Venous stenting across the inguinal ligament

Endovascular stenting of external iliac vein injury during anterior spine exposure

Anterior lumbar interbody fusion (ALIF) is a standard approach for the surgical management of patients with severe degenerative disease at the L4-L5 and lumbosacral (L5-S1) levels. ALIF is performed through retroperitoneal exposure but harbors a small risk of major vascular injury. In this case, we describe an emergent endovascular repair of an external iliac vein injury that occurred during ALIF with long-term follow-up. We discuss specific strategies in the decision making and technique that led to a successful outcome in this case. Endovascular stent grafting is a potential bailout option for serious iliac vein injury.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Extensive iliofemoral and femoropopliteal venous thrombosis in a young patient with iliocaval atresia

Inferior vena cava (IVC) atresia is a rare congenital anomaly. Standardized treatment is not well defined due to its uncommon presentation, with this pathology associated with an increased risk of unprovoked lower extremity deep vein thrombosis (DVT). We present a case of a 32-year-old man who was admitted for bilateral lower extremity edema and pain and was found to have bilateral extensive iliofemoral and femoropopliteal DVT, absence of IVC filling, and extensive tortuous collateralization arising from the pelvic veins to the azygos vein. Bilateral mechanical thrombectomy and endovascular iliocaval reconstruction was performed. Three months later, the patient demonstrated widely patent iliocaval stents and the absence of DVT. Endovascular treatment of IVC atresia is feasible and optimizes the reduction of thrombus burden.

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.

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.

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.

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.

Venous stent patency is independent of total stented length in nonthrombotic iliac vein and post-thrombotic venous stenoses

OBJECTIVE

Venous stenting has become the preferred treatment of symptomatic outflow obstruction due to nonthrombotic iliac vein lesions (NIVLs) and post-thrombotic venous stenoses (PTs). A paucity of data exists regarding the effect of stent length on patency rates after intervention. We evaluated the association between stent length and patency in patients treated for iliofemoral venous outflow obstruction.

METHODS

The institutional review board approved the present study. A total of 161 patients had undergone venous stenting for NIVLs and thrombotic disease from January 2016 to April 2021. For thrombotic disease, patients with PTs and those with acute deep vein thrombosis (DVT) with underlying outflow obstruction were included. The patient characteristics evaluated included gender, age, body mass index, diagnosed thrombophilia, a history of venous thromboembolism, and CEAP (clinical, etiologic, anatomic, pathophysiologic) score. All the patients had undergone multiplanar venography and intravascular ultrasound during the index procedure. The intravascular ultrasound findings were used to determine the diameter and length of the implanted stents. The patients were placed into two groups, those with stented lengths ≤100 mm and those with stented lengths >100 mm. The primary end point was stent patency between the two groups using duplex ultrasound at 6 months.

RESULTS

A total of 108 patients (58.3% female) had had 6-month duplex ultrasound scans available for review. Their mean age was 55.6 ± 17.2 years. The mean body mass index was 31.7 ± 6.9 kg/m². Overall, the 6-month patency was 89.9%. Of the 108 patients, 56 (51.9%) had had a total stented length of ≤100 mm with a 6-month patency of 92.9%. The remaining 52 patients (48.1%) had had a total stented length >100 mm with a 6-month patency of 86.5%. The rate of patency did not differ significantly between the two groups (P = .222). Stent patency at 6 months for patients with NIVLs was 98% (40 of 41). Stent patency for patients with PTs was 84% (32 of 38). Patency for patients with acute DVT who had undergone stenting after thrombectomy was 86% (25 of 29). Overall, 10 patients with thrombotic disease, including PT and acute DVT, had developed stent thrombosis. The total stented length was not predictive of the loss of patency.

CONCLUSIONS

These findings suggest that the length of stent coverage does not confer an increased likelihood of stent thrombosis for patients with iliofemoral venous obstruction. Interventionalists should treat the affected venous segments identified on intravascular ultrasound and effectively stent from normal to normal venous areas, regardless of the stent length required. These results suggest that the total stented length is not a risk factor for stent thrombosis for both NIVL and thrombotic iliofemoral venous lesions.

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

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

Effectiveness of Venous Stenting for the Treatment of Lower Extremity Chronic Thrombotic Venous Obstruction

BACKGROUND

Patients with venous hypertension (HTN) have significant morbidity and poor quality of life. Deep venous thrombosis (DVT) and congenital defects that led to chronic outflow blockage are frequent causes of venous HTN. It is known that the venovenous bypass has been the standard method used in the treatment of chronic iliofemoral vein occlusions. Percutaneous recanalization has earlier been shown to be technically possible. With venoplasty and stenting, we used an aggressive endovascular strategy to treat the iliofemoral venous thrombotic occlusion.

METHODS

From May 2019 to April 2021, the medical records were reviewed for 63 patients diagnosed with symptomatic iliofemoral thrombotic occlusive disease and treated with venous stenting. The procedures' results were analyzed at Al-Azhar University Hospitals.

RESULTS

The medical records of 63 cases (44 women with a median age of 49.52 years), with chronic outflow block of iliofemoral vein segment that were treated with endovascular venous stenting, were reviewed retrospectively. Optimal success was obtained in 56 cases (88.9%). The twelve-month primary, assisted primary, and secondary patency rates were 76.8%, 80.4%, and 87.5%, respectively, while it was 73.2%, 80.4%, and 87.5%, respectively, after 2 years. The procedure-related complication rate was 6.3%. Puncture site hematoma was observed in 2 patients (3.2%). Early (30 days) stent thrombosis occurred in 2 patients (3.2%). Most importantly, there was no procedure-related mortality.

CONCLUSIONS

Endovascular treatment with balloon angioplasty and stenting of chronic venous thrombotic occlusions is an effective and safe procedure associated with a high technical rate of success and excellent patency rates. Accordingly, it should be considered the first line in the treatment of symptomatic iliofemoral vein occlusion.

