Endovascular treatment for symptomatic iliac vein compression syndrome: a prospective consecutive series of 48 patients

Risk factors for low back pain after iliac vein stenting for non-thrombotic iliac vein lesions

OBJECTIVE

Iliac vein stenting is an option being explored to treat chronic venous insufficiency. We have noted that our most common postoperative complication is low back pain after stent placement, which is occasionally quite severe. We wanted to investigate risk factors that are involved in this phenomenon and identify potentially modifiable factors.

METHODS

Patients who failed 3 months of conservative therapy had iliac vein interrogation performed. We limited the scope of this database to non-thrombotic iliac vein lesions treated in the office in which Wallstents were placed. Data were collected from September 2012 to August 2020 for 2308 consecutive outpatients who underwent 3747 procedures. Before August 2016, patients received pre-procedure oral valium (n = 2679) and thereafter, patients received intravenous (IV) sedation (n = 1068). A pain score, on a Likert scale ranging from 0 to 10, was assessed within 1 hour postoperatively. We analyzed the medications administered and correlated them with pain scores.

RESULTS

The average of all the pain scores was 0.86 (range, 0-10; standard deviation [SD], 2.00). Age had a slight inverse effect on pain scores (r = -0.12; P < .00001). Presenting signs (based upon CEAP) (P = .11) and body mass index (P = .88) did not have a significant effect on pain scores. Average pain score for females (0.96) was slightly higher than for males (0.70), with P < .0001. Average pain score for procedures on the right side (0.67) was lower than for procedures on the left side (1.01), with P < .0001. Average pain score for patients who received IV sedation (mean, 0.68; SD, 1.58) was lower than that for those who did not (mean, 0.93; SD, 2.15), with P = .0004. When using a single agent, propofol was associated with the lowest pain scores (P < .0001). Toradol displayed a dose-dependent effect on pain score (P < .0001). The best combination of agents for pain control was propofol and toradol together.

CONCLUSIONS

Overall, the vast majority of pain scores were low. Factors that were associated with lower pain scores were older age, male sex, procedures on the right side, and IV sedation, in particular with the use of propofol. These data may help us better target patients anticipated to have high pain scores and suggest the preferential use of propofol and toradol.

The role of iliac vein stent placement in pelvic venous disorder management

Pelvic venous disease (PeVD) has historically been challenging to diagnose and treat. This paper describes a comprehensive approach to the diagnosis of PeVD and reviews the role of iliac vein stent placement in treatment. Patient selection is vital for non-thrombotic iliac vein lesions (NIVLs) as only a small subset of patients with an NIVL will benefit from stent placement. There is limited, inconclusive data on optimal treatment for patients with both primary ovarian vein reflux and an NIVL. Patients with chronic post-thrombotic outflow obstruction typically have a more favorable risk/benefit ratio for intervention but require anticoagulation and close follow-up due to poorer long-term stent patency. Intravascular ultrasound is a useful tool for identifying obstructive lesions, sizing stents, and planning landing zones. More research is needed to characterize underlying pathophysiology, validate thresholds for intervention, develop reliable methods for outcomes assessment, and determine treatment response. Until this data is produced, an individualized treatment approach is warranted.

Can cross-sectional imaging replace diagnostic venography in pelvic venous disorder (PeVD)?

OBJECTIVE

The primary etiology of pelvic venous disorder is multifactorial and challengeable in vascular surgery as it mandates multidisciplinary team cooperation for its evaluation and management.

METHODS

All patients investigated for pelvic venous disorder in a high-volume, tertiary referral university hospital were identified and analyzed retrospectively during the period (March 2021 through September 2022). Demographic and medical data were scored. Agreement between the noninvasive modalities (computed tomographic venography [CTV] or magnetic resonance venography [MRV]) and diagnostic venography in detecting the refluxing pelvic veins was analyzed. Sensitivity, specificity, and diagnostic accuracy are also measured. No patients' treatments were reported in this study as the treatment is scheduled in other sessions in some cases and is out of the scope of this article. All patients had a diagnostic venogram regardless of the axial imaging modality. The main goal was to compare cross-sectional imaging with diagnostic venography.

RESULTS

The total number of patients was 120 with a mean age of 34.4 ± 7.1 years; 86.7% were multiparous. All patients presented chronic pelvic pain with vulvoperineal and/or atypical lower limb varicosities. Then patients were divided into two groups: those with CTV and those with MRV. Sensitivity, specificity, and diagnostic accuracy of CTV were 50%, 33%, and 47% for the detection of incompetent ovarian veins, 83%, 33%, and 53% for the detection of incompetent internal iliac veins, and 50%, 40%, and 47% for the detection of incompetent pelvic plexus veins, respectively, whereas time-resolved MRV achieved sensitivity, specificity, and diagnostic accuracy of 73%, 25%, and 60% for the detection of incompetent ovarian veins, 75%, 46%, and 53% for the detection of incompetent internal iliac veins, and 67%, 33% and 60% for detection of incompetent pelvic plexus veins, respectively.

