Pivotal Study Evaluating the Safety and Effectiveness of the Abre Venous Self-Expanding Stent System in Patients With Symptomatic Iliofemoral Venous Outflow Obstruction

Final 3-Year Study Outcomes from the Evaluation of the Zilver Vena Venous Stent for the Treatment of Symptomatic Iliofemoral Venous Outflow Obstruction (The VIVO Clinical Study)

PURPOSE

To report 3-year outcomes from a prospective, multicenter, nonrandomized, single-arm study designed to assess the safety and effectiveness of the Zilver Vena Venous Stent for the treatment of symptomatic iliofemoral venous outflow obstruction.

MATERIALS AND METHODS

The VIVO study included patients with symptomatic obstruction of 1 iliofemoral venous segment (ie, 1 limb), characterized by a Clinical, Etiological, Anatomic, Pathophysiology (CEAP) clinical classification of ≥3 or a Venous Clinical Severity Score (VCSS) for pain of ≥2. Patients were retrospectively grouped based on baseline clinical presentation as postthrombotic syndrome (PTS), nonthrombotic iliac vein (NIVL) obstruction, or acute deep vein thrombosis (aDVT). Clinical improvement was assessed by change in VCSS, Venous Disability Score, Chronic Venous Disease Quality of Life Questionnaire (CIVIQ-20) scores, and CEAP C classification. Stent performance was evaluated by rates of patency by ultrasound (US), freedom from clinically driven reintervention, and freedom from stent fracture.

RESULTS

The 3-year results for the 243 patients in the VIVO cohort included a 90.3% rate of patency by US and a 92.6% rate of freedom from clinically driven reintervention. The 3-year rates of patency by US for the NIVL, aDVT, and PTS groups were 100%, 84.0%, and 86.1%, respectively. Sustained clinical improvement through 3 years was demonstrated by changes in VCSS, Venous Disability Score, CIVIQ-20, and CEAP C classification. No stent fractures were observed.

CONCLUSIONS

The VIVO study demonstrated sustained high rates of patency and freedom from clinically driven reintervention and improvements in venous clinical symptoms through 3 years. Each patient group (NIVL, aDVT, and PTS) showed clinical improvement and sustained patency through 3 years; some variation existed among groups (eg, only the NIVL group had a 100% patency rate).

Interventional treatment for post-thrombotic chronic venous obstruction: Progress and challenges

Chronic venous obstruction, including nonthrombotic iliac vein lesions and post-thrombotic syndrome, presents a significant burden on patients' quality of life and health care systems. Venous recanalization and stenting have emerged as promising minimally invasive approaches, yet challenges in patient selection, procedural techniques, and long-term outcomes persist. This review synthesizes current knowledge on the interventional treatment of post-thrombotic syndrome, focusing on the evolution of endovascular techniques and stenting. Patient selection criteria, procedural details, and the characteristics of dedicated venous stents are discussed. Particular emphasis is given to the role of inflow and other anatomical considerations, along with postoperative management protocols for an optimal long-term outcome.

The TOPOS study

Background: We aimed to study the long-term safety and efficacy of oblique venous stents for post-thrombotic syndrome (PTS) with iliac vein compression. Patients and methods: In the multinational, prospective, single-arm TOPOS study, PTS patients scheduled for endovascular therapy with the sinus-Obliquus® stent and optional distal extension with the sinus-Venous® or sinus-XL Flex® stent were enrolled at eight European vascular centres between October 2016 and December 2020. The primary outcome was primary stent patency at 24 months, and secondary outcomes included the clinical course of PTS (Villalta score, revised Venous Clinical Severity Score [rVCSS], Visual Analog Scale [VAS] of pain), quality of life changes (Chronic Venous Insufficiency Quality of Life Questionnaire, CIVIQ-20), and device-related complications. Results: We enrolled 60 patients (mean age 46±15 years, 68% women, 13% active ulcers): 80% required stent extension (70% below the inguinal ligament). The primary patency rate at 24 months was 80.7% (95%CI 68.1-90.0%); it was higher in patients without vs. those with stent extension (90.9% vs. 78.3%, p=.01). Compared to baseline, the Villalta, rVCSS, pain VAS, and CIVIQ-20 decreased by a median of 8 (interquartile range (IQR): 4-11), 5 (IQR: 3-7), 3 (IQR: 2-5), and 17 (IQR: 6-22) points, respectively; p<.001 for all parameters. Overall, 9 events of acute stent occlusion, 4 symptomatic stent stenosis, and 1 pulmonary embolism occurred. We did not observe major bleeding events or contralateral thrombosis. Conclusions: Endovascular treatment with the oblique stent and optional stent extension was safe and resulted in high patency rates at 24 months. The reduction in PTS severity was substantial and persisted over 2-year follow-up.