Venous Stenting for Postthrombotic Iliocaval Venous Obstructive Disease: Clinical Efficacy and Mid-term Outcomes

Postthrombotic syndrome (PTS) can cause both venous outflow obstruction and deep venous reflux, and results in severe symptoms of chronic venous disease. Venous stenting in the chronic iliocaval venous obstruction has been shown to be a safe and efficacious procedure. The long-term studies have shown the high patency rate, the good symptom relief, and the low recurrence rate of healed venous ulcerations. Although venous stenting has become a widely accepted treatment option in PTS with chronic venous occlusion or severe stenosis, it is not yet covered by insurance in Japan, and is being performed at limited facilities using off-label arterial stents. In this study, we performed venous stenting in 30 patients with the moderate and severe PTS. All patients showed significant improvement in their venous scores postoperatively, the Villalta score changed from a median of 16 before treatment to a median of 7 after treatment. Likewise, the Venous Clinical Severity Score and the Venous Disability Score dropped from a median of 13, 2.4 before treatment to 6, 1.2 after treatment, respectively. The primary patency and the secondary patency at 40 months were 93% and 96%, respectively. We report the excellent results and discuss current issues and future perspective in Japan. (This is secondary publication from J Jpn Coll Angiol 2021; 61: 99-105.).

Extension of Iliac Vein Stent into the Profunda Femoral Vein for Salvage

BACKGROUND

Extension of iliac vein stents into the common femoral vein is often required to correct stenoses found at or near the inguinal ligament. Very rarely, extension of the iliac stent into the profunda femoris vein may be required because of severe disease at the femoral trijunction. Profunda extension of iliac vein stents is a rare but useful technique for salvage. Our experience with extensions of iliac vein stents into the profunda femoris vein is described. Methods PATIENTS: Search of our Electronic medical records (EMR) identified 20 limbs (0.75%) among a total of 2641 stented limbs (years 2006-2017) in whom the iliac vein stent was extended into the profunda femoris vein. Patients had been followed at 6 weeks, 3 months, 6 months and yearly thereafter following the index procedure. Routine follow up consisted of detailed clinical evaluation including venous clinical severity score, visual analogue pain assessment, and edema grading by physical examination. Stent surveillance was performed at follow up visits.

TECHNIQUE

The iliac vein stent was declotted if needed and then extended into the profunda femoris vein at the same sitting. Antegrade access of the profunda femoris vein was preferred by direct puncture near the lesser trochanter or through a popliteal approach when a profunda-popliteal connection was present. An internal jugular access was used when an antegrade approach failed.

RESULTS

Stent extension into the profunda was a secondary procedure after the initial iliac-common femoral vein stent failed in 17/20 (85%) limbs. In 3 (15%) limbs, profunda extension was carried out at the initial iliac vein stent procedure as there was severe stenosis at the femoral confluence. One or more reinterventions after profunda extension were required in 50% of the limbs to maintain secondary patency or functionality. Fifteen of twenty(75%) limbs with profunda extensions remained patent on long term follow up. The median duration of secondary patency of stents that remained patent, those that occluded and overall were 23 months, 3 months, and 10 months respectively. Thirty percent of stents remained patent at 5 years.

CONCLUSION

Extension of an iliac vein into the profunda femoris vein is a rarely required but useful procedure for stent salvage and symptom relief. Corrective reinterventions are often required but can result in long term patency extending to many years.

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.

Short- and Mid-Term Outcomes of Endovascular Stenting for the Treatment of Post-Thrombotic Syndrome due to Iliofemoral and Caval Occlusive Disease: A Multi-Centric Study from the French Society of Diagnostic and Interventional Cardiovascular Imaging (SFICV)

PURPOSE

To assess the results of endovascular treatment in a large population of patients suffering from post-thrombotic syndrome (PTS) due to iliocaval occlusive disease.

METHODS

In this retrospective multi-center study, 698 patients treated by stenting for PTS in 15 French centers were analyzed. Primary, primary assisted, and secondary patency rates were assessed, and clinical efficacy was evaluated using Villalta and Chronic Venous Insufficiency Questionnaire in 20 questions (CIVIQ-20) scores. Outcomes were compared against pre-operative CT-based severity of the post-thrombotic lesions in the thigh (4 grades).

RESULTS

Technical success, defined as successful recanalization and stent deployment restoring rapid anterograde flow in the targeted vessel, was obtained in 668 (95.7%) patients with a complication rate of 3.9%. After a mean follow-up of 21.0 months, primary patency, primary assisted patency, and secondary patency were achieved in 537 (80.4%), 566 (84.7%), and 616 (92.2%) of the 668 patients, respectively. Venous patency was strongly correlated to the grade of post-thrombotic changes in the thigh, with secondary patency rates of 96.0%, 92.9%, 88.4%, and 78.9%, respectively, for grades 0 to 3 (p = .0008). The mean improvements of Villalta and CIVIQ-20 scores were 7.0 ± 4.7 points (p < .0001) and 19.1 ± 14.8 points (p < .0001), respectively.

CONCLUSION

Endovascular stenting as a treatment option for PTS due to chronic iliocaval venous occlusion generates a high technical success, low morbidity, high midterm patency rate, and clinical improvement. Venous patency was strongly correlated to the severity of post-thrombotic lesions in the thigh.

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.

Comparison of endovascular strategy versus hybrid procedure in treatment of chronic venous obstructions involving the confluence of common femoral vein

OBJECTIVE

Treatment of extensive chronic venous obstruction (CVO) with post-thrombotic trabeculation involving the common femoral vein with extension into the femoral vein or deep femoral vein remains a challenge and the best treatment technique for such cases is not clear. In the present study, we compared the results of endovascular alone vs endovascular with additional endophlebectomy (hybrid) procedures for such patients.

METHODS

The medical records of 102 consecutive patients (108 limbs) treated between 2015 and 2020 for iliofemoral CVO extending to the femoral confluence were retrospectively reviewed. The patients were divided into two groups: the hybrid procedure (HP) and endovascular treatment (EN) groups. The HP group consisted of those treated with stent implantation and endophlebectomy of the common femoral vein with creation of an arteriovenous fistula. The EN group included those who had undergone stent implantation alone. The patency rates, complications, and clinical outcomes were analyzed.

RESULTS

Of the 102 patients, 47 (49 limbs) were in the EN group and 55 (59 limbs) were in the HP group. The demographics of the two groups were similar with no statistically significant differences in cumulative primary, assisted primary, or secondary patency rates at 36 months (33.7% vs 36.3%, P = .839; 59.8% vs 64%, P = .941; 69% vs 72.7%, P = .851; respectively). The patients in the EN group, however, had better clinical improvement with a lower postoperative complication rate (P = .012), shorter procedure duration (P < .001), and shorter hospital stay (P = .025).

CONCLUSIONS

The EN and HP both provided similar patency rates for patients with CVO extending into the femoral confluence. The endovascular strategy has the benefit of fewer postoperative complications and a shorter procedure duration and hospital stay compared with the HP.

