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.

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.

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.

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.

Aiming for the Bottom Corner: How to Score a Field Goal When Landing Venous Stents in May-Thurner Syndrome.

PURPOSE: To report an iliac venous stent landing technique using only fluoroscopy in patients with May-Thurner syndrome (MTS). MATERIAL AND METHODS: Sixty-five patients (69% female) who had self-expanding nitinol stents deployed for symptomatic MTS were retrospectively analyzed. Mean age was 50 years (range 18-80). The cephalic stent right lower corner was deployed to the right of the lumbar vertebra spinous process (SP), but not as far to the right as the right pedicle lateral border. Mode stent diameter and length were 14 mm (range 12-18) and 120 cm (range 60-180), determined by venography, respectively. The anatomical positions of the right common iliac artery, inferior vena cava (IVC), and stent were assessed relative to these bony landmarks on computed tomography venography. RESULTS: Position of the proximal right common iliac artery right lateral border lay a mean distance of 12 mm (±8 to the right of the SP and 13 mm (±7) left of the right pedicle lateral border. Mean position of the IVC right lateral wall lay 1 mm (±6) to the right of the right pedicle lateral border. Mean position of the cephalic stent right lower corner was 6 mm (±6) to the left of the right pedicle lateral border and 19 mm (±7) to the right of the SP. The mean space left between the cephalic stent right lower corner and the IVC right lateral wall was 5 mm (±5). Primary patency rate at 1 year was 88%. CONCLUSIONS: Important vascular structures lie in predictable locations relative to bony landmarks, facilitating accurate venous stent placement using fluoroscopy only.

Predictors of Disease Recurrence after Venoplasty and Stent Placement for May-Thurner Syndrome.

PURPOSE: To identify factors independently associated with disease recurrence after venoplasty and stent placement for May-Thurner syndrome (MTS). MATERIALS AND METHODS: Fifty-nine consecutive patients (age, 47 y ± 15; 93% female) were identified who had undergone endovascular stent placement for MTS. Patient charts were reviewed for demographic data, risk factors for venous thrombosis, comorbidities, and venous inflow or outflow at first follow-up (3 wk to 6 mo after treatment). Logistic regression was used to identify independent predictors of symptom recurrence or repeat intervention, and multivariate analysis of variance and receiver operator characteristic curve analysis were used to assess relationships between degrees of in-stent stenosis and other variables in the 73% of patients with available cross-sectional imaging. Median follow up was 20.7 months (interquartile range, 4.7-49.5 mo). RESULTS: All procedures were technically successful. Disease recurrence, defined as symptom recurrence following initial postprocedural resolution, was observed in 38% of patients. No preprocedural variable was found to be independently predictive of disease recurrence; however, poor venous inflow or outflow were both strongly associated with recurrent disease, with adjusted odds ratios and 95% confidence intervals of 38.02 (3.76-384.20; P = .002) and 7.00 (1.15-42.71; P = .04), respectively. Higher degrees of in-stent stenosis were also associated with symptom recurrence, with an area under the curve of 0.93 (P = .000002) and 39%-41% stenosis being 78%-83% sensitive and 88%-92% specific for symptom recurrence. CONCLUSIONS: These results suggest that cross-sectional imaging can help differentiate patients in whom closer follow-up may be warranted after venoplasty and stent placement for MTS and also guide counseling regarding prognosis.

Single-Stage Treatment of AngioJet Rheolytic Thrombectomy and Stenting for Iliac Vein Compression Syndrome with Secondary Acute Iliofemoral Deep Vein Thrombosis.

BACKGROUND: We sought to evaluate the feasibility, safety, and effectiveness of single-stage endovascular treatment with AngioJet rheolytic thrombectomy followed by stenting for iliac vein compression syndrome (IVCS) with secondary acute iliofemoral deep vein thrombosis (DVT). METHODS: We conducted a multiple-center prospective nonrandomized study to enroll patients with left-sided acute iliac-common femoral DVT secondary to IVCS. We performed AngioJet rheolytic thrombectomy followed by stenting to evaluate the success rate, periprocedural complications, hospital stay, clinical outcomes, and stent-patency rate. RESULTS: A prospective cohort study of 19 consecutive patients diagnosed with IVCS and secondary acute iliac-common femoral DVT from October 2014 to April 2017 was conducted. The technique success rate was 94.7%, and the mean procedure time was 77 minutes. The 1-year primary and secondary patency rate was 84.2% and 94.7%, respectively. CONCLUSIONS: Single-staged endovascular treatment with AngioJet rheolytic thrombectomy and stenting is feasible, safe, and effective for IVCS with secondary acute iliofemoral DVT.

