Iliofemoral stenting for venous occlusive disease

Femoral vein stenting versus endovenectomy as adjuncts to iliofemoral venous stenting in extensive chronic iliofemoral venous obstruction

PURPOSE

To compare femoral endovenectomy with the creation of an arteriovenous fistula (FE + AVF), versus iliofemoral endovenous stenting with the concurrent extended femoral vein (FV-S) stenting in patients with chronic iliofemoral venous obstruction (IFVO).

MATERIALS AND METHODS

In a randomized prospective single-center study, 48 received (FV-S), while the other 54 had (FE + AVF).

RESULTS

There were no statistically significant differences in the primary outcomes between the two groups (FV-S) and (FE + AVF) (59% vs 56.8%, 75% vs 79.1%, respectively). At a median of 13 months after the treatment. However, the FV-S group's patients experienced fewer postoperative problems (p = .012), shorter procedures (p = .001), and shorter stays in the hospital (p = .025).

CONCLUSION

There is no difference between the efficacy and symptomatic resolution of the FV-S group and the FE + AVF group at the same time, FV-S has lower postoperative complications and a shorter procedure duration and hospital stay.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

In vivo evaluation of safety and performance of a tapered nitinol venous stent with inclined proximal end in an ovine iliac venous model

A tapered stent with inclined proximal end is designed for fitting the iliac anatomically. The aim of the present study was to evaluate the safety and performance of the new stent in ovine left iliac veins. The experiment was performed in 30 adult sheep, and one nitinol-based VENA-BT® iliac venous stent (KYD stent) was implanted into each animal's left common iliac vein. Follow-up in all sheep consisted of angiographic, macroscopic, and microscopic examinations at Day 0 (< 24 h), Day 30, Day 90, Day 180 and Day 360 post-stenting (six animals per each time-point). 30 healthy ~ 50 kg sheep were included in this study and randomly divided into five groups according to the follow-up timepoint. All stents were implanted successfully into the left ovine common iliac vein. No significant migration occurred at follow-up. There is no statistically significant difference between the groups (p > 0.05), indicating no serious lumen loss occurred during the follow-up period. Common iliac venous pressure was further measured and the results further indicated the lumen patency at follow-up. Histological examinations indicated that no vessel injury and wall rupture, stent damage, and luminal thrombus occurred. There was moderate inflammatory cell infiltration around the stent in Day-0 and Day-30 groups with the average inflammation score of 2.278 and 2.167, respectively. The inflammatory reaction was significantly reduced in Day-90, Day-180 and Day-360 groups and the average inflammation scores were 0.9444 (p < 0.001, Day-90 vs Day-0), 1.167 (p < 0.001, Day-180 vs Day-0) and 0.667 (p < 0.001, Day-90 vs Day-0), respectively. The microscopic examinations found that the stents were well covered by endothelial cells in all follow-up time points. The results suggested that the KYD stent is feasible and safe in animal model. Future clinical studies may be required to further evaluate its safety and efficacy.

Pathologic characteristics of human venous in-stent stenosis and stent occlusion

OBJECTIVE

The objective of this study was to determine the pathologic features of venous in-stent stenosis over time occurring in bare metal stents.

METHODS

Endovascular biopsy samples were obtained prospectively from venous bare metal stents implanted in 2009 through 2018. All samples were formalin-fixed, paraffin-embedded and stained with hematoxylin and eosin. Samples were examined by a cardiovascular pathologist to estimate the amount of its constituent components, which included fresh thrombus, organizing thrombus, old thrombus, or diffuse intimal thickening (DIT), and pathologic features including calcification, neovascularization, and hemosiderin deposition. This pathologic characterization was correlated with time following stent implantation to discern time-dependence of pathologic evolution of in-stent stenosis using both descriptive statistics and binary logistic regression.

RESULTS

A total of 254 post-stent venograms with biopsies of in-stent contents from 148 unique patients were studied. Fresh thrombus and organizing thrombus were both present across all studied time intervals. Old thrombus was seen beginning at approximately 2 weeks and DIT at approximately 4 weeks. Calcification was a rare finding encountered at later time intervals. The prevalence of each component varied with time: the probability of encountering fresh thrombus (P = .010) and organizing thrombus (P = .008) decreased over time. By contrast, the probability of finding DIT (P = .002) and calcifications (P < .001) increased over time. The presence of old thrombus, neovascularization, or hemosiderin did not demonstrate time dependence. Diffuse intimal thickening was frequently seen along with organizing thrombus as well as independently, and in many instances, these two features were directly merged.

CONCLUSIONS

The evolution of human venous in-stent restenosis appears to follow a time-dependent course, suggesting a possible progressive evolution from fresh and organizing thrombus to DIT. Contrasted with the literature on arterial in-stent restenosis, vein in-stent restenosis may have an increased thrombus prevalence (both organizing and old thrombus). DIT is a primary feature of late in-stent stenosis and may explain in part why many of these lesions may not respond to thrombolytic or anticoagulant treatment alone.

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.

Stent Migration Following Endovascular Intervention in May-Thurner Syndrome

Developments in endovascular therapies have made stenting a common practice in the treatment of peripheral vascular diseases, including venous disorders such as May-Thurner syndrome. The placement of a stent in the venous system carries the risk of stent migration which although small occurs with a 3% incidence rate and can be life-threatening given the risk of pulmonary infarction, tricuspid regurgitation, and right-sided heart failure. Herein we report a case of stent embolization from the common iliac vein into the right side of the heart causing tricuspid regurgitation. After the failure of percutaneous approach to retrieve the stent, it was successfully removed using a minimally invasive right thoracotomy approach along with repair of the tricuspid valve.