Treatment of Nutcracker Syndrome with Left Renal Vein Transposition and Endovascular Stenting

BACKGROUND

Nutcracker syndrome is a rare condition that occurs as a result of the entrapment of the left renal vein (LRV) between the aorta and the superior mesenteric artery. It is typically associated with symptoms such as left flank pain, hematuria, proteinuria, and pelvic congestion. The current treatment approach may be conservative in the presence of tolerable symptoms, and surgical or hybrid and stenting procedures in the order of priority in the presence of intolerable symptoms. The aim of this study is to review our experiences to evaluate the results of both methods in this series in which we have a greater tendency toward surgery instead of stenting.

METHODS

The clinical data of consecutive patients with nutcracker syndrome who underwent LRV transposition and LRV stenting between July 2019 and October 2023 were retrospectively reviewed. The patients were divided into 2 groups based on the methods of treatment: surgical and stenting. For procedure selection, LRV transposition was primarily recommended, with stenting offered to those who declined. Primary end points were morbidity and mortality. Secondary end points included late complications, patency, freedom from reintervention, and resolution of symptoms. Standard basic statistics and survival analysis methods were employed.

RESULTS

Nineteen patients with nutcracker syndrome (female: 100%) were treated with LRV stentings (n = 5) and LRV transposition (n = 14). The mean age was 24 (20-27, interquartile range [IQR]) years. The mean follow-up was 23 (9-32, IQR) months. There were no major complications and mortality after both procedures. The most frequent sign and symptom associated with LRV entrapment were left flank pain 100% (n = 19), proteinuria 88% (n = 15), and hematuria 47% (n = 9). The mean peak velocity ratio on Doppler ultrasound was 6.13 (6-6.44, IQR). Aortomesenteric angle, beak angle (beak sign), and mean diameter ratio on computed tomography were 26° (22.6-28.5, IQR), 25° (23.9-28, IQR), and 5.3 (5-6, IQR), respectively. Venous pressure measurements were only used to confirm the diagnosis in 5 patients in the stenting group. The measured renocaval gradient was 4 (3.9-4.4, IQR) mm Hg. After both procedures, the classical symptoms, including left flank pain, proteinuria, and hematuria, resolved in 89.5% (n = 17), 57.8% (n = 11), and 82.3% (n = 15) of the cases, respectively. A total of 4 patients required reintervention, 3 patients after LRV transposition (occlusion, n = 2; stenosis, n = 1), and 1 patient after stenting (occlusion, n = 1). The 1-year and 3-year primary patency for the 19 patients was 87% and 80%, respectively. Three-year primary-assisted patency was 100%. Similarly, the 1-year and 3-year freedom from reintervention rate was 83% and 72%, respectively. Additionally, the 1-year and 3-year primary patency for the surgical group was 91% and 81%, respectively, and the 1-year and 3-year primary patency for the stenting group was 75%.

CONCLUSIONS

Nutcracker syndrome should be kept in mind in cases where flank pain and hematuria cannot be associated with kidney diseases. Radiographic evidence must be accompanied by serious symptoms to initiate the treatment of nutcracker syndrome with LRV transposition and endovascular stenting procedures. Both procedures, along with their respective advantages and disadvantages, can be preferred as primary treatments for nutcracker syndrome. Our study demonstrates that both procedures can be safely and effectively performed, yielding good outcomes.

A meta-analysis of the medium- to long-term outcomes in patients with chronic deep venous disease treated with dedicated venous stents

OBJECTIVE

This review summarizes the safety profile, stent patency, and clinical effectiveness of dedicated venous stents for the treatment of chronic deep venous disease. The approaches to stenting and post-procedural management of different vascular units are also explored.

METHODS

The MEDLINE and Embase databases were searched for pertinent literature published from January 2010 to January 2023. Outcomes related to post-stenting symptoms and health-related quality of life were described narratively. A meta analysis was conducted to evaluate stent patency, ulcer healing, bleeding, and 30-day stent thrombosis, and these outcomes were presented as proportion event rates.

RESULTS

Seventeen studies were identified comprising of 2218 patients. 62.7% of individuals had post-thrombotic stenosis or occlusion. The majority of patients (78.6%) were noted to have complete occlusions of their deep veins before stenting. Eleven different dedicated venous stents were deployed. At 12 months, the primary patency rate was 83% (95% confidence interval [CI]: 76%-90%), the primary-assisted patency rate was 90% (95% CI: 85%-96%), and the secondary patency rate was 95% (95% CI: 92%-98%). A significant improvement in health-related quality of life was demonstrated after intervention. In total, 68.8% (95% CI: 52.0%-83.7%) of ulcers healed at the last follow-up. The remaining symptomatic changes were described narratively; improvements in pain, venous claudication, and edema after stenting were observed. Seventeen deaths occurred, but none were linked to the stenting procedures. A total of 159 cases (7.2% of patients) of in-stent stenosis were observed, whereas 110 stents (5.0% of patients) were occluded. The incidence of major and minor bleeding was 1.7% (95% CI: 1.0%-2.5%) and 3.2% (95% CI: 1.3%-5.6%), respectively, more commonly seen in patients undergoing hybrid intervention.

