Patency rates and clinical outcomes in a cohort of 200 patients treated with a dedicated venous stent

Indications, technical aspects, and outcomes of stent placement in chronic iliofemoral venous obstruction

BACKGROUND

Iliofemoral venous stent placement (IVS) has evolved to a well-established endovascular treatment modality for chronic iliofemoral venous obstruction (CIVO). Dedicated venous stents gained approval from the US Food and Drug Administration in 2019 and solidified IVS as a defined intervention with clear indications, contraindications, risks, benefits, and procedural management principles. This review focuses on the indications, technical aspects and outcomes of stenting for CIVO. Other aspects pertaining to IVS are covered in other articles that are a part of this series.

METHODS

This study conducted a literature search limited to English articles. Three search strategies were used, and references were managed in Covidence software. Four investigators screened and evaluated articles independently, excluding meta-analyses, clinical trial protocols, and nonrelevant studies. Eligible studies, focused on clinical outcomes and stent patencies, underwent thorough review.

RESULTS

The literature search yielded 1704 studies, with 147 meeting eligibility criteria after screening and evaluation. Exclusions were based on duplicates, irrelevant content, and noniliac vein stent placement.

CONCLUSIONS

Successful IVS for CIVO relies on meticulous patient selection, consistent use of intravascular ultrasound examination during procedures and attention to the technical details of IVS.

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.

Endovascular treatment of chronic ilio-femoral vein obstruction with extension below the inguinal ligament in patients with post-thrombotic syndrome

OBJECTIVE

This study aimed to evaluate postoperative outcomes of patients with chronic iliofemoral venous outflow obstruction and post-thrombotic syndrome (PTS) who underwent endovascular recanalization and stenting across the inguinal ligament.

METHODS

All consecutive patients with chronic iliofemoral venous outflow obstruction and PTS were included in the analysis, from January 2018 and February 2022. Preoperative, intraoperative, and postoperative outcomes were assessed. Primary endpoints analyzed were major adverse events (MAEs) at 30 days and primary patency rate at 2 years of follow-up. Secondary endpoints assessed were secondary patency rate, target vessel revascularization, and clinical improvement evaluated with the Venous Clinical Severity Score (VCSS) classification, Villalta scale, and visual analog scale (VAS), respectively.

RESULTS

A total of 63 patients (mean age, 48.1 ± 15.5 years; female, 61.9%) were evaluated. No intraoperative and 30-day postoperative complications were documented. The technical success rate was achieved at 100%. Overall, one in-stent occlusion and five in-stent restenosis were detected during follow-up. The primary patency rate was 93.7% (95% confidence interval [CI], 87.8%-99.9%) and 92.1% (95% CI, 85.6%-99%), at 1- and 2-year follow-up, respectively (Kaplan-Meier analysis). Target vessel revascularization was conducted in two cases, resulting in a secondary patency of 98.4% (95% CI, 95.4%-100%) at 2 years of follow-up. Stent fracture and/or migration were not observed during follow-up. A significant clinical improvement in the patient's quality of life was documented. The median improvement of VCSS and Villalta scores were 4 (interquartile range, 2-7; P = .001), and 3 (interquartile range, 1.5-5; P = .001) vs baseline at the last follow-up. Overall, pain reduction of 17 mm on the VAS scale was documented at 2 years of follow-up. At multivariate analysis, presence of trabeculation into the femoral vein and deep femoral vein (odds ratio, 1.89; 95% CI, 0.15-6.11; P = .043), and Villalta scale >15 points at admission (odds ratio, 1.89; 95% CI, 0.15-6.11; P = .043) were predictive for in-stent occlusion during the follow-up.

CONCLUSIONS

The use of a dedicated venous stent across the inguinal ligament was safe and effective for the treatment of symptomatic iliofemoral venous disease with acceptable primary and secondary patency rates at 2 years of follow-up.

Pivotal Evaluation of Novel Dedicated Venous Stent for Iliofemoral Venous Obstruction: A Prospective Cohort Study

PURPOSE

The purpose was to evaluate the clinical outcomes of a dedicated venous stent with the tripartite composite segments for the treatment of iliofemoral venous obstruction (IVO) in a mixed cohort of nonthrombotic iliac vein lesion (NIVL) and post-thrombotic syndrome (PTS) over a period of 12 months.

METHODS

The Grency Trial is a prospective, multicenter, single-arm, open-label, pivotal study, which was conducted at 18 large tertiary hospitals in China from August 2019 to October 2020. A total of 133 hospitalized patients were screened and 110 patients with clinical, etiology, anatomical, and pathophysiology clinical class (CEAP) clinical grade C>3 and iliac vein stenosis >50% or occlusion, including 72 patients with NIVL and 38 patients with PTS, were implanted with Grency venous stents. Primary endpoint was stent patency at 12 months follow-up, and secondary outcomes were technical success; improvement in venous clinical severity score (VCSS) at 3, 6, and 12 month follow-up; and rates of clinical adverse events.

RESULTS

Among 110 patients who were implanted with Grency venous stents, 107 patients completed the 12 month follow-up. All 129 stents were successfully implanted in 110 limbs. Twelve-month primary patency rate was 94.39% [95% confidence interval [CI]=88.19%-97.91%] overall, and 100% [94.94%-100%] and 83.33% [67.19%-93.63%] in the NIVL and PTS subgroups, respectively. Venous clinical severity score after iliac vein stenting improved significantly up to 12 months follow-up. There were 3 early major adverse events (1 intracerebral hemorrhage and 2 stent thrombosis events related to anticoagulation therapy), and 7 late major adverse events (1 cardiovascular death, 1 intracranial hemorrhage with uncontrolled hypertension, and 5 in-stent restenosis cases without stent fractures or migration).