CONCLUSIONS

The desire to avoid the drawbacks of diagnostic venography led to an increase in the use of noninvasive imaging modalities. Our results achieved acceptable sensitivity, specificity, and diagnostic accuracy outcomes for cross-sectional imaging with the superiority of MRV over CTV in diagnosing PCS.

Noninvasive and invasive imaging of lower-extremity acute and chronic venous thrombotic disease

The spectrum of venous thromboembolic (VTE) disease encompasses both acute deep venous thrombosis (DVT) and chronic postthrombotic changes (CPC). A large percentage of acute DVT patients experience recurrent VTE despite adequate anticoagulation, and may progress to CPC. Further, the role of iliocaval venous obstruction (ICVO) in lower-extremity VTE has been increasingly recognized in recent years. Imaging continues to play an important role in both acute and chronic venous disease. Venous duplex ultrasound remains the gold standard for diagnosing acute VTE. However, imaging of CPC is more complex and may involve computed tomography, magnetic resonance, contrast-enhanced ultrasound, or intravascular ultrasound. In this narrative review, we aim to discuss the full spectrum of venous disease imaging for both acute and chronic venous thrombotic disease.

Iliac vein compression syndrome by lumbar degenerative changes is associated with deep vein thrombosis after total knee arthroplasty

INTRODUCTION

This study aimed to identify whether iliac vein compression syndrome(IVCS) is associated with deep vein thrombosis(DVT) after total knee arthroplasty(TKA) and whether lower lumbar degenerative changes were risk factors for IVCS.

MATERIALS AND METHODS

A total of 259 consecutive patients who underwent TKA from January 2019 to March 2022 was retrospectively reviewed. Preoperative plain radiographs of lumbar spines and CT venography (CTV) for DVT diagnosis at postoperative 7 days were performed in all patients. Imaging findings of lower lumbar degenerative changes were analyzed on plain radiograph including lateral osteophytes, scoliosis, lateralolisthesis, retrolisthesis, anterolisthesis, and lower lumbar lordosis angle (LLLA). Percent compression at the left common iliac vein (LCIV) and right common iliac vein (RCIV) as well as DVT were evaluated on CTV. Moreover, IVCS was defined as greater than 50% of compression of the iliac vein on CTV.

RESULTS

DVT occurred in 79 patients (30.5%) after TKA. The overall occurrence of DVT was significantly higher in patients with IVCS of LCIV (52.8%) than those without (18.8%, P < 0.001). When DVT was further subdivided, compared to non-IVCS, IVCS of LCIV was significantly associated with bilateral DVT (P < 0.001, both), especially distal DVT (P < 0.001, both), and IVCS of RCIV was significantly associated with right-side DVT (P = 0.031), especially popliteal (P = 0.008) and distal DVT(P = 0.011). Female patients (OR: 3.945, P = 0.039), presence of left osteophyte (OR: 2.348, P = 0.006), and higher LLLA (OR: 1.082, P < 0.001) were significantly associated with IVCS of LCIV, and presence of right osteophyte (OR: 3.494, P = 0.017) was significantly associated with IVCS of RCIV.

CONCLUSION

IVCS was significantly associated with DVT after TKA and lumbar degenerative changes with lateral osteophytes and hyperlordosis were significant risk factors for IVCS.

The utility of computed tomography venography in the routine evaluation of patients who present to a lymphedema center with lower extremity edema

OBJECTIVE

Computed tomography venography (CTV) is not routinely used to screen patients presenting with a presumed lower extremity lymphedema diagnosis for left iliac vein obstruction (IVO) or May-Thurner syndrome (MTS). The objective of this study is to determine the utility of routine CTV screening for these patients by evaluating the proportion presenting with clinically significant CTV-identified left IVO.

METHODS

We retrospectively reviewed 121 patients who had presented to our lymphedema center with lower extremity edema between November 2020 and May 2022. Information regarding demographics, comorbidities, lymphedema characteristics, and imaging reports was collected. Cases of IVO present on CTV were reviewed by a multidisciplinary team to determine the clinical significance of the CTV findings.

RESULTS

Of the patients with complete imaging studies, 49% (n = 25) had abnormal lymphoscintigraphy findings, 45% (n = 46) had reflux on ultrasound, and 11.4% (n = 9) had IVO on CTV. Seven patients (6%) had CTV findings of IVO and edema of either the isolated left (n = 4) or bilateral (n = 3) lower extremities. Cases of IVO on CTV were determined by the multidisciplinary team to be the predominant cause of lower extremity edema for three of these seven cases (43%; or 2.5% of all 121 patients).

CONCLUSIONS

Six percent of patients presenting to a lymphedema center with lower extremity edema had left-sided IVO on CTV suggestive of MTS. However, the cases of IVO were determined to be clinically significant <50% of the time or for 2.5% of all patients. CTV should be reserved for patients with isolated left-sided or bilateral lower extremity edema with a greater left-sided component and a history of findings that raise clinical suspicion for MTS.