What are the ideal characteristics of a venous stent?

Historically, the stents used in the venous system were not dedicated scaffolds. They were largely adapted arterial stents. An essential feature of a venous stent is compliance, in order to adapt its crosssectional area to the vein. It should also be crush resistant, corrosion resistant and fatigue resistant. The material should be radiopaque, for follow-up. Another characteristic of the ideal venous stent is flexibility, to adapt its shape to the vein, not vice versa. The scaffold should be uncovered too, in order to avoid the occlusion of collaterals. The ideal venous stent should not migrate, so it is necessary a large diameter and a long length. The radial force is important to prevent migration. However, current stents derived from arterial use display high radial force, which could affect the patency of the thin venous wall. Alternatively, if the stent has an anchor point, that permits a passive anchoring, the radial force required to avoid migration will be lower. Dedicated venous stents were not available until very recently. Furthermore, there is a preclinical study about a new compliant nitinol stent, denominated Petalo CVS. Out of the commonest causes of large veins obstruction, dedicated venous stent could also treat other diseases described more recently, such as the jugular variant of the Eagle syndrome, JEDI syndrome and jugular lesions of the chronic cerebrospinal venous insufficiency that result unfavorable for angioplasty according to Giaquinta classification.

Endovenöse Therapie chronisch venöser Obstruktionen

Bei der chronisch venösen Obstruktion (CVO) liegt ein Abstromhindernis vor, welches eine venöse Hypertension im betroffenen Bein verursacht. Die CVO tritt vornehmlich auf dem Boden eines postthrombotischen Syndroms (PTS) oder eines May-Thurner-Syndroms (MTS) auf. Die CVO kann zu einer deutlichen Einschränkung des täglichen Lebens führen und hat erhebliche sozioökonomische Konsequenzen. Bei der endovenösen Rekanalisation zur Behandlung einer symptomatischen CVO handelt es sich um eine relativ neue therapeutische Option, die mittlerweile generell als Behandlung der ersten Wahl akzeptiert ist. Seit Verwendung spezieller venöser Stents können auch ausgedehntere Befunde, die eine anspruchsvollere Rekonstruktion erforderlich machen, erfolgreich therapiert werden.

Damit nach einer venösen Rekanalisation keine Stase des Blutstroms und ein Primärverschluss auftreten, müssen ein suffizienter Ein- und Ausstrom gewährleistet sein. Zur Verbesserung des Einstroms werden Hybrideingriffe mit Endophlebektomie der Vena femoralis communis und AV-Fistel-Anlage, zur Ausstromverbesserung werden spezielle Rekonstruktionen der Vena-cava-inferior-Konfluenz, z. B. die Skipped-Technik, empfohlen.

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.

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.

The impact of venous stenting across the inguinal ligament on primary patency: a systematic review

INTRODUCTION

Iliac venous stenting is an established treatment option for both post-thrombotic and non-thrombotic iliac venous obstructions. Nonetheless, there is still no consensus on the best medical practice regarding some of these interventions. One area of debate is the safety of extending venous stents across the inguinal ligament (IL), with contradictory results from various authors and overall poor-quality research. This review aims to summarise current knowledge on the effect of venous stent placement across the IL on primary patency.

EVIDENCE ACQUISITION

A literature search was performed on the MEDLINE, Scopus and Web of Science databases, which returned 531 studies. Eleven studies were included. Data were extracted using piloted forms, and, if necessary, authors were contacted to obtain further information.

EVIDENCE SYNTHESIS

Two studies were prospective cohorts, whereas the remaining 9 were retrospective cohorts. Overall study quality was weak. Four studies showed a statistically significant association between stent placement across the IL and decreased primary patency. A multivariate analysis was performed in two of those studies, yet only one maintained statistical significance after multivariate analysis. Two studies reported 4 cases of stent fracture in total, and one study reported 5 cases of stent compression. All cases of stent fracture or compression occurred at the inguinal ligament.

CONCLUSIONS

Although current expert opinion favours stent placement across the IL, there is still insufficient evidence to recommend for or against venous stenting across the IL. Further research is required on comparing alternatives for the treatment of iliac venous lesions that extend into the common femoral vein.

WHAT THIS PAPER ADDS

Despite the establishment of venous stenting as a viable treatment option for both post-thrombotic and non-thrombotic iliac venous obstructions, there is an ongoing debate on the safety of extending such stents across the inguinal ligament. There are several publications on this subject, with conflicting results and overall poor-quality research. This is the first systematic review of published clinical evidence on the impact of venous stent placement across the IL on primary patency.

Contemporary treatment of May-Thurner Syndrome

Compression of the left common iliac vein by the overlying right common iliac artery is a benign anatomic abnormality in most individuals. However, in patients with significant vein compression, outflow obstruction and chronic intraluminal venous damage may lead to May-Thurner Syndrome. This syndrome commonly manifests as unilateral left leg swelling or acute iliofemoral deep venous thrombosis. In addition to clinical findings, diagnosis is made with ultrasound, computed tomography venography, or magnetic resonance venography. The extent of compression of the iliac vein is best determined by venography with intravascular ultrasound. Symptoms and hemodynamic significance of the compression guides the ideal treatment approach. Iliocaval stenting has become the standard treatment for this condition and has promising patency rates and clinical outcomes. This review paper provides an overview of pathophysiology, and utility and limitations of the existing diagnostic modalities and treatment options in the management of May-Thurner Syndrome.

Role of venous stenting for venous thromboembolism

Endovenous stenting has emerged as the method of choice to treat iliofemoral venous outflow obstruction. It is used in patients with established postthrombotic syndrome (PTS) after previous deep vein thrombosis (DVT) to reduce symptoms of chronic pain and swelling and to aid ulcer healing in severe cases. Venous stenting is used to alleviate symptoms of obstruction in patients presenting with acute DVT, with the aim of preventing development of PTS. There is a low risk of morbidity and mortality associated with the use of endovenous stenting, and although significant advances have been made, particularly improvements in stent design for use in the venous circulation, data are lacking on beneficial long-term outcomes. Unmet research needs include optimal patient selection, anticoagulant choice and duration, best practice for postoperative surveillance, and use of validated assessment tools to measure outcomes. In this article, I address the potential benefits, as well as the challenges, of endovenous stenting.