A systematic review of current trends in pharmacologic management after stent placement in nonthrombotic iliac vein lesions

Objective

Stenting of the iliac vein is increasingly recognized as a treatment for chronic venous insufficiency (CVI). However, the pharmacologic management after stent placement is unclear. This review was conducted to illustrate recent trends in anticoagulation and antiplatelet regimens following stent placement for nonthrombotic iliac vein lesions (NIVL).

Methods

The MEDLINE database was searched using the term “iliac vein stent.” Retrieval of articles was limited to studies conducted on humans and published in English between 2010 and 2020. Studies were included that described iliac vein stent placement. Studies were excluded that contained fewer than 25 patients, performed procedures other than stent placement, did not specify the postoperative anticoagulant used, or treated lesions of thrombotic origin.

Results

12 articles were included in this review, yielding a total of 2782 patients with a male-to-female ratio of 0.77. The predominant CEAP classification encountered was C3. The most common stent used in the included studies was the Wallstent (9/12), and the most common pharmacologic regimen was 3 months of clopidogrel (6/12). Warfarin, aspirin, cilostazol, and rivaroxaban were among other agents used. Primary stent patency ranged from 63.1 to 98.3%. There was no apparent correlation between pharmacologic agent used and stent patency or subjective patient outcomes.

Conclusion

Multiple different approaches are being taken to pharmacologically manage patients following stent placement for NIVL. There is no consensus on which agent is best, nor is there a formal algorithmic approach for making this decision. Additionally, the findings in this study call into question whether anticoagulation following stenting for NIVL is necessary at all, given the similar outcomes among the different agents utilized. This review underscores the potential value of undertaking a multi-institutional prospective study to determine what is the best pharmacologic therapy following venous stent placement for NIVL.

Three-Year Results from the Venovo Venous Stent Study for the Treatment of Iliac and Femoral Vein Obstruction

Purpose

To assess safety and patency of the Venovo venous stent for the treatment of iliofemoral vein obstruction.

Materials and Methods

Twenty-two international centers enrolled 170 patients in the VERNACULAR study (93 post-thrombotic syndrome; 77 non-thrombotic iliac vein lesions). Primary outcome measures were major adverse events at 30 days and 12-month primary patency (freedom from target vessel revascularization, thrombotic occlusion, or stenosis > 50%). Secondary outcomes included the Venous Clinical Severity Score Pain Assessment and Chronic Venous Quality-of-Life Questionnaire assessments (hypothesis tested). Secondary observations included primary patency, target vessel and lesion revascularization (TVR/TLR), and assessment of stent integrity through 36 months.

Results

Freedom from major adverse events through 30 days was 93.5%, statistically higher than a pre-specified performance goal of 89% (p = 0.032) while primary patency at 12 months was 88.6%, also statistically higher than a performance goal of 74% (p < 0.0001). Mean quality-of-life measures were statistically improved compared to baseline values at 12 months (p < 0.0001). Primary patency at 36 months was 84% (Kaplan–Meier analysis) while freedom from TVR/TLR was 88.1%. There was no stent embolization/migration, and no core laboratory assessed stent fractures reported through 36 months. Six deaths were reported; none adjudicated as device or procedure related.

Conclusion

The Venovo venous stent was successfully deployed in obstructive iliofemoral vein lesions and met the pre-specified primary outcome measures through 12 months. At 3 years, primary patency was 84%, reintervention rates were low, standardized quality-of-life and pain measures improved from baseline, and there was no stent migration or fractures.

Level of Evidence

Level 2—prospective, multicenter, controlled clinical study without a concurrent control or randomization. Pre-specified endpoints were hypothesis-tested to performance goals derived from peer-reviewed clinical literature.

Registration clinicaltrials.gov

Unique Identifier NCT02655887.

Treatment of May-Thurner's Syndrome and Associated Complications: A Multicenter Experience

OBJECTIVE

To assess the treatment options and associated complications in patients with May-Thurner's syndrome (MTS).

METHODS

We retrospectively reviewed the charts of patients diagnosed with MTS. Thorough review was completed and data relevant to methods of diagnosis, treatment, complications, hospital readmission, and mortality were extracted from patient charts. The patients were followed for two years after diagnosis.

RESULTS

Of the 47 patients identified as having "MTS", 32 (70%) were diagnosed formally with either magnetic resonance venography, computed tomography venography, or ultrasound. Two patients were excluded for insufficient availability of follow-up records. Mean age of the population included (N = 30) was 50.24 ±15.33 years and 83% (N = 25) had female gender. The majority (40%) of patients were treated with anticoagulation, thrombolysis, and stent placement, and 13.3% received a combination of anticoagulation, antiplatelet agent, thrombolysis, and stent placement. Overall, we found 28 patients (93%) who underwent endovascular stenting. However, 39.3% (11/28) had stent-related complications that included stent thrombosis, stenosis, and migration. One patient underwent open heart surgery for stent retrieval. Duration of anticoagulation therapy ranged from 6 months to lifelong. Two patients (6.7%) suffered major bleeds requiring transfusion. Fourteen patients (46.6%) developed post-thrombotic syndrome. Seven (23.3%) patients required MTS-related readmission within 30 days. No mortality was noted at two-year follow-up.

CONCLUSION

Although our study only included 30 patients, it was evident to us that there is no consensus in the management of MTS. Furthermore, endovascular stenting, which has a major role in the management of MTS, has complication rates that hover close to 40%. Further research is needed to help develop a standardized evidence-based approach in the management of MTS that ensures a decreased risk of immediate and long-term complications.

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.

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.

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.

