the iliac vein. Most stents did not require stretching into the inferior vena cava and therefore seldom affected contralateral blood flow. Fifteen patients required stenting; the diameters of the stents ranged from 10 to 16 mm. All symptoms were alleviated, and the ulcers healed postoperatively. The remaining single patient with superficial varicose veins did not have an indication for endovascular therapy. During follow-up, all patients were symptom free, and the stents showed excellent patency.

CONCLUSIONS

CTV is a simple, accurate, and important method for diagnosing RIVCS. Endovascular therapy is an effective therapeutic method for RIVCS. Compared with the left side, stent implantation for RIVCS is safer and has fewer effects on contralateral blood flow.

Long-term outcome and quality of life in patients with iliac vein compression syndrome after endovascular treatment

Purpose

Deep venous thrombosis induced by iliac vein compression syndrome often interferes with patients’ work or daily living. This study aims to investigate the long-term outcome and quality of life in patients with iliac vein compression syndrome after endovascular treatment.

Methods

From October 2011 until June 2016, 28 patients with acute deep venous thrombosis diagnosed as iliac vein compression syndrome by ultrasonography were enrolled in this perspective study. Fifteen patients underwent balloon dilation and stent insertion (group A); 13 patients received anticoagulation treatment, thrombolysis, or balloon dilation without stenting (group B). The Medical Outcomes Study-Short Form-36 was used to assess the quality of life preoperatively and after endovascular treatment. The follow-up of Short Form-36 questionnaire was obtained within 12.13 ± 12.04 months after repair.

Results

There was no operative mortality in two groups, and technical success was achieved in 14 (93.3%) patients in group A. Thirteen (86.7%) patients were cured in group A, which was significantly higher than that of group B (46.2%, p = 0.042). Only one patient showed occlusion of stent in group A, with a secondary patency rate of 93.3%. Except for ‘Role emotion’, all remaining domains were significantly improved in group A when compared with preoperative score ( p < 0.01). The scores of ‘Physical functioning’, ‘Role physical’, and ‘General health’ in group A were significantly higher than those of group B ( p < 0.05).

Conclusions

Endovascular stenting to treat iliac vein compression syndrome shows beneficial clinical outcome, cumulative patency rate, and quality of life, with high technical success and low complications.

Illusory Angiographic Signs of Significant Iliac Vein Compression in Healthy Volunteers

OBJECTIVE

Iliac vein compression syndrome can cause severe leg symptoms. In clinical practice, it remains a challenge to differentiate which compression is clinically relevant. The aim of the current study was to assess the general treatment indications and the prevalence of angiographic signs of iliac vein compression in a group of healthy participants.

METHODS

This was a prospective cohort study. A total of 20 healthy volunteers (median age 21, range 20-22 years) were recruited through advertisement and underwent angiography of the iliac veins. When no compression signs were present, a balloon occlusion was performed. Additionally, a 10 item survey regarding indications for venous stenting was developed and sent to 30 vascular specialists treating patients with deep venous obstruction.

RESULTS

In 16 (80%) participants, at least two signs indicative of May-Thurner compression were seen. In three (15%) subjects, narrowing of the common iliac vein without collaterals was shown and one (5%) did not show any signs of obstruction. In 23 (70%) of the survey responders, collaterals were found to be the most typical sign indicative of significant venous obstruction. An angiographic sign of >50% compression was found to be an indication to stent in 55% of responders.

CONCLUSION

This study demonstrates a remarkably high percentage of generally accepted signs of significant iliac vein obstruction (May-Thurner compression) on venography in healthy young subjects. Diagnosis of true iliac vein obstruction remains a major challenge, which mostly leans on improvement of clinical symptoms rather than imaging findings. Treating the patient rather than the image seems to be a valid principle all the more.

Left iliac vein compression is not associated with infrainguinal deep venous thrombosis but is associated with iliac vein involvement

OBJECTIVE

The purpose of this study was to investigate whether left iliac vein (LIV) compression had similar correlation with the risk of left iliac deep venous thrombosis (DVT; iliac vein involvement) and infrainguinal DVT (without iliac vein involvement).