Endovascular management of the deep venous thrombosis: A new challenging role for the endovascular specialist in 2020

Over the last years, the endovascular approach to the management of the acute and chronic deep vein thrombosis (DVT) has gained more and more attention from the scientific community. DVT is the third most common cardiovascular disease after coronary heart disease and stroke, with classic treatment based on anticoagulation. Recent evidences have highlighted the risk of postthrombotic syndrome as high as 30%-50% in proximal ilio-femoral lesions, with irreversible clinical symptoms and impact on the quality of life of the population. Since 2000s, the new concept of thrombus removal in the acute phase has been supported by the introduction of different techniques based on the endovascular ablation of the clot by in-situ fibrinolysis and, more recently, fragmentation and aspiration. In the chronic phase, recanalization of the thrombosed segment is recommended by stent placement to remove the obstruction and eventually reduce the congestion. Immediate technical success of these procedures is widely satisfying, whereas the long-term clinical benefits are still debated. This paper presents an overview of the modern management of the DVT by endovascular approach with regard to the clinical contexts, interventional strategies and clinical outcomes. Endovascular specialist needs to be aware of this incoming challenge, as local expertise is demanded for the modern management of these patients in multidisciplinary theaters.

Dyeless iliac vein stenting

OBJECTIVE

Iliac vein stenting is increasingly being explored for the treatment of chronic venous insufficiency. While venography is considered the gold standard for assessing iliac veins, some have proposed that intravascular ultrasound should be utilized instead due to its greater sensitivity at detecting stenotic lesions. Routinely, our service uses both intravascular ultrasound and venography, but we have noted that some patients cannot tolerate dye due to allergy, renal insufficiency, or deemed high-risk by the interventionalist due to uncontrolled medical co-morbidities. This study aimed to investigate whether forgoing dye had an impact on iliac vein stent thrombosis.

METHODS

From 2012 to 2016, 1482 iliac vein procedures (91 intravascular ultrasound-only and 1391 intravascular ultrasound plus venography) were performed on 992 patients who failed conservative treatment for chronic venous insufficiency. Our mean patient age was 65.8 years (range 21-99; SD ± 14.3) with 347 male and 645 female patients. The clinical presenting symptoms per clinical-etiology-anatomy-pathophysiology classification for the intravascular ultrasound-only cohort were C1:0, C2:3, C3:31, C433, C5:5, C6:20 and for the intravascular ultrasound plus venography cohort were C1:0, C2:24, C3:566, C4:583, C5:30, C6:188. Stent thrombi that developed within or at 30 days of stenting were categorized as early and greater than 30 days as late. Transcutaneous duplex ultrasound classified stent thrombi as either partial or occlusive. Our average follow-up time was 19.4 months (0-42, SD ± 12.5).

RESULTS

A total of 2.2% intravascular ultrasound-only patients versus 2.75% intravascular ultrasound plus venogram patients developed early stent thrombosis, p = 0.35. Early partial stent thrombosis occurred in 1.1% of the intravascular ultrasound-only group versus 2.6% of the intravascular ultrasound plus venogram group, p = 0.38. Early occlusive stent thromboses occurred in 1.1% of intravascular ultrasound-only patients and 0.15% of intravascular ultrasound plus venogram patients, p = 0.06. Late stent thromboses developed in 4% of patients in the intravascular ultrasound-only cohort and 4% in the intravascular ultrasound plus venogram cohort, p = 0.97. Late partial stent thromboses occurred in 2.7% of intravascular ultrasound-only patients versus 2.6% in intravascular ultrasound plus venogram patients, p = 0.99. Late occlusive stent thromboses occurred in 1.3% of intravascular ultrasound-only patients versus 1.4% of intravascular ultrasound plus venogram patients, p = 0.95. Moreover, the formation of any stent was 6.2% in the intravascular ultrasound-only versus 6.75% in the intravascular ultrasound plus venogram group, p = 0.55.

CONCLUSION

Results of our study show no significant difference in stent thrombosis between the intravascular ultrasound-only and intravascular ultrasound plus venogram cohorts. This concludes that using intravascular ultrasound alone is safe for iliac vein stenting.

Braided or laser-cut self-expanding nitinol stents for the common femoral vein in patients with post-thrombotic syndrome

BACKGROUND

Chronic obstruction of the common femoral vein in patients with post-thrombotic syndrome after iliofemoral or iliocaval deep vein thrombosis has remained a challenge for endovascular treatment. The patency rates and clinical outcomes of laser-cut and braided nitinol stents extending to the common femoral vein have not yet been studied.

METHODS

From the Swiss and Arnsberg Venous Stent Registries, we included 150 patients with post-thrombotic syndrome (mean age, 44 ± 16 years; 48% women) with laser-cut (n = 101) or braided nitinol (n = 49) stents placed into the common femoral vein across the inguinal ligament. Routine follow-up included duplex ultrasound examinations and assessment of clinical scores. The primary study outcomes were the primary and secondary patency rates at 12 months.

RESULTS

Overall, the mean number of implanted stents was 2.6 ± 1.7. The proximal stent landing zone was the inferior vena cava in 32 patients (21%), the iliac vein in 106 patients (76%), and the common femoral vein in 5 patients (3%). The primary patency rate was 67.3% (95% confidence interval [CI], 58.0%-76.6%) in the laser-cut group and 86.7% (95% CI, 75.3%-98.1%) in the braided stent group (log-rank, P = .016). The corresponding secondary patency rates were 93.9% (95% CI, 89.2%-98.6%) and 100% (log-rank, P = .10). The median improvement in the Villalta score from baseline to the latest follow-up was 4 points (interquartile range, 2-6 points), without significant differences between the two groups. Symptomatic common femoral vein stent fractures were observed in four patients (4%) with laser-cut stents but in no patient with braided stents.

CONCLUSIONS

The use of braided nitinol stents for common femoral vein obstruction appeared to be associated with favorable primary patency rates at 12 months compared with laser-cut nitinol stents. Further studies are needed to confirm that braided nitinol stents remain patent and might be less prone to fractures in the long term.

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.

Anticoagulation reduces iliocaval and iliofemoral stent thrombosis in patients with cancer stented for nonthrombotic venous obstruction

OBJECTIVE

To identify factors associated with venous stent thrombosis in patients with cancer treated for nonthrombotic iliocaval or iliofemoral venous obstruction.

METHODS

We performed a retrospective review of relevant imaging and medical records from 30 consecutive patients with cancer treated at a single center who underwent venous stent placement for nonthrombotic iliocaval or iliofemoral venous obstruction between 2008 and 2018. Follow-up imaging was used to assess stent patency. Variables examined included patient demographics, cancer type, stent characteristics, anticoagulant, and antiplatelet medications and complications of treatment.