Postinterventional antithrombotic management after venous stenting of the iliofemoral tract in acute and chronic thrombosis: A systematic review

Venous stenting has become a common treatment option for central deep venous outflow obstructions and postthrombotic syndrome. Following successful recanalization and stenting, stent patency is endangered by in-stent thrombosis and recurrent venous thromboembolism. Antithrombotic therapy might reduce patency loss. This systematic review summarizes the literature on antithrombotic therapy following (post)thrombotic venous stenting. A systematic PubMed, MEDLINE, EMBASE, and Cochrane search was performed for studies addressing antithrombotic therapy prescribed following venous stenting of the iliofemoral tract indicated by acute or chronic thrombotic pathology. A total of 277 articles was identified of which 64 (56 original studies) were selected. Overall, a mean primary patency rate of 82.3% was seen 1 year after the intervention, which decreased to 73.3% after 2 years. In the majority (43 of 56 studies, 77%), treatment was based on use of vitamin K antagonists, either with (18%) or without (59%) use of antiplatelet drugs. Only two studies (4%) directly assessed the effect of antithrombotic therapy on treatment outcomes. The impact of postinterventional antithrombotic therapy on stent patency remains unknown because of limited and insufficient data available in current literature. Further clinical research should more clearly address the role of antithrombotic therapy for preservation of long-term patency following venous stenting.

Effect of thrombophilia on clinical outcomes of chronic post-thrombotic patients after iliofemoral stenting with nitinol venous stents

OBJECTIVE

Thrombophilia is a prothrombotic condition that increases the risk of venous thromboembolism. It is unclear whether the presence of thrombophilia alters the clinical outcomes after deep venous stenting. The aim of the present study was to examine the relationship between thrombophilia and outcomes after stenting for post-thrombotic syndrome.

METHODS

Consecutive patients (2012-2017) receiving a nitinol venous stent for chronic post-thrombotic venous occlusive disease with a minimum of 18 months of follow-up in one center using the same anticoagulation protocol were included. The clinical history and thrombophilia testing results were reviewed. The outcomes were stent patency, which was assessed using duplex ultrasonography at 24 hours, 2 and 6 weeks, 3 months, 6 months, and annually thereafter; and reinterventions, which were performed when the stent diameter was <50% or occluded.

RESULTS

Of the 136 patients who had undergone intervention, 55 (40%) had had a provoked deep vein thrombosis (DVT) and 81 (60%) had had an unprovoked DVT and had therefore undergone thrombophilia testing. Of the 81 patients, 38 (47%) had had either inherited (n = 19; 50%) or acquired (n = 19; 50%) thrombophilia. Of the 136 patients who had undergone stenting, 68 had required reintervention (50%) during follow-up to maintain stent patency. Of the 55 patients with a provoked DVT, 29 (53%) had required reintervention. Of the 81 patients with an unprovoked DVT, 39 (48%) had required reintervention (P = .420). Of the 38 patients with unprovoked DVT and thrombophilia, 17 (45%) had required reintervention. Of the 43 patients with unprovoked DVT and no thrombophilia, 22 (51%) had required reintervention (P = .766). The cumulative patency rate was 80% for patients with provoked DVT and 88% for those with unprovoked DVT (P = .193). The presence of thrombophilia was not associated with patency loss (92% cumulative patency for patients with thrombophilia and 84% for patients without thrombophilia; P = .307).

CONCLUSIONS

Using our anticoagulation protocol, patients with and without thrombophilia had similar clinical outcomes after deep venous stenting and should not be excluded from iliofemoral venous stenting. We found no significant differences in outcomes in conjunction with appropriate postoperative anticoagulation therapy.

Intravascular ultrasound in the diagnosis and treatment of central venous diseases

Intravascular ultrasound (IVUS) has been used extensively in coronary applications. Its use in venous applications has increased as endovascular therapy has increasingly become the mainstay therapy for central venous diseases. IVUS has been used for both diagnostic and therapeutic purposes in managing venous stenotic disease, venous occlusive disease, and IVC filter placement and removal. IVUS has been proven to be effective in providing detailed measurement of the venous anatomy, which aid in determining the appropriate size and the approach for venous stent placement. In IVC filter placement, IVUS can provide detailed measurement and guide IVC filter placement in emergent and critical care settings. It also has certain utility in filter removal. At any rate, to date there are only a few studies examining its impact on patient outcomes. Prospective randomized controlled trials are warranted in the future.

PERFORMANCE TEST AND EXPERIMENTAL STUDY OF SPECIAL STENT FOR TREATMENT OF ILIAC VEIN STENOSIS

Objective: Animal experiments and clinical trials were carried out to evaluate the efficiency of a new stent for the treatment of iliac vein stenosis. Methods: The new iliac vein stent and the control stent were implanted, respectively, into the 12 experimental pigs. Digital Subtraction Angiography was done separately at the same day, 14th, 30th, 60th and 90th day after stent implantation to observe the stent deployment. One patient was implanted with a new iliac vein stent. Digital subtraction angiography (DSA) was done after the operation to calculate the lumen loss value and lumen loss rate of the stent and evaluate the performance of the new iliac vein stent at 12 months of follow-up. Results: The mechanical experiment and finite element analysis of the stent proved that the radial support force of the new stent is significantly better than that of the control stent. In animal experimental verification, both groups of stent were released satisfactorily during implantation. No obvious stent displacement was found at each time point. The patency rate of stents was 100%. Except for a small amount of old thrombosis in the stent in the control group, no other stents were found in that condition. The diameter of the stent lumen was retracted in different degrees in both groups after the operation, but no significant statistical difference was found in the comparison of the stent lumen loss rate at each relative inspection day. Conclusion: The new nickel-titanium alloy iliac vein stent has excellent radial support performance, which may be an ideal iliac vein stent.

Association between deep vein thrombosis and stent patency in symptomatic iliac vein compression syndrome: Systematic review and meta-analysis

BACKGROUND

The study intended to evaluate stent primary patency rates for patients with iliac vein obstruction related with iliac vein compression syndrome according to clinic presentation.