A case of duplicated inferior vena cava with bilateral iliac vein compression

Duplicated inferior vena cava with bilateral iliac vein compression is extremely rare. We report a case of an 87-year-old man presented with bilateral lower extremity swelling, who was noted to have duplicated inferior vena cava, as revealed by computed tomography angiography (CTA). This revealed bilateral iliac vein compression caused by surrounding structures. Anticoagulant treatment combined with stent implantation completely alleviated this chronic debilitating condition during the follow-up of 2 months with no recurrence.

CFD Study of the Effect of the Angle Pattern on Iliac Vein Compression Syndrome

Iliac vein compression syndrome (IVCS, or May-Thurner syndrome) occurs due to the compression of the left common iliac vein between the lumbar spine and right common iliac artery. Because most patients with compression are asymptomatic, the syndrome is difficult to diagnose based on the degree of anatomical compression. In this study, we investigated how the tilt angle of the left common iliac vein affects the flow patterns in the compressed blood vessel using three-dimensional computational fluid dynamic (CFD) simulations to determine the flow fields generated after compression sites. A patient-specific iliac venous CFD model was created to verify the boundary conditions and hemodynamic parameter set in this study. Thirty-one patient-specific CFD models with various iliac venous angles were developed using computed tomography (CT) angiograms. The angles between the right or left common iliac vein and inferior vena cava at the confluence level of the common iliac vein were defined as α1 and α2. Flow fields and vortex locations after compression were calculated and compared according to the tilt angle of the veins. Our results showed that α2 affected the incidence of flow field disturbance. At α2 angles greater than 60 degrees, the incidence rate of blood flow disturbance was 90%. In addition, when α2 and α1 + α2 angles were used as indicators, significant differences in tilt angle were found between veins with laminar, transitional, and turbulent flow (p < 0.05). Using this mathematical simulation, we concluded that the tilt angle of the left common iliac vein can be used as an auxiliary indicator to determine IVCS and its severity, and as a reference for clinical decision making.

Effect of stent treatment on hemodynamics in iliac vein compression syndrome with collateral vein

BACKGROUND

Iliac vein compression syndrome (IVCS) leads to blood flow obstruction in the lower extremities and is usually treated with stents, but stenting may worsen the hemodynamics and increase the risk of thrombosis in the iliac vein. The present work evaluates the advantages and disadvantages of the stent on IVCS with a collateral vein.

METHODS

The computational fluid dynamics method is adopted to analyze the preoperative and postoperative flow fields in a typical IVCS. The geometric models of the iliac vein are constructed from medical imaging data. The porous model is used to simulate the flow obstruction in IVCS.

RESULTS

The preoperative and postoperative hemodynamic characteristics in the iliac vein are obtained, e.g., the pressure gradient at two ends of the compressive region and the wall shear stress. It is found that the stenting restores the blood flow in the left iliac vein.

CONCLUSION

Impacts of the stent are classified into short-term and long-term effects. The short-term effects are beneficial in relieving IVCS, i.e., shortening the blood stasis and reducing the pressure gradient. The long-term effects increase the risk of thrombosis in the stent, i.e., enlarging wall shear stress due to a large corner and a diameter constriction in the distal vessel, and suggests the need to develop a venous stent for IVCS.

Endovascular Repair of Iatrogenic Inferior Vena Cava and Iliac Vein Injury: A Case Series and Review of the Literature

OBJECTIVE

Iatrogenic injury to the large abdominopelvic veins can he highly morbid, and open surgical repair is technically challenging. Endovascular repair with covered stenting across the injured segment offers an alternative to open surgical management. We present a series of patients with operative injury to the inferior vena cava (IVC) and iliac veins who were treated utilizing an endovascular approach and review the available literature on this technique.

METHODS

A PubMed keyword and MeSH term search was performed, and titles were reviewed for relevance by the first author. Studies related to endovascular repair of iatrogenic injury to the IVC and iliac veins were then read in detail for possible inclusion in the review. Those deemed appropriate were further analyzed for interventional approach, stent type and size, technical success, post-procedural pharmacologic management, complications and surveillance strategy.

RESULTS

The initial search resulted in 6221 publications. A total of 17 met criteria for inclusion, all of which were case reports or series. Twenty-six patients were described as suffering iatrogenic injury to the IVC or iliac veins, treated with various types and sizes of stents. All cases achieved technical success with hemorrhage control. Procedural complications occurred in 15.4% of cases, including 3 cases of acute thrombus formation and 1 case of stenosis caudal to the initial stent edge requiring additional stenting. Two additional patients experienced stent occlusion in the surveillance period.

