A systematic review of venous stents for iliac and venacaval occlusive disease

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.

Lower extremity woven and nonwoven venous stent morphology and luminal changes

OBJECTIVE

Venous stents are a common treatment modality for obstructive venous disease. Venous stents differentiate themselves by either a woven or braided structure, open or closed cell arrangement or based on material composition (elgiloy vs nitinol). Changes in the morphology of venous stents over time may contribute to restenosis or thrombosis. Woven elgiloy stents are prone to proximal and distal edge deformation compared with dedicated venous stents, which offer increased radial force at stent edges. The objective of this study is to describe luminal morphological changes among various venous stents and between woven to nonwoven venous stent configuration, over time.

METHODS

A retrospective review at a single institution between January 2014 and June 2021 identified patients treated with venous stents. Patients with iliac and/or femoral venous stents with intraoperative intravascular ultrasound and a postoperative computed tomography scan were included in the study. Cross-sectional diameters measurements were taken at proximal, middle, and distal portions of each stent from intravascular ultrasound examination at the time of initial stenting and compared with the cross-sectional diameter measurements taken from computed tomography imaging at follow-up. A paired t test was used to compare the luminal change with a D'Agostino-Pearson test used for normality.

RESULTS

Fifty-four stents distributed among 38 patients were identified. The mean time to follow-up was 17.5 months. Stents were placed in the common iliac vein (n = 37, 68.5%), external iliac vein (n = 14, 25.9%), and common femoral vein (n = 3, 5.6%). Implanted stents included the Boston Scientific Wallstent (n = 23, 42.6%), Bard Venovo (n = 3, 5.6%), Boston Scientific Vici (n = 23, 42.6%), and Medtronic Abre (n = 5, 9.3%). The mean luminal loss was measured at 2.12 mm proximally (95% confidence interval [CI], 1.64-2.60; P<.001), 1.29 mm at the mid-stent (95% CI, 0.83-1.74, P<.001), and 1.56 mm distally (95% CI, 0.99-2.12; P<.001). There was no significant difference in luminal changes between woven and nonwoven stents at proximal (P = .374), middle (P = .179), and distal (P = .609) stent measurements.

CONCLUSIONS

This study reports morphological changes within venous stents and between woven and nonwoven venous stents. Our findings demonstrate that the edge-stent luminal decrease traditionally attributed to woven configurations also occurs with the newer nonwoven stents. Additional factors such as anatomical location, pelvic curvature, and other external forces may be accountable for this change rather than geometrical configuration of the stent.

Optimizing Venous Stenting: Consensus Recommendations for Enhanced Management of Lower Extremity Deep Vein Thrombosis

INTRODUCTION

 Deep vein thrombosis (DVT) poses a complex challenge and often leads to postthrombotic syndrome (PTS), a debilitating complication. The emergence of venous stents offers a potential preventive avenue against this complication. This study aimed to provide consensus recommendations on the use of venous stent for DVT.

MATERIALS AND METHODS

 From June to July 2023, 20 internal medicine, angiology and vascular surgery, and vascular and interventional radiology experts were involved in the Delphi process. Thirty-one recommendations, categorized into three thematic areas, were rigorously evaluated: indications for stent use, stent selection and placement, and monitoring and prevention of complications. Agreement was evaluated using a Likert scale, with consensus defined as agreement by two-thirds of the participants.

RESULTS

 Consensus was reached for 23 (74.2%) of 31 recommendations. The agreement was centered on considerations, such as stent placement in specific acute DVT scenarios, emphasizing pivotal stent characteristics. However, there were divergences in the recommended stent length to prevent migration and stent characteristics based on iliocaval bifurcation morphology. Notably, there was no consensus on whether patients with DVT caused by a major transient risk factor need more than 3 months of anticoagulation therapy or whether aspirin should be added to anticoagulant treatment after venous stenting.

CONCLUSIONS

 These consensus recommendations offer practical insights into optimizing venous stent use to prevent PTS in DVT patients. Addressing the critical aspects of stent selection, placement, and postprocedural care, these recommendations contribute to clinical decision-making. The identified divergences underscore the importance of consensus and thus indicate the need for further investigation.

Treating Chronic Iliac Vein Stent Occlusion in an Office-Based Lab Setting

Iliac vein stenting is performed when sufficient venous patency is not achieved via angioplasty or lysis. Iliac vein stenting is known to be effective; however, occlusion of the stent occurs occasionally. There is a lack of effective treatment options for those with failed prior venous stents, and traditional methods may involve the removal of the stent and surgical reconstruction. We present a patient with a right leg post-thrombotic syndrome and narcotic abuse after occlusion of a previously placed right common iliac/external iliac vein stent 25 years prior. After transfer to an office-based lab (OBL), femoral vein access was achieved. Then, a second stent was deployed adjacent to the previously chronically thrombosed stent. Imaging confirmed adequate deployment of the new stent and venous flow. Treatment resulted in a significant decrease in patient pain and cessation of narcotics. We demonstrate successful recanalization of a right iliac vein thrombosis via parallel deployment of a stent adjacent to a chronically thrombosed stent.

Histological Features of In-Stent Restenosis after Iliac Vein Thrombus Removal and Stent Placement in a Goat Model

PURPOSE

To establish an animal model for in-stent restenosis (ISR) after postthrombotic iliac vein stent placement and characterize histopathological changes in tissue within the stented vein.

MATERIALS AND METHODS

Iliac vein thrombosis was induced using balloon occlusion and thrombin injection in 8 male Boer goats. Mechanical thrombectomy and iliac vein stent placement were performed 3 days after thrombosis induction. Restenosis was evaluated by venography and optical coherence tomography (OCT) at 1 and 8 weeks after stent placement, and stent specimens were taken for pathological examination after the animals were euthanized.

RESULTS

Thrombosis induction was successful in all 8 goats, with >80% iliac vein occlusion. After thrombus removal, OCT revealed considerable venous intimal thickening and a small number of mural thrombi. Neointimal hyperplasia with thrombus formation was observed in all goats 1 week after stent implantation; the degree of ISR was 15%-33%. At 8 weeks, the degree of ISR was 21%-32% in 3 goats, and stent occlusion was observed in 1 goat. At 1 week, the neointima predominantly consisted of fresh thrombi. At 8 weeks, proliferplastic fibrotic tissue and smooth muscle cells (SMCs) were predominant, and the stent surfaces were endothelialized in 2 of 3 goats and partially endothelialized in 1 goat.

CONCLUSIONS

In the goat model, postthrombotic neointimal hyperplasia in the venous stent may result from time-dependent thrombus formation and organization, accompanied by migration and proliferation of SMCs, causing ISR. These results provide a basis to further explore the mechanism of venous ISR and promote the development of venous stents that reduce neointimal hyperplasia.

Iliocaval and iliofemoral venous stenting for obstruction secondary to tumor compression

BACKGROUND

Cancer patients with pelviabdominal masses can suffer from lower extremity symptoms due to venous compression. The effectiveness of venous stenting has been established in extrinsic venous compression in benign conditions like May-Thurner syndrome. In this retrospective study we evaluate the efficacy and safety of caval, iliocaval and iliofemoral venous stenting for cases of extrinsic venous compression caused by malignant masses in cancer patients.

METHODS

IRB-approved retrospective review of patients who underwent iliofemoral venography with venoplasty and stenting between January 2018 and February 2022 was performed. Patients with extrinsic venous compression caused by malignant masses were included. Data on patient demographics, pre-procedure symptoms, procedural technique, stent characteristics, outcomes and follow-up were collected. Descriptive statistics were used to assess technical success, clinical success, primary stent patency and adverse events of the procedure.