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.

Guidance of Venous Stent Implantation after Catheter-directed Thrombosis in Patients with Acute Left Lower Extremity Deep Venous Thrombosis based on Pressure Gradient Differences between the Iliac Vein and Inferior Vena Cava: A Single-center Retrospective Study.

BACKGROUND: Iliac vein compression syndrome (IVCS) can lead to acute deep venous thrombosis (DVT) and post-thrombotic syndrome (PTS). Endovascular venous stenting has become a preferred treatment for IVCS. In this article, we guide stent implantation by the pressure gradient of iliac vein and inferior vena cava. To evaluate the feasibility of guidance of venous stent implantation based on venous pressure gradient difference. METHODS: A retrospective analysis was performed on patients with acute left lower extremity DVT who were treated in our center from March 2012 to December 2017. The patients were divided into 2 groups: group 1: from January 2015 to December 2017, patients were treated with catheter-directed thrombolysis (CDT) and stent implantation was guided by the pressure gradient of iliac vein and inferior vena cava after thrombectomy; group 2: from May 2012 to December 2014, patients underwent CDT treatment without stent implantation. In group 1, the patients were divided into 2 groups according to the difference in pressure gradient after CDT: the stent group (>2 mm Hg) and the control group (≤2 mm Hg). All patients were evaluated by color Doppler ultrasound at 1, 3, and 6 months after the operation to evaluate the patency of the iliofemoral vein. The Villalta score was used to evaluate the incidence of PTS. RESULTS: The primary and secondary patency rate of group 1 at 1, 3, and 6 months after operation were higher than that in group 2 (P < 0.05). In group 1, there was no significant difference in the primary and secondary patency rate between the stent group and the control group at 1, 3, and 6 months after the operation. The incidence of PTS in group 1 at 6 months after the operation was lower than that in group 2 (P < 0.05). In group 1, there was no significant difference in the incidence of PTS between the stent group and the control group at 6 months after the operation. CONCLUSIONS: Practice proves that it is simple and effective to guide stent implantation according to differences in pressure gradients. Two millimeter of mercury is the traditional standard for venous pressure interference in the pelvic area, and the effectiveness of this method was proved.

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.

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

BACKGROUND: The efficacy of endovascular interventional treatment for iliac vein compression syndrome (IVCS) is not well studied. The purpose of our study was to investigate the clinical outcome of endovascular interventional treatment for IVCS. METHODS: Data of 68 patients with IVCS, who underwent interventional treatment in our hospital, were analyzed retrospectively. Among these patients, 46 had lower extremity varicose veins. Sixty-five patients underwent stent implantation, and 3 patients underwent simple balloon angioplasty. Fourteen patients had post-thrombotic syndrome (PTS) and 11 patients had acute deep venous thrombosis (DVT). Among these 14 patients with PTS, 12 underwent stent implantation and 2 underwent iliac venous simple balloon angioplasty. On the other hand, 9 of the 11 patients with DVT underwent catheter-directed thrombolysis (CDT) and then stent implantation. Of the remaining 2 patients, one underwent Angiojet Rheolytic thrombectomy (ART) before CDT and the other underwent CDT with simple balloon angioplasty. The stenosis rate of iliac vein and the circumference differences between the affected limb and healthy one were measured before and after operation. These patients were followed up with duplex ultrasound postoperatively. RESULTS: A total of 75 stents were placed in 65 patients. The diameter and the length of stent were 6 to 14 mm (mean 12.5 ± 2.0 mm) and 40 to 260 mm (mean 82.5 ± 36.9 mm), respectively. CDT with/without ART was performed, using urokinase and/or alteplase, after inferior vena cava filtration in all of 11 patients with DVT, without the recurrence of pulmonary embolism. The difference in iliac venous stenosis was statistically significant ([91.2% ± 8.4%] [70.0% ∼ 100.0%] vs. 3.9% ± 13.0% [0 ∼ 70.0%], P < 0.01). The patency rates at 1-, 3-, 6- months, 1 year, and 2 years were 98.5%, 95.6%, 94.1%, 92.4%, and 90.7%, respectively. Four patients (5.9%) suffered from minor bleeding at puncture point and were successfully treated with compression. However, 1 (1.5%) patient underwent stent implantation of right iliac vein that became complicated due to migration of stent to the right ventricle which was successfully arrested by Amplatz Goose Neck Snare Kit. The incidence of PTS was 10.3% (7/68) during the follow-up at 1 to 24 (mean 18.2 ± 7.7) months. CONCLUSIONS: Interventional therapy for patients of IVCS is safe and effective. Satisfactory outcomes were obtained for stent placement for IVCS.