CONCLUSIONS

Endovascular repair of iatrogenic injury to the IVC and iliac veins can be an effective management option. However, due to limited data regarding this approach, many technical questions remain, including ideal size and type of stent graft, necessity and duration of post-procedural anticoagulant or antiplatelet therapy and appropriate surveillance. Additionally, long term outcomes in this population have not yet been described.

Clinical implications of hemodynamic analysis for the three-dimension iliac vein model with different stenosis

Background

The aim of this study was to perform hemodynamic simulations of a three-dimension ideal inferior vena cava-iliac vein model with artificial stenosis to determine the degree of stenosis that requires clinical intervention.

Methods

Four three-dimension stenosis models (30%, 50%, 70%, and 90% stenosis) were constructed using commercial software (Solidworks). The inlet flow rates were acquired from previous literatures to perform the hemodynamic simulations. Changes in the old blood volume fraction, as well conventional hemodynamic parameters including pressure, differential pressure, wall shear stress, and flow patterns, over time were recorded. The pressure at the telecentric region of the stenosis increased with increasing degree of stenosis.

Results

For the 70% stenosis model, the pressure at the telecentric region of the stenosis reached 341 Pa, and the differential pressure between the two ends of the stenosis was 363 Pa (approximately 2.7 mmHg). Moreover, in the 70% and 90% stenosis models, there was a marked change in wall shear stress in the stenosis and the proximal end region, and the flow patterns began to show the phenomenon of flow separation. Blood stasis analysis showed that the 70% stenosis model had the slowest decrease in old blood volume fraction, while the proximal end region had the largest blood residue (15%).

Conclusion

Iliac vein stenosis of approximately 70% is associated with clinically relevant hemodynamic changes, and is more closely related to DVT than other degrees of stenosis.

Case report: Non-thrombotic iliac vein lesion: an unusual cause of unilateral leg swelling in a patient with endometrial carcinoma

81-year-old female presented with subacute right lower extremity edema due to iliac vein compression by a markedly enlarged external iliac lymph node later identified as newly relapsed metastatic endometrial carcinoma. The patient underwent a full evaluation of the iliac vein lesion and cancer and had an intravenous stent placed with complete resolution of symptoms post-procedure.

The Clinical Problem of Pelvic Venous Disorders

Pelvic venous disorders are inter-related pathologic conditions caused by reflux and obstruction in the pelvic veins. It can present a spectrum of clinical features based on the route of transmission of venous hypertension to either distal or caudal venous reservoirs. Imaging can help to visualize pelvic vascular and visceral structures to rule out other gynecologic, gastrointestinal, and urologic diseases. Endovascular treatment, owing to its low invasive nature and high success rate, has become the mainstay in the management of pelvic venous disorders. This article reviews the pathophysiology, clinical presentations, and diagnostic and therapeutic approaches to pelvic venous disorders.

Treatment of Non-thrombotic Iliac Vein Stenosis: Where is the Evidence?

Non-thrombotic iliac vein lesions (NIVLs) refer to iliac vein lumen stenosis, usually secondary to extrinsic compression, without associated thrombosis. Clinical presentation varies; patients may be asymptomatic, have symptoms of lower extremity venous hypertension, or in women, may be associated with chronic pelvic pain. Given the significant variability in symptomatology, thorough history and physical examination are mandatory in excluding other causes of symptoms. Non-invasive imaging, such as venous duplex/insufficiency ultrasound examinations, and axial imaging aid in the diagnosis of a NIVL in the appropriate clinical context. Catheter venography and intravascular ultrasound remain the primary modalities for definitive diagnosis, treatment planning, and ultimately placement of self-expanding venous stents to resolve the causative iliofemoral venous obstruction. In appropriately selected patients, stent placement can lead to marked improvements in symptoms, heal stasis ulceration when present, and improve disease-specific and overall quality of life. Stents placed in patients with NIVL demonstrate high long-term primary patency. In this article, the authors discuss clinical presentation, diagnostic workup, endovascular interventions and outcomes of NIVL treatment.

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.

Novel technique of stent retrieval after migration to the right heart

Central venous obstruction in the symptomatic patient is often treated with endovascular stenting. A rare, but serious, complication of this treatment is migration of the stent from the original site of deployment. Treatment of this complication requires either open or endovascular retrieval of the displaced stent. To treat a rare, but potentially devastating, complication, we have presented an effective endovascular method for migrated stent retrieval using a combination of a large bore sheath, balloon, and snare.

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

BACKGROUND

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

METHOD AND RESULTS

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

CONCLUSIONS

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

Single-stage treatment with iliac vein stenting and stripping of great saphenous veins for patients with left iliac vein compression syndrome

BACKGROUND

We sought to evaluate the safety and feasibility of single-stage treatment with left iliac vein stenting and saphenous stripping in patients with left iliac vein compression (LIVC) and left great saphenous vein (GSV) incompetence.

