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.

Spontaneous iliac vein rupture and thrombosis in patients with May-Thurner syndrome: A narrative review.

Spontaneous iliac vein rupture (SIVR) is extremely rare and can lead to serious complications, including death. Etiologies include inflammatory processes and hormonal and mechanical triggers, with concomitant May-Thurner syndrome (MTS) being a rare cause. Management can be challenging due to the difficult balance between reducing thrombotic burden and life-threatening hemorrhage that can result from aggressive anticoagulation. Furthermore, surgical interventions are associated with high mortality, making conservative management more desirable. We report a case of SIVR with retroperitoneal hematoma and concurrent MTS that was successfully managed using conservative measures. We further provide a narrative review of the current literature addressing the diagnosis, management, and outcome of SIVR focusing on cases with concurrent MTS.

Imaging Signs of May-Thurner Syndrome in Asymptomatic Patients: Computed Tomography Angiography Analysis of Kidney Donors.

BACKGROUND: The current study aimed to evaluate the distance between the right common iliac artery (RCIA) and lumbar vertebra in asymptomatic patients in order to determine whether such distance was statistically correlated with the left common iliac vein (LCIV) diameter (LCIVD) and to investigate if both measures were related to demographic characteristics and anthropometric data, such as sex, age, height, and body mass index (BMI). METHODS: In this descriptive and uncontrolled anatomic study, data from high-definition computed tomography (CT) angiography images of living kidney donors without a medical history of chronic venous insufficiency or past deep vein thrombosis (DVT) were analyzed. The RCIA crossed over the LCIV in 311 individuals, who were then included in this study. CT scans were reviewed to measure (1) the narrowest space between the RCIA and fifth lumbar vertebral body and (2) the LCIVD. Measures were subjected to normality tests and were divided according to the sex of the study population. Correlations of measures with age, BMI, and height were calculated. RESULTS: Of the 311 patients analyzed, 66.6% (n = 207) were female. The mean lumbar vertebral body-iliac artery distance (LVBIAD) was 7.2 mm, whereas the mean LCIVD was 8.5 mm; both were higher in men (P < 0.001). The statistical analysis of LVBIAD and LCIVD distributions revealed no normality pattern (P < 0.05). The analysis of the correlation between them showed a weak statistically significant relationship with age. A linear regression model considering the normality percentile interval indicated a strong positive correlation between LVBIAD and LCIVD (R2 = 0.884). CONCLUSIONS: The LVBIAD was <5 mm and <3 mm in 25% and 5% of asymptomatic individuals, respectively. The LCIVD correlated with the space between the RCIA and lumbar vertebra. The distance between the RCIA and lumbar vertebra and the LCIVD were higher in male subjects and older patients, but did not correlate with BMI and height.

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

OBJECTIVES: To explore the etiology of May-Thurner syndrome (MTS) with acute iliofemoral deep vein thrombosis (DVT) regarding imaging findings and clinical features. METHODS: We retrospectively analyzed 57 patients with acute left iliofemoral DVT from 2015 to 2020. The diameter of left common iliac vein (LCIV) at the maximal compression site and its percent compression regarding the average diameter of the uncompressed iliac vein were recorded in central and distal portions of the LCIV according to the location in the quadrant of lumbar vertebral body. Compression was categorized into simple and bony MTS; Simple MTS as LCIV compressed by the right common iliac artery (RCIA) versus Bony MTS as LCIV by lower lumbar degenerative changes regardless of RCIA compression. Initial computed tomographic venography (CTV) regarding chronic change of LCIV such as fibrotic atrophy or cordlike obliteration, extent of thrombus, and lumbar degenerative changes were evaluated. Therapeutic effect after initial therapy was assessed in follow-up CTVs after 3-6 months. RESULTS: All patients showed LCIV compression with 19 simple MTS (mean age, 42.8 ± 14.1 years [23-67 years]; 12 females; symptom for 4.4 ± 5.5 days) and 38 bony MTS (mean age, 73.0 ± 10.2 years [49-85 years]; 26 females; symptom for 5.5 ± 4.8 days). There was significant difference in age (p < .001) and no significant difference in sex or symptom duration between two groups (p = .691 and 0.415, respectively). All simple MTS showed compression only in the central LCIV and half of bony MTS showed compression in both central and distal LCIV (p < .001). Among the lumbar degenerative changes, symmetric anterolateral osteophyte (p < .001) and asymmetric osteophyte (p < .001) were significantly associated with bony MTS, but not scoliosis (p = .799), compared to simple MTS. Although there was no significant difference in chronic change of LCIV, thrombosis extent, and therapeutic effect between two groups (p > .05), chronic change of LCIV showed significant difference between single and dual compression (23.7% vs. 57.9%, p = .024) and residual thrombus after initial therapy was occurred in 21.1% of single compression and 47.4% in dual compression with non-significant trend (p = .082). CONCLUSION: Bony MTS related to lumbar degenerative changes with acute iliofemoral DVT occurs in older patients, presenting more than one stenosis at LCIV, inducing more chronic change with possibly weaker therapeutic effect than simple MTS.