CONCLUSIONS

The Grency venous stent system appeared excellent preliminary safe and effective for IVO treatment. Further large-scale studies with longer-term follow-up are needed to evaluate long-term patency and durability of stent.

CLINICAL IMPACT

The design of venous stents for iliofemoral venous obstruction (IVO) must address engineering challenges distinct from those encountered in arterial stenting. The Grency venous stent, a nitinol self-expanding stent specifically tailored for IVO, features a composite structure designed to meet the stent requirements of various iliac vein segments. The Grency Trial is a prospective, multicenter, single-arm, open-label pivotal study aimed at evaluating the efficacy and safety of the Grency stent system. Following a 12-month follow-up period, the Grency venous stent system has demonstrated both safety and efficacy in treating iliofemoral venous outflow obstruction.

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.

Novel venous balloon for compliance measurement and stent sizing in a post-thrombotic swine model

Objective: Real-time accurate venous lesion characterization is needed during endovenous interventions for stent deployment. The goal of this study is to validate a novel device for venoplasty sizing and compliance measurements. Methods: A compliance measuring sizing balloon (CMSB) uses real-time electrical conductance measurements based on Ohm's Law to measure the venous size and compliance in conjunction with pressure measurement. The sizing accuracy and repeatability of the CMSB system were performed with phantoms on the bench and in a swine model with an induced post thrombotic (PT) stenosis in the common femoral vein of swine. Results: The accuracy and repeatability of the CMSB system were validated with phantom bench studies of known dimensions in the range of venous diameters. In 9 swine (6 experimental and 3 control animals), the luminal cross-sectional areas (CSA) increased heterogeneously along the PT stenosis when the CMSB system was inflated by stepwise pressures. The PT stenosis showed lower compliance compared to the non-PT vein segments (5 mm2 vs. 10 mm2 and 13 mm2 at a pressure change of 40 cm H2O). Compliance had no statistical difference between venous hypertension (VHT) and Control. Compliance at PT stenosis, however, was significantly smaller than that at Control and VHT (p < 0.05, ANOVA). Conclusion: The CMSB system provides accurate, repeatable, real-time measurements of CSA and compliance for assessment of venous lesions to guide interventions. These findings provide the impetus for future first-in-human studies.

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.

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.

Long-term integrity of 53 iliac vein stents after catheter-directed thrombolysis

BACKGROUND

Long-term surveillance data on venous stent integrity is sparse. There is limited knowledge on whether duplex ultrasound (DUS) can detect potential stent deformities such as kinking, straightening, and fracture, which may impact long-term patency of the stented veins.

PURPOSE

To assess venous stent integrity after at least five years of follow-up and to establish the efficacy of DUS as surveillance in patients with venous stent.

MATERIAL AND METHODS

A total of 45 patients with acute iliac-femoral deep vein thrombosis (DVT) treated with catheter directed thrombolysis (CDT) and stenting >5 years before follow-up. Stents were evaluated with 3D volume low dose non-contrast computed tomography (CT) and DUS for kinking, straightening, stent fracture, and patency. Results from CT scans and DUS were compared to assess the overall agreement between the methods.

RESULTS

Median follow-up was 13.2 years (mean = 11.2 years; range = 5.2-15.8 years). 3D CT reconstructions showed normal stent configuration in 47 stents (89%). All intact stents were identified by DUS. In the remaining six stents, 3D CT reconstructions showed compression, tapering, kinking, and minor fracture. DUS recognized all stent complications except the minor fracture. Overall agreement between CT and DUS was 98% (kappa = 0.90). Two cases of stent occlusion were found.

CONCLUSION

The long-term physical resilience of iliac vein stents evaluated with 3D CT in patients treated with CDT for iliofemoral DVT was high. Stent deformities were mostly compression, whereas fracture was rarely seen. DUS seems to be sufficient to evaluate venous stent integrity.

Performance of Open and Closed Cell Laser Cut Nitinol Stents for the Treatment of Chronic Iliofemoral Venous Outflow Obstruction in Patients Treated at a Single Centre

OBJECTIVE

A number of dedicated self expanding nitinol stents have been developed for use in the venous system, with both open cell (OC) and closed cell (CC) designs available. Data comparing these different designs are lacking. The objective of this study was to evaluate outcomes in patients treated with open and closed cells for unilateral chronic iliac vein obstruction.

METHODS

A single centre retrospective cohort study was conducted, including all patients treated with a dedicated nitinol venous stent between 2014 and 2019. Stent patency and details of re-interventions (including lysis, venoplasty, reinforcement, extension, arteriovenous fistula formation) were examined in the first post-operative year. Subgroup analysis described outcomes for patients treated with OC and CC stents ending above the inguinal ligament and those who required extension into the common femoral vein. Cox regression analysis was used to identify factors associated with loss of primary patency.