CONCLUSIONS

Deep venous stenting using dedicated venous stents is a safe technique to treat chronic deep venous stenosis and/or occlusion. Within the limitations of this study, deep venous stenting is associated with good patency rates and symptomatic improvement.

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.

Safety and Effectiveness of Abre Self-Expanding Venous Stent for Treatment of Superior Vena Cava Syndrome

PURPOSE

Superior vena cava (SVC) syndrome is a constellation of symptoms that results from partial or complete SVC obstruction. Endovascular SVC stenting is an effective treatment for SVC syndrome with rapid clinical efficacy and low risk of complications. In this study, we assess the technical and clinical outcomes of a cohort of patients with SVC syndrome treated with the AbreTM self-expanding venous stent (Medtronic, Inc, Minneapolis, MN, USA).

METHODS

An institutional database was used to retrospectively identify patients with SVC syndrome treated with AbreTM venous self-expanding stent placement between 2021-2023. Patient demographic data, technical outcomes, treatment effectiveness, and adverse events were obtained from the electronic medical record. Nineteen patients (mean age 58.6) were included in the study. Thirteen interventions were performed for malignant compression of the SVC, 5 for central venous catheter-related SVC stenosis, and 1 for HD fistula-related SVC stenosis refractory to angioplasty.

RESULTS

Primary patency was achieved in 93% of patients (17/19). Two patients (7%) required re-intervention with thrombolysis and angioplasty within 30 days post-stenting. Mean duration of clinical and imaging follow-up were 228.7 ± 52.7 and 258.7 ± 62.1 days, respectively. All patients with clinical follow-up experienced significant improvement in clinical symptoms post-intervention. No stent related complications were identified post-intervention.

CONCLUSIONS

Treatment of SVC syndrome with the AbreTM self-expanding venous stent has high rates of technical and clinical success. No complications related to stent placement were identified in this study.

The role and principles of stenting in acute iliofemoral thrombosis

Catheter-directed interventions for acute iliofemoral deep venous thrombosis (DVT) have been increasingly used over the past 15 years to target severe symptomatology and prevention of post-thrombotic syndrome incidence or reduce its severity if it were to develop. Aside from successful thrombus removal, adjunctive stents are frequently required to treat an uncovered lesion or significant residual thrombus to ensure quality of life improvement besides retarding DVT recurrence and post-thrombotic syndrome. As the evidence is mounting, the need and role for stenting, as well as the principles of an optimal technique, in the acute DVT setting are now better understood. Accumulating experience appears to favor stenting in the acute setting. The diameter of the stent, the length, the extent of overlapping, and the landing zones are crucial determinants of a successful durable outcome. This article endeavors to guide the interventionalist on stenting when encountering a patient with acute symptomatic iliofemoral DVT with concerns of quality of life impairment.

Principles of Optimal Antithrombotic Therapy for Iliac VEnous Stenting (POATIVES): A national expert-based Delphi consensus study

OBJECTIVE

Management of antithrombotic therapy in patients undergoing venous stents has not yet reached consensus, and there are not any recommendations from published guidelines. We undertook a Delphi consensus from Chinese experts to develop recommendations regarding the preferred antithrombotic therapy in patients following venous stenting.

METHODS

The phase 1 questionnaire was comprised of three clinical scenarios of venous stenting for non-thrombotic iliac vein lesions (NIVL), acute deep vein thrombosis (DVT), and post-thrombotic syndrome (PTS) and was sent to venous practitioners across China. In phase 2, the results of phase 1 were distributed to a panel of experts for evaluation along with a questionnaire encompassing a series of statements produced during phase 1. A modified Delphi method was used to reach consensus on recommendations through two rounds of surveys.

RESULTS

The phase 1 questionnaire was completed by 283 respondents. In phase 2, an expert panel consisting of 28 vascular surgeons and interventional radiologists was assembled and voted 17 statements relating to antithrombotic management after venous stenting for NIVL (4 statements), DVT (6 statements), and PTS (7 statements). The majority of the statements about the antithrombotic agent selection received a high consensus strength.

CONCLUSIONS

Based on the national Delphi consensus of Chinese experts regarding antithrombotic therapy following iliac venous stenting in three common scenarios, most of the statements could be used to guide antithrombotic management following venous stenting. Further studies are required to clarify controversial issues including the dose and duration of anticoagulants, the role of antiplatelet agents, especially in patients with NIVL.

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

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

Review of the literature supporting international clinical practice guidelines on iliac venous stenting and their applicability to Australia and New Zealand practice

BACKGROUND

The overall goal of this report is to provide a high-level, practical approach to managing venous outflow obstruction (VOO).