METHODS

A systematic review and meta-analysis was conducted of studies that compared: unexposed patients with nonthrombotic iliac vein lesion (NIVL, group 1) vs exposed patients with iliac acute deep vein thrombosis (DVT, group 2); and NIVL (group 1) vs exposed patients with iliac vein obstruction and post-thrombotic syndrome (PTS, group 3). The following databases were searched: EMBASE, PubMed, Web of Science, Scopus, SciELO, and LILACS. Two reviewers independently selected the potential studies and extracted data. The pooled odds ratio (OR) and 95% confidence interval (95% CI) are shown for each outcome.

RESULTS

Five studies with a total of 1050 participants and 1169 lower limbs were included. Five hundred eighty-eight lower limbs presented NIVL (50.3%), 91 lower limbs presented acute DVT (7.7%), and 490 lower limbs presented PTS (42%). The endovascular technical success rate of stenting did not differ in any of the groups: 99.6% in NIVL, 94.5% in acute DVT, and 96.5% in PTS (P = .0632). The primary stent patency rates in the 6-month follow-up were 98.3% in NIVL vs 90.9% in PTS, with a statistical difference showing reduced stent patency rates in PTS (OR, 0.17; 95% CI, 0.06-0.48; P = .0008; I² = 0%), and 100% in the NIVL group vs 91.6% in acute DVT, with no statistical difference (OR, 0.30; 95% CI, 0.06-2.32; P = .30; I² = 0%). The primary stent patency rates in the 12-month follow-up were 94.6% in NIVL vs 84.1% in PTS, with a statistical difference showing decreases stent patency rates in the PTS group (OR, 0.29; 95% CI, 0.14-0.63; P = .0008; I² = 0%), and 91.1% in NIVL vs 90.9% in acute DVT, with no statistical difference (OR, 1.03; 95% CI, 0.26-4.07; P = .96; I² = 0%).

CONCLUSIONS

There is no statistical difference for the stent primary patency rates when the treatment is conducted in NIVL as compared with acute DVT lower limbs (at 6 and 12 months); therefore, other criteria must be considered for the indication of this treatment in NIVL patients. However, because there were better results of stent primary patency rates for NIVL vs PTS patients, this finding favors the treatment of acute DVT instead of PTS in lower limbs, once PTS renders smaller stent patency rates at 6 and 12 months.

Recurrent unilateral cellulitis: is it May-Thurner syndrome (MTS)?

May-Thurner syndrome (MTS) is a differential diagnosis to be considered in a patient with recurrent unilateral cellulitis. A 73-year-old woman initially presented with recurrent unilateral cellulitis of her left lower limb. A CT scan demonstrated a stenosed left common iliac vein (CIV) narrowed at its origin by the proximal right common iliac artery consistent with MTS. The chronicity of the condition at the time of diagnosis made attempts to recanalise the CIV unsuccessful. A diagnosis of MTS should be considered in a patient with chronic unilateral limb oedema/cellulitis as it represents a potentially treatable condition if detected early.

May-Thurner syndrome presenting as pelvic congestion syndrome and vulvar varicosities in a nonpregnant adolescent

May-Thurner syndrome (MTS) refers to compression of the left common iliac vein (CIV) by the common iliac artery. Although this is typically manifested as acute left lower extremity deep venous thrombosis, MTS is a rare cause of pelvic congestion syndrome. A 17-year-old girl presented with a 5-year history of worsening painful vulvar and labial varicosities. Venography demonstrated pelvic collateralization and left CIV stenosis consistent with MTS. The left CIV was stented with complete radiographic resolution. At 1-year follow-up, the patient is asymptomatic with a widely patent stent. This case highlights the role of endovascular therapy for patients presenting with MTS causing pelvic congestion syndrome.

Acute bilateral pulmonary embolism in a 21-year-old: is May-Thurner syndrome in our differential?

May-Thurner syndrome (MTS) is a clinical condition where the left common iliac vein gets compressed by the overlying right common iliac artery anterior to the fifth lumbar vertebra and the sacral promontory. It results in vessel wall injury and predisposition to thrombosis. We present a case of a 21-year-old African-American man with no significant past medical history who came to the emergency department with left lower limb swelling associated with shortness of breath, and was eventually diagnosed to have extensive left lower extremity deep vein thrombosis (DVT) along with acute bilateral extensive pulmonary embolism (PE) as a consequence to MTS. MTS should be considered in the differential when young patients present with unprovoked or recurrent left-sided DVT. Diagnosis of this anatomical variant is critical as it may need long-term anticoagulation and consideration of pharmaco-mechanical intervention such as mechanical thrombectomy and venoplasty with or without stenting.

Early Venous Stent Failure Predicted by Platelet Count and Neutrophil/Lymphocyte Ratio

BACKGROUND

Inflammation and platelet activation have been shown to be involved in acute thromobogenicity following venous occlusive conditions. The aim of this study was to identify the association of baseline platelet count and neutrophil/lymphocyte ratio (NLR) with venous stent failure. Methods and Results: Patients who underwent technically successful iliocaval venous stent placement with available baseline complete blood count and follow-up stent patency data were selected (n=50). Stent failure was defined as >50% stenosis or occlusion at follow-up angiography, contrast-enhanced CT, MRI or duplex US. Median patient age was 49.5 years (range, 13-76 years), and 62% were female. Median follow-up time was 10.2 months (range, 0.1-76.4 months). Stent failure occurred in 13 patients (26%) after a median of 1.2 months (range, 1 day-76.4 months). On multivariable-adjusted Cox modeling, baseline platelets (HR, 2.28; P=0.004) and WBC count (HR, 2.03; P=0.013) were significantly associated with stent failure on follow-up; neutrophils (HR, 16.10; P=0.050); and NLR (HR, 12.19; P=0.050) had borderline significance. Compared with patients without stent failure, those with early, but not late, stent failure had higher baseline platelets (P=0.031) and neutrophils (P=0.025), and NLR (P=0.026).