RESULTS

A total of 207 patients were included (OC 100 patients, CC 107 patients). There was no significant difference between the groups for age (OC 42 years, CC 44 years); gender (OC and CC 67% female); presence of post-thrombotic lesions (OC 71%, CC 73%); stenting across the inguinal ligament (OC 58%, CC 56%), or presence of inflow disease (OC 49%, CC 47%). Primary and cumulative patency at 12 months were similar between groups (primary: OC 63%, CC 65%; cumulative: OC 93%, CC 90%). Patients with a CC stent across the inguinal ligament had a greater risk of needing multiple re-interventions at one year compared with those with an OC stent (odds ratio 2.84, 95% confidence interval [CI] 1.16 - 6.9) but overall, the only factor significantly associated with loss of primary patency was inflow vessel disease (hazard ratio 3.39, 95% CI 1.73 - 6.62, p < .001).

CONCLUSION

OC and CC dedicated nitinol venous stents were observed to perform similarly in terms of patency and symptom improvement at one year. Disease of the inflow vessels was the most important factor associated with a loss of stent patency irrespective of stent design.

Treatment of Inferior Vena Cava Thrombosis by Endovascular Stenting: A Case Report

Optimal treatment of inferior vena cava (IVC) thrombosis remains unclear, especially given the contraindications to anticoagulation use and because interventional options remain limited. We present a case of a 62-year-old man with advanced liver cirrhosis who developed IVC thrombosis with symptoms of severe abdominal pain and leg swelling. IVC flow was restored via successful recanalization with a transjugular and common femoral approach after deploying a 22 × 70 mm Wallstent. On follow-up, the patient had a resolution of his symptoms.

An overview of in-stent restenosis in iliofemoral venous stents

BACKGROUND

Although endovenous stents have been associated with overall low morbidity, they can require reinterventions to correct stent malfunction due to in-stent restenosis (ISR). ISR has often occurred iliofemoral venous stents but has not been well described. It has been reported to develop in >70% of patients who have undergone iliofemoral venous stenting. We sought to provide an overview of ISR in iliofemoral venous stents, including the pathologic, diagnostic, and management considerations and the identification of several areas of potential research in the future.

METHODS

A search of reported English-language studies was performed in PubMed and the Cochrane Library. "In-stent restenosis," "vein," "venous," "iliac," and "iliofemoral" were used as keywords. The pertinent reports included in the present review had addressed the pathology, diagnosis, and current management options for ISR.

RESULTS

ISR refers to the narrowing of the luminal caliber of the stent owing to the development of stenosis inside the stent itself. ISR should be differentiated from stent compression. Two main types of ISR have been described: soft and hard lesions. These lesions respond differently to angioplasty. Stent inflow and shear stress are important factors in the development of ISR. The treatment options available at present include balloon angioplasty (hyperdilation or isodilation), laser ablation, atherectomy, and Z-stent placement.

CONCLUSIONS

Reintervention for ISR should be determined by the presence of residual or recurrent symptoms and not simply by a numeric value obtained from an imaging study. Overall stent occlusion due to ISR is rare, and no role exists for prophylactic angioplasty to treat asymptomatic ISR. The current treatment options for ISR are mostly durable and effective. However, more research is needed on methods to prevent the development of ISR. The role of antiplatelet and anticoagulant agents in the prevention of ISR requires further investigation, with particular attention to unique subset of patients (after thrombosis vs nonthrombotic iliac vein lesions). For high-risk, post-thrombotic patients, anticoagulation can be considered to prevent ISR. The role of triple therapy (anticoagulation and dual antiplatelet therapy) in the prevention of ISR remains unclear.

Timing of Endovascular Interventions for Iliac Vein Compression Syndrome With Thrombus

The aim of this study is to explore the timing and method of endovascular intervention for iliac vein compression syndrome (IVCS) with thrombus. Data from 111 patients with IVCS, complicated acute deep vein thrombosis (DVT), or post-thrombotic syndrome (PTS) who underwent endovascular interventions were analyzed retrospectively. Patients were divided into Group A (DVT group), including 56 patients with IVCS and iliofemoral DVT, with or without femoropopliteal DVT, with sudden lower limb swelling, and Group B (PTS group) included 55 patients with IVCS and PTS, including 18 with lower extremity wet ulcers and 32 with lower limb infections. Interventional therapies were used to treat the thrombus and eliminate stenosis and occlusion of the iliac vein. In both groups, clinical symptoms in the lower limbs after surgery were reduced significantly, and PTS incidence was low during long-term follow-up. The cumulative patency rate was 75.2% in the DVT group and 88.6% in the PTS group. Comprehensive interventional therapies are safe and effective in patients with IVCS and thrombi. Long-term efficacy in the PTS group tended to be better than that in the DVT group.

Artifact quantification of venous stents in the MRI environment: Differences between braided and laser-cut designs

PURPOSE

To quantify B₀- and B₁-induced imaging artifacts of braided venous stents and to compare the artifacts to a set of laser-cut stents used in venous interventions.

METHODS

Three prototypes of braided venous stents with different geometries were tested in vitro. B₀ field distortion maps were measured via the frequency shift Δf using multi-echo imaging. B₁ distortions were quantified using the double angle method. The relative amplitudes B₁^rel were calculated to compare the intraluminal alteration of B₁. Measurements were repeated with the stents in three different orientations: parallel, diagonal and orthogonal to B₀.