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

INTRODUCTION: This study aimed to identify whether iliac vein compression syndrome(IVCS) is associated with deep vein thrombosis(DVT) after total knee arthroplasty(TKA) and whether lower lumbar degenerative changes were risk factors for IVCS. MATERIALS AND METHODS: A total of 259 consecutive patients who underwent TKA from January 2019 to March 2022 was retrospectively reviewed. Preoperative plain radiographs of lumbar spines and CT venography (CTV) for DVT diagnosis at postoperative 7 days were performed in all patients. Imaging findings of lower lumbar degenerative changes were analyzed on plain radiograph including lateral osteophytes, scoliosis, lateralolisthesis, retrolisthesis, anterolisthesis, and lower lumbar lordosis angle (LLLA). Percent compression at the left common iliac vein (LCIV) and right common iliac vein (RCIV) as well as DVT were evaluated on CTV. Moreover, IVCS was defined as greater than 50% of compression of the iliac vein on CTV. RESULTS: DVT occurred in 79 patients (30.5%) after TKA. The overall occurrence of DVT was significantly higher in patients with IVCS of LCIV (52.8%) than those without (18.8%, P < 0.001). When DVT was further subdivided, compared to non-IVCS, IVCS of LCIV was significantly associated with bilateral DVT (P < 0.001, both), especially distal DVT (P < 0.001, both), and IVCS of RCIV was significantly associated with right-side DVT (P = 0.031), especially popliteal (P = 0.008) and distal DVT(P = 0.011). Female patients (OR: 3.945, P = 0.039), presence of left osteophyte (OR: 2.348, P = 0.006), and higher LLLA (OR: 1.082, P < 0.001) were significantly associated with IVCS of LCIV, and presence of right osteophyte (OR: 3.494, P = 0.017) was significantly associated with IVCS of RCIV. CONCLUSION: IVCS was significantly associated with DVT after TKA and lumbar degenerative changes with lateral osteophytes and hyperlordosis were significant risk factors for IVCS.

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.

Comparing the efficacy of endovascular treatment for iliac vein compression syndrome with or without acute deep venous thrombosis: A single-center retrospective study.

BACKGROUND: To compare the efficacy of endovascular treatment for iliac vein compression syndrome (IVCS) with or without acute deep venous thrombosis of lower extremity. METHODS: This study retrospectively analyzed the clinical data of 300 IVCS patients, who received endovascular treatment between January 2013 and December 2017. According to whether IVCS was complicated by deep venous thrombosis or not, these patients were divided into non-thrombotic iliac vein lesion group (NIVL group, n = 127) and post-thrombotic iliac vein lesion group (PIVL group, n = 173). After endovascular treatment, all patients were followed up to assess the symptoms improvement and to evaluate the patency of iliac vein. RESULTS: The technical success rate was 98% (294/300), and percutaneous transluminal angioplasty with stenting was adopted in 294 cases. The incidence of perioperative complications was 36.33% (109/300), but no severe complications occurred. During a mean follow-up of 22.3 months (range 6-30 months), 9(6.82%, 9/132) patients in PIVL group had recurrence of deep venous thrombosis, but nobody had deep venous thrombosis and varicose veins recurrence in NIVL group. The effective rate of endovascular treatment in NIVL group and PIVL group was 96.88% and 90.15% (P = 0.050), while the cumulative primary patency of iliac vein in NIVL group was significantly higher than that in PIVL group (P = 0.008). CONCLUSIONS: The endovascular treatment is an effective, feasible, safe method for treating IVCS. There is no difference in the efficacy of IVCS patients with or without deep venous thrombosis, but the medium and long-term patency of patients with deep venous thrombosis is lower than that in patients without deep venous thrombosis.