RESULTS

Overall primary stent patency was 83% (25/30). The median follow-up period was 44 days (range, 3-365 days). Ten percent of patients occluded owing to in-stent thrombosis and 7% owing to tumor compression of the stent without thrombosis. Therapeutic poststent anticoagulation with enoxaparin, warfarin, or a factor Xa inhibitor was initiated in 87% of the patients. Stent thrombosis occurred in one patient in the anticoagulation group (4%) at 50 days. Stent thrombosis occurred in two patients in the nonanticoagulation group (50%), one at 9 days and the other at 91 days. Anticoagulation was found to be protective against stent thrombosis in this population (hazard ratio, 0.015; P = .011). No statistically significant associations were found among the remaining variables. One patient in the anticoagulation group experienced major bleeding (1/26 [4%]).

CONCLUSIONS

Iliocaval and iliofemoral stent placement for nonthrombotic malignant venous obstruction is safe with favorable primary patency rates. Therapeutic anticoagulation is associated with less stent thrombosis in patients with cancer stented for nonthrombotic iliocaval and iliofemoral venous obstruction.

Venous Biomechanics of Angioplasty and Stent Placement: Implications of the Poisson Effect

PURPOSE

To characterize the Poisson effect in response to angioplasty and stent placement in veins and identify potential implications for guiding future venous-specific device design.

MATERIALS AND METHODS

In vivo angioplasty and stent placement were performed in 3 adult swine by using an established venous stenosis model. Iron particle endothelium labeling was performed for real-time fluoroscopic tracking of the vessel wall during intervention. A finite-element computational model of a vessel was created with ADINA software (version 9.5) with arterial and venous biomechanical properties obtained from the literature to compare the response to radial expansion.

RESULTS

In vivo angioplasty and stent placement in a venous stenosis animal model with iron particle endothelium labeling demonstrated longitudinal foreshortening that correlated with distance from the center of the balloon (R² = 0.87) as well as adjacent segment narrowing that correlated with the increase in diameter of the treated stenotic segment (R² = 0.89). Finite-element computational analysis demonstrated increased Poisson effect in veins relative to arteries (linear regression coefficient slope comparison, arterial slope 0.033, R² = 0.9789; venous slope 0.204, R² = 0.9975; P < .0001) as a result of greater longitudinal Young modulus in veins compared with arteries.

CONCLUSIONS

Clinically observed adjacent segment narrowing during venous angioplasty and stent placement is a result of the Poisson effect, with redistribution of radially applied force to the longitudinal direction. The Poisson effect is increased in veins relative to arteries as a result of unique venous biomechanical properties, which may be relevant to consider in the design of future venous interventional devices.

Catheter Interventions for Acute Deep Venous Thrombosis: Who, When and How

Deep venous thrombosis (DVT) is common and can be a source of morbidity by way of pulmonary embolism and post-thrombotic syndrome. Recent trials have demonstrated both early and late symptomatic benefit in venous thrombolysis and early recanalisation of the iliocaval system of selected patients. Based on the emerging evidence, national societies have published guidelines that recommend early thrombus removal in iliofemoral DVT in patients with low bleeding risk and good life expectancy. In light of these recommendations, endovenous thrombolysis and/or thrombectomy have become more popular among vein specialists. As more venous technology becomes available, surgeons and interventionalists should take pause and ensure their patient selection and treatment algorithms parallel that of existing and emerging evidence. This article summarises current evidence, technology, and the approach used at a high-volume academic centre in treating iliofemoral DVT.

Toward Data-Driven Learning Healthcare Systems in Interventional Radiology: Implementation to Evaluate Venous Stent Patency

We developed a code and data-driven system (learning healthcare system) for gleaning actionable clinical insight from interventional radiology (IR) data. To this end, we constructed a workflow for the collection, processing and analysis of electronic health record (EHR), imaging, and cancer registry data for a cohort of interventional radiology patients seen in the IR Clinic at our institution over a more than 20-year period. As part of this pipeline, we created a database in REDCap (VITAL) to store raw data, as collected by a team of clinical investigators and the Data Coordinating Center at our university. We developed a single, universal pre-processing codebank for our VITAL data in R; in addition, we also wrote widely extendable and easily modifiable analysis code in R that presents results from summary statistics, statistical tests, visualizations, Kaplan-Meier analyses, and Cox proportional hazard modeling, among other analysis techniques. We present our findings for a test case of supra versus infra-inguinal ligament stenting. The developed pre-processing and analysis pipelines were memory and speed-efficient, with both pipelines running in less than 2 min. Three different supra-inguinal ligament veins had a statistically significant improvement in vein diameters post-stenting versus pre-stenting, while no infra-inguinal ligament veins had a statistically significant improvement (due either to an insufficient sample size or a non-significant p value). However, infra-inguinal ligament stenting was not associated with worse restenosis or patency outcomes in either a univariate (summary-statistics and Kaplan-Meier based) or multivariate (Cox proportional hazard model based) analysis.

Etiology of iliocaval stent thrombosis

OBJECTIVE

Although correction of iliac vein stenosis is safe and efficacious, one of its major complications is iliac vein stent thrombosis. In an attempt to examine the cause of iliac vein stent thrombosis, we reviewed the location of underlying lesions encountered after thrombectomy or thrombolysis of iliac vein stents.

METHODS

A retrospective analysis was performed of all iliac vein venograms with intravascular ultrasound examinations at our office-based surgical center from February 2012 to July 2016. Patients included in the study had chronic venous insufficiency and failed compression therapy. All procedures were performed with local anesthesia and conscious sedation. Wallstents were used in all procedures for nonthrombotic iliac vein stenosis, ranging from 8 to 24 mm in diameter and 40 to 90 mm in length. Patients were followed with transcutaneous duplex every 3 months for the first year and every 6 to 12 months thereafter. Patients were placed on clopidogrel for 3 months or continued on their preexisting anticoagulants.