May-Thurner Syndrome Presenting as Acute Unexplained Deep Venous Thrombosis.

May-Thurner syndrome (MTS) is a rare cause of deep venous thrombosis and occurs due to an anatomic anomaly which produces chronic compression of the left common iliac vein by the overlying right common iliac artery when it passes between the right common iliac artery and the spine. Prolonged compression on the vein potentiates thrombus formation by impairing the intima and by leading to the development of membranes within the lumen that may decrease and/or block venous flow. In this case presentation, we elaborate on a case of a 43-year-old woman who presented with worsening left leg swelling and pain. The patient was diagnosed with MTS and underwent successful stent placement to relieve the compressed vein.

Is May-Thurner Syndrome Combined with Left Iliac Arteriovenous Fistularare or Neglected?: Cases Report and Literature Review.

May-Thurner syndrome (MTS) is a condition in which the left common iliac vein is compressed by the right common iliac artery, which may cause swelling, pain or deep venous thrombosis of the left lower extremity.1 Postthrombotic syndrome, nonthrombotic chronic venous insufficiency, and recurrence after venous thrombosis are also possible complications. Although MTS combined with left iliac arteriovenous fistula is rarely reported, we treated 3 such cases in the past year.

Studies on the relationship between perforating vein insufficiency and iliac compression syndrome.

OBJECTIVE: To study correlation among number(n), diameter (D), and blood reflux time(t) and the left common iliac vein stenosis degree of the expansion of perforating veins, so as to guide the clinical formulation and adjust the treatment plan. METHODS: Retrospective analysis of 45 PVs patients with left common iliac vein in different degrees of compression in our hospital from 2010 to 2012 was performed. Left common iliac vein was divided into 50%-69%, 70%-99%, 30%-49% and occlusion of the stenosis to avoid the error of the left iliac vein stenosis. Pearson's correlation analysis among the number, diameter, and blood reflux time of perforating veins and left common iliac vein was performed. RESULTS: Pearson's correlation analysis among the number, diameter, and blood back flow time of perforating veins, and the degree of stenosis was performed, and these results showed that correlation coefficients among the number, diameter, and blood return the PVs between flow time and the degree of stenosis were rp-n = 0.784, rp-d = 0.893, rp-t = 0.845 (P < .001), respectively. The two variables exist positive correlation and correlation was significant. CONCLUSION: With the increase in left common iliac vein stenosis, the number of perforating veins and the diameter increased, and the time of blood flow were prolonged.

Placement of closed-cell designed venous stents in a mixed cohort of patients with chronic venous outflow obstructions - short-term safety, patency, and clinical outcomes.

BACKGROUND: To evaluate the performance of a closed-cell designed venous stent for the treatment of chronic ilio-femoral venous outflow obstruction (VOO) in the shortterm. PATIENTS AND METHODS: Safety, stent patency and clinical outcome after placement of the Vici Venous Stent® in patients with chronic ilio-femoral venous obstruction were assessed retrospectively. Stent patency was evaluated by duplex ultrasound scanning, and clinical outcome was determined using the revised Venous Clinical Severity score (rVCSS). RESULTS: 75 patients (49 % female; median age 57 years; 82 limbs) with symptomatic significant VOO had stents placed in the ilio-femoral veins. Lower limb venous skin changes including ulcers (C-class in CEAP 4-6) were found in 31 patients (41 %). Nonthrombotic iliac vein lesions (NIVLs) and post-thrombotic obstruction (PTO) were found in 40 and 42 limbs, respectively. There were no safety issues. Cumulative primary, assisted-primary, and secondary stent patency in the entire cohort at 12 months were 94 %, 94 % and 96 %, respectively. Five limbs presented with stent occlusion. Two limbs had no intervention, 2/3 remained patent after reintervention. Clinical improvement (a decrease ≥ 2 rVCSS points) was observed in 81 %, 81 %, and 77 % of patients at 1 month, 6 months, and 12 months, respectively. There was a marked drop in the frequency of more marked pain and swelling (VCSS ≥ 2) from 62 % to 5 % and 93 % to 19 %, respectively. Four limbs had venous ulcers, three healed during the follow-up. Cumulative pri- mary stent patency at 12 months was 100 % and 87 % in patients with NIVL and PTO, respectively (p= 0.032). There was no statistical difference in clinical outcome between these subgroups. CONCLUSIONS: The Vici Venous Stent® placed in the ilio-femoral vein segment in patients with symptomatic VOO revealed no safety issues, had excellent primary patency and substantial symptom improvement. Long-term studies are needed to evaluate the durability of this stenting procedure.