CONCLUSIONS

Baseline platelet count and NLR are associated with early but not late failure of iliocaval venous stents. This suggests different pathophysiologic mechanisms and a role for both platelet activation and inflammatory mechanisms in early rather than late stent thrombosis. Future research is needed to better explain this novel finding.

Left Common Femoral to Right Common Iliac Venous Bypass Through a Retroperitoneal Exposure

The endovascular recanalization of the iliocaval system has replaced venous surgical reconstructions as the primary treatment option in severe post-thrombotic syndrome (PTS). We herein present a 51-year-old female with previous deep venous thrombosis, complicated with PTS with a large and complex circumferential calf ulcer measuring 25 cm of length in the left lower extremity. Venogram revealed a complete and extensive occlusion in the left iliofemoral system. A surgical bypass from the left common femoral vein to the right common iliac vein was performed. Patient recovered well and after 12 months postoperation her large wound is healing favorably with a clean and well granulated bed. Iliofemoral venous bypass is a feasible treatment for non-healing ulcer of lower extremity.

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.

A novel endovenous scaffold for the treatment of chronic venous obstruction in a porcine model: Histological and ultrastructural assessment

OBJECTIVE

To investigate the biological effects of a novel endovenous scaffold in a porcine model.

METHODS

Petalo is a compliant venous scaffold implanted into the internal jugular veins of 12 healthy pigs. The pigs were sacrificed at one, two, three, and six months, respectively. Microscopic investigations were performed at two blinded laboratories.

RESULTS

Neo-intima formation progressively covering up the stent metallic bars was observed. The inflammatory response of the venous wall showed a peak after three months by the implant, followed by marked reduction after six months. The device induced a significant ( p < 0.01) increase of the thickness respect to the control regions, but was comparable in sections obtained after three and six months.

CONCLUSIONS

The implant of Petalo compliant venous scaffold in the venous wall of this porcine model is characterized by neointima formation and by an inflammatory reaction which tends to decrease after six months. Our data point against the induction of smooth muscle cells proliferation and migration as confirmed by electronic transmission microscopy analyses.

Preliminary report of a new type of braided vein stent in animals

Background

Iliofemoral vein stenosis or occlusion is a common cause of severe chronic venous insufficiency. Endovascular venous stenting has become a preferred treatment because it is minimally invasive and has a high safety profile. Despite the wide application of the wallstent, it is not specifically designed for veins. There are currently few studies on braided stents in the field of veins. We designed a novel braided vein stent, which has higher radial resistive force and more optimized looped ends structure compared with the wallstent. The purpose of this study was to evaluate the safety and performance of the stent in animals, providing a reference for further clinical trials.

Methods

The Wallstent is used as a control group. The novel stent and the Wallstent were implanted in the iliac vein of sheep. After 30 days and 90 days, vascular injury, thrombus, neointima coverage, and luminal stenosis were evaluated through venous angiography, endoscopic observation of stent specimen and histopathology. Imaging, histology, and integration data were analyzed by t-test for comparisons between the groups.

Results

Two groups of stents were successfully implanted. Follow-up observation showed that there was no thrombosis or obstruction >50% occurred in any group and no significant differences in patency, vascular injury, or intimal hyperplasia compared with the Wallstent.

Conclusion

The novel stent significantly increases the radial resistive force and does not increase vascular injury, thrombus and stent stenosis during 30-day and 90-day follow-up. The next step is to further validate the effectiveness of the stent through long-term animal observation and human clinical trials.

Endovascular and Open Surgery for Deep Vein Thrombosis

The surgical treatment of deep venous thrombosis (DVT) has significantly evolved and is focused on different strategies of early thrombus removal in the acute phase and deep venous recanalization or bypass in the chronic phase. Along with the use of anticoagulation agents, endovascular techniques based on catheter-directed thrombolysis and pharmacomechanical thrombectomy have been increasingly used in patients with acute extensive DVT. Patient selection is crucial to provide optimal outcomes and minimize complications.

Mid-and long-term efficacy of endovascular-based procedures for Cockett syndrome

To investigate the mid- and long-term results of endovascular-based procedures for Cockett syndrome. The clinical data of 412 patients with Cockett syndrome treated between January 2003 and September 2017 were retrospectively analyzed. In these patients, 231 cases were acute left iliac femoral vein thrombosis (group A), and 181 cases were chronic venous insufficiency (group B), and different endovascular procedures and/or hybrid procedures were performed. In group A, the technique success rate was 100% (231/231); the left iliac vein in 5 patients showed no stenosis or occlusion, and the incidence of pathological changes in the left iliac vein was 97.8% (226/231); a total of 182 stents were implanted. In group B, the technique success rate was 99.4% (180/181); the average pressure difference between the proximal and distal portion of the pathological left iliac veins decreased from preoperative (18 ± 4.45) cmH2O to postoperative (4 ± 3.02) cmH2O (P < 0.01); 89 patients, complicated with valvular incompetence in the left superficial femoral vein, underwent a second-stage femoral valve repair. Follow-up ranged from 3 months to 8 years, with an average of 35.6 months, and intrastent thrombosis occurred in 15 cases of group A and in 2 cases of group B. Endovascular-based procedures offer favorable mid- and long-term results in treatment of Cockett syndrome, which in combination with Fogarty catheter thrombectomy or catheter-directed thrombolysis is a beneficial complementary treatment for patients with acute iliac femoral vein thrombosis.

The evidence supporting treatment of reflux and obstruction in chronic venous disease

On July 20, 2016, a Medicare Evidence Development and Coverage Advisory Committee panel convened to assess the evidence supporting treatment of chronic venous disease. Several societies addressed the questions posed to the panel. A multidisciplinary coalition, representing nine societies of venous specialists, reviewed the literature and presented a consensus opinion regarding the panel questions. The purpose of this paper is to present our coalition's consensus review of the literature and recommendations for chronic venous disease.