METHODS

A group of vascular surgeons from Australia and New Zealand with specific interest, training, and experience in the management of VOO were surveyed to assess current local practices. The results were analyzed and areas of disagreement identified. After this, the group performed a literature review of consensus guidelines published by leading international organizations focused on the management of chronic venous disease, namely, the Society for Vascular Surgery, American Venous Forum, European Society for Vascular Surgery, American Vein and Lymphatic Society, Cardiovascular and Interventional Radiology Society of Europe, and American Heart Association. These guidelines were compared against the consensus statements obtained through the surveys to determine how they relate to Australian and New Zealand practice. In addition, selected key studies, reviews, and meta-analyses on venous stenting were discussed and added to the document. A selection of statements with >75% agreement was voted on, and barriers to the guideline's applicability were identified. The final recommendations were further reviewed and endorsed by another group of venous experts.

RESULTS

The document addresses two key areas: patient selection and technical aspects of venous stenting. Regarding patient selection, patients with clinically relevant VOO, a Clinical-Etiologic-Anatomic-Physiologic score of ≥3 or a Venous Clinical Severity Score for pain of ≥2, or both, including venous claudication, with evidence of >50% stenosis should be considered for venous stenting (Level of Recommendation Ib). Patients with chronic pelvic pain, deep dyspareunia, postcoital pain affecting their quality of life, when other causes have been ruled out, should also be considered for venous stenting (Level of Recommendation Ic). Asymptomatic patients should not be offered venous stenting (Level of Recommendation IIIc). Patients undergoing thrombus removal for acute iliofemoral deep vein thrombosis, in whom a culprit stenotic lesion of >50% has been uncovered, should be considered for venous stenting (Level of Recommendation Ib).

CONCLUSIONS

Patients with VOO have been underdiagnosed and undertreated for decades; however, in recent years, interest from physicians and industry has grown substantially. International guidelines aimed at developing standards of care to avoid undertreating and overtreating patients are applicable to Australia and New Zealand practice and will serve as an educational platform for future developments.

Editor's Choice - Management of Lower Extremity Venous Outflow Obstruction: Results of an International Delphi Consensus

OBJECTIVE

The endovascular treatment of venous obstruction has expanded significantly in recent years. Best practices for optimal patient outcomes are not well established and the evidence base is poor. The purpose of this study was to obtain consensus on management criteria for patients with lower extremity venous outflow obstruction.

METHODS

The study was conducted as a two round Delphi consensus. Statements addressed imaging, symptoms and other baseline measures, differential diagnosis, treatment algorithm, indications for stenting, inflow and outflow assessment, successful procedural outcomes, post-procedure therapies and stent surveillance, and clinical success factors. Statements were prepared by six expert physicians (round 1, 40 statements) and an expanded panel of 24 physicians (round 2, 80 statements) and sent to a pre-identified group of venous experts who met qualifying criteria. A 9 point Likert scale was used and consensus was defined as ≥ 70% of respondents rating a statement between 7 and 9 (agreement) or between 1 and 3 (disagreement). Round 1 results were used to guide rewording and splitting compound statements for greater clarity in round 2.

RESULTS

In round 1, 75 of 110 (68%) experts responded, and 91 of 121 (75%) experts responded in round 2. Round 1 achieved consensus in 32/40 (80%) statements. Consensus was not reached in the treatment algorithm section. Round 2 achieved consensus in 50/80 (62.5%). Statements reaching consensus were imaging (2/3, 66%), symptoms and other baseline measures (12/24, 50%), differential diagnosis (2/8, 25%), treatment algorithm (10/17, 59%), indications for stenting (10/10, 100%), inflow and outflow assessment (2/2, 100%), procedural outcomes (2/2, 100%), post-procedure therapies and stent surveillance, (5/7, 71%), and clinical success factors (5/7, 71%).

CONCLUSION

This study demonstrated that considerable consensus was achieved between venous experts on the optimal management of lower extremity venous outflow obstruction. There were multiple domains where consensus is lacking, highlighting important areas for further investigation and research.

The Pulsating Stent Sign in May-Thurner Syndrome

PURPOSE

To report a case of a patient with May-Thurner syndrome who underwent endovenous stenting and was found to have pulsating arterial compression on the venous stent.

REPORT

A 74-year-old man presented with 18 months of progressive right thigh and calf edema. After an extensive work-up, the patient underwent a venogram with intravascular ultrasound (IVUS), revealing compression of the right iliac vein by the external iliac artery and psoas muscle. Following stent deployment, fluoroscopy revealed extrinsic compression by an artery, but IVUS confirmed sufficient stent expansion. On follow-up, there was a significant resolution of right limb edema, and adjacent arterial pulsation/compression was deemed non-significant.

CONCLUSION

The choice of venous stents is essential to prevent collapse from extrinsic compression, such as that from an adjacent artery.

CLINICAL IMPACT

Carefully choosing venous stents is essential to ensure stent patency in the face of external compression.