RESULTS

From February 2012 to July 2016, we performed 2228 iliac vein venograms with intravascular ultrasound examination in 1381 patients. The mean age of the patient population was 65 ±14 years (range, 21-99 years), among which 876 were female. A total of 1037 procedures were performed in the left lower extremity. Of these, 240 venograms were diagnostic. Presenting symptoms based on CEAP classification included C2 (n = 21), C3 (n = 633), C4 (n = 1065), C5 (n = 269), and C6 (n = 241). Complete thrombosis of the iliac vein stent was noted in 18 patients (0.8%) who thereafter underwent suction thrombectomy with thrombolysis. None of these patients had a prior history of deep vein thrombosis. In-stent restenosis was noted in 11 patients. Proximal lesions were found in no patients. An external iliac vein lesion was found distal to the common iliac vein stent in two patients. Common femoral vein lesions were found in six patients. These encountered lesions were then stented. All patients who underwent thrombectomy were placed on anticoagulation for 6 months. No patient were noted to suffer rethrombosis upon follow-up. No correlation with stent thrombosis was encountered for age, gender, laterality, location, presenting symptoms, or length or diameter of the stent.

CONCLUSIONS

Based on our experience, in-stent restenosis followed by inflow lesions in the common femoral vein are the most common causes of stent thrombosis. These data suggest a need for future research to target these areas.

Single- versus multiple-stage catheter-directed thrombolysis for acute iliofemoral deep venous thrombosis does not have an impact on iliac vein stent length or patency rates

BACKGROUND

Incomplete venous thrombolysis and residual nonstented iliac vein disease are known predictors of recurrent deep venous thrombosis (DVT). Controversy exists as to whether the number of thrombolysis sessions affects total stent treatment length or stent patency. The goal of this study was to evaluate the outcomes of patients who underwent single vs multiple catheter-directed lysis sessions with regard to stent extent and patency.

METHODS

Consecutive patients who underwent thrombolysis and stenting for acute iliofemoral DVT between 2007 and 2018 were identified and divided into two groups on the basis of the number of treatments performed (one vs multiple sessions). Operative notes and venograms were reviewed to determine the number of lytic sessions performed and stent information, including size, location, total number, and length treated. End points included total stent length, 30-day and long-term patency, and post-thrombotic syndrome (Villalta score ≥5). The χ2 comparisons, logistic regression, and survival analysis were used to determine outcomes.

RESULTS

There were 79 patients who underwent lysis and stenting (6 bilateral interventions; mean age, 45.9 ± 17 years; 48 female). Ten patients (12 limbs) underwent single-stage treatment with pharmacomechanical thrombolysis, and the remaining 69 (73 limbs) had two to four operating room sessions combining pharmacomechanical and catheter-directed thrombolysis. Patients who underwent a single-stage procedure were older and more likely to have a malignant disease. These patients received less tissue plasminogen activator compared with the multiple-stage group (17.2 ± 2.2 mg vs 27.6 ± 11.6 mg; P = .008). Average stent length was 8.8 ± 5.2 cm for the single-stage group vs 9.2 ± 4.6 cm for the multiple-stage group (P = .764). Patients who underwent a single-stage procedure had no difference in average length of stay from that of patients who underwent multiple sessions (8.5 days vs 5.9 days; P = .269). The overall 30-day rethrombosis rate was 7.3%. Two-year patency was 72.2% and 74.7% for the single and multiple stages, respectively (P = .909). The major predictors for loss of primary patency were previous DVT (hazard ratio [HR], 5.99; P = .020) and incomplete lysis (HR, 5.39; P = .014) but not number of procedures (HR, 0.957; P = .966). The overall post-thrombotic syndrome rate was 28.4% at 5 years and was also not associated with the number of treatment sessions.

CONCLUSIONS

Single- vs multiple-stage thrombolysis for DVT is not associated with a difference in extent of stent coverage. Patency rates remain high for iliac stenting irrespective of the number of lytic sessions, provided lysis is complete and the diseased segments are appropriately stented.

Safety, procedural success and outcome of the Aspirex®S endovascular thrombectomy system in the treatment of iliofemoral deep vein thrombosis – data from the Arnsberg Aspirex registry

Summary. Background: Percutaneous mechanical thrombectomy (PMT) represents a treatment option in addition to conventional therapy for patients with iliofemoral deep vein thrombosis (DVT). We sought to determine the safety, patency and short-term outcome of the Aspirex®S catheter as a rotational mechanical thrombectomy device in the endovascular treatment of iliofemoral DVT. Patients and methods: 56 patients (66 % female, median age 51 years) undergoing mechanical thrombectomy with the Aspirex®S catheter for endovascular treatment of iliofemoral DVT were included in the analysis. Device- and procedure-related complications, prevention of post-thrombotic syndrome (PTS) and patency rates were determined at baseline and at 1, 6 and 12 months after intervention. Results: No device-related complications or malfunction occurred. Procedure-related complications (rehospitalization, re-occlusion of target vein, prolonged hospitalization resulting from access site complication) were seen in 14 % of patients. PMT was followed by implantation of a dedicated venous stent in all patients. Low PTS reflected by a revised venous clinical severity score (rVCSS) of < 3 and a clinical, etiologic, anatomic and pathophysiologic (CEAP) score of < 3 were achieved in 64 % of the patients at 12 months. Patency was 95 % after 1 month, 94 % after 6 months and 87 % after 12 months. Conclusions: Even though long-term studies are missing, PMT of iliofemoral DVT using the Aspirex®S rotational thrombectomy device as a standalone approach exhibited an excellent patency at short term associated with substantial prevention of moderate to severe PTS and low device-related complications including bleeding.

Endovascular Treatment of Post-thrombotic Venous Ilio-Femoral Occlusions: Prognostic Value of Venous Lesions Caudal to the Common Femoral Vein

OBJECTIVES

To propose a scale of severity for post-thrombotic venous lesions (PTVLs) after ilio-femoral deep venous thrombosis and to compare the grade with the results of endovascular treatment of ilio-femoral PTVLs.

METHODS

In this retrospective monocentric observational study, we included 95 patients treated for ilio-femoral PTVLs. We proposed a four-grade scale evaluating the severity of PTVLS caudal to the common femoral vein based on CT phlebography and per-operative phlebography. For most patients, venous patency was assessed with color duplex ultrasonography and the clinical efficacy of the intervention using the Villalta and CIVIQ scores.

RESULTS

Recanalization was successful in 100% of patients with a morbidity rate of 4%. After a mean follow-up of 21 months, the overall primary patency was 75%, the assisted primary patency 82%, and the secondary patency 93%. Secondary patency was 100% for grade 0-1, 90% for grade 2, and 63% for grade 3 (p < 0.002). There was no correlation between the extension of stenting caudally of the common femoral vein and venous patency. The mean improvements in the Villalta and CIVIQ-20 scores were, respectively, 4.6 (p < 0.0001) and 18 (p < 0.0001); scores were not correlated with the grade of PTVLs in the thigh.