METHODS

A retrospective analysis of records and enhanced computed tomography images was conducted of 278 patients with left-sided DVT (iliac DVT, 228 patients; infrainguinal DVT, 50 patients) and 232 control patients without DVT on either side. The influences of LIV compression on the risk of left iliac DVT and infrainguinal DVT were investigated using logistic regression analysis.

RESULTS

Mean percentage compression of the LIV in left iliac DVT (74.64% ± 0.99%) patients was significantly higher than in non-DVT patients (53.42% ± 1.49%; P < .01). However, mean percentage compression of the LIV in left infrainguinal DVT patients (45.37% ± 2.71%) was significantly lower than in non-DVT patients (53.42% ± 1.49%; P < .01). LIV compression was associated with increased odds of left iliac DVT (odds ratio, 1.88; 95% confidence interval, 1.64-2.15; P < .01) for each 10% increase in percentage compression of the LIV. However, LIV compression was not associated with increased odds of infrainguinal DVT (odds ratio, 0.89; 95% confidence interval, 0.76-1.03; P = .126).

CONCLUSIONS

Left iliac DVT patients had more severe LIV compression than left infrainguinal DVT patients did. LIV compression was not associated with development of left infrainguinal DVT, but it did correlate with the presence of left-sided DVT with iliac vein involvement.

Application of computed tomography venography in the diagnosis and severity assessment of iliac vein compression syndrome: A retrospective study

The objectives are to evaluate the application of computed tomography venography (CTV) in the diagnosis of iliac vein compression syndrome (IVCS), and to assess the factors related to the incidence and development of IVCS and the recurrence of varicose veins.Imaging data of 120 patients with chronic venous disease (CVD) of the lower extremity and 68 subjects without CVD (control) were retrospectively reviewed by radiologists blinded to the groups. CTV, conventional venography, and Doppler ultrasound were compared in the diagnosis and contributing factors for IVCS were also analyzed.CTV required less procedure time than venography or color ultrasonography (P < .001). The rate of iliac venous compression diagnosed by CTV was higher in the CVD group (53.3%) than in the control group (22.1%) (χ = 17.425, P < .001). Risk factors for IVCS included gender, hyperlipidemia, and course of disease (P < .05). Development of femoral vein collateral was more common in patients with IVCS (P < .05). The duration of disease was positively associated with the severity of iliac vein compression (r = 0.321, P < .001). IVCS was an important contributing factor for varicose vein recurrence (51.2%). In patients with IVCS and venous ulcer (C5-C6), the healing time of the ulcer treated with stent was significantly shorter compared with those without stent treatment (P < .001).CTV is accurate for the diagnosis and severity evaluation of IVCS. IVCS might be a contributing factor for varicose vein recurrence. Iliac vein stent implantation as a safe and effective interventional therapy promotes the healing of venous ulcer caused by IVCS.

Standards for recanalisation of chronic venous outflow obstructions

Abstract. Postthrombotic syndrome (PTS) is the most common complication after iliofemoral deep vein thrombosis. It reduces quality of life and increases deep vein thrombosis (DVT)-related costs. The clinical symptoms and severity of PTS may vary; the most common symptoms include edema, pain (venous claudication), hyperpigmentation, lipodermatosclerosis, and ulceration. PTS is based on the principle of outflow obstruction, which may be caused by venous hypertension and may lead to valvular damage and venous reflux or insufficiency. Recent technical developments and new stent techniques now allow recanalisation of even complex venous outflow obstructions within the iliac vein and the inferior vena cava. This manuscript gives an overview on the latest standards for venous recanalisation.

Diagnosis and endovascular treatment of iliac venous compression syndrome

OBJECTIVES

To report *The first two authors contributed equally to this work. our clinical experience on diagnostic criteria and endovascular management in patients with iliac venous compression syndrome.

METHOD

Between July 2013 and May 2015, 85 consecutive patients with suspected iliac venous compression syndrome were evaluated by transfemoral venography and intravascular ultrasonography. Venographic evidence of iliac venous occlusion, stenosis, or pelvic collateral vessels, and the degree of stenosis as examined with intravascular ultrasonography were recorded. The endovascular procedure, complications, clinical outcome, and the Venous Clinical Severity Score were evaluated before and after the intervention.