METHOD

s: We conducted a prospective cohort study of 72 patients diagnosed with LIVC and left GSV incompetence between June 2012 to Oct 2018. We evaluated the periprocedural, 30-day, and 1-year outcomes of venous clinical severity score (VCSS), Chronic Venous Insufficiency Questionnaire 2 (CIVIQ2), the success rate of stent placement, duration of intervention, length of hospital stay, duplex recurrence, and clinically visible recurrence.

RESULTS

There were 43 patients in the two-staged group and 29 patients in the single-staged group. The clinical characteristics of the two groups were similar. There were no differences between the two groups in the technical success rate, perioperative mortality, and surgical morbidity. There was no significant difference in the duplex and clinically visible recurrence. The length of hospital stay was significantly lower in the single-staged group. The single-staged group was associated with a higher complication rate of ecchymosis. There was no death, pulmonary embolism, or contrast-induced nephropathy among the patients. The 1-year primary patency rate was similar.

CONCLUSIONS

Both treatment approaches were equally effective and had a high technical success rate. The single-staged group had a higher complication rate of ecchymosis due to heparin applying during the procedure.

Treatment of Nonthrombotic Iliac Vein Lesions

Nonthrombotic iliac vein lesions (NIVLs) most frequently result from extrinsic compression of various segments of the common or external iliac vein. Patients develop symptoms associated with chronic venous insufficiency (CVI); female patients may develop symptoms of pelvic venous disease. Given that iliac vein compression can be clinically silent, a thorough history and physical examination is mandatory to exclude other causes of a patient's symptoms. Venous duplex ultrasound, insufficiency examinations, and axial imaging are most commonly used to assess for the presence of a NIVL. Catheter venography and intravascular ultrasound (IVUS) are the mainstay for invasive assessment of NIVLs and planning prior to stent placement. IVUS in particular has become the primary modality by which NIVLs are evaluated; recent evidence has clarified the lesion threshold for stent placement, which is indicated in patients with moderate to severe symptoms. In appropriately selected patients, stent placement results in improved pain, swelling, quality of life, and, when present, healing of venous stasis ulcers. Stent patency is well preserved in the majority of cases, with a low incidence of clinically driven need for reintervention. In this article, we will discuss the clinical features, workup, endovascular management, and treatment outcomes of NIVL.

May-Thurner Syndrome, an Often Overlooked Cause of Deep Vein Thrombosis: A Case Report

Deep vein thrombosis (DVT) is a common medical condition, but the predisposing anatomical factors, which may be amenable to definitive treatment, are usually overlooked. Therefore, a high index of clinical suspicion is the key to early diagnosis. We report here one such case of May-Thurner syndrome (MTS) to raise awareness. MTS (also known as iliac vein compression syndrome) should be suspected in cases of extensive DVT of the leg, particularly involving the iliac vein on the left side. The prognosis is improved with thrombolysis followed by angioplasty and stent to address the venous stenosis.

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.

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.

Comparing the efficacy of endovascular treatment for iliac vein compression syndrome with or without acute deep venous thrombosis: A single-center retrospective study

BACKGROUND

To compare the efficacy of endovascular treatment for iliac vein compression syndrome (IVCS) with or without acute deep venous thrombosis of lower extremity.

METHODS

This study retrospectively analyzed the clinical data of 300 IVCS patients, who received endovascular treatment between January 2013 and December 2017. According to whether IVCS was complicated by deep venous thrombosis or not, these patients were divided into non-thrombotic iliac vein lesion group (NIVL group, n = 127) and post-thrombotic iliac vein lesion group (PIVL group, n = 173). After endovascular treatment, all patients were followed up to assess the symptoms improvement and to evaluate the patency of iliac vein.

RESULTS

The technical success rate was 98% (294/300), and percutaneous transluminal angioplasty with stenting was adopted in 294 cases. The incidence of perioperative complications was 36.33% (109/300), but no severe complications occurred. During a mean follow-up of 22.3 months (range 6-30 months), 9(6.82%, 9/132) patients in PIVL group had recurrence of deep venous thrombosis, but nobody had deep venous thrombosis and varicose veins recurrence in NIVL group. The effective rate of endovascular treatment in NIVL group and PIVL group was 96.88% and 90.15% (P = 0.050), while the cumulative primary patency of iliac vein in NIVL group was significantly higher than that in PIVL group (P = 0.008).

CONCLUSIONS

The endovascular treatment is an effective, feasible, safe method for treating IVCS. There is no difference in the efficacy of IVCS patients with or without deep venous thrombosis, but the medium and long-term patency of patients with deep venous thrombosis is lower than that in patients without deep venous thrombosis.

May-Thurner syndrome and deep vein thrombosis: A series of 8 patients

OBJECTIVES

To analyze the prevalence of May-Thurner syndrome (MTS) among patients with deep vein thrombosis (DVT) of left lower limb (LLL), and outcomes after long-term follow-up.

METHOD

Retrospective observational study that included patients older than 18 diagnosed with acute DVT and MTS.