Venous compression syndromes in females: A descriptive review

Venous compression syndromes have been described, yet the role of sex is poorly understood. Although iliac vein compression has been discussed more often with the advent of newer technologies, research has fallen short on defining epidemiology, best practices for evaluation and treatment, and differences in responses to treatment between men and females. The authors report on iliac vein compression, nonthrombotic renal vein compression, and other venous compression syndromes in females. Literature searches of PubMed were performed using the following keywords: females/females and May Thurner, venous stenting, venous outcomes, deep venous disease, deep venous compression, venous stenting, renal vein compression, renal vein surgery/stent, popliteal vein entrapment, venous thoracic vein entrapment, and popliteal vein entrapment. The articles prompted the authors to research further as the referenced articles were reviewed. Sex representation has not been addressed adequately in the research of venous compression syndromes, making the discussion of best treatment options and long-term outcomes difficult. More specific understanding of epidemiology and response to interventions will only come from research that addresses these issues directly, understanding that some of these syndromes occur rarely.

Case Report: It's not always about the veins; intervention of bilateral May-Thurner Syndrome secondary to iliac aneurysm

May-Thurner Syndrome (MTS) remains evasive because of the insidiousness and variable etiologies by which it can manifest. In this study, we examine a unique presentation of MTS resulting from compression of both common iliac veins by a right common iliac artery aneurysm that required complex endovascular venous and arterial intervention.

Society of Interventional Radiology Position Statement on the Management of Chronic Iliofemoral Venous Obstruction with Endovascular Placement of Metallic Stents

PURPOSE

To state the position of the Society of Interventional Radiology (SIR) on the endovascular management of chronic iliofemoral venous obstruction with metallic stents.

MATERIALS AND METHODS

A multidisciplinary writing group with expertise in treating venous disease was convened by SIR. A comprehensive literature search was conducted to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements.

RESULTS

A total of 41 studies, including randomized trials, systematic reviews and meta-analyses, prospective single-arm studies, and retrospective studies were identified. The expert writing group developed 15 recommendations on the use of endovascular stent placement.

CONCLUSIONS

SIR considers the use of endovascular stent placement for chronic iliofemoral venous obstruction to be likely to help selected patients, but the risks and benefits have not been fully quantified in well-designed randomized studies. SIR recommends urgent completion of such studies. In the meantime, careful patient selection and optimization of conservative therapy are recommended prior to stent placement, with attention to appropriate stent sizing and quality procedural technique. The use of multiplanar venography with intravascular ultrasound is suggested in diagnosing and characterizing obstructive iliac vein lesions and in guiding stent therapy. After stent placement, SIR recommends close patient follow-up to ensure optimal antithrombotic therapy, durable symptom response, and early identification of adverse events.

Stenting of innominate vein compression syndrome

We report the case of a 60-year-old woman who sought medical attention for left cervical and supraclavicular pain and swelling. Previous computed tomography, intravascular ultrasound, and venography studies were reviewed, confirming extrinsic compression of the left innominate vein by the left common carotid artery against the left clavicle head. Stenting of the lesion was performed, with good mid-term symptom relief and patency. It is, to the best of our knowledge, the first case study in the literature to report endovascular treatment of this syndrome.

Early experience with the Abre venous stent for central venous stenoses and occlusions in hemodialysis patients

BACKGROUND

Hemodialysis patients are prone to stenoses and occlusions throughout the access circuit. Central venous stenoses or occlusions (CVO) can be particularly challenging. There are many different types of balloons and stents available for treatment, including a new generation of dedicated venous stents (VS). In this study, we report our experience and patency rates with the Abre VS in central venous lesions in hemodialysis patients.

METHODS

From April 2020 to May 2023, all procedures with Abre VSs placed for central venous lesions in hemodialysis patients were retrospectively analyzed from a prospectively collected database of 980 hemodialysis access interventions. Follow up outcomes were obtained from angiographic images on follow up angiography and included primary patency and primary assisted patency. Effective hemodialysis was considered a surrogate for access patency if no angiographic follow-up was available.

RESULTS

A total of 15 patients with CVO were treated with the Abre VS. Technical success was 100%. All patients were able to achieve adequate hemodialysis after VS placement. Stents were placed across the thoracic inlet in 73% of patients. Post procedure primary patency at the target lesion site was 85% at 6 months and 70% at 12 months. Primary assisted patency of the circuit was 93% at 6 and 12 months. No stent fractures were observed.

CONCLUSION

Treatment of CVO remains extremely challenging, especially when the lesion is located at the thoracic inlet. In these patients, VSs provide acceptable primary patency rates and allow patients to continue to receive effective hemodialysis. However, routine follow-up and re-interventions will likely be necessary to maintain patency in the long term.

Identifying venous clinical severity score thresholds for Clinical-Etiology-Anatomy-Pathophysiology classifications of venous edema and higher

OBJECTIVE

Venous Clinical Severity Score (VCSS) is a widely used standard for assessing and grading the severity of chronic venous disease (CVD). Prior research highlighted its high validity in detecting and quantifying venous disease. However, there is little, if any, known about the precise thresholds at which VCSS discriminates important stages of deep venous disease. This study sought to elucidate the diagnostic accuracy, thresholds, and correlation at which VCSS detects salient CEAP (Clinical-Etiology-Anatomy-Pathophysiology) classes in deep venous disease progression.