RESULTS

Of the 85 limbs, 66 cases of iliac venous compression syndrome were confirmed and 19 cases were excluded. In all of the 66 patients, we successfully performed endovascular intervention (22 balloon dilations, 44 balloon dilations + stenting). Two patients with stent implantation developed acute lower extremity deep vein thrombosis, resulted in successful lysis of the thrombus with catheter-directed thrombolysis.

CONCLUSIONS

The presence of intraluminal spurs and pelvic collateral vessels represents not only pathological and anatomical changes by long-term mechanical compression, but also indicators of the severity of iliac venous compression syndrome. The degree of stenosis cannot accurately represent the severity and treatment of iliac venous compression syndrome, especially in the right iliac vein. Endovascular intervention is a safe and effective treatment that reduces lower extremity symptoms. Full and intentional dilation of the intraluminal spurs is an important technical aspect, which is often ignored.

The Midterm Effect of Iliac Vein Stenting following Catheter-directed Thrombolysis for the Treatment of Deep Vein Thrombosis

BACKGROUND

When following catheter-directed thrombolysis (CDT) for deep vein thrombosis (DVT), the stenosed iliac veins is controversy. To evaluate the mid-term outcomes of CDT with or without stent implantation for DVT in the presence of iliac vein compression.

METHODS

Seventy-three patients with iliac vein compression following CDT for acute lower extremity DVT from January 2009 to December 2014 were retrospectively analyzed. There were 32 males and 41 females, with average age of 53.57 ± 15.60 years (median: 45 years, range: 20-79 years). After CDT, patients with iliac vein compression were divided into 2 groups: the stenting group (n = 40) and the nonstenting group (n = 33). Patency rate of the deep vein, chronic change of vessels, clinical, etiological, anatomical, and pathological elements (CEAP) classification, venous clinical severity score, and Villalta scale were chosen to evaluate the midterm and long-term outcomes.

RESULTS

Eighty-eight limbs among the patients (58 unilateral and 15 bilateral) were followed with mean time of 38.38 ± 14.91 months. The difference in vein patency between 2 groups (85.17 ± 25.62 vs. 54.61 ± 40.42) was statistically significant (P < 0.05). According to the C in CEAP classification, the difference in clinical manifestations between the 2 groups was statistically significant (P < 0.05). In addition, the Villalta scale scores were also significantly different between the 2 groups (1.73 ± 2.86 vs. 4.39 ± 5.16, P < 0.05).

CONCLUSIONS

Stent implantation in severely stenosed iliac segments following CDT for lower extremity DVT increased the patency of deep veins and improved midterm quality of life compared with that of nonstenting.

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.

May-Thurner syndrome: an often overlooked cause for refractory venous leg ulcers

We report a 53-year-old female patient presenting with a refractory venous leg ulcer and unremarkable findings in the doppler Ultrasound venous mapping of the leg veins. Further comprehensive diagnostics demonstrated an underlying May-Thurner syndrome. After resolution of the primary mechanical obstruction, rapid wound healing in the following 3 weeks was documented. Iliac vein compression syndrome, commonly known as May-Thurner syndrome, is a distinguishable anatomical variant that results from an external compression over the left iliac vein exerted by the overriding adjacent right common iliac artery. It is mostly seen among young, healthy female patients and can easily be under-diagnosed. Lower extremities duplex ultrasonography remains the gold standard in diagnosing venous insufficiency, but it should not solely depend on it. Instead, clinicians should consider other possibilities, assessing the patency within the truncal veins, which in turn might contribute to the venous insufficiency along the lower limbs. An active early diagnostic approach can prevent significant overall morbidity and help patients to ease back into their daily-life activities. Therefore, it is recommended that all patients with suspected venous insufficiency and normal lower limbs duplex findings should undergo further evaluation of the truncal venous system pattern. May-Thurner syndrome, along with other causes of iliac veins compression, should be considered in the differential diagnosis in unclear persistent cases of unilateral venous symptoms.

Lower extremity venous reflux

Venous incompetence in the lower extremity is a common clinical problem. Basic understanding of venous anatomy, pathophysiologic mechanisms of venous reflux is essential for choosing the appropriate treatment strategy. The complex interplay of venous pressure, abdominal pressure, venous valvular function and gravitational force determine the venous incompetence. This review is intended to provide a succinct review of the pathophysiology of venous incompetence and the current role of imaging in its management.