RESULTS

Thirty-seven patients (19 males, 18 females) who underwent 45 procedures were included. Deep venous thrombosis (DVT) was present in 21 (57%) patients. Twenty-nine patients (78%, 95% CI 62-90%) reported clinical improvement of the presenting symptoms. The median overall survival after the procedure was 4.7 months (95% CI 3.58-5.99). Eight (22%) patients were alive at last follow up with median follow up of 10.33 months (Range 2-25 months). Twenty-six patients had patent stents on their last follow up imaging (70%, 95% CI 61%-91%). Two patients had a small access site hematoma which resolved spontaneously. Two patients developed moderate, and 1 patient developed severe adverse events related to post procedure therapeutic anticoagulation.

CONCLUSION

Venous stenting is a safe procedure and should be considered as part of the palliative care for patients with debilitating lower extremity symptoms related to iliocaval and iliofemoral venous compression.

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.

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.

Clinical Outcomes at 3 Years After Stenting for Thrombotic and Non-thrombotic Iliac Vein Compression Syndrome Patients

Iliac vein stenting for the treatment of iliac vein compression syndrome (IVCS) has been gradually developed. This article investigated the long-term patency and improvement of clinical symptoms after endovascular stenting for iliac vein obstruction patients. From 2020 to 2022, 83 patients at a single institution with IVCS underwent venous stent implantation and were divided into two groups: non-thrombotic IVCS (n = 55) and thrombotic IVCS (n = 28). The main stent-related outcomes include technical success, long-term patency, and thrombotic events. The technical success rate of all stent implantation was 100%. The mean length of hospital stay and cost were higher in the thrombotic IVCS group than in the non-thrombotic ICVS group, as well as the length of diseased vessel segment and the number of stents implanted were higher than in the control non-thrombotic group. The 1-, 2-, and 3-year patency rates were 85.4%, 80% and 66.7% in the thrombosis group, which were lower than 93.6%, 88.7%, and 87.5% in the control group (P = .0135, hazard ratio = 2.644). In addition, patients in both groups had a foreign body sensation after stent implantation, which resolved spontaneously within 1 year after surgery. Overall, there were statistically significant differences in long-term patency rate outcome between patients with thrombotic and non-thrombotic IVCS, the 1-, 2-, and 3-year patency rates in non-thrombotic IVCS patients were higher than those in thrombotic IVCS patients.

Iliocaval and Iliofemoral Venous Stenting for Obstruction Secondary to Tumor Compression: Single Center Experience

Background

Cancer patients with pelviabdominal masses can suffer from lower extremity symptoms due to venous compression. The effectiveness of venous stenting has been established in extrinsic venous compression in benign conditions like May-Thurner syndrome. In this retrospective study we evaluate the efficacy and safety of caval, iliocaval and iliofemoral venous stenting for cases of extrinsic venous compression caused by malignant masses in cancer patients.

Methods

IRB-approved retrospective review of patients who underwent iliofemoral venography with venoplasty and stenting between January 2018 and February 2022 was performed. Patients with extrinsic venous compression caused by malignant masses were included. Data on patient demographics, pre-procedure symptoms, procedural technique, stent characteristics, outcomes and follow-up were collected. Descriptive statistics were used to assess technical success, clinical success, primary stent patency and adverse events of the procedure.

Results

Thirty-seven patients (19 males, 18 females) who underwent 45 procedures were included. Deep venous thrombosis (DVT) was present in 21 (57%) patients. Twenty-nine patients (78%, 95% CI 62-90%) reported clinical improvement of the presenting symptoms. The median overall survival after the procedure was 4.7 months (95% CI 3.58-5.99). Eight (22%) patients were alive at last follow up with median follow up of 10.33 months (Range 2-25 months). Twenty-six patients had patent stents on their last follow up imaging (70%, 95% CI 61%-91%). Two patients had a small access site hematoma which resolved spontaneously. Two patients developed moderate, and 1 patient developed severe adverse events related to post procedure therapeutic anticoagulation.

Conclusion

Venous stenting is a safe procedure and should be considered as part of the palliative care for patients with debilitating lower extremity symptoms related to iliocaval and iliofemoral venous compression.

Editor's Choice - Quality of Life after Stenting for Iliofemoral Venous Obstruction: A Randomised Controlled Trial with One Year Follow Up

OBJECTIVE

Deep venous obstruction (DVO) is a great burden on the healthcare system and patients' quality of life (QoL). Case series show stenting is safe and effective, however most studies lack control groups and QoL changes have not been compared with conventional treatment. The aim was to assess the difference in QoL changes from baseline to 12 months between stent and conventionally treated patients with DVO.

METHODS

Subjects > 18 years old with DVO due to post-thrombotic (PTS) or non-thrombotic iliac vein lesions (NIVLs) in a tertiary hospital were prospectively randomised to best medical therapy (BMT) or stent placement with BMT in a ratio 2:1, stratified for PTS or NIVL. The primary outcome was the between group difference in VEINES-QoL scores change from baseline to 12 months after treatment. Secondary outcomes included the difference in score changes for EuroQoL 5-Dimension 5 Level (EQ-5D-5L), Pain Disability Index (PDI), Venous Clinical Severity Score (VCSS), and the Villalta score.

RESULTS

After three years, the inclusion rate dropped to almost zero, therefore the study had to be stopped. Sixty-three patients were randomised to either the stent (n = 42) or control group (n = 21). Overall, 50 patients had available data for primary outcome analysis. The adjusted mean difference between 12 month scores for VEINES-QoL and VEINES-Sym was 8.07 (95% CI 3.04 - 13.09) and 5.99 (95% CI 0.75 - 11.24) (p = .026), respectively, in favour of the stent group. The differences were significant, but a pre-defined meaningful 14 point improvement in QoL was not reached. The mean difference between 12 month scores for VCSS was -2.93 (95% CI -5.71 - 0.16, p = .040), -11.83 (95% CI -20.81 - 2.86, p = .011) for PDI, 0.015 (95% CI -0.12 - 0.15, p = .82) for the EQ-5D index, and -2.99 (95% CI -7.28 - 1.30, p = .17) for the Villalta score.

CONCLUSION

Symptomatic patients with DVO who received dedicated venous stents had significantly higher VEINES-QoL/Sym scores at 12 months compared with the control group, but the between group difference was lower than the pre-specified clinically relevant QoL difference of at least 14 points.

STUDY REGISTRATION NUMBER

NCT03026049.

Iliac vein stenting and pregnancy

Venous stenting is the mainstay treatment of symptomatic iliofemoral venous outflow obstruction. However, because pregnancy and the postpartum period are hypercoagulable, concerns exist regarding stent placement in women of childbearing age. We performed a systematic review up to April 2023 of studies reporting on the performance of venous stents in women who subsequently became pregnant. The data collected included demographics, indication for stenting, stent characteristics, stent-related complications, incidence of venous thromboembolism, medical management during pregnancy, and follow-up. The indications for stenting included acute iliofemoral deep vein thrombosis in 39 patients (51%), nonthrombotic iliac vein lesions in 35 (46%), and post-thrombotic lesions in 2 patients. A total of 76 women with 87 subsequent pregnancies after stenting were included. Of the 76 women, 1 (1.14%) experienced stent occlusion, 2 (2.29%) developed asymptomatic nonocclusive in-stent thrombus, and 2 (2.29%) experienced permanent stent compression. The only patency loss occurred because of inadequate anticoagulation therapy in a patient with antiphospholipid antibodies. The two cases of permanent compression occurred in an arterial stent and a balloon-fenestrated Vici stent (Boston Scientific). Venous stents performed well through pregnancy and can be safely used in women of childbearing age. Given the increased risk of venous thromboembolism and the low bleeding risk, it is prudent to recommend anticoagulation therapy for all stented patients until more data are available.