METHODS

A registry of 840 patients who presented with chronic proximal venous outflow obstruction (PVOO) secondary to non-thrombotic iliac vein lesions from August 2011 to June 2021 was retrospectively analyzed. VCSS and CEAP classifications were used to evaluate preoperative symptoms. VCSS was compared to CEAP classes to determine the precise VCSS composite values at which the instrument was able to detect CEAP C3 and higher, C4 and higher, and C5 and higher. Receiver operative characteristic (ROC) curve and area under the curve (AUC) were used to evaluate VCSS for its ability to discriminate disease at these stages of CEAP classification. Spearman's rank coefficient was used to determine the correlation between CEAP VCSS composite as well as individual VCSS components (pain, varicose vein, edema, pigmentation, inflammation, induration, ulcer number, ulcer size, ulcer duration, compression).

RESULTS

VCSS composite was able to detect venous edema (C3) and higher at a sensitivity of 68.9% and a specificity of 54.8% at an optimized threshold of 8.5 (AUC = 0.648; 95% C.I. = 0.575-0.721). To detect changes in skin and subcutaneous tissue from CVD (C4) and higher, an optimal threshold of 11.5 was found with a sensitivity of 51.7% and specificity of 76.5% (AUC = 0.694; 95% C.I. = 0.656-0.731). Healed venous ulcer (C4) and higher was detectable at an optimized threshold of 13.5 at a sensitivity of 67.7% and a specificity of 88.9% (AUC = 0.819; 95% C.I. = 0.766-0.873). The correlation between VCSS composites and CEAP was weak (ρ = 0.372; p < .001). Attributes of VCSS that reflect more severe venous disease correlated more closely with CEAP classes, namely pigmentation (ρ = 0.444; p < .001), inflammation (ρ = 0.348; p < .001), induration (ρ = 0.352; p < .001), number of active ulcers (ρ = 0.497; p < .001), active ulcer size (ρ = 0.485; p < .001), and ulcer duration (ρ = 0.497; p < .001). The correlation between CEAP class and the other four components of VCSS were not statistically significant.

CONCLUSION

VCSS composite thresholds of 8.5, 11.5, and 13.5 are threshold values for detecting CEAP classification C3 and higher, C4 and higher, and C5 and higher, respectively. Consistent with prior work, VCSS appears to have a better ability to discriminate CVD at more severe CEAP classifications. In this registry, the correlation between VCSS and CEAP was found to be weak while components of VCSS that suggest more advanced disease exhibited the strongest correlation with CEAP.

Preprocedural imaging modalities in patients undergoing iliocaval venous recanalization and stent placement

PURPOSE

To determine the diagnostic accuracy of preinterventional imaging modalities in patients being evaluated for iliocaval venous recanalization and stent placement.

METHODS

Consecutive patients with iliocaval postthrombotic obstructions or nonthrombotic iliac vein lesions (NIVL), who were scheduled for recanalization, underwent duplex ultrasound (DUS), magnetic resonance venography (MRV), multiplanar venography (MPV), and intravascular ultrasound (IVUS). The diagnostic accuracies of DUS, MRV, and MPV were analyzed using IVUS as reference.

RESULTS

A total of 216 limbs in 108 patients (80 patients with postthrombotic obstructions, 28 patients with NIVL) were examined. In patients with postthrombotic obstructions, the diagnostic sensitivities for the detection of lesions of the common femoral vein were 81% (95% CI 71-89%) for DUS, 76% (95% CI 65-85%) for MRV, and 86% (95% CI 76-93%) for MPV. The sensitivities for detecting lesions of the iliac veins were 96% (95% CI 89-99%) for DUS, 99% (95% CI 92-100%) for MRV, and 100% (95% CI 94-100%) for MPV. Regarding the inferior vena cava, the sensitivities were 44% (95% CI 24-65%) for DUS, 52% (95% CI 31-73%) for MRV, and 70% (95% CI 47-86%) for MPV. The sensitivities for detecting NIVL were 58% (95% CI 34-79%) for DUS, 90% (95% CI 68-97%) for MRV, and 95% (95% CI 73-99%) for MPV.

CONCLUSION

In patients scheduled for recanalization of iliocaval postthrombotic obstructions, the sensitivities of DUS, MRV, and MPV were similar. In patients with suspected inferior vena cava involvement and in patients with NIVL, additional imaging with MR or conventional venography is required.

