Three-Year Outcomes of the Abre Venous Self-Expanding Stent System in Patients with Symptomatic Iliofemoral Venous Outflow Obstruction.

PURPOSE: To report 36-month outcomes and subgroup analysis of the ABRE study evaluating the safety and effectiveness of the Abre venous self-expanding stent system for the treatment of symptomatic iliofemoral venous outflow obstruction disease. METHODS: The ABRE study was a prospective, multicenter, nonrandomized study that enrolled and implanted Abre venous stents in 200 participants (mean age 51.5 years [SD ± 15.9], 66.5% women) with symptomatic iliofemoral venous outflow obstruction at 24 global sites. Outcomes assessed through 36 months included patency, major adverse events, stent migration, stent fracture, and quality-of-life changes. Adverse events and imaging studies were adjudicated by independent clinical events committee and core laboratories, respectively. RESULTS: Primary, primary-assisted, and secondary patency through 36 months by Kaplan-Meier estimates were 81.6%, 84.8%, and 86.3%, respectively. The cumulative incidence of major adverse events through 36 months was 10.2%, mainly driven by 12 thrombosis events. Subgroup analyses demonstrated a primary patency of 76.5% in the acute deep vein thrombosis group, 70.4% in the postthrombotic syndrome group, and 97.1% in the nonthrombotic iliac vein lesion group through 36 months. The overall mean lesion length was 112.4 mm (SD ± 66.1). There were no stent fractures or migrations in this study. Quality of life and venous functional assessments demonstrated significant improvements from baseline to 36 months across all patient subsets. CONCLUSIONS: Results from the ABRE study demonstrated sustained patency with a good safety profile after implantation of a dedicated venous stent in patients with symptomatic iliofemoral venous outflow obstruction disease.

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.

Effect of body mass index on initial presentation and outcomes after stenting for quality of life-impairing chronic iliofemoral venous obstruction.

OBJECTIVE: The incidence of obesity has been increasing, with recent data indicating that the age-adjusted mean body mass index (BMI) is close to 30 kg/m2 in the United States. Prior studies have raised concerns for an increased incidence of chronic venous insufficiency in the obese population. We aimed to build on current knowledge by assessing the effects of BMI on the initial presentation and outcomes after intravascular ultrasound (IVUS) luminal area-guided stenting in patients presenting with quality of life (QOL)-impairing chronic iliofemoral venous obstruction (CIVO). METHODS: A retrospective analysis of contemporaneously entered electronic medical record data on 464 continuous patients (464 limbs) with initial iliofemoral stents (2014-2017) for QOL-impairing CIVO was performed. The characteristics evaluated and compared included the degree of iliofemoral compression, CEAP (clinical, etiologic, anatomic, pathophysiologic) clinical class, venous clinical severity score (VCSS), grade of swelling (GOS), visual analog scale (VAS) for pain score, ulcer healing, reflux (venous segmental disease score; venous filling index-90), calf pump function (ejection fraction; residual volume fraction), and quality of life (CIVIQ-20 [chronic lower limb venous insufficiency 20-item questionnaire]) for those with a BMI <30 kg/m2 (group I) and a BMI ≥30 kg/m2 (group II). Paired and unpaired t tests were used for comparisons of the clinical variables and a Kaplan-Meier analysis was used to evaluate stent patency. RESULTS: Of the 464 limbs in the study cohort, 122 were in group I and 342 in group II. The median BMI was 26.3 kg/m2 (interquartile range, 19.6-29.9 kg/m2) in group I and 38.9 kg/m2 (interquartile range, 30.0-66.9 kg/m2) in group II. The IVUS luminal area-determined degree of compression was higher in group I than in group II across the common iliac, external iliac, and common femoral segments (P < .01). The supine foot venous and femoral venous pressures were higher in group II than in group I (P < .001). The ejection fraction was higher (57.4% vs 45.6%; P = .0008) and residual volume fraction was lower (27.5% vs 40.5%; P = .0008) in group II than in group I. Although the baseline VCSS and GOS were lower in group I than in group II (P < .05), no differences were found in the VAS for pain scores or ulcer prevalence. The median follow-up was 22 months. At 24 months after stenting, improvement was found in the VCSS, GOS, and VAS for pain score in both groups. The CIVIQ-20 QOL score had improved from 58.1 to 18.8 in group I (P = .0002) and from 60 to 37.5 in group II (P < .0001). At 5 years, primary patency was 70% in group I and 73% in group II (P = .6) and primary assisted patency was 100% in both groups (P = .99) without a significant difference in the reintervention rate (P = .5). CONCLUSIONS: Obese patients with CIVO-impairing QOL have a lesser degree of iliofemoral venous stenosis, more severe venous hypertension, and better calf pump function than their nonobese counterparts. After stenting, no differences were found in the clinical, stent patency, or QOL-related outcomes between the two groups.