Ultrasound-guided stenting in the common femoral vein for accurate stent distal landing

Objective/Background

Venous stenting has been reported with excellent clinical results; however, inadequate inflow can increase the risk of stent occlusion. When extending the stent into the common femoral vein (CFV), it is essential to ensure adequate inflow from the femoral vein, deep femoral vein (DFV), and great saphenous vein. Accurate identification of the distal landing zone (DLZ) of the stent is crucial to ensure adequate inflow. The DLZ is usually determined by venography or intravascular ultrasound (IVUS) with reference to bony landmarks. However, the uncertainty can lead to misidentification of the DLZ and inadequate stent placement, resulting in stent occlusion.

Methods

From December 2016 to December 2022, 42 venous stent placements were performed in 40 patients with post-thrombotic iliofemoral vein obstruction and/or stenosis. Three patients had developed early stent occlusion owing to a misidentified DLZ. To improve accuracy in identifying the DLZ during venous stenting, ultrasound-guided placement was performed in the CFV of five patients (four on the left and one on the right) with post-thrombotic changes in the CFV and occlusion of the common iliac vein and external iliac vein. The distal end of the stent was adjusted just above the saphenofemoral junction in two cases and just proximal to the DFV confluence in three cases. Stent placement was verified using both long-axis ultrasound and fluoroscopy.

Results

Ultrasound images of the CFV region provided clear visualization of the stent deployment site and accurate landmark locations, such as the saphenofemoral junction and DFV confluence, allowing for precise adjustments during stent deployment. This technique enabled easier and more definitive identification of other branches of the CFV than previously provided by IVUS and venography. No complications were observed in any of the 42 cases, and long-term patency was achieved at the final follow-up after stenting (average, 10 months; range, 3-14 months).

Conclusions

Ultrasound-guided stenting in the CFV allows for real-time and accurate stent deployment with precise adjustment to the optimal DLZ. Using this technique, combined with venography and IVUS, missed distal lesions and subsequent stent occlusion can be prevented, potentially contributing to better treatment outcomes.

Patient-Reported Outcomes of Endovascular Treatment of Post-Thrombotic Syndrome: Ancillary Study of a French Cohort

Excellent outcomes of angioplasty/stenting for the post-thrombotic syndrome (PTS) have been reported, notably regarding objective criteria in the vast French SFICV cohort. Differences may exist between patient-reported and objective outcomes. We investigated this possibility by using validated scales because significative correlations are discordant in the literature between patency and patient-reported characteristics. Patient-reported outcomes seem to be a more consistent tool than radiologic patency for the diagnosis and follow-up of patients displaying PTS. We retrospectively reviewed the Villalta scale and 20-item ChronIc Venous dIsease quality-of-life Questionnaire (CIVIQ-20) scores recorded after endovascular stenting for PTS at 14 centres in France in 2009-2019. We also collected patency rates, pre-operative post-thrombotic lesion severity, and the extent of stenting. We performed multivariate analyses to identify factors independently associated with improvements in each of the two scores. The 539 patients, including 324 women and 235 men, had a mean age of 44.7 years. The mean Villalta scale improvement was 7.0 ± 4.7 (p < 0.0001) and correlated with the thrombosis sequelae grade and time from thrombosis to stenting. The CIVIQ-20 score was available for 298 patients; the mean improvement was 19.2 ± 14.8 (p < 0.0001) and correlated with bilateral stenting, single thrombosis recurrence, and single stented segment. The objective gains demonstrated in earlier work after stenting were accompanied by patient-reported improvements. The factors associated with these improvements differed between the Villalta scale and the CIVIQ-20 score. These results proved that clinical follow-up with validated scores is gainful in patients treated for PTS thanks to a mini-invasive procedure.

Silent Migration of a Left Common Iliac Venous Stent to the Right Atrium: A Case Report and Review of Literature

In the past decade, percutaneous endovenous stenting has emerged as the primary procedure for treating symptomatic venous outflow obstruction. Stent migration is a rare but serious and well-recognized complication of venous stenting. Cardiopulmonary complications following stent migration can manifest in a number of ways, including damage to the valves, arrhythmias, endocarditis, tamponade, and acute heart failure. Both extracardiac and intracardiac dislodgement of stents may be treated with catheter-directed extraction, stent redeployment, or surgical extraction. The decision on the type of procedure depends on multiple factors including the location of the stent, the size and accessibility of the stent, the symptoms, the extent of damage to the vital structures, and the overall health of the patient. We present the case of a 68-year-old male who presented with tachycardia. On further evaluation and workup, he was found to have an iliac venous stent that had migrated to the right atrium.

Evaluation of safety and performance of a new prototype self-expandable nitinol venous stent in an ovine model

Objective

Our study was a prospective in vivo study performed on an animal model to evaluate the safety and performance of a novel venous stent designed specifically for venous applications.

Methods

The novel stents were implanted in the inferior vena cava of nine sheep. The stents were deployed with different distances between the closed cell rings to test for if the segments might migrate after being deployed at maximal distance. Three different total lengths were 9, 11, and 13 cm. After 1, 3, and 6 months, vascular injury, thrombus, neointima coverage, and stent migration were evaluated through computed tomography venography and histopathology. Imaging, histology, and integration data were analyzed for each group.

Results

All stents were deployed successfully, and all sheep survived until the time of harvesting. In all cases, the native blood vessel sections were intact. The segmented stent parts showed a differently pronounced tissue coverage, depending on the duration of the implantation.

Conclusions

The new nitinol stent is safe and feasible to implant in the venous system with a rapid surface coverage. Alteration of stent length did not affect the development of neointimal formation and did not cause migration.

Stenting across inferior vena cava filters can be a safe and effective alternative to complex retrieval

OBJECTIVE

Venous stenting for acute and chronic venous disease has been increasingly used as more evidence has accumulated on the efficacy and durability of these interventions for symptomatic patients. Inferior vena cava (IVC) filters that could have been present for years will often be implicated in the obstructive pathology and removal can be challenging. The purpose of the present study was to evaluate whether stenting across an indwelling IVC filter is a safe and effective alternative to removal.

METHODS

Consecutive patients who had undergone iliocaval stenting at our institution from 2007 to 2020 were identified and divided into groups stratified by the presence of an IVC filter. The operative notes, venography findings, and the electronic health records were queried to obtain the operative details, patient characteristics, postoperative outcomes, stent patency, and survival outcomes. The primary end point was iliocaval stent patency. The patients were divided into two groups according to the presence of an IVC filter with or without overstenting. We used the χ2 test and survival analysis as appropriate.

RESULTS

A total of 224 consecutive patients were identified, of whom 71 were found to have undergone iliocaval stenting (age, 48 ± 18 years; 47.9% male; body mass index, 31 ± 9 kg/m2). Of the 71 patients, 15 had had stents placed across an indwelling IVC filter (overstented group) and 56 had not had an IVC filter present (non-overstented group). No differences were found in presentation between the overstented group (acute occlusion, 4 of 15 [26.7%]; chronic occlusion, 8 of 15 [53.3%]; and nonocclusive lesions, 3 of 15 [20%]) and the non-overstented group (acute occlusion, 29 of 56 [52%]; chronic occlusion, 18 of 56 [32%]; nonocclusive lesions, 9 of 56 [16%]; P = .2). Comparisons between the two groups revealed no differences in the baseline characteristics except for age (overstented, 57 ± 15 years; non-overstented, 46 ± 18 years; P = 0.03), preoperative anticoagulation therapy (overstented, 66.6%; non-overstented, 26.9%; P = .01), and bilateral leg symptoms (overstented, 86.7%; non-overstented, 23.2%; P < .001). Primary patency at 30 months was 85.6% in the overstented group and 86.1% in the non-overstented group (P = .78). At follow-up, no adverse events related to filter crushing were reported, and no differences were found in 30-month survival.