RESULTS

Among 760 patients diagnosed with DVT in the LLL, 8 patients were diagnosed with MTS (1.05%), with a mean age of 39 years. All patients received long-term anticoagulation, with a mean of 31.9 (±25.2) months. Invasive treatment with pharmaco-mechanical thrombectomy was performed in 5 patients (62.5%). During follow-up (mean of 32.4 months), 25% of patients suffered DVT recurrence. Only 1 case presented major bleeding, and no deaths were registered.

CONCLUSIONS

May-Thurner syndrome constitutes a permanent and underdiagnosed risk factor for the development of DVT of LLL. Our findings suggest that long-term anticoagulation therapy might be considered in selected cases.

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Case Report: Rare Iliac Vein Compression (May-Thurner) Syndrome in a Pediatric Patient

Iliac vein compression syndrome (IVCS) or May-Thurner syndrome occurs predominantly in young to middle-aged women. Here we reported a case of IVCS in a 5-year-old boy. The child was admitted to our vasculocardiology department with left lower extremity that had been swollen for 1 month. Blood tests revealed coagulation routine and platelets in the normal ranges. Computer tomography angiography (CTA) and magnetic resonance imaging (MRI) showed the left common iliac vein had become narrow before it entered the right common iliac vein. To further clarify, we performed angiography, which clearly showed the stenosis and the blood return of the left common iliac vein. So IVCS was diagnosed. What is more, we found the aorta descended to the right of the spine, and this may be the reason for the apparent compression of the left common iliac vein. Given the young age and mild symptoms of the child, the treatment was conservative mainly including elevation of the affected limb, wearing medical elastic socks, and short-term oral aspirin for anticoagulation. Meanwhile, the boy is being followed up closely. If the swelling of the left lower extremity significantly increases, stent placement may need to be considered in the future.

Venovo venous stent for treatment of non-thrombotic or post-thrombotic iliac vein lesions – long-term efficacy and safety results from the Arnsberg venous registry

Summary: Background: Endovascular venous stenting with dedicated venous stents for the treatment of chronic venous outflow obstruction is developing as efficacious alternative to conservative therapy or open surgery. However, so far, mid- and long-term evidence on effectiveness and safety is poor. Patients and methods: The prospective, single-center, observational study enrolled consecutive patients with chronic non-thrombotic iliac vein lesions (NIVL) or post-thrombotic iliofemoral obstructions (PTO). From February 2016 to April 2017, patients underwent implantation of open cell, self-expandable dedicated venous stents. Short-term symptomatic improvement, patency, and complication rate were favorable. Evaluation at 2-years included improvement in the revised venous clinical severity score (rVCSS), patency, stent migration, major target limb events, clinically important pulmonary embolism, major bleeding, and all-cause mortality. Results: A total of 79 patients (57 ± 16 years, 44 female) were evaluated. At 2 years, rVCCS improved by 4.3 ± 2.7 (p < 0.001). Substantial clinical improvement of ≥ 2 score points was achieved in 86.4% (38 of 44) of patients. Improvement was not associated with thrombotic pathogenesis (regression coefficient [B] with PTO = 0.6 [95%CI: −1.1 to 2.3], p = 0.48). At 2 years, all ulcers (in 8 of 79 patients) were healed and none recurred. Two-year primary patency was 95.5% (95%CI: 86.5 to 98.5) with no difference between NIVL- and PTO-patients (log-rank p = 0.83). Target vessel revascularization was conducted in two PTO- and one NIVL-patients in the period of 34 days to 156 days from index procedure, resulting in a secondary patency of 100%. No stent migration, target limb deep vein thrombosis, major amputation, pulmonary embolism, or death occurred. Conclusions: Venovo venous open cell self-expanding stent implantation for chronic outflow obstruction was efficacious and provided a sufficient level of safety throughout 2 years.

Venous Stent Migrating to the Right Heart Causing Severe Regurgitation

Venous stent migration to the cardiopulmonary system is a rare but serious complication. Cardiopulmonary involvement has various presentations such as valvulopathy, acute heart failure, arrhythmias, endocarditis, and tamponade. The presenting symptoms depend on the eventual location of the stent in the heart or lungs, size of the stent, and valve involvement. Extracardiac dislodgement can be managed by catheter-directed extraction or proper deployment within the containing vessel or surgical extraction. Intracardiac stents may require open surgery to prevent life-threatening complications. We present an asymptomatic patient with stent migration that lead to severe tricuspid regurgitation and required tricuspid valve replacement

Endovascular versus medical treatment of venous compression syndrome of the iliac vein - a systematic review

The treatment of non-thrombotic iliac vein lesions (NIVL) remains debatable with many advocating conservative treatments, whilst others offering venous stenting. The objective of this review was to systematically assess the treatment options for symptomatic iliac vein compression syndrome (IVCS) in patients without evidence of thrombotic disease at the time of diagnosis. An online search of published literature looking for randomised controlled trials and observational studies that evaluated the treatment for symptomatic NIVL was performed. Nine studies were included with a total 953 patients of which 782 patients had NIVL. Patency rates ranged between 94.8%-100% in the first month, 88.2%-94.1% in six months and 73.4%-98% in 12 months, in patients with NIVL post stenting. Longer follow-up of up to 5 years shows promising patency rates of 94% in patients with IVCS. Patients with IVCS are likely to benefit from a combination of endovenous treatment at the time of diagnosis including stent placement to maintain lumen patency and prevent recurrent deep venpus thrombosis and/or postthrombotic syndrome.