RESULTS

At 1.5 T, the braided stents induced a maximum frequency shift of Δfx<100Hz. Signal voids were limited to a distance of 2 mm to the stent walls at an echo time of 3 ms. No substantial difference in the B₀ field distortions was seen between laser-cut and braided venous stents. B₁^rel maps showed strongly varying distortion patterns in the braided stents with the mean intraluminal B₁^rel ranging from 63±18% in prototype 1 to 98±38% in prototype 2. Compared to laser-cut stents the braided stents showed a 5 to 9 times higher coefficient of variation of the intraluminal B₁^rel.

CONCLUSION

Braided venous stent prototypes allow for MR imaging of the intraluminal area without substantial signal voids due to B₀-induced artifacts. Whereas B₁ is attenuated homogeneously in laser-cut stents, the B₁ distortion in braided stents is more inhomogeneous and shows areas with enhanced amplitude. This could potentially be used in braided stent designs for intraluminal signal amplification.

The effect of stent compression on in-stent restenosis and clinical outcomes in iliac vein compression syndrome

Background

To evaluate the effect of stent compression on in-stent restenosis (ISR) and clinical outcomes in patients with iliac vein compression syndrome (IVCS) after iliac vein stenting.

Methods

Fifty patients with IVCS treated with iliac vein stenting (Smart Control, Cordis, USA) between March 2017 and October 2018 were consecutively enrolled in this study. Computed tomography venography (CTV) was performed to assess stent compression and ISR. Based on the degree of stent compression, patients were allocated to a significant stent compression (SSC) group and an insignificant stent compression (ISC) group. The incidence of ISR was analyzed between the SSC and ISC groups. Patients' venous clinical severity scores (VCSSs) and responses to the chronic venous insufficiency questionnaire (CIVIQ) one year after stenting were compared between the two groups to evaluate the clinical improvement of venous insufficiency.

Results

In total, 34% of patients had SSC. There were significant differences in the incidence of ISR (52.9% vs. 21.2%, P=0.023), and in each group, there was one case of stent occlusion (5.88% vs. 3.03%, P=0.999). Patients in the SSC group had a higher VCSS score (8.41±5.92 vs. 3.15±2.87, P=0.04) and a lower CIVIQ score (83.35±8.86 vs. 92.21±4.32, P=0.001).

Conclusions

SSC has a significant effect on the incidence of ISR and the clinical outcomes of venous insufficiency. Thus, a dedicated iliac venous stent with sufficient radial resistive force, crush resistance, and outward radial force is needed to prevent the occurrence of stent compression.

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 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.

Braided nitinol stent for chronic iliofemoral venous disease - the real-world BLUEFLOW registry

Background: In patients with iliofemoral chronic venous disease (CVD) secondary to post-thrombotic or non-thrombotic obstruction, venous outflow obstruction after adequate anticoagulation alone is still frequent and post-thrombotic syndrome is a common complication. Thus, we aimed to evaluate mid-term effectiveness and safety of a novel braided venous stent for venous outflow obstruction treatment. Patients and methods: Consecutive patients who underwent venous recanalization with a new braided, closed cell, venous stent for non- or post-thrombotic CVD were eligible for inclusion in our retrospective, observational study. Effectiveness outcomes were primary patency and change in the revised venous clinical severity score (rVCSS) and the clinical score of the comprehensive classification system for chronic venous disease (CEAP) at 6- and 12-month follow-up. Safety outcomes were recurrent DVT, clinically driven target vein revascularization, index limb major amputation, or death. Results: A total of 67 participants (50.7% female, aged 46.7±18.1 years) who underwent blueflow Venous Stent implantation between February 2018 and March 2019 were enrolled. Primary patency of the target segment was present in 91.7% (95%CI: 76.8-97.7) of participants at the 6-month examination and in 79.8% (95%CI: 66.4-93.2) at the 12-month examination. Twelve-month primary patency was 91.7% (95%CI: 76.0-100) in non-thrombotic, and 72.6% (95%CI: 53.9-91.3) in postthrombotic disease (log-rank p=0.14). Median rVCSS improved from 8 (interquartile range [IQR]: 9-7) at baseline to 4 (IQR: 6.3-2.8) at 12 months (p<0.001) with a substantial clinical improvement of ≥2 points in 86.1% (31 of 36 participants). No significant association of rVCSS improvement with thrombotic pathogenesis could be found. Median clinical CEAP score improved from 3 (IQR: 3-3) to 2 (IQR: 3-2), p>0.001. No safety signal occurred. Conclusions: blueflow Venous Stent implantation for the treatment of iliofemoral CVD was associated with promising patency and favorable clinical improvement over the mid-term.

Clinical outcomes and overview of dedicated venous stents for management of chronic iliocaval and femoral deep venous disease

OBJECTIVES

Venous stenting of the lower extremities has grown in popularity and is now considered a key component of the primary treatment strategy for the management of pathologically obstructive or stenotic lesions of the deep venous system. This review 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.

METHODS

An overview of venous stents design and current role of stenting procedure in individuals presenting with Chronic Venous Insufficiency (CVI) and presenting the current trials of dedicated venous stenting in management of chronic deep venous lesions. This review provides a focused insight on venous stent design, physical properties and the available dedicated venous stents selected studies with their related patency outcome based on selective literature search of the PubMed database and Cochrane library.

CONCLUSIONS

Dedicated venous stent technology is advancing at a rapid pace alongside the increased undertaking of endovascular deep venous stent reconstruction in the management of iliocaval vein pathologies. The ideal design(s) for venous stents remain unknown, although it is hoped that the presence of new dedicated venous stents in clinical practice will allow the generation of experience and data to advance our understanding in this area.

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.