CONCLUSIONS

In our single-center, retrospective study of iliocaval stenting, patients who had undergone overstenting across an indwelling IVC filter had had patency rates similar to those whose stents had been placed with no IVC filter in place. Thus, complex IVC filter removal, when not possible or when the risk of operative complications is too high, can be forgone in favor of stenting across the IVC filter, with no implications on midterm patency or adverse events.

A systematic review of reported outcomes in people with lower limb chronic venous insufficiency of the deep veins

OBJECTIVE

The prevalence of lower limb chronic venous insufficiency (CVI) of the deep veins is increasing and presents a significant burden to patients and health care services. To improve the evaluation of interventions it is necessary to standardise their reporting. The aim of this study was to perform a systematic review of the outcomes of interventions delivered to people with CVI of the deep veins as part of the development of a novel core outcome set (COS).

METHODS

Following the Core Outcome Measures in Effectiveness Trials (COMET) framework for COS development, a systematic review was conducted to PRISMA guidance. The protocol was preregistered on PROSPERO (CRD42021236795). MEDLINE, Embase, Emcare, CINAHL, and the Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews and Clinicaltrials.gov were searched from January 2018 to January 2021. Clinical trials and observational studies involving more than 20 participants, reporting outcomes for patients with CVI of the deep veins were eligible. Outcomes were extracted verbatim, condensed into agreed outcome terms and coded into domains using standard COMET taxonomy. Outcome reporting consistency, where outcomes were fully reported throughout the methods and results of their respective articles was also assessed.

RESULTS

Some 103 studies were eligible. There were 1183 verbatim outcomes extracted, spanning 22 domains. No outcome was reported unanimously, with the most widely reported outcome of primary patency featuring in 51 articles (<50%). There was a predominant focus on reporting clinical outcomes (n = 963 [81%]), with treatment durability (n = 278 [23%]) and clinical severity (n = 108 [9%]) reported frequently. Life impact outcomes were relatively under-reported (n = 60 [5%]). Outcome reporting consistency was poor, with just 50% of outcomes reported fully.

CONCLUSIONS

Outcome reporting in studies of people with CVI of the deep veins is currently heterogeneous. Life impact outcomes, which likely reflect patients' priorities are under-reported. This study provides the first step in the development of a COS for people with lower limb CVI of the deep veins.

The Efficacy of Stenting in the Iliofemoral Vein of Patients with Venous Obstruction and Secondary Lymphedema from Malignancy

OBJECTIVE

To investigate the safety and effectiveness of venous stenting in patients with chronic iliofemoral venous obstruction and secondary lymphedema from malignancy.

METHODS

From July 2012 to December 2020, patients with iliofemoral venous obstruction and secondary lymphedema who underwent venous stenting in our institution were retrospectively reviewed. Clinical characteristics, surgical complications, and symptom relief were assessed. Stent patency was evaluated with duplex ultrasound or computed tomographic venography. Twelve-month outcomes were reported.

RESULTS

Fifty-three patients with concurrent secondary lymphedema who had stents placed for iliofemoral venous obstruction were included. There were 42 females, and the mean age was 56.9 years. Nonthrombotic iliac vein lesions were identified in 16 (30.1%) patients. Immediate technical success was 100%, with an average of two stents implanted. The median Villalta score, and Chronic venous disease quality of life questionnaire scores decreased from 12 (IQR, 10-15) and 58 (IQR, 50-66) at baseline, respectively, to 5 (IQR, 4-6) and 28 (IQR, 22-45) at 12 months after the procedure (p <.05), showing significant improvement in the quality of life. At the end of a median follow-up of 12 months (range 3-25 months), the cumulative primary, assisted primary, and secondary patency rates were 70.8%, 76.9%, and 90.1%, respectively.

CONCLUSION

In patients with secondary lymphedema from malignancy, venous stent placement is safe and effective for iliofemoral venous obstruction.

A Systematic Review of the Safety and Efficacy of Inferior Vena Cava Stenting

OBJECTIVE

Inferior vena cava (IVC) stenting may provide benefit to patients with symptomatic obstruction; however, there are no devices currently licensed for use in the IVC and systematic reviews on the topic are lacking. The aim of this study was to carry out a systematic review of the literature and meta-analysis to investigate the safety and efficacy of IVC stenting in all adult patient groups.

DATA SOURCES

The Medline and Embase databases were searched for studies reporting outcomes for safety and effectiveness of IVC stenting for any indication in series of 10 or more patients.

REVIEW METHODS

A systematic review of the literature was carried out according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

Thirty-three studies were included describing 1 575 patients. Indications for stenting were malignant IVC syndrome (229 patients), thrombotic disease (807 patients), Budd-Chiari syndrome (501 patients), and IVC stenosis post liver transplantation (47 patients). The male:female ratio was 2:1 and the median age ranged from 30 to 61 years. The studies included were not suitable for formal meta-analysis as 30/33 were single centre retrospective studies with no control groups and there was considerable inconsistency in outcome reporting. There was significant risk of bias in 94% of studies. Median reported technical success was 100% (range 78 - 100%), primary patency was 75% (38 - 98%), and secondary patency was 91.5% (77 - 100%). Major complications were pulmonary embolism (three cases), stent migration (12 cases), and major bleeding (15 cases), and there were three deaths in the immediate post-operative period. Most studies reported improvement in clinical symptoms but formal reporting tools were not used consistently.

CONCLUSION

The evidence base for IVC stenting consists of predominantly single centre, retrospective, observational studies that have a high risk of bias. Nonetheless the procedure appears safe with few major adverse events, and studies that reported clinical outcomes demonstrate improvement in symptoms and quality of life. Randomised controlled trials and prospective registry based studies with larger patient numbers and standardised outcome are required to improve the evidence base for this procedure.

Nutcracker syndrome: A case report and review of the literature

Background

Nutcracker syndrome (NS) is an uncommon condition resulting from the compression of the left renal vein (LRV) between the aorta and superior mesenteric artery (SMA), resulting in symptoms such as flank pain and hematuria.

Case presentation

We present the case of a 30-year-old woman complaining of abdominal pain who was found to have nutcracker syndrome and treated with endovascular stenting of the left renal vein.

Discussion

We review the literature related to endovascular treatment of NS with focus on the distribution of the sizes of stents and rates of stent migration.

Conclusion

NC is a rare condition requiring a high index of suspicion for diagnosis. Endovascular treatment is a reasonable option, but its limitations must be considered.

Utilization of and Outcomes Associated with Intravascular Ultrasound during Deep Venous Stent Placement among Medicare Beneficiaries

PURPOSE

To evaluate temporal trends, practice variation, and associated outcomes with the use of intravascular ultrasound (US) during deep venous stent placement among Medicare beneficiaries.

MATERIALS AND METHODS

All lower extremity deep venous stent placement procedures performed between January 1, 2017, and December 31, 2019 among Medicare beneficiaries were included. Temporal trends in intravascular US use were stratified by procedural setting and physician specialty. The primary outcome was a composite of 12-month all-cause mortality, all-cause hospitalization, or repeat target vessel intervention. The secondary outcome was a composite of 12-month stent thrombosis, embolization, or restenosis.