Common iliac vein stenting for May-Thurner syndrome and subsequent pregnancy.

BACKGROUND: For women with left common iliac vein compression (ie, May-Thurner syndrome) who undergo venous stenting and subsequently become pregnant, concerns have been raised regarding a possible compromise of stent patency due to compression from the gravid uterus and the hypercoagulability induced by pregnancy. Only a small body of literature exists on this subject, and limited management guidelines are available. The present study was designed to evaluate the safety of iliac vein stenting for May-Thurner syndrome (MTS) with subsequent pregnancy. METHODS: Female patients who had undergone common iliac vein stenting at our center who were aged 18 to 45 years and had subsequently become pregnant were identified. A retrospective medical record review of eight eligible patients was conducted, recording the demographics, procedural characteristics, and anticoagulation strategies. The primary outcome evaluated was stent patency. RESULTS: All eight patients had undergone left common iliac vein stenting for MTS. A total of eight stents were placed, and all demonstrated duplex ultrasound patency throughout pregnancy and postpartum. Seven patients delivered healthy pregnancies, and one experienced a stillbirth. The clinical CEAP (clinical, etiologic, anatomic, pathophysiologic) class remained unchanged or improved from pregnancy to postpartum for all patients. The average age at stent placement was 31 ± 5 years, and the average interval from stent placement to pregnancy was 28 ± 19 months. One patient developed nonobstructive deep vein thrombosis (DVT) of the left femoral vein during pregnancy and was treated with therapeutic enoxaparin. The nonobstructive DVT did not compromise the iliac vein stent. Two patients received low-dose aspirin and prophylactic doses of enoxaparin, one for a history of DVT and factor V Leiden and one for a recent history of fertility treatment. The five remaining patients received no anticoagulation, three received low-dose aspirin, and two received no antiplatelet therapy. CONCLUSIONS: Common iliac vein stent patency was not compromised by subsequent pregnancy in our eight patients with MTS. Furthermore, the stents remained patent throughout pregnancy in patients receiving a wide range of anticoagulation and antiplatelet treatments, suggesting that no uniform therapeutic threshold exists and treatment should be individualized. For most patients, low-dose aspirin alone or no treatment was adequate. This could have implications for counseling women who require intervention for MTS and are of child-bearing age.

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

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

Contemporary treatment of May-Thurner Syndrome.

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

The Symptoms-Varices-Pathophysiology classification of pelvic venous disorders: A report of the American Vein & Lymphatic Society International Working Group on Pelvic Venous Disorders.

As the importance of pelvic venous disorders (PeVD) has been increasingly recognized, progress in the field has been limited by the lack of a valid and reliable classification instrument. Misleading historical nomenclature, such as the May-Thurner, pelvic congestion, and nutcracker syndromes, often fails to recognize the interrelationship of many pelvic symptoms and their underlying pathophysiology. Based on a perceived need, the American Vein and Lymphatic Society convened an international, multidisciplinary panel charged with the development of a discriminative classification instrument for PeVD. This instrument, the Symptoms-Varices-Pathophysiology ("SVP") classification for PeVD, includes three domains-Symptoms (S), Varices (V), and Pathophysiology (P), with the pathophysiology domain encompassing the Anatomic (A), Hemodynamic (H), and Etiologic (E) features of the patient's disease. An individual patient's classification is designated as SVPA,H,E. For patients with pelvic origin lower extremity signs or symptoms, the SVP instrument is complementary to and should be used in conjunction with the Clinical-Etiologic-Anatomic-Physiologic (CEAP) classification. The SVP instrument accurately defines the diverse patient populations with PeVD, an important step in improving clinical decision making, developing disease-specific outcome measures and identifying homogenous patient populations for clinical trials.

Doppler ultrasound and contrast-enhanced ultrasound in detection of stent stenosis after iliac vein stenting.