Endovascular Treatment for Iliofemoral Vein Thrombosis with Composite Stents

BACKGROUND

To evaluate the applicability of endovascular treatment for iliofemoral vein thrombosis with composite stents.

METHODS

Between September 2013 and August 2016, 29 consecutive patients underwent endovascular therapy with composite stents for iliofemoral vein thrombosis and were followed up at our institution. All the patients with acute or chronic iliofemoral vein thrombosis enrolled in this study were evaluated by color Doppler ultrasonography and diagnosed by venography. Treatment measures and related complications were recorded, and cumulative stent patency was assessed with Kaplan-Meier curves.

RESULTS

Patients with acute iliofemoral vein thrombosis (n = 7) were successfully treated with catheter-directed thrombolysis treatment, balloon angioplasty, and stents, whereas patients (n =  = 22) with chronic deep vein thrombosis were treated successfully by balloon angioplasty and stent only. Among all patients, 2 stents were inserted in 25 patients, whereas 3 stents were deployed in 4 patients. Endovascular treatment for iliofemoral vein thrombosis with laser-cut stents combined with Wallstents showed primary patency of treated limbs at 6, 12, and 24 months was 96.6%, 93.1% and 93.1%, respectively. Mean duration of follow-up was 23 months, and there was no occurrence of contralateral vein thrombosis during follow-up by ultrasound.

CONCLUSIONS

Iliofemoral vein thrombosis was successfully recanalized by endovascular therapy with composite stents, and there was no occurrence of contralateral vein thrombosis by ultrasound during follow-up.

Novel Compliant Scaffold with Specific Design for Venous System: Results of a Porcine Model Study

Background

Stenting has become the first-line treatment of obstructive venous disease because of poor results of balloon angioplasty. This preclinical study aimed to investigate the safety and efficacy profile of a novel compliant venous scaffold (CVS) denominated Petalo CVS, specifically designed for venous diseases.

Materials and Methods

Twelve healthy pigs weighing 90 kg were used to test Petalo CVS. The devices were implanted into the internal jugular veins (IJVs) using a femoral vein percutaneous approach. The safety profile including the success rate of device releasing, anchoring, and positioning was evaluated immediately. Fracture, migration, primary patency, and endothelial response were assessed at 1, 2, 3, and 6 months after the study procedure.

Results

A total of 32 devices were successfully released in both IJVs. No procedure- or device-related complications were reported, and all pigs successfully completed the different scheduled follow-up periods. The primary patency rate was 100%, and no fracture or migration of the device into the brachiocephalic trunk was reported. Histological examination revealed only minimal lesions with minimal or absent inflammatory reaction surrounding the incorporated metallic rods.

Conclusions

This porcine model study showed a promising safety and efficacy profile of Petalo CVS, a novel endovenous device based on specific concepts.

Results of catheter-directed thrombolysis for acute ilio-femoral deep venous thrombosis - A retrospective cohort study

Background

Catheter-directed thrombolysis may prevent post-thrombotic syndrome in patients with ilio-femoral deep venous thrombosis. We performed a retrospective review of prospectively collected follow-up data to evaluate the results of catheter-directed thrombolysis at our institution.

Method

Patients admitted for venous thrombolysis were included in the study and their files screened for information regarding results and technical aspects of treatment and patient status on follow-up. A catheter was inserted under imaging guidance into the thrombosed vein. Through the catheter tissue plasminogen activator was administered. Daily catheter-based venographies were performed to monitor progression in thrombus resolution. After thrombolysis flow-limiting stenosis was stented. Patients started wearing compression stockings and were started on oral anticoagulant therapy. Follow-up visits with ultrasound, magnetic resonance venography and clinical assessment were scheduled at six weeks and three, six, 12 and 24 months.

Results

A total of 48 patients underwent catheter-directed thrombolysis, including 36 female patients. Median age was 28 years. Complete lysis of the thrombus was achieved in 43 cases and partial lysis in two cases and 26 stents were placed. No deaths or life-threatening bleeding events occurred. Thirty-two of the patients who achieved full lysis and were followed up remained patent at follow-up. At 12 months seven patients had symptoms of post-thrombotic syndrome.

Conclusion

Catheter-directed thrombolysis represents a safe and effective alternative to systemic anticoagulative treatment of deep venous thrombosis with rapid resolution of the thrombus and few complications. Long-term patency shows good validity and this study suggests that catheter-directed thrombolysis is effective in preventing post-thrombotic syndrome.

Iliac Vein Compression Syndrome in an Asymptomatic Patient Population: A Prospective Study

BACKGROUND

Iliac vein compression syndrome (IVCS) is an important cause of deep vein thrombosis, but the incidence of IVCS is still unclear. The purpose of this prospective study was to determine the incidence of IVCS in an asymptomatic patient population and to evaluate the risk factors in patients with and without IVCS.

METHODS

From October 2011 to November 2012, a total of 500 patients (228 women and 272 men; mean age of 55.4 ± 14.7 years) with no vascular-related symptoms were enrolled in this study. Computed tomography was performed to evaluate all patients. The degree of venous compression was calculated as the diameter of the common iliac vein at the site of maximal compression divided by the mean diameter of the uncompressed proximal and caudal left common iliac vein (LCIV). We compared the stenosis rate of the common iliac vein in women and men according to age and followed up patients to evaluate outcomes.

RESULTS

The mean compression degree of the LCIV was 16% (4%, 36%); 37.8% of patients had a compression degree ≥25% and 9.8% had a compression degree ≥50%. There was a significant difference between men and women in the LCIV compression degree (9% [3%, 30%] vs. 24% [8%, 42%]; U = 4.66, P< 0.01). In addition, the LCIV compression degree among younger women (≤40 years) was significantly different compared with that in older women (>40 years) (42% [31%, 50%] vs. 19% [5%, 39%]; U = 5.14, P< 0.001). Follow-up was completed in 367 patients with a mean follow-up of 39.5 months (range, 6-56 months). The incidence of IVCS in the follow-up period was 1.6%. Stenosis rate and the diameter of the site of maximal compression correlated with the incidence of IVCS. Multivariable Cox regression analysis showed that the stenosis rate was an independent risk factor of IVCS (Wald χ2 = 8.84, hazard ratio = 1.13, P< 0.001).