Effect of Pre-Procedure Clopidogrel With Iliac Vein Stenting in Non-Thrombotic Vein Lesions

OBJECTIVES

Iliac vein stenting is a relatively new procedure in the treatment of chronic venous insufficiency. Research has shown that it is a safe and effective form of treatment, however, one of the well-known risks is in-stent thrombosis. We hypothesize that a single 75 mg dose of Clopidogrel the night prior to the procedures along with a 3-month regimen post-op would decrease the 30-day thrombosis rate.

METHODS

A retrospective study was performed on 3,518 patients from September 2012 to August 2018 who received an iliofemoral stent. Patients were broken down into 2 main groups: those given Clopidogrel post-stent and those given Clopidogrel both pre- and post-stent. In our practice, we prescribe a 3-month course of Clopidogrel after iliac vein stenting. Patients were also checked for any anticoagulant medications pre- and/or post-stent. The 30-day thrombosis rates were recorded for each patient.

RESULTS

1,205 patients received Clopidogrel pre-procedurally and post-procedurally, 1,941 patients received Clopidogrel only post-procedurally. 372 patients were excluded from the study because they were on other anti-coagulant medications. Mean follow-up for this cohort was 17 months. 112 total patients developed some degree of 30 day in-stent thrombosis (3.6%). 74 patients developed a complete thrombosis of the stent and 38 developed a partial (≤60% occlusion) thrombosis. Of the 1,205 patients who were on clopidogrel pre-stenting, 28 had a complete thrombosis and 10 had a partial in-stent thrombosis. Of the 1,941 patients on Clopidogrel only post-stenting, 46 had a complete thrombosis and 28 had a partial in-stent thrombosis. Using the Chi-squared test, there were no statistically significant differences between the group of patients receiving Clopidogrel pre- and post-stent vs. just post-stent with respect to 30-day any degree of thrombosis rates (complete and partial thrombosis) (p = .33). Using the Chi-squared test, there were no statistically significant differences between the group of patients receiving Clopidogrel pre- and post-stent vs. just post-stent with respect to 30-day complete thrombosis rates (p = .93).

CONCLUSIONS

There appears to be no statistical difference in 30-day thrombosis rates between those receiving Clopidogrel the night prior vs. those who do not receive Clopidogrel the night prior. Therefore, we conclude that it is not necessary to give this single dose the night prior to iliac vein stenting procedures.

Endovascular Treatment for Lower Extremity Deep Vein Thrombosis: An Overview

Lower extremity deep vein thrombosis (DVT) is a serious medical condition that can result in local pain and gait disturbance. DVT progression can also lead to death or major disability as a result of pulmonary embolism, postthrombotic syndrome, or limb amputation. However, early thrombus removal can rapidly relieve symptoms and prevent disease progression. Various endovascular procedures have been developed in the recent years to treat DVT, and endovascular treatment has been established as one of the major therapeutic methods to treat lower extremity DVT. However, the treatment of lower extremity DVT varies according to the disease duration, location of affected vessels, and the presence of symptoms. This article reviews and discusses effective endovascular treatment methods for lower extremity DVT.

Quality of life outcomes for patients undergoing venous stenting for chronic deep venous disease

OBJECTIVE

The objective of the study was to evaluate change in venous disease-specific quality of life (QoL) after iliac vein stenting for chronic venous outflow obstruction.

METHODS

We performed a retrospective analysis of all Venous Insufficiency Epidemiological and Economic Study - Quality of Life/Symptoms (VEINES-QoL/Sym) questionnaires completed at a single-center between 2016 and 2019 by patients treated with iliac vein stenting for chronic venous outflow obstruction. Patients were asked to complete the questionnaire at baseline (before stenting) and at subsequent follow-up appointments (after stenting), at 6, 12, 24, and 36 months. The Villalta score was recorded by a venous nurse specialist. The initial unpaired analysis compared all completed VEINES-QoL/Sym and Villalta scores at baseline to all follow-up time-points, and then compared them individually between baseline and each follow-up point. A secondary paired analysis included data only from patients who had completed the questionnaire at baseline and at least one follow-up.

RESULTS

A total of 385 questionnaires from 187 patients who completed the VEINES-QoL/Sym between 2016 and 2019 were included. The median follow-up was 12 months, 127 patients (68%) were female, and 148 (79%) were treated for post-thrombotic syndrome. The median VEINES-QoL score at baseline was 35.69 (interquartile range [IQR], 20.85-46.67). Significant improvement was observed postoperatively and sustained throughout the study period (6 months, 64.81 [IQR, 38.12-83.88]; 12 months, 60.52 [IQR, 33.6-82.3]; 24 months, 60.37 [IQR, 34.31-80.65]; 36 months, 55.98 [IQR, 39.18-81.47]). The VEINES-Sym scores demonstrated similar improvement. A secondary analysis of paired baseline/follow-up data from 61 patients confirmed significant improvement from baseline for VEINES-QoL (6 months +26.45; 12 months, +25.81; 24 months, +30.09; P ≤ .0001), VEINES-Sym (6 months, +23.86; 12 months, +20.43; 24 months, +27.55; P > .001), and Villalta scores (6 months, -3.7; 12 months, -4.2; 24 months, -6.4; P < .0001). The median Villalta score was 14 (IQR, 10-16). This score improved to 9 (IQR, 5-13) at 6 months of follow-up; to 8 (IQR, 5-11) at 12 months; to 7 (IQR, 4-12) at 24 months; and to 6 (IQR, 3.75-10.25) at 36 months (P ≤ .0001). Good correlation between the Villalta and both VEINES-QoL and SYM scores was observed at follow-up (r = 0.69 and r = 0.71, respectively; P < .0001).