BACKGROUND: To compare the diagnostic accuracy of Doppler ultrasound (DUS) with contrast-enhanced ultrasound (CEUS) for detection of iliac vein stent stenosis using multidetector computed tomography venography (MDCTV) as the reference method. METHODS: Patients with iliac vein obstructive disease treated with nitinol stents (Smart Control, Cordis, USA) between January 2016 and December 2017 were consecutively included in this study. DUS, CEUS, and MDCTV were carried out in all patients within one week of each other at 1 year post stenting to investigate the presence of stent compression and in-stent restenosis (ISR). RESULTS: The study included 139 patients (87 females; mean age 58 ± 15 years). For detecting stent compression, the kappa coefficient between the ultrasound modality of gray-scale imaging and MDCTV was 0.901, indicating very good agreement between these two modalities. ISR was detected in 50, 61, and 65 patients by DUS, CEUS, and MDCTV, respectively. DUS and CEUS (kappa = 0.449) and DUS and MDCTV (kappa = 0.516) had moderate agreement for ISR diagnosis, while for which CEUS and MDCTV (kappa 0.884) had very good agreement. The sensitivity and specificity of DUS and CEUS for diagnosing ISR were 63.1% and 90.8%, 87.8% and 97.3%, respectively. CONCLUSIONS: CEUS is probably superior to DUS in terms of diagnostic accuracy for the follow-up of patients with iliac vein stent stenosis.

Association between deep vein thrombosis and stent patency in symptomatic iliac vein compression syndrome: Systematic review and meta-analysis.

BACKGROUND: The study intended to evaluate stent primary patency rates for patients with iliac vein obstruction related with iliac vein compression syndrome according to clinic presentation. METHODS: A systematic review and meta-analysis was conducted of studies that compared: unexposed patients with nonthrombotic iliac vein lesion (NIVL, group 1) vs exposed patients with iliac acute deep vein thrombosis (DVT, group 2); and NIVL (group 1) vs exposed patients with iliac vein obstruction and post-thrombotic syndrome (PTS, group 3). The following databases were searched: EMBASE, PubMed, Web of Science, Scopus, SciELO, and LILACS. Two reviewers independently selected the potential studies and extracted data. The pooled odds ratio (OR) and 95% confidence interval (95% CI) are shown for each outcome. RESULTS: Five studies with a total of 1050 participants and 1169 lower limbs were included. Five hundred eighty-eight lower limbs presented NIVL (50.3%), 91 lower limbs presented acute DVT (7.7%), and 490 lower limbs presented PTS (42%). The endovascular technical success rate of stenting did not differ in any of the groups: 99.6% in NIVL, 94.5% in acute DVT, and 96.5% in PTS (P = .0632). The primary stent patency rates in the 6-month follow-up were 98.3% in NIVL vs 90.9% in PTS, with a statistical difference showing reduced stent patency rates in PTS (OR, 0.17; 95% CI, 0.06-0.48; P = .0008; I2 = 0%), and 100% in the NIVL group vs 91.6% in acute DVT, with no statistical difference (OR, 0.30; 95% CI, 0.06-2.32; P = .30; I2 = 0%). The primary stent patency rates in the 12-month follow-up were 94.6% in NIVL vs 84.1% in PTS, with a statistical difference showing decreases stent patency rates in the PTS group (OR, 0.29; 95% CI, 0.14-0.63; P = .0008; I2 = 0%), and 91.1% in NIVL vs 90.9% in acute DVT, with no statistical difference (OR, 1.03; 95% CI, 0.26-4.07; P = .96; I2 = 0%). CONCLUSIONS: There is no statistical difference for the stent primary patency rates when the treatment is conducted in NIVL as compared with acute DVT lower limbs (at 6 and 12 months); therefore, other criteria must be considered for the indication of this treatment in NIVL patients. However, because there were better results of stent primary patency rates for NIVL vs PTS patients, this finding favors the treatment of acute DVT instead of PTS in lower limbs, once PTS renders smaller stent patency rates at 6 and 12 months.

Long-term outcomes following use of a composite Wallstent-Z stent approach to iliofemoral venous stenting.