Delphi Consensus on Reporting Standards in Clinical Studies for Endovascular Treatment of Acute Iliofemoral Venous Thrombosis and Chronic Iliofemoral Venous Obstruction

Acute iliofemoral deep vein thrombosis and chronic iliofemoral venous obstruction cause substantial patient harm and are increasingly managed with endovascular venous interventions, including percutaneous mechanical thrombectomy and stent placement. However, studies of these treatment elements have not been designed and reported with sufficient rigor to support confident conclusions about their clinical utility. In this project, the Trustworthy consensus-based statement approach was utilized to develop, via a structured process, consensus-based statements to guide future investigators of venous interventions. Thirty statements were drafted to encompass major topics relevant to venous study description and design, safety outcome assessment, efficacy outcome assessment, and topics specific to evaluating percutaneous venous thrombectomy and stent placement. Using modified Delphi techniques for consensus achievement, a panel of physician experts in vascular disease voted on the statements and succeeded in reaching the predefined threshold of >80% consensus (agreement or strong agreement) on all 30 statements. It is hoped that the guidance from these statements will improve standardization, objectivity, and patient-centered relevance in the reporting of clinical outcomes of endovascular interventions for acute iliofemoral deep venous thrombosis and chronic iliofemoral venous obstruction in clinical studies and thereby enhance venous patient care.

Time-Driven Activity-Based Costing for Capturing the Complexity of Healthcare Processes: The Case of Deep Vein Thrombosis and Leg Ulcers

Time-driven activity-based costing (TDABC) is suggested to assess costs within the value-based healthcare approach, but there is a paucity of applications in chronic diseases such as deep vein thrombosis (DVT) and leg ulcers. In this context, we applied TDABC in a cost-effectiveness analysis comparing venous stenting to compression ± anticoagulation (standard of care-SOC) from both hospital and societal perspectives in Italy. TDABC was applied to both treatments to assess costs that were included in a cost-effectiveness model. Clinical inputs were retrieved from the literature and integrated with real-world data. The Incremental Cost Utility Ratio (ICUR) of stenting compared to SOC was EUR 10,270/QALY and EUR 8962/QALY for hospital and societal perspectives, respectively. The mean cost per patient for venous stenting of EUR 5082 was higher than the Diagnosis-Related Group (DRG) reimbursement (EUR 4742). For SOC, an ulcer healing in 3 months costs EUR 1892, of which EUR 302 (16%) is borne by the patient versus a reimbursement of EUR 1132. TDABC showed that venous stenting may be cost-effective compared with SOC but that reimbursement rates may not completely cover the real costs, which are partially sustained by the patients. A more efficient policy for covering the real costs may be beneficial for both clinical centers and patients.

Twelve-month end point results from the evaluation of the Zilver Vena venous stent in the treatment of symptomatic iliofemoral venous outflow obstruction (VIVO clinical study)

BACKGROUND

In the present study, we evaluated the safety and effectiveness of the Zilver Vena venous stent in the treatment of patients with symptomatic iliofemoral outflow obstruction.

METHODS

The VIVO clinical study was a prospective, nonrandomized, multicenter study that enrolled patients with symptomatic obstruction of one iliofemoral venous segment. Included were patients with Clinical, Etiological, Anatomical, Pathophysiological (CEAP) clinical classification of ≥3 or a Venous Clinical Severity Score (VCSS) pain score of ≥2. All patients received a self-expanding venous stent (Zilver Vena venous stent; Cook Ireland Ltd, Limerick, Ireland). The primary safety end point was 30-day freedom from major adverse events. The primary effectiveness end point was the 12-month rate of primary quantitative patency by venography as determined by the core laboratory. The secondary end point was the change in the VCSS from baseline to 1 and 12 months. Additional measures included freedom from clinically driven reintervention; change in the CEAP C classification, Venous Disability Score (VDS), and Chronic Venous Disease Quality of Life Questionnaire (CIVIQ) scores from baseline to 12 months; and stent durability measures.

RESULTS

Between December 2013 and October 2016, 243 patients (70% female; mean age, 53 ± 15 years; 67.5% with current or previous deep vein thrombosis) were enrolled at 30 institutions. Iliac vein compression by the iliac artery (n = 191; 78.6%) was the primary indication for stent placement. The mean lesion length was 98.6 ± 69.8 mm. The 30-day freedom from major adverse events rate was 96.7%, greater than the literature-defined performance goal of 87% (95% confidence interval [CI], 93.5%-98.6%; P < .0001). The 12-month primary quantitative patency rate was 89.9%, greater than the literature-defined performance goal of 76% (95% CI, 85.1%-93.4%; P < .0001). The change in the VCSS from baseline was -3.0 (95% CI, -3.5 to -2.6; P < .0001) at 1 month and -4.2 (95% CI, -4.7 to -3.7; P < .0001) at 12 months, demonstrating clinical improvement. Similarly, significantly (P < .0001) fewer symptoms over time (from preprocedure through 12 months) were measured using the clinical measures of VDS, CEAP C classification, and CIVIQ. The 12-month rate of freedom from clinically driven reintervention was 95.8% ± 1.3%. Through 12 months, no stent fractures and one clinical migration (Clinical Events Committee adjudicated the latter as technique-related due to device undersizing at placement) had occurred.