CONCLUSIONS

Venous disease-specific QoL improves and severity of post-thrombotic syndrome is decreased after iliac vein stenting for chronic venous outflow obstruction. These improvements are sustained at 36-month follow-up.

The Protégé Nitinol Self-Expanding Stent for the Treatment of Iliofemoral Veno-Occlusive Disease

PURPOSE

To evaluate the safety and effectiveness of the Protégé nitinol self-expanding stent for the treatment of iliofemoral veno-occlusive disease.

MATERIALS AND METHODS

A retrospective review was performed of 376 (284 left, 92 right) Protégé stents in 212 limbs of 183 patients (mean age: 53 ± 17 years, 52% female) treated for iliofemoral veno-occlusive disease between 2011 and 2018. Binary patency was assessed with duplex ultrasound and calculated by Kaplan Meier analysis. Clinical outcomes were evaluated by clinical-etiology-anatomy-pathophysiology (CEAP) classification and Villalta scores. Adverse events were recorded and categorized per Society of Interventional Radiology reporting standards.

RESULTS

Of the 212 limbs, 125 presented with acute thrombosis and 28 with chronic thrombosis requiring thrombectomy (n = 44), catheter directed thrombolysis (n = 32), or both (n = 77). Fifty-nine limbs were non-thrombotic. Mean follow-up time was 11.44 ± 11.37 months. Kaplan Meier analysis revealed a primary limb-level patency of 92.3%, 88.6%, 86.9% and 86.9% at 6, 12, 24 and 36 months, respectively. CEAP and Villalta scores improved from a median of C3 (range: 0-6) to C1 (0-5) (p < 0.001) and from a mean of 13.4 ± 7.5 to 5.3 ± 4.9 (p < 0.001), respectively. Nine minor and 2 major adverse events were recorded.

CONCLUSIONS

Endovascular treatment of iliofemoral veno-occlusive disease with the Protégé self-expanding stent appears to have good mid-term patency.

LEVEL OF EVIDENCE

Level 4, Case Series.

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

Background

To compare the diagnostic accuracy of Doppler ultrasound (DUS) with contrast-enhanced ultrasound (CEUS) for detection of iliac vein stent stenosis using multidetector computed tomography venography (MDCTV) as the reference method.

Methods

Patients with iliac vein obstructive disease treated with nitinol stents (Smart Control, Cordis, USA) between January 2016 and December 2017 were consecutively included in this study. DUS, CEUS, and MDCTV were carried out in all patients within one week of each other at 1 year post stenting to investigate the presence of stent compression and in-stent restenosis (ISR).

Results

The study included 139 patients (87 females; mean age 58 ± 15 years). For detecting stent compression, the kappa coefficient between the ultrasound modality of gray-scale imaging and MDCTV was 0.901, indicating very good agreement between these two modalities. ISR was detected in 50, 61, and 65 patients by DUS, CEUS, and MDCTV, respectively. DUS and CEUS (kappa = 0.449) and DUS and MDCTV (kappa = 0.516) had moderate agreement for ISR diagnosis, while for which CEUS and MDCTV (kappa 0.884) had very good agreement. The sensitivity and specificity of DUS and CEUS for diagnosing ISR were 63.1% and 90.8%, 87.8% and 97.3%, respectively.

Conclusions

CEUS is probably superior to DUS in terms of diagnostic accuracy for the follow-up of patients with iliac vein stent stenosis.

Use of the VENOVO™ and Sinus Obliquus™ venous stents in the treatment of non-thrombotic or post-thrombotic iliac vein lesions - Short-term results from a multi-centre Asian cohort

OBJECTIVES

Deep venous stenting with intravascular ultrasound (IVUS) guidance is gaining favour as the treatment modality of choice for symptomatic ilio-femoral venous occlusive disease. The aim was to determine the short-term patency and symptomatic relief gained using the Bard Venovo™ and Optimed Sinus Obliquus™ stents in the endovascular treatment of non-thrombotic iliac vein lesions (NIVL) and post-thrombotic venous obstruction (PTO) from two Asian tertiary vascular centres.

METHODS

Sixty patients (males = 21/60 (35.0%); median age 67 years (interquartile range 54-77)) who underwent IVUS interrogation and ilio-femoral stenting (June 2018-May 2019) in two Asian centres were prospectively followed. Clinical improvement was determined by the revised Venous Clinical Severity Score (rVCSS), pain using the Visual Analogue Scale (VAS) and ulcer healing rate. Patency rates were evaluated using Duplex ultrasound and computer tomography venogram.

RESULTS

Seventy-one legs were interrogated and stented; 11/60 (18.3%) patients had a bilateral procedure. Indications for surgery were PTO (n = 11/71 (15.5%)) and NIVL (n = 60/71 (84.5%)). Twenty-seven of 71 (38.0%) patients had CEAP 6 disease. The median follow-up was 283 (interquartile range 211-370) days. Technical and procedural success was both 100%. Twenty-one of 71 (29.6%) legs had a combination of Venovo™ and Sinus Obliquus™ stents inserted for concurrent ilio-caval and iliac lesions. There were no major post-operative complications. Six-month primary, assisted primary and secondary patency rates were 94.1, 97.1 and 100%, respectively. There were no stent fractures. Mean rVCSS and VAS improved from 12.26 (±3.31) to 4.33 (±2.78) and 6.97 (±1.38) to 2.03 (±1.65), respectively, at three months (p < 0.01). Complete ulcer healing was seen in 27/27 (100%) patients at three months.