An efficacy and safety study of rivaroxaban for the prevention of deep vein thrombosis in patients with left iliac vein compression treated with stent implantation (PLICTS): study protocol for a prospective randomized controlled trial

BACKGROUND

Balloon dilatation with stent implantation has been proved to be an effective option for left iliac vein compression syndrome (LIVCS), but thrombosis may still occur after the operation. Currently, warfarin is used for anticoagulant therapy, but long-term monitoring is required, while rivaroxaban does not need laboratory monitoring, which can simplify treatment. Therefore, this study aimed to compare the efficacy and safety of rivaroxaban and warfarin in anticoagulation.

METHODS

This study is a multicenter, randomized controlled trial. We will recruit 224 patients with thrombotic LIVCS from 9 hospitals. Moreover, these patients will be randomized to either the experimental group (rivaroxaban) or the control group (warfarin plus nadroparin). The primary outcome is stent occlusion rate. Secondary outcomes are quality of life scale survey results, all-cause mortality, anticoagulation-related mortality, and the proportion of participants with stent displacement/fracture, thrombosis, hemorrhage, and other vascular events.

DISCUSSION

This study will provide reliable, evidence-based clinical evidence for the efficacy and safety of rivaroxaban antithrombotic therapy after stent implantation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04067505 . Registered on August 26, 2019.

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.

Iliac vein stenting is a safe and effective treatment for iliac vein compression syndrome: A systematic review of Chinese data

OBJECTIVES

This study was a systematic review of available data from China, and our aim was to evaluate the safety and efficacy of stenting in iliac vein compression syndrome.

METHODS

We searched the PubMed, National Knowledge Infrastructure, Chongqing Weipu Information Company, and Cochrane Central Register for Controlled Trials databases, and key references.

RESULTS

Twelve studies were included (nine retrospective analyses, two retrospective case series studies, and one prospective cohort study) involving 2292 patients and 1897 stented limbs. The overall primary patency rates ranged from 81.8% to 100%. Studies showed significant improvements in patients' symptoms, and ulcer healing rates ranged from 71.4% to 100% in stented limbs. The incidence of severe complications ranged from 0 to 16.8%.

CONCLUSIONS

For Chinese patients with iliac vein compression syndrome, stenting provided significant efficacy regarding favorable patency rates, symptom relief, and complications. However, the quality of evidence to support the use of iliac vein stenting to treat iliac vein compression syndrome is currently weak, especially for Chinese patients.

Venous stenting for patients with outflow obstruction and leg ulcers: cost–effectiveness and budget impact analyses

Aim: To perform cost–effectiveness analysis (CEA) and budget impact analysis (BIA) comparing stenting to standard medical treatment (SMT) for the management of deep venous outflow obstruction and leg ulcers from the Italian Healthcare Service perspective. Materials & methods: A Markov model was developed to project costs and quality-adjusted life-years (QALYs) over 3 years, based on data from literature combined with real-world data. Moreover, a BIA was performed comparing the current scenario (100% SMT) with increasing utilization rates of stenting over SMT from 0.5 to 5%, in the next 5 years. Results: Stenting is a cost-effective (incremental cost-utility ratio €12,388/QALY) or dominant option versus SMT, according to in-patient or day-hospital settings, respectively. Increasing use of stenting over SMT, in the next 5 years, is expected to yield additional costs of 39.5 million Euros (in-patient) or savings of 5.1 million Euros (day-hospital). Conclusion: Stenting is a cost-effective option compared with SMT for patients with deep vein occlusion and ulceration in Italy.

Atypical May-Thurner syndrome caused by endovascular aortic aneurysm repair

May-Thurner syndrome is characterized by unilateral lower extremity venous hypertension and stasis due to compression of an iliac vein between an iliac artery and the lumbar spine. In almost all cases, the left common iliac vein is compressed by the right common iliac artery; however, other patterns have been described. Rarely, May-Thurner syndrome may be created iatrogenically as a result of iliac artery stenting. We present an unusual case of new left common iliac vein thrombosis caused by ipsilateral left iliac artery compression after aortobi-iliac endovascular aneurysm repair.