CONCLUSIONS

The 12-month results of the VIVO study have demonstrated the safety and effectiveness of the Zilver Vena venous stent for the treatment of symptomatic iliofemoral venous outflow obstruction, including clinical symptom improvement compared with baseline.

Deep venous stenting in females

Deep venous stenting has gained increasing prominence in recent years. This issue focuses on special considerations in female patients. The specific challenge relates to the fact that these patients are often much younger than those in whom arterial stents are placed. The stents have to perform adequately over potentially 60 years- and there is no data of that length available.

An Overview of Specific Considerations in Chronic Venous Disease and Iliofemoral Venous Stenting

Unlike arterial disease, chronic venous disease (CVD) is rarely life-threatening or limb-threatening. However, it can impose substantial morbidity on patients by influencing their lifestyle and quality of life (QoL). The aim of this nonsystematic narrative review is to provide an overview of the most recent information on the management of CVD and specifically, iliofemoral venous stenting in the context of personalized considerations for specific patient populations. The philosophy of treating CVD and phases of endovenous iliac stenting are also described in this review. Additionally, the use of intravascular ultrasound is described as the preferred operative diagnostic procedural tool for iliofemoral venous stent placement.

Society of Interventional Radiology Position Statement on the Endovascular Management of Acute Iliofemoral Deep Vein Thrombosis

PURPOSE

To establish the updated position of the Society of Interventional Radiology (SIR) on the endovascular management of acute iliofemoral deep vein thrombosis (DVT).

MATERIALS AND METHODS

A multidisciplinary writing group with expertise in treating venous diseases was convened by SIR. A comprehensive literature search was conducted to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements.

RESULTS

A total of 84 studies, including randomized trials, systematic reviews and meta-analyses, prospective single-arm studies, and retrospective studies were identified and included in the review. The expert writing group developed 17 recommendations that pertain to the care of patients with acute iliofemoral DVT with the use of endovascular venous interventions.

CONCLUSIONS

SIR considers endovascular thrombus removal to be an acceptable treatment option in selected patients with acute iliofemoral DVT. Careful individualized risk assessment, high-quality general DVT care, and close monitoring during and after procedures should be provided.

Midterm and Long-Term Outcomes following Dedicated Endovenous Nitinol Stent Placement for Symptomatic Iliofemoral Venous Obstruction: Three- to 5-Year Results of the VIRTUS Study

PURPOSE

To assess the midterm patency and long-term safety of placement of a dedicated venous stent (Vici Venous Stent System) for the treatment of venous lesions of the iliofemoral outflow tract.

MATERIALS AND METHODS

Patients with unilateral obstructive disease of the iliofemoral veins and a Clinical, Etiological, Anatomical, Pathophysiological class of 3 or higher or a Venous Clinical Severity Score of 2 or greater were enrolled in this prospective, multicenter, single-arm study at 23 sites in the United States and Europe. The patients were followed up for 36 months after the index procedure for the assessment of patency and up to 60 months for the assessment of safety. The clinical outcomes in 11 patients with a stent fracture were assessed.

RESULTS

A total of 200 patients enrolled in 2 cohorts (ie, feasibility cohort, n = 30; pivotal cohort, n = 170) were combined for this analysis. The overall 36-month primary patency rate was 71.7% (86/120), and the 36-month primary patency rate was 96.4% (27/28) for the nonthrombotic group and 64.1% (59/92) for the postthrombotic group. The freedom from major adverse events was 81.2% (53/65) through 60 months. The 60-month Kaplan-Meier estimate of freedom from target vessel revascularization (TVR) was 84.3%. In 9 of the 11 patients who had a stent fracture (1 patient with nonthrombotic etiology and 10 patients with postthrombotic etiology) identified at 12 months, the stents extended into the common femoral vein. The TVR rates and clinical outcomes were similar between patients with and without a stent fracture.

CONCLUSIONS

The results of the VIRTUS study demonstrated good midterm patency and long-term safety following the placement of a dedicated venous stent for iliofemoral obstruction.

Antithrombotic Therapy after Deep Venous Intervention

Chronic deep venous disease (CVD) can result in significant morbidity and impact on quality of life due to a spectrum of symptoms, including lower extremity edema, venous claudication, and venous ulcers. CVD can be secondary to both thrombotic and nonthrombotic disease processes, including postthrombotic syndrome from prior deep vein thrombosis (DVT) or iliac vein compression syndrome. Endovascular therapy has become a mainstay therapy for CVD patients, with venous stent placement frequently performed. However, the management of anticoagulation following venous stent placement is not well-studied, with no large trials or consensus guidelines establishing an optimal regimen. The current knowledge gap in antithrombotic therapy is magnified by heterogeneity in practice and data collection, along with incomplete reporting in available studies. Furthermore, most published datasets are antiquated in the setting of rapid evolution in technique and technology available for deep venous intervention. Herein, we summarize the current available literature and offer an approach to anticoagulation and antiplatelet management following deep venous intervention for CVD.