OBJECTIVE: An endovascular approach has essentially replaced open surgery in the management of symptomatic chronic obstructive iliofemoral venous disease. In the last several years, such a minimally invasive approach has shifted from use of Wallstents alone to a combination of Wallstent-Z stent (composite stenting) to better deal with the iliocaval confluence. This study evaluates the clinical and stent related outcomes following use of composite stenting. METHODS: A retrospective review of contemporaneously entered EMR data on 535 patients (545 limbs) with initial iliofemoral stents placed over a 4-year period from 2014 to 2017 for symptomatic chronic iliofemoral venous obstruction was performed. Patients who underwent stenting after intervention for acute deep venous thrombosis were excluded. The impact of stenting on clinical outcomes before and after the intervention were evaluated through use of the visual analog scale pain score (0-10), grade of swelling (0-4), and Venous Clinical Severity Score (0-27). Quality of life was appraised using the Chronic Venous Disease quality of life Questionnaire 20 instrument. Kaplan-Meier analysis was used to assess primary, primary assisted and secondary stent patencies, and paired and unpaired t-tests were used to examine clinical outcomes. RESULTS: Of the 545 limbs that underwent stenting, 183 were in men and 362 were in women. The median age was 60 years. Laterality was right in 205 limbs and left in 340 limbs. Post-thrombotic syndrome was seen in 441 limbs and nonthrombotic iliac vein lesions/May-Thurner syndrome in 104 limbs. At 24 months, visual analog scale pain score went from 5 to 2 (P < .0001), grade of swelling went from 3 to 1 (P < .0001), and Venous Clinical Severity Score went from 6 to 4 (P < .0001). Ulcers were present in 67 limbs and had healed in 49 limbs (73%) over a median follow-up of 26 months. Global Chronic Venous Disease quality of life Questionnaire scores improved from 60 to 36 (P < .0001) after stenting. Cumulative primary, primary-assisted, and secondary patencies at 60 months were 70%, 99% and 91%, respectively. Thirty limbs (5.5%) required contralateral stenting. There was only one instance (0.2%) of contralateral iliofemoral deep venous thrombosis. One hundred eleven limbs (20%) underwent reintervention, including for in-stent restenosis in 44 limbs, stent compression in 2 limbs, in-stent restenosis and stent compression in 48 limbs, and stent occlusion in 17 limbs. CONCLUSIONS: In patients undergoing iliofemoral venous stenting for obstructive disease, clinical improvement, quality of life improvement, and stent patencies after use of a composite stent configuration are comparable with those seen after exclusive use of Wallstents. However, the use of a composite stent configuration not only decreases the need for contralateral stenting to relieve chronic obstruction, but also decreases the incidence of contralateral iliofemoral deep venous thrombosis.

Clinical outcomes of radiofrequency ablation for patients with varicose veins of the lower extremities combined with grade II iliac vein compression.

BACKGROUND: Iliac vein compression (IVC) is a common condition in patients with varicose veins (VVs) of the legs. IVC has been classified into three grades in previous studies. Grade II IVC is defined by >50% stenosis without the development of collateral circulation. The purpose of the present study was to investigate the outcomes of radiofrequency ablation (RFA) for patients with VVs combined with grade II IVC. METHODS: A retrospective analysis was conducted of 339 patients who had undergone RFA for VVs of the left leg from March 2017 to January 2019. Duplex ultrasonography, computed tomography venography, and venography were performed to evaluate for grade II IVC. All the patients were divided into two groups. Group 1 included patients with VVs only, and group 2, patients with VVs combined with grade II IVC. Propensity score matching was used to ensure an even distribution of confounding factors between groups. The venous clinical severity score (VCSS) and chronic venous insufficiency questionnaire (CIVIQ) score were recorded during the 12-month follow-up. Occlusion of the truncal veins was evaluated using duplex ultrasound scans. RESULTS: Using 1:1 propensity score matching, 50 pairs of patients were enrolled in the present analysis. The average age of groups 1 and 2 was 58.7 ± 13.1 and 60.1 ± 7.1 years, respectively. The VCSS had decreased significantly from baseline to 12 months postoperatively (group 1, from 5 to 1; group 2, from 4 to 1; P < .01). A significant increase in the CIVIQ score was found between the baseline and 12-month evaluations for both groups (group 1, from 62.5 to 69; group 2, from 63 to 70; P < .01). The truncal occlusion rate was 98% in both groups at 12 months. No significant differences were found between the two groups in the VCSS, CIVIQ score, procedure complications, or occlusion rate during the 12-month follow-up. CONCLUSIONS: RFA is effective for patients with VVs combined with grade II IVC.

A retrospective comparison of thrombectomy followed by stenting and thrombectomy alone for the management of deep vein thrombosis with May-Thurner syndrome.