CONCLUSION

Use of Venovo™ and Sinus Obliquus™ stents for symptomatic ilio-femoral venous disease showed excellent six-month primary patency rate with no stent fractures. There were significant clinical improvement and low-device-related complications. Longer follow-up is awaited to see how these dedicated venous stents perform.

Early clinical outcomes for treatment of post-thrombotic syndrome and common iliac vein compression with a hybrid Oblique self-expanding nitinol stent – the TOPOS study

Summary: Background: Physical attributes of conventional stents used in the ilio-caval territory are often unfavorable in the presence of external compression close to the bifurcation. A hybrid oblique stent was developed for the treatment of common iliac vein compression without compromising the contralateral iliac vein inflow. Patients and methods: The ongoing international monitored TOPOS study enrolled 60 patients with post-thrombotic syndrome (PTS) treated with the sinus-Obliquus stent (optimed) and provisional distal stent extension. At 3-month follow-up, patency rates were obtained from duplex ultrasound, and clinical outcomes were assessed by the Villalta score, revised venous severity score (rVCSS), pain intensity score and chronic venous disease quality of life questionnaire (CIVIQ-20). Results: Mean age was 46.6 ± 14.9 years (68.3 % women). Mean number of implanted stents was 1.9 ± 0.6; 12 (20 %) patients received the hybrid oblique stent only. Forty-eight (80 %) patients had distal stent extension, and 42 (70 %) had stents below the inguinal ligament. Four (7 %) patients (all with stent extension) developed stent thrombosis. Primary and secondary patency rates at 3 months were 93.1 % (95 %CI 83.3–98.1 %), and 100 % (95 %CI 93.8–100 %), respectively. Improvement in Villalta, rVCSS, CIVIQ-20, and pain intensity score from baseline to 3-month follow-up was 6.9 ± 1.4 points (95 %CI 4.1–9.8; p < 0.0001), 3.4 ± 1.0 points (95 %CI 1.3–5.4 points; p < 0.01), 13.6 ± 2.7 points (95 %CI 8.2–19.0 points; p < 0.0001), and 2.4 ± 0.5 (95 %CI 1.4–3.3; p < 0.0001), respectively. At follow-up, 38 (63 %) patients were free from the PTS and none developed contralateral deep vein thrombosis. Conclusions: In patients with PTS and common iliac vein compression, treatment with the hybrid oblique stent with provisional stent extension resulted in high patency rates and improvement in PTS severity and quality of life at 3-month. Two-year results of TOPOS will assess the durability of this treatment.

[Antithrombotic therapy after iliac vein stenting]

Stenting for iliac vein stenosis or compression has become a common therapeutic approach in recent years. The antithrombotic therapy after the stent deployment, however, reaches no consensus. Medications strategies and patients' prognoses differ in non-thrombotic, acute thrombotic and chronic thrombotic these three circumstances. Non-thrombotic patients usually possess satisfactory stent patency whatever antithrombotic therapy is used. Anticoagulant is the basic medication for acute thrombotic patients, benefits from additional antiplatelet drug remains to be clarified. In terms of chronic thrombotic patients, their prognoses are unsatisfactory under all antithrombotic therapies. In this review, we outlined the recent progress of antithrombotic therapy after iliac vein stenting, aiming to provide feasible medication plans for each circumstance.

Contralateral deep vein thrombosis after stenting across the iliocaval confluence in chronic venous disease – A systematic review

Objective

Stenting of the iliac veins is increasingly considered in the presence of symptomatic obstructive chronic lesions in the iliac vein segment. However, it is often necessary to extend the stented zone into the inferior vena cava, increasing the risk of contralateral iliac vein thrombosis. This study aims to review the current literature concerning the incidence of contralateral deep vein thrombosis after stenting across the iliocaval confluence.

Methods

A systematic review from potentially relevant published articles reporting contralateral deep vein thrombosis after iliac venous stenting between January 2007 and February 2019 was performed.

Results

A total of 764 references were retrieved initially. Twelve studies reporting events of contralateral deep vein thrombosis were selected for review, with a total of 1864 patients. Contralateral deep vein thrombosis incidence varied between 0% and 15.6%. The post-interventional and follow-up anticoagulation regimens were heterogeneous between studies. The decision to maintain patients on anticoagulation and the duration of treatment was based on the presence of comorbidities, hypercoagulable states, post-thrombotic syndrome and history of recurrent deep vein thrombosis. Patients with non-thrombotic iliac vein lesions were either anticoagulated for three or six months after stenting or received no anticoagulation. Patients with post-thrombotic syndrome were anticoagulated for longer periods. Most studies (eight studies) used an oral vitamin K antagonist agent. The data on compliance with anticoagulation treatment is scarce and few references present data on whether contralateral deep vein thrombosis occurred during anticoagulation treatment. The use of antiplatelet agents in addition to the anticoagulant treatment in the follow-up period was also variable.