RESULTS

Among the 20,984 deep venous interventions performed during the study period, 15,184 (72.4%) utilized intravascular US. Moderate growth in intravascular US use was observed during the study period in all clinical settings. There was a variation in the use of intravascular US among all operators (median, 77.3% of cases; interquartile range, 20.0%-99.2%). In weighted analyses, intravascular US use during deep venous stent placement was associated with a lower risk of both the primary (adjusted hazard ratio, 0.72; 95% confidence interval [CI], 0.69-0.76; P < .001) and secondary (adjusted hazard ratio, 0.32; 95% CI, 0.27-0.39; P < .001) composite end points.

CONCLUSIONS

Intravascular US is frequently used during deep venous stent placement among Medicare beneficiaries, with further increase in use from 2017 to 2019. The utilization of intravascular US as part of a procedural strategy was associated with a lower cumulative incidence of adverse outcomes after the procedure, including venous stent thrombosis and embolization.

Novel therapy for recanalization of chronic iliocaval venous occlusion using radiofrequency

OBJECTIVE

Chronic venous disease of the lower extremities is one of the most common diseases in the United States. The sequelae of this disease process are the source of a significant amount of morbidity, and its prevalence is expected to increase in the coming decades. Interventional therapy is warranted for relief of patients with CEAP C3-C6 disease. With advances in endovascular therapy, chronic iliocaval venous occlusion (CICVO) pathology can be corrected through minimally invasive approaches with limited morbidity and mortality. However, failure to recanalize the venous system leads to high failure rates. The purpose of this study was to assess the procedural success for recanalization of CICVO in the community setting using the novel technique of the Baylis radiofrequency (RF) wire in patients who had failed previous endovascular intervention.

METHODS

A retrospective review of patients who underwent RF recanalization for CICVO at our institution from 2019 to 2020 was conducted. All patients had failed previous endovascular attempts at recanalization. The primary outcome was recanalization (defined as restoration of >70% of luminal patency as determined on multiplanar venography [MPV] and intravascular ultrasound [IVUS]) confirmed on both IVUS and MPV. Secondary outcomes included adjunctive interventions and complications (hematoma, pulmonary embolism, new onset renal insufficiency).

RESULTS

A total of 10 patients, 50% male with a mean (standard deviation) age of 58.4 (10.4), were evaluated in the study. Successful recanalization was achieved in 60% of cases, with a resolution of >70% of luminal obstruction observed using MPV and IVUS. Adjunctive interventions were performed in 70% of cases. There were no clinically significant complications or blood transfusion requirements.

CONCLUSIONS

New techniques and technologies continue to be developed for advanced endovascular management of CICVO, especially with the expanding market for Food and Drug Administration approved venous stents. The Baylis RF wire can assist in recanalization and treatment of patients who had failed previous endovascular therapy.

Quality of life after stenting for chronic iliocaval obstruction

Background

Iliocaval stenting is widely used for treatment of symptomatic iliocaval obstruction. The aim of our study was to compare quality of life before and after iliocaval stenting.

Method

Prospectively collected data using CIVIQ20 questionnaire, Venous Clinical Severity Score (rVCSS) and Villalta-Prandoni score (VP) of patients following iliocaval stenting for non-thrombotic and post-thrombotic venous obstruction were analysed.

Result

One hundred and one limbs (87 patients) were stented between May 2017 and May 2019. Baseline CIVIQ20 median value was 50 (34–66); 1 month after surgery CIVIQ20 value was 36 (26–58) and the scores then remained steady for the rest of the first year. Both rVCSS and VP scores decrease by 3.09 (95% CI: 2.39, 3.89; p < .001) and 5.21 (95% CI: 4.14, 6.48; p < .001) units, respectively, throughout the first year.

Conclusion

Quality of life of patients with iliocaval obstruction significantly improves after successful percutaneous reconstruction. Severity of symptoms measured by rVCSS and VP scores decreases.

Editor's Choice - Clinical Efficacy of Venastent - A Novel Iliac Vein Stent for Non-Thrombotic Iliac Vein Lesions: A Multi-Centre Randomised Controlled Trial

OBJECTIVE

To determine the efficacy of Venastent - a novel iliac vein stent for non-thrombotic iliac vein lesions (NIVLs).

METHODS

From October 2018 to January 2021, 256 NIVL patients were recruited at 19 Chinese hospitals. A randomised controlled trial was conducted to compare the efficacy of the new iliac vein stent-Venastent (Tianhong China) with Zilver stent (Cook USA). All patients were allocated randomly to two groups: the experimental group patients used Venastent, while the control group received the Zilver stent. The trial was registered in Chinese Clinical Trial Registry (ChiCTR2200057851).

RESULTS

A total of 123 patients in the experimental group and 122 patients in the control group had a full set of data collected (p = ns). The technical success rate was 100% (n = 245/245). The patency rate was 100% (n = 123/123) in the experimental group and 98.4% (n = 120/122) in control group one year after operation (p = ns). The lower extremity swelling remission rate was 79.1% (n = 87/110) in the experimental group and 78.4% (n = 91/116) in the control group (p = ns). The lower extremity pain relief rate was 68.8% (n = 50/80) in the experimental group and 77.2% (n = 71/92) in the control group (p = ns). The ulcer healing rate was 90% (n = 18/20) in the experimental group and 87% (n = 20/23) in the control group (p = ns). There was no difference in stent re-stenosis or clinical remission between the two groups.

CONCLUSION

The new iliac vein stent, Venastent, had a comparable high patency rate and safety profile as the Zilver stent (Cook) in NIVLs patients. Venastent significantly reduced symptoms of chronic venous disease.

P- and E- selectin in venous thrombosis and non-venous pathologies

Venous thromboembolism is a very common and costly health problem worldwide. Anticoagulant treatment for VTE is imperfect: all have the potential for significant bleeding, and none prevent the development of post thrombotic syndrome after deep vein thrombosis or chronic thromboembolic pulmonary hypertension after pulmonary embolism. For these reasons, alternate forms of therapy with improved efficacy and decreased bleeding are needed. Selectins are a family (P-selectin, E-selectin, L-selectin) of glycoproteins that facilitate and augment thrombosis, modulating neutrophil, monocyte, and platelet activity. P- and E-selectin have been investigated as potential biomarkers for thrombosis. Inhibition of P-selectin and E-selectin decrease thrombosis and vein wall fibrosis, with no increase in bleeding. Selectin inhibition is a promising avenue of future study as either a stand-alone treatment for VTE or as an adjunct to standard anticoagulation therapies.

Antithrombotic Therapy After Venous Interventions: AJR Expert Panel Narrative Review

Interventions for thrombotic and nonthrombotic venous disorders have increased with technical advances and more trained venous specialists. Antithrombotic therapy is essential to clinical and procedural success; however, post-procedural therapeutic regimens exhibit significant heterogeneity due to limited prospective randomized data as well as incomplete mechanistic understanding of the critical factors driving long-term patency. Post-interventional antithrombotic therapy for thrombotic venous disorders should adhere to existing venous thromboembolism management guidelines, which include 3-6 months of therapeutic anticoagulation at minimum and consideration of extended therapy in patients with higher risk of thrombosis due to procedural or patient factors. The additive benefit of antiplatelet agents in the acute and intermediate period is unknown, having shown improved long-term stent patency in some retrospective studies. Dual and/or triple agent therapy should be limited based on individual risks of thrombosis and bleeding. The treatment of non-thrombotic disorders is more heterogeneous, though patients with limited flow, extensive stent material, or underlying prothrombotic states such as malignancy or chronic inflammation may benefit from single- or multi-agent antithrombotic therapy. However, the agent, dose, and duration of therapy remain indeterminate. Future prospective studies are warranted to improve patient risk stratification and standardize post-procedural antithrombotic therapy in patients receiving venous interventions.