OBJECTIVE: To summarize the clinical results of thrombectomy with stenting (TBS) in patients with deep venous thrombosis (DVT) secondary to May-Thurner syndrome (MTS) compared with the outcomes in patients treated with thrombectomy alone (TB). METHODS: A retrospective observation of patients with proximal DVT secondary to MTS was conducted in our institution. Patients accepted treatment including either catheter-directed TBS or TB. The complications and stent patency rates were recorded after treatments. The clinical results were assessed in both groups. The independent predictors for in-stent restenosis were further calculated in this study. RESULTS: We included 372 patients with DVT secondary to MTS. Two hundred twenty-one patients received treatment with thrombectomy with TBS and 151 with TB. A longer mean procedure time (65.1 ± 13.9 minutes vs 49.5 ± 15.7 minutes; P < .001) and higher venous perforation rate (23 patients vs 5 patients; P = .011) were observed in the TBS group than in the TB group. The median follow-up time was 34 months. The patency rates in the TBS group at 36 months were as follows: primary patency rate of 74.0% and secondary patency rate of 92.1%. Independent predictors for restenosis included visible remaining collateral vessels (hazard ratio [HR], 1.12-3.29; P = .02), residual thrombus (HR, 1.40-4.38; P = .002), and tapered iliac vein (HR, 1.26-4.06; P = .006). Clinical results, including Venous Clinical Severity Scores (TBS, 8.0 ± 3.0; TB, 11.4 ± 3.2), Chronic Venous Insufficiency Questionnaire score (TBS, 76.4 ± 4.0; TB, 83.1 ± 4.6), Villalta scores (TBS, 3.8 ± 1.7; TB, 6.6 ± 3.2), and edema scores (TBS, 0.7 ± 0.7; TB, 1.6 ± 0.6), improved significantly in the TBS group. CONCLUSIONS: TBS is effective and feasible for patients with proximal DVT secondary to MTS. Furthermore, compared with TB, additional stenting might be effective in improving the venous clinical results at follow-up observations.

Los puntos oscuros de la insuficiencia venosa pélvica / The dark spots of pelvic venous insufficiency

La insuficiencia venosa pélvica es un tema de mucho debate en congresos de nuestro ámbito profesional. Sin embargo, cuanto más se reconoce y se trata esta patología en nuestro medio, más casos encontramos en los que, aplicando un tratamiento estándar de embolización venosa o stenting, se obtiene un resultado desfavorable. Para evitar este patrón de resultados, debemos estudiar con detenimiento la circulación venosa abdominopélvica estableciendo paralelismos con la circulación venosa infrainguinal y, además, aplicar tecnología IVUS en los casos de duda. Con estas dos medidas, podemos afrontar esta patología en su conjunto con unos resultados muy positivos para nuestros pacientes

Pelvic Venous Insufficiency is a topic of much debate in Congresses of our professional field. However, the more this pathology is recognized and treated in our setting, the more cases we find in which applying a standard venous embolization or stenting, treatment results in an unfavorable result. To avoid this type of results, we must carefully study the abdomino-pelvic venous circulation, establishing parallels with the infrainguinal venous circulation, and also apply IVUS technology in cases of doubt. With these two measures, we can face this pathology as a whole with very positive results for our patients

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.

A Case of Isolated External Iliac Vein Compression Syndrome and the Role of Advanced Imaging.

Isolated external iliac vein compression syndrome is an uncommon cause of nonthrombotic venous stenosis that causes chronic venous hypertension leading to painful swelling, skin discoloration, and ulcer formation. We present a case of an 86-year old man with refractory lower extremity edema for several years who had been treated with diuretics and antibiotics without relief of symptoms. With the help of invasive and noninvasive imaging modalities, we were able to diagnose and manage isolated nonthrombotic left external iliac vein stenosis as a result of ipsilateral external iliac artery compression.

A Comprehensive Review of the Pathophysiology and Clinical Importance of Iliac Vein Obstruction.

OBJECTIVE: The purpose of this comprehensive review is to give a historical account of iliac vein compression and to analyse the pathophysiological aspects and their clinical implications. METHODS: An extensive search of the databases was performed from inception until 2019. The patterns, length and site of compression, wall and luminal changes, and anatomical variations were some of the factors recorded and analysed. RESULTS: Twenty-seven studies were included in this review, divided into cadaveric, histological, and imaging. According to the literature 22%-32% of the asymptomatic population shows "spurs" at the origin of the left common iliac vein (LCIV). Imaging studies also show the presence of direct and indirect compression signs such as the presence of collateral venous flow in axial, transpelvic, or ascending lumbar collaterals, and >50% compression in 37%-44% of the asymptomatic population. In patients without thrombosis it is unknown what produces the signs and symptoms, as the obstruction pre-exists their development. Haemodynamic evaluation is found in only a few studies often including patients with previous deep vein thrombosis. Furthermore, most of the tests are performed with the patient in the supine position and therefore the haemodynamic information is relatively poor. CONCLUSION: Patients with venous obstruction have various clinical presentations from being asymptomatic to having venous claudication and skin damage. Obstruction should be placed into clinical context, together with other contributing factors. Proper evaluation and clinical judgement are important in selecting patients for treatment. Given that such selection is not always clear, further work is needed.