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.

Endovascular Repair of Spontaneous Iliac Vein Rupture.

Spontaneous iliac vein rupture is a relatively rare but fatal disease. Herein, 2 cases are reported. The two middle-aged and elderly females complaining of abdominal pain were admitted without any history of trauma. The computed tomography image both showed one huge hematoma in the lower abdominal cavity and the left external iliac venous thrombus. Venogram showed ruptures of the left external iliac vein and stenosis of the left common iliac vein after percutaneous mechanical thrombectomy. Stent grafts were implanted by endovascular technique. Favorable outcomes were achieved in both cases.

A Novel Approach to a Patient with both Aortoiliac and Venous Occlusive Disease.

Radiation-induced arteritis is a well-recognized complication of radiotherapy; however, radiation-induced venous stenosis is very rare (Zhou W, Bush RL, Lin PH, et al. Radiation-associated venous stenosis: endovascular treatment options. J Vasc Surg 2004;40:179-182). We describe a case of mixed aortoiliac arterial occlusive disease and iliac venous outflow obstruction secondary to radiation-induced vascular disease. Several endovascular procedures were undertaken to treat aortoiliac occlusive disease, which was followed by stenting for venous occlusive disease.

Iliac vein stenting guided by intravascular ultrasound without iodinated contrast medium.

Iliac vein compression syndrome, also known as May-Thurner Syndrome, is a type of vein reflux disorders which is often ignored due to lack of efficient diagnostic methods. The traditional gold standard of diagnosis is venography, but this has been challenged and largely replaced by intravascular ultrasound (IVUS). Here we report a case that a patient suffered with iodine anaphylaxis was successfully performed iliac vein stenting guided by using IVUS alone. This case provides the evidence that IVUS can offer necessary information for physicians in the diagnosis and treatment of iliac vein compression. We also find that balloon dilatation notch cannot precisely reflect the whole lesion, indicating it may be unreliable for diagnosis. Differ from the commonly accepted opinion, we find that comparing to IVUS, the notch of balloon dilatation cannot completely reflect the extent of lesion narrowness. Thus, we think the notch should not be used as a reference for seriousness of the lesion, and the diagnosis of stenosis cannot be ruled out even if there is no presence of notch.

Venovo venous stent for treatment of non-thrombotic or post-thrombotic iliac vein lesions - long-term efficacy and safety results from the Arnsberg venous registry.