Immediate postprocedure anticoagulation with factor Xa inhibitors of venous stents for nonthrombotic venous lesions does not increase stent patency

BACKGROUND

Many clinicians will prescribe anticoagulation therapy for patients after iliac vein stenting to prevent early or late stent thrombosis. At present, it is unknown whether therapeutic anticoagulation has any effect on stent patency. Thus, we assessed the role of short-term anticoagulation on iliac vein stent patency in patients with nonthrombotic iliac vein lesions (NIVLs).

METHODS

We performed a retrospective medical record review of all iliac vein stents placed for NIVLs at the Center for Vascular Medicine from January 2018 to December 2019. We compared the stent patency in the two groups. The anticoagulation (AC) group had received rivaroxaban or apixaban postoperatively for a minimum of 90 days and were compared with a group that had received no postoperative anticoagulation (NAC). Stent patency was assessed using transabdominal ultrasound at 3, 6, 12, 18, 24, and 30 months. At the discretion of the treating physician, the patients who demonstrated thrombus layering on surveillance ultrasound scanning continued rivaroxaban or apixaban until thrombus resolution was observed. The demographics and stent location, diameter, and length were assessed. Stent patency was analyzed using life table analyses. Differences in stent patency were analyzed using GraphPad Prism, version 8, statistical software (GraphPad Software Inc, La Jolla, Calif) and the log-rank (Mantel-Cox) test.

RESULTS

The number of patients and stents in each group were as follows: AC group, 299 patients and 308 stents; and NAC group, 77 patients and 90 stents. The average age was 52.24 ± 13.44 years and 55.63 ± 14.49 years in the AC and NAC groups, respectively (P ≤ .065). Women constituted 76% of the patients in the AC group and 72% in the NAC group. The average stent diameter and length for the AC group was 20 ± 2 mm and 77 ± 13 mm and for the NAC group was 19 ± 2 mm and 82 ± 9 mm, respectively. The stents had been placed in the right common iliac vein, bilaterally, or left common iliac vein territory in 15%, 3%, and 82% in the AC group and 18%, 2%, and 80% in the NAC group, respectively. The cumulative stent patency at 30 months was 98.7% and 94.6% for the NAC and AC groups, respectively (P ≤ .83). All the stents placed were Wallstents (Boston Scientific, Marlborough, Mass). A total of eight insertion site thromboses occurred that did not affect stent patency: five in the AC group (1.6%) and three in the NAC group (4.5%; P = .15). In addition, 19 patients demonstrated evidence of thrombus layering, with 6 receiving extended anticoagulation.

CONCLUSIONS

Our data indicate that perioperative stent thrombosis in patients with NIVLs is uncommon. Thus, anticoagulation for perioperative stent thrombosis prophylaxis is not necessary. Anticoagulation should only be used for patients with insertion site thromboses and should be considered if thrombus layering is observed on surveillance scanning.

A Systematic Review and Meta-Analysis of 12-Month Patency After Intervention for Iliofemoral Obstruction Using Dedicated or Non-Dedicated Venous Stents

BACKGROUND

Endovascular stenting of the deep venous system has been proposed as a method to treat patients with symptomatic iliofemoral outflow obstruction. The purpose of this systematic review and meta-analysis was to compare the effectiveness of this treatment at 1-year following the development of dedicated venous stents.

METHOD AND RESULTS

We searched MEDLINE and EMBASE for studies evaluating the effectiveness of venous stent placement. Data were extracted by disease pathogenesis: non-thrombotic iliac vein lesions (NIVL), acute thrombotic (DVT), or post-thrombotic syndrome (PTS). Main outcomes included technical success, stent patency at 1 year and symptom relief. A total of 49 studies reporting outcomes in 5154 patients (NIVL, 1431; DVT, 950; PTS, 2773) were included in the meta-analysis. Technical success rates were comparable among groups (97%-100%). There were no periprocedural deaths. Minor bleeding was reported in up to 5% of patients and major bleeding in 0.5% upon intervention. Transient back pain was noted in 55% of PTS patients following intervention. There was significant heterogeneity between studies reporting outcomes in PTS patients. Primary and cumulative patency at 1 year was: NIVL-96% and 100%; DVT-91% and 97%; PTS (stents above the ligament)-77% and 94%, and; PTS (stents across the ligament)-78% and 94%. There were insufficient data to compare patency outcomes of dedicated and nondedicated venous stents in patients with acute DVT. In NIVL and PTS patients, stent patency was comparable at 1 year. There was inconsistency in the use of validated tools for the measurement of symptoms before and after intervention. When reported, venous claudication, improved in 83% of PTS patients and 90% of NIVL patients, and ulcer healing occurred in 80% of PTS patients and 32% of NIVL patients.

CONCLUSIONS

The first generation of dedicated venous stents perform comparably in terms of patency and clinical outcomes to non-dedicated technologies at 1 year for the treatment of patients with NIVL and PTS. However, significant heterogeneity exists between studies and standardized criteria are urgently needed to report outcomes in patients undergoing deep venous stenting.

Optimal Medical Therapy Following Deep Venous Interventions: Proceedings from the Society of Interventional Radiology Foundation Research Consensus Panel

The optimal medical management of patients following endovascular deep venous interventions remains ill-defined. As such, the Society of Interventional Radiology Foundation (SIRF) convened a multidisciplinary group of experts in a virtual Research Consensus Panel (RCP) to develop a prioritized research agenda regarding antithrombotic therapy following deep venous interventions. The panelists presented the gaps in knowledge followed by discussion and ranking of research priorities based on clinical relevance, overall impact, and technical feasibility. The following research topics were identified as high priority: 1) characterization of biological processes leading to in-stent stenosis/rethrombosis; 2) identification and validation of methods to assess venous flow dynamics and their effect on stent failure; 3) elucidation of the role of inflammation and anti-inflammatory therapies; and 4) clinical studies to compare antithrombotic strategies and improve venous outcome assessment. Collaborative, multicenter research is necessary to answer these questions and thereby enhance the care of patients with venous disease.

Deep venous stenting improves healing of lower extremity venous ulcers

BACKGROUND

Long standing, recalcitrant venous ulcers fail to heal despite standard compression therapy and wound care. Stenting of central veins has been reported to assist in venous ulcer healing. This study reports outcomes of deep venous stenting for central venous obstruction in patients with recalcitrant venous ulcers at a single comprehensive wound care center.

METHODS

A single center retrospective analysis was conducted of patients with CEAP (Clinical, Etiology, Anatomy, and Pathophysiology) 6 disease that had undergone deep venous stenting in addition to wound care and compression therapy. Intra-operative details, wound healing, and stent patency rates were recorded. Stent patency and intra-operative details were compared between the healed and unhealed groups.

RESULTS

Between 2010 and 2019, 15 patients met inclusion criteria (mean age: 63 years old, 12 males). Pre-operative mean wound area was 14.1 cm2 with mean wound duration of 30 months. 93% of patients healed the ulcers at mean healing time of 10.6 months. Wound recurrence rate was 57% with mean recurrence time of 14.8 months. Ten patients presented with an inferior vena cava (IVC) filter, 4 in the healed group and 6 in the unhealed group. The common iliac vein was stented in all patients. Extension into the IVC was required in 4, the common femoral vein in 11, and femoral vein in 2 patients. The average stent length was 190cm. During the follow-up period, primary patency rates in healed patients (mean follow-up time: 19.2 months) was 83% and 59% in the unhealed group (mean follow-up time: 36.6 months); secondary patency rates were 83% and 89%, respectively.

CONCLUSIONS

In patients with recalcitrant venous ulcers with central venous obstruction, deep venous stenting resulted in a high rate of healing. However, a prolonged 10 month healing time was observed and despite high stent patency, wound recurrence rate was high.