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

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

Endovascular interventions in the treatment of pelvic congestion syndrome caused by May-Thurner syndrome.

OBJECTIVE: The objective of this study was to assess the effect of various endovascular interventions on the clinical manifestations of the pelvic congestion syndrome (PCS) caused by May-Thurner syndrome (MTS). METHODS: The study included 12 female patients with PCS caused by MTS. Patients were examined by duplex ultrasound, computed tomography of the pelvic veins, and ovarian and pelvic venography. All 12 patients underwent endovascular stenting of the left common iliac vein (CIV), and 10 of them underwent subsequent endovascular embolization of the left gonadal vein. The indication for stenting was the presence of stenosis (>50%) of the CIV with clinical symptoms and signs of PCS. Self-expanding stents (Wallstent, 14-16 mm × 60-90 mm; Boston Scientific, Marlborough, Mass) were used. Patients with persistent symptoms of PCS after stenting underwent gonadal vein embolization with MReye metal coils (diameter, 10-15 mm; length, 10-20 cm; Cook Medical, Bloomington, Ind). RESULTS: Technical success of stenting, namely, the restoration of normal patency of the left CIV, was achieved in 12 patients. In two patients, a stent was displaced toward the inferior vena cava, which required implantation of a second stent. In another patient, the stent was displaced into the inferior vena cava at 6 months after the intervention, which was not associated with any complication during the follow-up period. The mean venous pelvic pain severity score decreased from 7.7 ± 0.8 at baseline to 4.8 ± 0.3 after 1 month and stayed at this level during the 6-month follow-up period. Complete elimination of PCS symptoms at 6 months after stenting was achieved in 2 patients, and 10 patients underwent embolization of the left gonadal vein 6 months after stenting because of persistent pelvic pain. CONCLUSIONS: Endovascular stenting of the left CIV is an effective technique for relieving symptoms of PCS due to MTS in only 16.6% of patients. Stenting of the left CIV in combination with embolization of gonadal veins results in elimination of the signs of PCS in 83.4% of patients. Probably only gonadal vein embolization can be used in the treatment of MTS-related PCS. To confirm this hypothesis, further comparative studies are warranted.

Factors Affecting Recurrent Deep Vein Thrombosis after Pharmacomechanical Thrombolysis and Left Iliac Vein Stent Placement in Patients with Iliac Vein Compression Syndrome.

PURPOSE: This study evaluated the factors affecting contralateral and ipsilateral recurrent deep vein thrombosis (DVT) after iliac vein stent placement in patients with iliac vein compression syndrome (IVCS). MATERIALS AND METHODS: Data from 130 patients (95 female patients) who underwent catheter-directed thrombolysis and stent placement for IVCS with left lower leg thrombosis at a single institution were retrospectively analyzed. Mean patient age was 69.0 ± 14.0 years old. Median follow-up was 14 months (range, 3-164 months). Anticoagulation therapy was prescribed for 6 months, followed by lifelong antiplatelet therapy. Multivariate logistic regression analysis was performed to evaluate the factors affecting the development of contralateral and ipsilateral recurrent DVT. RESULTS: Seven patients (5.4%) developed contralateral DVT (median, 26 months; range, 2-61 months), and 11 patients (8.5%) developed ipsilateral DVT (median, 1 month; range, 0-53 months). Stent location (odds ratio [OR], 11.564; 95% confidence interval [CI], 1.159-115.417) and in-stent thrombosis during follow-up (OR, 15.142; 95% CI, 1.406-163.119) were predictors of recurrent contralateral DVT. Thrombophilia (OR, 47.560; 95% CI, 2.369-954.711), remaining inferior vena cava filter (OR, 30.552; 95% CI, 3.495-267.122), and in-stent thrombosis during follow-up (OR, 82.057; 95% CI, 2.915-2309.848) were predictors of ipsilateral DVT. CONCLUSIONS: Contralateral DVT occurs late and is associated with extension of the iliac vein stent to the inferior vena cava and in-stent thrombosis. Ipsilateral DVT occurs relatively early and is associated with thrombophilia, remaining inferior vena cava filter, and in-stent thrombosis.