Background: Endovascular venous stenting with dedicated venous stents for the treatment of chronic venous outflow obstruction is developing as efficacious alternative to conservative therapy or open surgery. However, so far, mid- and long-term evidence on effectiveness and safety is poor. Patients and methods: The prospective, single-center, observational study enrolled consecutive patients with chronic non-thrombotic iliac vein lesions (NIVL) or post-thrombotic iliofemoral obstructions (PTO). From February 2016 to April 2017, patients underwent implantation of open cell, self-expandable dedicated venous stents. Short-term symptomatic improvement, patency, and complication rate were favorable. Evaluation at 2-years included improvement in the revised venous clinical severity score (rVCSS), patency, stent migration, major target limb events, clinically important pulmonary embolism, major bleeding, and all-cause mortality. Results: A total of 79 patients (57 ± 16 years, 44 female) were evaluated. At 2 years, rVCCS improved by 4.3 ± 2.7 (p < 0.001). Substantial clinical improvement of ≥ 2 score points was achieved in 86.4% (38 of 44) of patients. Improvement was not associated with thrombotic pathogenesis (regression coefficient [B] with PTO = 0.6 [95%CI: -1.1 to 2.3], p = 0.48). At 2 years, all ulcers (in 8 of 79 patients) were healed and none recurred. Two-year primary patency was 95.5% (95%CI: 86.5 to 98.5) with no difference between NIVL- and PTO-patients (log-rank p = 0.83). Target vessel revascularization was conducted in two PTO- and one NIVL-patients in the period of 34 days to 156 days from index procedure, resulting in a secondary patency of 100%. No stent migration, target limb deep vein thrombosis, major amputation, pulmonary embolism, or death occurred. Conclusions: Venovo venous open cell self-expanding stent implantation for chronic outflow obstruction was efficacious and provided a sufficient level of safety throughout 2 years.

Endovascular versus medical treatment of venous compression syndrome of the iliac vein - a systematic review.

The treatment of non-thrombotic iliac vein lesions (NIVL) remains debatable with many advocating conservative treatments, whilst others offering venous stenting. The objective of this review was to systematically assess the treatment options for symptomatic iliac vein compression syndrome (IVCS) in patients without evidence of thrombotic disease at the time of diagnosis. An online search of published literature looking for randomised controlled trials and observational studies that evaluated the treatment for symptomatic NIVL was performed. Nine studies were included with a total 953 patients of which 782 patients had NIVL. Patency rates ranged between 94.8%-100% in the first month, 88.2%-94.1% in six months and 73.4%-98% in 12 months, in patients with NIVL post stenting. Longer follow-up of up to 5 years shows promising patency rates of 94% in patients with IVCS. Patients with IVCS are likely to benefit from a combination of endovenous treatment at the time of diagnosis including stent placement to maintain lumen patency and prevent recurrent deep venpus thrombosis and/or postthrombotic syndrome.

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

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

Acute pulmonary embolism unmasking underlying chronic thromboembolic pulmonary hypertension and iliac vein compression syndrome.

We describe the case of a 72-year-old gentleman who was referred to our institution for management of cardiogenic shock from a massive pulmonary embolism. Right heart catheterization revealed a low cardiac index and markedly elevated pulmonary pressures, suggested long-standing venous thromboembolic (VTE) disease that evolved into chronic thromboembolic pulmonary hypertension (CTEPH). The patient was cannulated to veno-arterial extra-corporeal membrane oxygenation and eventually treated with pulmonary embolectomy and thromboendarterectomy. Subsequently discovered inferior vena cava clot and left iliac deep vein thrombosis were treated with suction and mechanical thrombectomy. Intravascular ultrasound of the left lower extremity venous system identified iliac vein compression syndrome (IVCS) as the culprit of the patient's VTE and CTEPH. A left iliac stent was placed and the patient was discharged on Warfarin for anticoagulation. The case illustrates the rapidly expanding armamentarium for VTE treatment and proposes IVCS as a new, potentially underrecognized risk factor for CTEPH.

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

PURPOSE: An automated segmentation technique (AST) for computed tomography (CT) venography was developed to quantify measures of disease severity before and after stent placement in patients with left-sided nonthrombotic iliac vein compression. MATERIALS AND METHODS: Twenty-one patients with left-sided nonthrombotic iliac vein compression who underwent venous stent placement were retrospectively identified. Pre- and poststent CT venography studies were quantitatively analyzed using an AST to determine leg volume, skin thickness, and water content of fat. These measures were compared between diseased and nondiseased limbs and between pre- and poststent images, using patients as their own controls. Additionally, patients with and without postthrombotic lesions were compared. RESULTS: The AST detected significantly increased leg volume (12,437 cm3 vs 10,748 cm3, P < .0001), skin thickness (0.531 cm vs 0.508 cm, P < .0001), and water content of fat (8.2% vs 5.0%, P < .0001) in diseased left limbs compared with the contralateral nondiseased limbs, on prestent imaging. After stent placement in the left leg, there was a significant decrease in the water content of fat in the right (4.9% vs 2.7%, P < .0001) and left (8.2% vs 3.2%, P < .0001) legs. There were no significant changes in leg volume or skin thickness in either leg after stent placement. There were no significant differences between patients with or without postthrombotic lesions in their poststent improvement across the 3 measures of disease severity. CONCLUSIONS: ASTs can be used to quantify measures of disease severity and postintervention changes on CT venography for patients with lower extremity venous disease. Further investigation may clarify the clinical benefit of such technologies.