CONCLUSIONS

The incidence of IVCS was low and correlated with the stenosis rate of iliac vein. Preventative therapy may be warranted for common iliac vein compression in patients at an increased risk of venous thromboembolism, especially patients with a higher iliac vein compression degree.

Investigation of adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents in the iliac vein: insights into developing a better iliac vein stent

We analyzed the adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents for the treatment of iliac venous thromboembolism and investigated their relationships with the anatomical features of the iliac vein, to gain insights into the development of a better iliac vein stent. Reports of adverse events following the use of stents in the iliac vein were retrieved from the Manufacturer and User Facility Device Experience (MAUDE) database that contain suspected device-associated complications reported to the Food and Drug Administration. Data from 2006 to 2016 were investigated. The literature analysis was also conducted using PubMed, Cochrane Library, EMBASE, and Web of Science focusing on English articles published up to 4 October 2016. The analysis of 88 adverse events from the MAUDE database and 182 articles from the literature revealed that a higher number of adverse events had been reported following the use of arterial stents in the iliac vein compared to CE-marked iliac vein stents. While stent migration and shortening were reported only for the arterial stents, stent fracture and compression occurred regardless of the stent type, even though a vein does not pulsate. A study of the anatomical features of the iliac vein implies that bending, compression, and kink loads are applied to the iliac vein stents in vivo. For designing, developing, and pre-clinical testing of stents intended for use in the iliac vein, the above mechanical load environments induced by the anatomical features should be considered.

Detecting stent geometry changes after venous recanalization using duplex ultrasound

Background

Patients with post-thrombotic syndrome due to chronic venous obstruction and resistant to conservative management can benefit from endovenous revascularization. The current study investigated the usefulness of duplex ultrasound in monitoring the stent changes over the time.

Method

All duplex ultrasound images of treated patients were reviewed retrospectively. The stent diameter and area during the follow-up visits have been analyzed.

Result

A total of 210 stents were placed in 137 limbs. Duplex ultrasound findings showed a decrease in area of stent in all patients (mean: 0.69 cm2). Reduction of stent area over the time was a predictor of stent patency (odds ratio: 0.910; confidence interval: 0.832–0.997).

Conclusion

Duplex ultrasound has sufficient accuracy in detection of stent changes and its patency. There is a discrepancy between diameter of the stent lumen in vitro and after deployment in all patients. Stent occlusion is related to reduction of stent lumen over the time rather than the percent of the stenosis.

Treatment of Femoral Vein Obstruction Concomitant with Iliofemoral Stenting in Patients with Severe Post-thrombotic Syndrome

BACKGROUND

The aim was to assess the clinical and anatomical outcomes of iliofemoral stenting, with concomitant femoral stenting or balloon angioplasty alone, in patients with severe post-thrombotic syndrome (PTS) and compromised inflow.

METHODS

A database of patients with severe PTS who successfully underwent endovascular iliofemoral stenting was reviewed retrospectively. Patients with impaired inflow with chronic post-thrombotic obstructive lesions in the femoral vein (FV), but patent profunda vein, were selected and divided into two groups: the FV stenting (FV-S) group and the FV angioplasty (FV-A) group. Patients in the FV-S group were treated with concomitant iliofemoral and FV stenting, and patients in the FV-A group were treated with iliofemoral stenting and balloon angioplasty alone of the obstructed femoral vein. The clinical and stent outcomes were recorded and compared in the two groups.

RESULTS

There were 45 patients in the FV-S group and 69 patients in the FV-A group. The groups were well matched for age, gender, and diseased limbs. The pre-procedural symptoms, CEAP classifications, VCSS scores, Villalta scores, and prevalence of active ulcers were also similar between the two groups. Immediate failure (<30 days post-procedure) in the femoral segment occurred more frequently in the FV-A group (70% in FV-A group vs. 24% in FV-S group, p < .001); however, all treated femoral vein segments had occluded at 12 months. There was no significant difference between the FV-S and FV-A groups in cumulative primary and secondary patency rates of the iliofemoral stent at 3 years (55% vs. 52%, p = .71, and 77% vs. 85%, p = .32, respectively). Complete pain relief, swelling relief, VCSS score, Villalta score, and freedom from ulcers at a median of 22 months (1-48 months) following the procedure were similar in the two groups.

CONCLUSIONS

Stent placement to treat post-thrombotic iliofemoral obstruction with concomitant obstructed femoral vein but patent profunda vein shows cumulative patency rates and clinical outcomes similar to previous reports. Adjunctive femoral stenting or angioplasty of the obstructed femoral vein does not appear to improve clinical or stent outcomes in patients with severe PTS.

Stent extension into a single inflow vessel is a valuable option after endophlebectomy

Background

Venous stenting with an endophlebectomy and arteriovenous fistula can be performed in patients with extensive post-thrombotic changes. However, these hybrid procedures can induce restenosis, sometimes requiring stent extension, into a single inflow vessel. This study investigates the effectiveness of stenting into a single inflow vessel.

Methods

All evaluated patients had temporary balloon occlusion of the arteriovenous fistula to evaluate venous flow into the stents. When stent inflow was deemed insufficient, AVF closure was postponed and additional stenting was performed. Patency rates and clinical outcomes were evaluated.

Results

Twenty-four (38%) of 64 patients had additional stenting. The primary, assisted primary and secondary patency were 60 %, 70% and 70% respectively. Villalta score reduced by 6.1 points (p < 0.001), and venous clinical severity score by 2.7 points (p = 0.034).