Patency and Clinical Outcomes of a Dedicated, Self-Expanding, Hybrid Oblique Stent Used in the Treatment of Common Iliac Vein Compression.

PURPOSE: To investigate the clinical outcomes of a dedicated hybrid oblique nitinol stent that has been specifically designed to treat common iliac vein compression. METHODS: The Bern Venous Stent Registry database was interrogated to identify all patients who had at least 6-month follow-up after treatment with the sinus-Obliquus hybrid stent for common iliac vein compression. The search identified 24 patients (mean age 39±18 years; 20 women) who matched the search criteria. Ten patients had postthrombotic syndrome (PTS), another 10 patients had acute iliofemoral thrombosis after catheter-directed therapy, and 4 patients had nonthrombotic iliac vein compression. Primary treatment success was defined as antegrade flow and stenosis <30% on venography and evidence of a spontaneous Doppler signal in the treated segment. Stent patency was assessed using duplex ultrasound. Clinical outcomes were evaluated using a clinical symptom score (Villalta) and the revised venous clinical severity score (rVCSS) at 3, 6, and 12 months in follow-up. RESULTS: Primary treatment success was achieved in all patients. Mean follow-up was 10±3 months. Primary patency estimates by Kaplan-Meier analysis were 92% at 6 months [95% confidence interval (CI) 71% to 98%] and 83% (95% CI 54% to 95%) at 10 months. Three symptomatic patients underwent reintervention for early and late stent thromboses and the third for in-stent restenosis, resulting in secondary patency of 100%. Overall, all patients had clinical improvement at the latest follow-up; 50% reported complete resolution of symptoms. In patients with PTS, the Villalta score decreased by 6±6 points (p=0.02) and the rVCSS score by 3±1 points (p=0.05). Among deep vein thrombosis patients, none developed PTS. CONCLUSION: In patients with common iliac vein compression, the oblique hybrid nitinol stent appears to provide excellent early patency and clinical outcomes.

Endovascular Management of May-Thurner Syndrome in Adolescents: A Single-Center Experience.

PURPOSE: To report a single-center experience in regard to the technique, safety, and clinical outcomes of endovascular therapy for treatment of May-Thurner syndrome (MTS) in adolescent patients. MATERIALS AND METHODS: A retrospective review identified 10 patients (6 female; mean age, 16 y; range, 12-18 y; mean weight, 73 kg; range, 50-116 kg) treated by endovascular therapy for MTS from 1998 to 2015. Clinical presentations consisted of acute thrombotic MTS (n = 6) and nonthrombotic MTS (n = 4). Catheter-directed thrombolysis was performed in all cases of thrombosis. Venoplasty and stent placement were performed in all cases. Self-expanding stents 12-16 mm in diameter and 4-9 cm in length were deployed. RESULTS: No major periprocedural complications were observed. Median follow-up was 32 months (range, 6-109 mo). Primary and secondary patency rates were 79% and 100% at 12 months and 79% and 89% at 36 months, respectively. In a single patient with permanent loss of flow in the treated segment, multiple risk factors for thrombosis were identified. Rates of posttreatment symptoms were 0% by Villalta score and 60% (n = 6; mild symptoms) by modified Villalta score at the last clinical follow-up. CONCLUSIONS: Endovascular therapy for the treatment of MTS in our adolescent cohort was safe and effective in relieving venous obstruction. Stent placement in patients with underlying thrombophilic disorders is associated with loss of secondary patency, suggesting the need for further consideration in this population.