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.

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.

Deep vein thrombosis due to May-Thurner syndrome: a case report.

BACKGROUND: May-Thurner syndrome (MTS) or Cockett's syndrome is a rare clinical syndrome, which refers to the compression of the left common iliac vein (LCIV) by right common iliac artery and vertebral body. Complications of MTS include deep vein thrombus formation and even life-threatening pulmonary embolism. CASE PRESENTATION: Here, we report the case of a 60-year-old female patient with a complaint of swelling in the left lower limb and pain for 5 days. Computed tomography angiography indicated MTS, and thrombus formation of left external iliac vein and femoral vein. The patient was diagnosed with deep venous thrombosis (DVT) and MTS. The patient underwent ascending venography from the lower extremity to inferior vena cava (IVC) and then to the pulmonary artery with IVC filter implantation, left iliac vein balloon plasty, and stent placement. The patient visited the hospital for the removal of IVC filter, 28 days after the operation. After the interventional therapy, the patient had no in-stent restenosis and had remission during the 2-year follow-up. CONCLUSIONS: This case presents a successful management of MTS in presence of DVT. Although clinicians are rarely aware, the presence of unilateral lower limb swelling and thrombosis may be the manifestations of MTS.

Iliac Vein Stenting for Chronic Proximal Venous Outflow Obstruction in a Predominantly Asian-American Cohort.

BACKGROUND: We investigated the outcome of vein stenting placement for chronic proximal venous outflow obstruction (PVOO) in a predominantly Asian-American cohort to improve patient selection, enhance technical approach, and better define quality measurements of this emerging vascular intervention. METHODS: A total of 462 consecutive patients, 73% Asian American (n = 336), who underwent iliac vein stenting for chronic PVOO from October 2013 to July 2016 were reviewed. Postoperative outcomes at five follow-up visits were assessed. Wilcoxon-Mann-Whitney and Kruskal-Wallis tests were run for demographic and operative variables. Ordered logistic regressions were run for the outcome at each time point, and Chi-squared tests as well as Fisher's exact tests were used for categorical variables. RESULTS: Follow-up was maintained in 90% of patients, with a mean follow-up time of 695 days. Asian-American patients were more likely to present with varicose veins (77.4% vs. 54.8%, P < 0.001), and non-Asian patients were more likely to present with active ulceration (26.2% vs. 5.1%, P < 0.001). Asian-American patients were more likely to have bilateral stents placed (61.6% vs. 50%, P = 0.026) and were less likely to have reinterventions (11.3% vs. 27.8%, P < 0.001), a history of deep vein thrombosis (8.3% vs. 29.4%, P < 0.001), or intraoperative findings of chronic postphlebitic changes (17.6% vs. 33.3%, P < 0.001). Kruskal-Wallis tests were significant for improvement in patients of all the Clinical, Etiology, Anatomy, Pathophysiology classes at 30 days (P = 0.041), 90 days (P = 0.045), 6 months (P = 0.041), and 1 year (P < 0.01). The Asian-American population had improved but comparatively lower follow-up scores at the 30-day mark (48% significantly improved or better vs. 63%, P = 0.008) but higher follow-up scores at the >1 year mark (80% significantly improved or better vs. 59%, P < 0.001). CONCLUSIONS: Asian-American patients undergoing vein stent placement for chronic PVOO had comparatively worse outcomes than non-Asian patients at 30 days and better outcomes after one year. These patient groups had different outcomes postoperatively and outcomes which evolve differently over time.