CONCLUSION

Venous patency after endovascular treatment of ilio-femoral PTVLs was strongly linked to the severity of PTVLs caudal to the common femoral vein but not to the extent of stenting.

Update on diagnosis and treatment strategies in patients with post-thrombotic syndrome due to chronic venous obstruction and role of endovenous recanalization

OBJECTIVE

After a first episode of lower extremity deep venous thrombosis, post-thrombotic syndrome (PTS) develops in 20% to 50% of patients despite adequate anticoagulation. Symptoms of PTS can vary from leg swelling to venous ulceration with disabling venous claudication. It significantly affects the patient's quality of life and has considerable socioeconomic consequences. This review gives an update on diagnosis and current treatment strategies in patients with PTS due to chronic venous obstruction, in particular regarding the role of endovenous procedures.

METHODS

This review article is based on a selective literature search in PubMed and the Cochrane Library. The terms "postthrombotic syndrome," "post-thrombotic syndrome," "chronic venous obstruction," "venous outflow obstruction," and "venous stent" were used as keywords. Selected publications addressed the diagnosis of and therapy for PTS. Acute deep venous thrombosis, thrombolysis, case reports, complications as a result of caval vein filters, animal experiments, PTS of the upper extremity, and PTS in children were excluded.

RESULTS

In addition to conservative treatment of PTS, the following invasive procedures are also available: open surgical reconstructions, hybrid procedures, and endovenous recanalization of the occluded iliocaval venous tract with stent angioplasty. Since introduction of dedicated venous stents in 2012, technical success, patency rates, and improvement in quality of life have been at least as good as results of open surgical reconstruction if not better.

CONCLUSIONS

First-line treatment should be conservative therapy. In case of therapy-resistant PTS with poor quality of life, the possibility of an invasive treatment should be evaluated. All invasive procedures are recommended with low levels of evidence. Therefore, deciding on an invasive treatment and type of procedure should be made individually. Because PTS is rarely a threat to life or limb, a minimally invasive treatment is preferred. Therefore, endovenous recanalization appears to be appropriate as the therapy of choice. In patients with involvement of the femoral confluence, endophlebectomy of the common femoral vein in addition to venous recanalization is inevitable to ensure an adequate inflow into the recanalized venous tract. It also secures a sufficient drainage of blood from the peripheral venous system. Because this hybrid procedure is burdened with a significantly higher risk of complications, strict criteria must be fulfilled to legitimize the indication for this procedure. For the best possible results to be achieved, the following perioperative and postoperative management must be considered: therapeutic anticoagulation, early mobilization, compression therapy, and systematic follow-up with duplex ultrasound.

Outcomes and predictors of failure of iliac vein stenting after catheter-directed thrombolysis for acute iliofemoral thrombosis

OBJECTIVE

Iliac vein stenting is recommended to treat venous outflow obstruction after catheter-directed thrombolysis for acute iliofemoral deep venous thrombosis (DVT). Data on the outcome of proximal and distal stent extension are limited. Proximal stent extension to the vena cava may obstruct the contralateral iliac vein, whereas distal extension below the inguinal ligament contradicts common practice for arterial stents. The aim of this retrospective study was to assess outcomes and predictors of failure of iliac vein stents and contralateral iliac vein thrombosis, taking into consideration stent positioning.

METHODS

Consecutive patients who underwent thrombolysis and stenting for DVT between May 2007 and September 2017 were identified from a prospectively maintained database. The intraoperative venograms were reviewed for proximal stent placement (covering >50% contralateral iliac vein orifice) and distal placement across the inguinal ligament. End points were ipsilateral DVT recurrence, post-thrombotic syndrome (PTS; Villalta score ≥5), and contralateral DVT. Patients with chronic contralateral DVT or contralateral iliac vein stenting at baseline were excluded from the contralateral DVT outcome evaluation. Survival analysis and Cox regression models were used to determine outcomes.

RESULTS

Of 142 patients lysed, 73 patients (12 bilateral DVTs; mean age, 45.8 ± 17.2 years; 46 female patients) were treated with various combinations of thrombolytic techniques and at least one self-expanding iliac stent (77 stented limbs). Thirty-day recurrence developed in nine (12.3%) patients. The 3-year primary patency and secondary patency rates were 75.2% and 82.2%, respectively. The single predictor for loss of primary patency was incomplete thrombolysis (≤50%; hazard ratio [HR], 7.41; P = .002). Overall, 3 of 12 (25%) stents extending below the inguinal ligament occluded at 1 month, 2 months, and 9 months, respectively. The overall rate of PTS (Villalta score ≥5) in the stented cohort was 14.4% at 5 years. This was predicted by incomplete lysis (<50%; HR, 7.09; P = .040), stent extension below the inguinal ligament (HR, 6.68; P = .026), and male sex (HR, 6.02; P = .041). Of the 17 stents that extended into the contralateral common iliac vein and 58 stents that did not, there were 1 (5.9%) and 5 (8.6%) contralateral DVTs (P = .588) at an average follow-up of 27.4 ± 33.7 and 22.2 ± 22.3 months (P = .552), respectively.

CONCLUSIONS

Iliac stenting after thrombolysis for acute DVT guarantees high patency and low PTS rates, provided adequate thrombus resolution has been achieved before stent placement. Stent placement below the inguinal ligament does not affect the patency but may be associated with a higher PTS rate. Stenting proximal to the iliocaval confluence, although a precipitating factor, may not independently increase the likelihood of contralateral DVT.

Usefulness of Direct Computed Tomography Venography in Predicting Inflow for Venous Reconstruction in Chronic Post-thrombotic Syndrome

PURPOSE

The purpose of this paper is to assess the applicability of direct computed tomography venography (DCTV) in assessing dominant inflow vein in the femoral confluence in extensive chronic iliofemoral venous obstruction, using venography as the gold standard.

METHODS

All DCTVs performed in symptomatic patients with previous iliofemoral deep vein thrombosis subsequently submitted to venography in the period from January 2014 to August 2018 were retrospectively reviewed. Two groups were defined depending on whether the femoral vein (FV) or the deep femoral vein (DFV) was the dominant inflow on venography in order to identify predictors of DFV as dominant inflow in DCTV. Statistical analysis was performed with SPSS V25.