Conclusion

The incidence of contralateral deep vein thrombosis due to iliac vein jailing is not negligible and reported being as high as 15.6%. Large-scale studies on the ideal antithrombotic treatment and its impact are necessary. It is possible that patients with stent crossing the iliocaval confluence might benefit from long-term antithrombotic treatment.

Global guidelines trends and controversies in lower limb venous and lymphatic disease: Narrative literature revision and experts' opinions following the vWINter international meeting in Phlebology, Lymphology & Aesthetics, 23-25 January 2019

Guidelines are fundamental in addressing everyday clinical indications and in reporting the current evidence-based data of related scientific investigations. At the same time, a spatial and temporal issue can limit their value. Indeed, variability in the recommendations can be found both among the same nation different scientific societies and among different nations/continents. On the other side, Garcia already published in 2014 data showing how, after three years in average, one out of five recommendations gets outdated (Martinez Garcia LM, Sanabria AJ, Garcia Alvarez E, et al. The validity of recommendations from clinical guidelines: a survival analysis. CMAJ 2014;186(16):1211–1219). The present document reports a narrative literature revision on the major international recommendations in lower limb venous and lymphatic disease management, focusing on the different countries’ guidelines, trends and controversies from all the continents, while identifying new evidence-based data potentially influencing future guidelines. World renowned experts’ opinions are also provided. The document has been written following the recorded round tables scientific discussions held at the vWINter international meeting (22–26 January 2019; Cortina d’Ampezzo, Italy) and the pre- and post-meeting literature search performed by the leading experts.

Diagnosis and management of right external iliac vein "sandwich": A rare cause of iliofemoral deep venous thrombosis

Several anatomic abnormalities predispose patients to iliofemoral deep venous thrombosis, the most common of which is compression of the left iliac vein between the right common iliac artery and lumbar vertebrae, or May-Thurner syndrome. Other areas of venous compression can occur but are rare. This case report describes the presentation, diagnosis, and management of a patient with compression of the right iliac vein "sandwiched" between the right internal and external iliac arteries. After treatment, the patient demonstrated significant improvement in symptoms.

A comparison between intravascular ultrasound and venography in identifying key parameters essential for iliac vein stenting

OBJECTIVE

Deep venous stenting has become the primary treatment option for obstructive venous disease. Precise identification and quantification of the disease as well as localization of optimal landing zones are key elements to success. Compared with venography (anteroposterior projection), intravascular ultrasound (IVUS) seems to be more sensitive in determining those parameters. This study was a blinded comparison of the relative accuracy of venography compared with IVUS in determining key parameters essential for iliac vein stenting.

METHODS

Between October 2013 and November 2015, there were 155 limbs (152 patients) that underwent an endovascular intervention for chronic iliofemoral vein stenosis. Venography and IVUS data were reviewed by vascular surgeons and radiologists, respectively, each blinded to the other to identify location and severity of maximal stenosis, location of iliac-caval confluence, and optimal distal landing zone. Data from venography were compared with data from IVUS. Maximal stenosis was defined as the most severe stenosis found among the four segments-common iliac vein, external iliac vein, common femoral vein, and infrarenal vena cava. IVUS was the "gold standard" for comparisons.

RESULTS

Venography failed to identify lesion existence in 19% of limbs. The median maximal area stenosis was significantly higher with IVUS than with venography (69% vs 52%; P < .0001). Furthermore, venographic correlation with IVUS for the anatomic location of maximal stenosis was present in only 32% of the limbs; venography missed the location of maximal stenosis in more than two-thirds of limbs. The iliac-caval confluence location on venography correlated with IVUS findings in only 15% of patients. In 74%, it was located higher with IVUS than with venography. The mean difference was one vertebral body. Agreement between venography and IVUS on location of the distal landing zone was only 26%. The distal landing zone defined with IVUS was lower than with venography in 64% of limbs.

CONCLUSIONS

Compared with IVUS, venography substantially and significantly misses stenotic lesions-their location and severity; venography also misidentifies the location of the iliac-caval confluence and the distal landing zone in the majority of limbs. Those differences between IVUS and venography suggest that IVUS is the better diagnostic and procedural tool in iliac-caval stenting.

Central Venous Pathologies: Treatments and Economic Impact

Chronic venous insufficiency (CVI) is responsible for significant costs to society in the form of medical and surgical treatment and, importantly, unmeasurable lost work productivity due to pain and disability. Symptomatic chronic central vein obstruction, a cause of CVI, is potentially treatable using open surgical and endovascular techniques to restore vessel patency. Although upper extremity central vein obstruction often requires an open surgical procedure for durable relief, endovascular stents have proven remarkably useful for iliofemoral disease. Containment of healthcare resources requires accurate diagnosis, durable treatment modalities, and appropriate patient selection so that therapy is targeted to those individuals most likely to benefit. In this regard, identification of appropriate lesions should be based on intravascular ultrasound and 3-dimensional imaging studies. Treatment with dedicated venous stents offers the potential for long-term symptomatic improvement and increased work productivity when used in a well-defined, anatomically appropriate population with significant, symptomatic CVI.

Surgical Scarring after Arterial Bypass, an Etiology of Venous Hypertension

Venous ulcers can be a chronic debilitating condition with a high rate of recurrence. Herein, we describe a case of a patient who successfully underwent an arterial bypass for rest pain but returned with lower extremity swelling and venous ulcers. Venography demonstrated a focal common femoral vein stenosis due to scarring from the surgical exposure. This was treated with endovenous stenting and resulted in resolution of the swelling and ulceration.