Iliac vein stenting is safe when performed in an office based laboratory setting

BACKGROUND

Venous stenting for iliac vein outflow obstruction is associated with excellent long-term stent patency and symptom resolution. However, the safety of iliac vein stenting performed in an office-based laboratory (OBL) setting is not well-defined. The purpose of our investigation was to determine the safety profile of iliac vein stenting in an OBL setting.

METHODS

Data were prospectively collected in the Center for Vascular Medicine electronic medical record system (NextGen Healthcare Information System, Irvine, Calif) and retrospectively analyzed. Standardized patient safety and sedation protocols were used in accordance with the accreditation standards of the Joint Commission for Accreditation of Hospital Organizations for office-based surgery centers. Patient consultations, interventions, and follow-up at 1 to 6 weeks were included in the present analysis. All the patients had received moderate sedation during their procedure. Complications requiring hospitalization were classified as major complications. Minor complications consisted of bleeding, hematoma, vasovagal response, in-stent thrombosis resulting in complete occlusion of the iliac vein stent, an allergic reaction, hematemesis, hypotension, pelvic discomfort, and pseudoaneurysm.

RESULTS

Between January 2015 and January 2019, 1223 iliac vein stents were placed in 1104 patients (23.7% male; 76.3% female). A total of 90 minor complications (7.36%) and 5 major complications (0.41%) were observed. The major complications included the following: one allergic reaction, one episode of atrial fibrillation, one episode of supraventricular tachycardia, one episode of chest pain, and one case of acute stent occlusion. The minor complications were primarily insertion site hematomas. No complications were related to sedation or acute renal failure. No patient died.

CONCLUSIONS

Major complications were rare after iliac vein stenting in an OBL setting. Minor complications were primarily insertion site hematomas, which did not require inpatient hospitalization. Our analysis has shown that iliac vein stenting in an OBL setting is a safe and well-tolerated procedure.

Long-term outcome of dedicated venous stents in management of chronic iliofemoral obstruction

OBJECTIVE

To study the long-term outcomes in patients with occlusive Iliofemoral chronic venous insufficiency (CVI) of benign etiology treated by dedicated venous stents (Zilver Vena stents; Cook, Bloomington, Ind) placed at a single center.

METHODS

We performed retrospective analysis of prospectively collected data from 58 patients with symptomatic benign lower limb CVI during the period from January 2013 to October 2020. Patients underwent recanalization using Zilver Vena stents at Ain Shams University hospitals. We excluded patients requiring stenting after intervention for acute deep venous thrombosis, CVI due to malignancy or vascular malformations, previous ipsilateral venous interventions, or CVI due to nonobstructive pathology (reflux). Patients were clinically classified at enrollment by the clinical, etiology, anatomy, pathology class, venous disability score, and Villalta score. Primary, assisted primary, and secondary stent patency were assessed. Patients were followed clinically and by duplex, at 1, 3, 6, 12 months and annually for 5 years.

RESULTS

There were 31 males and 27 females, with ages ranging between 25 and 60 years (mean, 43.84 years). All patients had post-thrombotic syndrome with a mean Villalta score of 16.8 (range, 10-31). Patients were treated with dedicated venous stents and had a median follow-up of 60 months. The median venous disability score was 3 at the start of the study with a significant decrease to 1 at 5-year follow-up (P < .001). Twelve-month primary patency, assisted primary patency, and secondary patency were 91.4%, 96.6%, and 98.3%, respectively. At the 5-year follow-up, primary patency was 60.3%, assisted primary patency 65.5%, and secondary patency 81%. There were no instances of stent fracture, migration, or structural deformities.

CONCLUSIONS

Treating iliofemoral venous occlusive disease with a dedicated venous stent is an excellent choice for patients with occlusive post-thrombotic syndrome. The technique has good 1-year and 5-year patency and is associated with significant clinical improvement and few complications.

A clinical guide to Deep venous stenting for chronic iliofemoral venous obstruction

INTRODUCTION

An increase in endovenous interventions for deep venous pathologies has been observed. This article aims to provide an overview of the role of venous stenting in the management of chronic conditions affecting the deep venous system of the lower limbs, with a focus on intervention relating to the vena cava and iliofemoral venous segments.

METHOD

An overview of the literature on the minimally invasive venous stenting procedures that are being increasingly used in the management of chronic conditions affecting the deep venous system of the lower limbs.

RESULTS

We discuss key areas of interest to a venous specialist practicing in this area, including diagnostic imaging in chronic deep venous disease, with a focus on the use of intravascular ultrasound in this context; treatment of chronic venous outflow obstruction, including the rationale and structural indications for stenting, current guidance regarding stent placement, and fundamental points to consider during decision-making (endophlebectomy and stenting, stenting across the inguinal ligament, optimal sizing of venous stents, extension of venous stenting to beyond the common femoral vein confluence, the role of thrombolysis useful in chronic venous disease, and arteriovenous fistulae); outcomes and initial reports of stenting; and the future of venous stents.

CONCLUSION

Deep venous stenting has become a key treatment option for chronic (thrombotic or non-thrombotic) obstructive venous disease. Dedicated venous stents and intravascular ultrasound represent important technological advances in the minimally invasive treatment of symptomatic chronic deep venous obstruction, which previously required open surgical reconstruction.

A systematic review and meta-analysis of the treatment of obstructive chronic deep venous disease using dedicated venous stents

OBJECTIVES

This review aims to summarise the efficacy and safety of dedicated venous stenting for the treatment of obstructive chronic deep venous disease. The approaches to stenting and post-procedural management of different vascular units are also highlighted.

METHODS

MEDLINE and Embase were searched to identify relevant literature on dedicated venous stents published from January, 2010 to May, 2020. The patient population and study characteristics; procedural characteristics; and outcomes related to post-stenting symptoms, health-related quality of life, patency and complications were analysed.

RESULTS

Sixteen single-arm observational studies were included from 2,366 studies identified from key-word searches. In total, 1,688 patients were included, of which 70.5% had post-thrombotic syndrome and the remainder had non-thrombotic iliac vein lesions. Nine studies (n = 848), stated whether lesions were stenotic (36.6%) or occlusive (63.4%). Seven studies did not report the lesion characteristics (n = 840). Eight different dedicated venous stent brands were employed. 73.4% of ulcers healed at last follow-up. The remaining symptomatic changes were described narratively; sustained improvements in pain, venous claudication and oedema following stenting were observed. Significant post-stenting improvements in health-related quality of life were noted, as measured by the Chronic Venous Insufficiency Questionnaire-20 instrument. Overall, the most frequently reported complications were in-stent occlusion (n = 204), in-stent stenosis (n = 149) and minor bleeding (n = 77). At 12 months, the primary patency ranged from 59% to 94%, whilst the secondary patency ranged 87% to 100%. The pooled-primary and secondary stent patency rates at 12 months were 74.0% and 90.4%, respectively. The incidence of major and minor bleeding was 1.9% and 4.7%, respectively; bleeding complications were more common in patients undergoing hybrid intervention.

CONCLUSION

Deep venous stenting using dedicated venous stents is a safe technique to treat obstructive chronic deep venous disease and within the limitations of this study, is associated with good patency outcomes and symptomatic improvement.

Outcomes of endovenous laser ablation with additional iliac vein stenting of nonthrombotic lesions in patients presenting with active venous ulcers

OBJECTIVE

We evaluated the clinical outcomes of superficial and perforator ablation and the effects on wound healing by adding iliac vein stenting of nonthrombotic iliac vein lesions (NIVLs) in patients presenting with active venous ulcers.