Conclusion

Stenting through the femoral confluence into a single inflow vessel is a feasible bailout option if primary hybrid intervention fails with relative high patency rates and clinical improvement.

Venous Compression Syndromes

Venous compression syndromes occur due to extrinsic compression causing complications of venous hypertension or venous thrombosis. This review focuses on 4 venous compression syndromes involving the left common iliac vein, subclavian vein, left renal vein, and popliteal vein. Clinical presentation, diagnostic methods, and management options are reviewed. When properly diagnosed and treated, long-term consequences can be avoided.

Sonography’s Role in the Diagnosis of May–Thurner Syndrome

May–Thurner syndrome (MTS), also known as Cockett syndrome or iliac vein compression syndrome, is a condition in which patients develop swelling, deep vein thrombosis (DVT), venous insufficiency, and other symptoms of the left lower extremity due to an anatomic variant in which the right common iliac artery overlies and compresses the left common iliac vein against the lumbar spine. Although it is an uncommonly diagnosed condition, it is estimated to compose up to half of cases of left lower extremity venous disease. Although having some degree of iliac vein compression is considered a normal anatomic variant in an asymptomatic patient, those who experience severe swelling, venous reflux, and DVT often have anatomically abnormal veins with a spur formation. With proper technique and proficiency, transabdominal sonography can be used as a valuable diagnostic tool in the discovery and to facilitate treatment of May–Thurner syndrome. Diagnostic ultrasound also can monitor the development of recurring DVT and identify symptoms of postthrombotic syndrome.

First Experience of Performing Hybrid Operations in Chronic Venous Obstructions of Iliofemoral Segments in Patients With Postthrombotic Syndrome

OBJECTIVE

To assess the first results of hybrid operations in chronic venous obstructions of iliofemoral segments in patients with postthrombotic syndrome (PTS).

METHODS

Hybrid operations (open endovenectomy from the common femoral vein with arteriovenous fistula creation and iliac vein stenting) were performed in 12 patients diagnosed with PTS. All of the patients were diagnosed with severe chronic venous insufficiency. The degree of manifestations of PTS was assessed by means of the Villalta score 7 months before and after the surgical intervention. Diagnostic methods of study included ultrasound duplex scanning, magnetic resonance and/or multispiral computed venography, and contrast venography.

RESULTS

Technical success of the procedure was 92%. The outcomes of hybrid operations after 7 months were followed up in 6 patients and in 4 patients in 3 months. Secondary patency rates of the stented iliac veins amounted to 100%. No recurrences of venous ulcers were observed. Median Villalta scores improved from 15 to 7 ( P = .012).

CONCLUSION

The first experience of hybrid operations for obstructive lesions of veins of the iliofemoral segments demonstrated their high efficacy and safety.

Endophlebectomy of the common femoral vein and arteriovenous fistula creation as adjuncts to venous stenting for post-thrombotic syndrome

Background

Good results have been reported for angioplasty and stenting of post-thrombotic lesions of the iliac and proximal femoral veins. If lesions at the origin of the superficial femoral and profunda veins are stented, the intraluminal synechiae can be pushed against the orifices of inflow vessels, potentially decreasing stent inflow. Surgical disobliteration of the common femoral vein (endophlebectomy) has been suggested to mitigate this problem. Because of a temporary increase in thrombogenicity, this procedure may be accompanied by arteriovenous fistula creation.

Methods

Data on consecutive patients treated by hybrid venous reconstruction, between December 2010 and May 2015, were analysed. Standard recording consisted of clinical scoring systems (including Villalta scale) and imaging. Patency was assessed with duplex ultrasonography.

Results

Seventy-six legs (70 patients) were included. Median follow-up was 379 (range 73–1508) days. Primary, assisted primary and secondary patency rates at 12 months were 51, 70 and 83 per cent respectively. Sixty per cent of loss of primary patency (24 of 40 legs) was related to common femoral vein stenosis, and the rest to rethrombosis. Other complications included wound infection (29 per cent) and lymphatic leak (39 per cent). The Villalta score had decreased by a median of 7 points at 1-year follow-up.

Conclusion

The combination of venous stenting, endophlebectomy and arteriovenous fistula creation for patients with extensive post-thrombotic vein damage and severe post-thrombotic syndrome is feasible.

Minimally invasive treatments for venous compression syndromes

The management of venous compression syndromes has historically been reliant on surgical treatment when conservative measures fail. There are, however, several settings in which endovascular therapy can play a significant role as an adjunct or even a replacement to more invasive surgical methods. We explore the role of minimally invasive treatment options for three of the most well-studied venous compression syndromes. The clinical aspects and pathophysiology of Paget-Schroetter syndrome (PSS), nutcracker syndrome, and May-Thurner syndrome are discussed in detail, with particular emphasis on the role that interventionalists can play in minimally invasive treatment.

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

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

Diagnosis and Treatment of Lower Extremity Deep Vein Thrombosis: Korean Practice Guidelines

Lower extremity deep vein thrombosis is a serious medical condition that can result in death or major disability due to pulmonary embolism or post-thrombotic syndrome. Appropriate diagnosis and treatment are required to improve symptoms and salvage the affected limb. Early thrombus clearance rapidly resolves symptoms related to venous obstruction, restores valve function and reduces the incidence of post-thrombotic syndrome. Recently, endovascular treatment has been established as a standard method for early thrombus removal. However, there are a variety of views regarding the indications and procedures among medical institutions and operators. Therefore, we intend to provide evidence-based guidelines for diagnosis and treatment of lower extremity deep vein thrombosis by multidisciplinary consensus. These guidelines are the result of a close collaboration between interventional radiologists and vascular surgeons. The goals of these guidelines are to improve treatment, to serve as a guide to the clinician, and consequently to contribute to public health care.