RESULTS

A total of 30 DCTVs and subsequent venographies were reviewed. Venography identified the FV as the dominant inflow in 18 (60%) and the DFV in 12 (40%) patients. Predictors for DFV as dominant inflow were identified as follows: larger DFV diameter 50 mm and 250 mm below lesser trochanter (8.73 ± 4.34 mm vs. 11.9 ± 3.52 mm; p = 0.043 and 5.4 ± 3.90 mm vs. 8.90 ± 2.70 mm; p = 0.011); lower FV/DFV ratio 150 mm below lesser trochanter (11.39 ± 20.01 mm vs. 1.05 ± 0.47 mm; p = 0.043); and presence of FV scarring/synechiae, collaterals and abnormal wall thickness (p = 0.003, p = 0.003 and p < 0.0001).

CONCLUSION

In cases of extensive chronic iliofemoral venous obstruction, especially when stent deployment into the DFV is entertained, the key to success is thorough pre-procedure planning focusing on choosing the access site. This study suggests DCTV is valuable in defining the dominant iliac vein inflow, but additional findings are necessary to validate these preliminary data.

Patency rates, safety and clinical results of the sinus-Obliquus venous stent in the treatment of chronic ilio-femoral venous outflow obstruction - data from the Arnsberg venous registry

Background: We sought to determine the patency and clinical symptom relief following the usage of the sinus-Obliquus venous stent in the endovascular treatment of venous obstruction of the ilio-femoral track in short-term. Patients and methods: 48 patients (62 % female, mean age 57 years) with chronic unilateral post-thrombotic obstruction (PTO) and non-thrombotic iliac vein obstructive lesions (NIVL) without involvement of inferior vena cava receiving a sinus-Obliquus venous stent was included in the analysis. Clinical improvement determined by the revised venous clinical severity score (rVCSS) as well as the clinical, etiologic, anatomic and pathophysiologic score (CEAP), safety, and stent patency rates were determined at baseline and at 1, 6 and 12 months after stent placement. Ten of the 48 included patients had a venous ulceration. Results: Primary patency rates were 98 % at FU1, 94 % at FU2 and 94 % at FU3, respectively. Secondary patency was 100 % at FU1, 96 % at FU2 and remained 96 % at FU3. At 12 months, the mean rVCSS dropped from 9.0 to 4.8 points (p < 0.001) whereas the mean CEAP improved from 3.45 to 2.96 (p < 0.001). A substantial healing of ulcerations was observed in 8 of 10 patients with initial venous ulceration. There were no relevant safety concerns noticed. Conclusions: Even though long-term studies are missing, the sinus-Obliquus venous stent already showed very promising patency rates at short term, associated with substantial clinical improvement and low device-related complications in both NIVL and PTS.

Infrainguinal inflow assessment and endovenous stent placement in iliofemoral post-thrombotic obstructions

Purpose

To assess the technical success, patency, and clinical outcome, following assessment of inflow and infrainguinal endovenous stent placement in patients with iliofemoral post-thrombotic obstruction with infrainguinal involvement.

Methods

A retrospective analysis of 39 patients with iliofemoral post-thrombotic venous obstruction accepted for infrainguinal stent placement in the period November 2009–December 2016. The clinical status was categorized according to the Clinical Etiological Anatomical Pathophysiological (CEAP) classification and symptom severity was assessed using Venous Clinical Severity Score (VCSS). The inflow was categorized as “good”, “fair”, or “poor” depending on vein caliber and extent of post-thrombotic changes in the inflow vessel(s). Stent patency was assessed by duplex ultrasound. Median follow-up was 44 months (range 2–90 months).

Results

Stent placement was successful in all 39 patients. Primary patency after 24 months was 78%. Thirty of 39 patients (77%) had open stents at final follow-up. Re-interventions were performed in four patients and included catheter-directed thrombolysis (CDT) in all and adjunctive stenting in two. Twenty-eight of 39 patients (72%) reported a sustained clinical improvement. Patients with “good” inflow had better patency compared to those with “fair”/“poor” (p = 0.01). One patient experienced acute contralateral iliofemoral thrombosis; this segment was successfully treated with CDT and stenting. No other complications required intervention.

Conclusion

Infrainguinal endovenous stent placement was a feasible and safe treatment with good patency and clinical results, and should be considered in patients with substantial symptoms from post-thrombotic obstructions with infrainguinal involvement. Stents with good inflow have better patency and inflow assessment is essential in deciding the optimal stent landing zone.

Characteristics and outcomes of stent occlusion after iliocaval stenting

OBJECTIVE

With increasing use of iliocaval stenting, complications have become more noticeable. Stent occlusion is one such outcome that has not been studied in detail. Characteristics of stent occlusion in addition to outcomes after recanalization are presented.

METHODS

An analysis of 3468 initial iliocaval stents placed during an 18-year period from 1997 to 2015 was performed. A total of 102 stent occlusions were identified, amounting to a 3% stent occlusion rate. Characteristics evaluated included onset after stent placement, techniques used for restoring patency, and their outcome. Kaplan-Meier analysis was used to assess stent patency. Regression analysis was used to evaluate risk factors for stent occlusion.

RESULTS

Stent occlusions occurred at a median of 5.8 months after placement. The occluded stent could be reopened after a wide range of intervals, the longest being 14 years. The majority (69%) of occlusions were chronic (>30 days) and the remainder (31%) were acute; 77% of the occlusions occurred in post-thrombotic limbs. The most common technique used to recanalize the acutely occluded stent was pharmacomechanical thrombectomy, whereas wire recanalization with balloon angioplasty was the technique most used for chronic occlusions. Of the 102 occluded stents, patency was achieved in 75 of 88 (84%) attempts. After successful recanalization, the median primary patency was 7 ± 1.9 months, median primary assisted patency was 7.5 ± 3.5 months, and median secondary patency was 25 ± 8.3 months. Clinically, there was improvement in the visual analog scale pain scores from a median of 3.5 to 1 (P < .01), in the median grade of swelling from 2 to 1 (P < .01), and in the mean Venous Clinical Severity Score from 6.4 to 3.8 (P < .01) after recanalization. A 40% ulcer healing rate was noted after recanalization during a median follow-up period of 17 months. There were no significant adverse events or mortality. Regression analysis revealed stent placement for native vein occlusion as the only statistically significant predictor of stent occlusion.

CONCLUSIONS

Stent occlusion after iliocaval stenting is a rare occurrence. Recanalization of occluded stents can be performed with minimal morbidity even months to years after occlusion with good outcomes. Long-term patency of occluded stents that were recanalized is poor compared with patency of the initially placed stent.