METHODS

A retrospective analysis was performed of patients who had presented with venous ulcers and had a diagnosis of NIVLs from January 2017 to December 2019. Patients with a >50% diameter reduction in the iliac vein as determined by computed tomography venography had undergone transfemoral venography for further confirmation. Patients were divided into the endovenous laser ablation (EVLA) group and EVLA with stenting (EVLAS) group. The EVLA group had undergone endovascular laser treatment of superficial venous reflux, and the EVLAS group had undergone EVLA and stenting for NIVLs. The clinical outcomes were compared between the two groups. The primary endpoint was cumulative ulcer healing at 12 months. The secondary endpoints included complications, venous clinical severity score improvements, and pain scores during the follow-up period. Univariable and multivariable regression models were used to determine the refractory ulcer predictors.

RESULTS

A total of 157 patients were included, 93 in the EVLAS group and 64 in the EVLA group. Of the 93 patients in the EVLAS group and patients in the EVLA group, 30 (32.26%) and 17 (26.56%) had presented with iliac venous occlusion, respectively (P = .48). The mean percentage of stenosis was 78.0% ± 13.6% in EVLAS group and 77.0% ± 14.0% in the EVLA group (P = .36). No significant differences in the general preoperative data were observed between the two groups. Cumulative ulcer healing at 1 year was 86.8% and 65.6% in the EVLAS and EVLA groups, respectively (P = .001). After a mean follow-up of 22 months (median, 24 months), the EVLAS group had a significantly improved venous clinical severity score compared with the EVLA group (EVLAS group, 8.3; EVLA group, 11.7; P = .01). Multivariable analysis of the entire cohort showed that obesity and employment that requires standing were predictive of refractory ulcers and that iliac venous stent placement was a protective factor for ulcer healing.

CONCLUSIONS

The results of the present study have suggested an association between improvement in the overall success of venous leg ulcer healing when including treatment of NIVLs with stents into a treatment plan that already includes saphenous and perforator vein ablation.

Mid-term patency of iliac venous stenting for post-thrombotic syndrome

INTRODUCTION

Post-thrombotic syndrome (PTS) is the most common chronic complication of deep vein thrombosis. Recent studies suggested that iliac stenting in chronic obstructive venous disease is safe and effective. However, systematic reviews focusing on mid-term efficacy of iliac stenting in post-thrombotic syndrome are lacking. This systematic review aimed to analyze mid-term stent patency rates and clinical outcomes of iliac stenting in post-thrombotic syndrome.

EVIDENCE ACQUISITION

Two databases were searched: Pubmed/Medline and Scopus. Articles published between January 2000 and July 2020 were selected and titles and abstracts were independently reviewed. Eighteen articles were included for the qualitative analysis. From this initial set of articles, fourteen articles were included for the quantitative analysis.

EVIDENCE SYNTHESIS

Overall, 1008 patients were included in this study. The pooled technical success rate was 96%. The pooled primary and secondary patency rates were 98.2% and 100% at 30 days, 78.1% and 94.5% at 12 months and 66.3% and 89.4% at 36 months, respectively. The rates of ulcer healing, pain and edema relief were 78.1%, 53.4% and 48.8%, respectively. The pooled rate of complications including intraoperative venous injury, back pain and stent fracture were 28%, 57.1%, and 5.9%, respectively.

CONCLUSIONS

Iliac venous stenting in PTS presents durable mid-term patency rates, as well as significant symptomatic improvement. Therefore, endovascular treatment should be considered in symptomatic patients with PTS.

Endovascular Repair of a Post-Renal Transplant Internal Iliac Artery Pseudoaneurysm

Anastomotic site pseudoaneurysm following renal transplantation is a rare vascular complication. Its etiology include defective suture techniques and infections. The clinical presentation includes allograft dysfunction, local mass effect, exsanguination, and rupture. Open surgical repair is associated with significant morbidity and allograft dysfunction. Endovascular stent-graft can be a less invasive, alternative approach. We describe a case of large pseudoaneurysm arising from the internal iliac artery in a post-renal transplant patient. It was successfully treated with the stent-graft. The externally compressed right common iliac vein was also treated with a self-expanding non-graft stent. Thus, endovascular approach can be an effective alternative to open repair for post-renal transplant iliac artery pseudoaneurysm.

Diagnostic and Technical Challenges in the Care of a Complex Patient With Post-Thrombotic Syndrome

Iliofemoral deep vein thrombosis can lead to post-thrombotic syndrome, a costly and morbid condition. Endovascular treatment is increasingly used for symptomatic relief, but clinical success depends on accurate patient evaluation and selection. This case describes the diagnostic and technical challenges in the care of a complex patient with post-thrombotic syndrome following stroke and extensive deep vein thrombosis. It highlights the multi-disciplinary work-up for a patient with post-thrombotic syndrome presenting with confounding symptoms, as well as the importance of considering alternative access for successful lower extremity venous recanalization.

Hybrid CT-angiography to facilitate lower extremity sharp venous recanalization: a novel approach to a common procedure

Background

Post-thrombotic syndrome due to chronic venous occlusion is associated with high morbidity and healthcare costs. Sharp venous recanalization has been used with success when conventional techniques fail to cross the occlusion, permitting endovascular reconstruction with angioplasty and stenting. However, manipulation of a needle, especially in extra-anatomic locations, risks damage to adjacent structures, thus necessitating adequate imaging guidance.

Case presentation

This report describes the novel use of hybrid CT-angiography in a successful recanalization of a complex iliofemoral chronic venous occlusion, after multiple failed attempts with traditional recanalization techniques. The procedure was performed without complications, and stent patency was confirmed at three-month follow-up with patient-reported improvement in severe post-thrombotic syndrome.

Conclusions

This case demonstrates effective incorporation of hybrid CT-angiography to facilitate complex sharp venous recanalization for chronic lower extremity thrombosis, as an alternative to standard fluoroscopic techniques requiring multiple projections with or without cone-beam CT. Further studies are needed to understand the implications of this strategy.

An image analysis of the major angles along the pathway of iliac veins involved in endovenous interventions

OBJECTIVE

The specific anatomic characteristics of the iliac veins are often important reasons for stent failure. However, to the best of our knowledge, the inherent angles and configurations of the iliac veins have not been thoroughly studied.

METHODS

Fifty patients without venous diseases who had undergone computed tomography urography for diagnosis of urolithiasis were included in this study. The pathways of the iliac veins were mapped out, and the major angles were measured. The factors associated with steep angles were also evaluated.

RESULTS

There were two relatively constant angles on the right side and three on the left side along the common femoral vein, external iliac vein, and common iliac vein. All these were measured with the patients in the supine position. The angles at the inguinal region (γ) and internal-external iliac vein confluence (β) were at similar sites for both sides. There was a third angle in front of the fifth vertebra for the left side (α). The γ angle was 125.03 ± 11.68 degrees for the right side and 122.26 ± 9.64 degrees for the left side. The β angle was 136.91 ± 14.24 degrees for the right side and 125.61 ± 20.76 degrees for the left side. According to the β angle of the left side, the iliac veins could be categorized into three types. For type I, the angle was >150 degrees (14% [7/50]). For type II, it was 120 to 150 degrees (50% [25/50]). For type III, it was ≤120 degrees (36% [18/50]). The angles between the anterior border of the fifth vertebra and pelvic inlet plane (0.866; 95% confidence interval, 0.777-0.966) and age (1.087; 95% confidence interval, 1.004-1.177) were related to type III configurations on multilogistic regression analysis.

CONCLUSIONS

There were several relatively constant angles along the pathway of the iliac veins. The pathway of the left side was more complex than that of the right side. This difference in the angles might be related to the patients' age and bone structures. These angles should be considered in planning iliac vein stenting as well as in designing stents specifically for the iliac veins.