Magnetic Resonance Imaging Evaluation of Left Common Iliac Vein Compression in Patients With and Without Symptoms of Venous Disease

BACKGROUND

The goal of this study was to assess the degree of the left common iliac vein (LCIV) compression by the right common iliac artery (RCIA) on magnetic resonance imaging (MRI), and verify differences in compression measurements in end-inspiration, end-expiration, supine, and prone decubitus between patients with and without symptoms in the lower limbs.Methods and Results:A total of 82 consecutive participants provided informed consent and underwent pelvic MRI for different clinical indications other than vascular-related disorders. The participants answered a questionnaire about venous disease in the lower limbs and history of previous deep vein thrombosis. This study measured the area and diameter of the LCIV at the site of the crossing with the RCIA and in the uncompressed caudal LCIV segment. Statistical analysis was performed to compare the degree of LCIV compression by the RCIA and verify differences in compression measurements. A total of 71 participants were included; 46.6% were in group A and did not experience signs and symptoms in lower limbs and 53.6% were in group B and answered at least one question with a positive answer. It was observed that there was a statistically significant difference between groups for end-expiration. No statistically significant differences were observed for all other measurements.

CONCLUSIONS

A substantial percentage of the asymptomatic and symptomatic population showed compression of the LCIV, suggesting there are no clear relationships between stenosis and non-specific symptomatology in the general population.

May-Thurner syndrome: History of understanding and need for defining population prevalence

Patients with May-Thurner syndrome (MTS) are at elevated risk of developing an extensive left iliofemoral deep vein thrombosis (DVT; localized blood clot) due to an anatomical variant where the right common iliac artery compresses the left common iliac vein against the lumbar spine. While MTS was initially presumed to be rare when it was first anatomically defined in 1957, case reports of this syndrome have recently become more frequent, perhaps due to improved imaging techniques allowing for enhanced visualization of the iliac veins. Still, the population burden of this condition is unknown, and there is speculation it may be higher than generally perceived. In the present review, we (a) review history of how MTS became recognized, (b) describe practical challenges of studying MTS in population-based settings due to the specialized imaging required for diagnosis, (c) discuss why the contribution of MTS to DVT may be underestimated, (d) describe uncertainty regarding the degree of venous compression which leads to DVT, and (e) outline future research needs. Our goal is to raise awareness of MTS and spark additional research into the epidemiology of this condition, which may be an underappreciated causative venous thromboembolism risk factor.

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

Objective

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

Methods

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

Results

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

Conclusion

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

The role of multidetector CT angiography in characterizing vascular compression syndromes of the abdomen

Background

Various abdominal vessels can compress the adjacent structures or in turn can get compressed by them. Most of these compression syndromes present with non-specific symptoms. Unlike the common causes of acute abdomen, the various vascular compression syndromes have bizarre clinical presentations and subtle imaging findings, which can easily be missed by the physicians as well as the radiologists.

Main body of the abstract

This is a retrospective study which was done for a period of 3 years from April 2015 to April 2018 using a 64-slice CT scanner. Among 2412 cases that came for evaluation, 114 patients were diagnosed to have one of the various vascular compression syndromes. These 114 cases were further managed either conservatively or surgically depending on the pathology and the severity of the compression. The syndromes discussed in this article include median arcuate ligament syndrome (29 cases), superior mesenteric artery syndrome (23 cases), portal biliopathy (3 cases), nutcracker syndrome (6 cases), pelvi-ureteric junction obstruction due to crossing of vessels (8 cases), and retrocaval ureter and May-Thurner syndrome (45 cases).

Conclusions

The primary goal of this article is to reinforce the knowledge of the radiologists of the various vascular compression syndromes and to make them possess a high degree of vigilance to detect them. This article elaborates the imaging findings of these syndromes and the role of multidetector CT angiography in diagnosing them.

Endovenous Intervention of May-Thurner Syndrome with Thrombus beyond Iliac Vein Stenosis

Purpose

With the increase in the incidence of venous thrombosis, interest in May-Thurner syndrome (MTS) accompanying iliac vein compression has increased. Some patients with MTS have inferior vena cava thrombosis or thrombosis beyond iliac vein stenosis (TBIVS). This study aimed to identify the characteristics of MTS with TBIVS including pulmonary embolism (PE) and post-thrombotic syndrome (PTS) compared to those of MTS without TBIVS.

Materials and Methods

Thirty-five patients with deep vein thrombosis associated with MTS were treated between March 2012 and February 2016. Demographic data, medical history, computed tomography findings (iliac vein size of stenosis and stenotic ratio compared with the other side), and clinical outcomes (preoperative PE and PTS) were retrospectively collected and reviewed by dividing into groups with or without TBIVS.

Results

Eight of the 35 patients with MTS had TBIVS. The group with TBIVS had a statistically significantly greater iliac vein size (P<0.001) and ratio (P=0.001). PE was more prevalent in the group with TBIVS (63% vs. 15%, P=0.007). However, no statistically significant intergroup difference in PTS prevalence was found.

Conclusion

The presence of mild iliac vein stenosis in MTS can be used to predict TBIVS and the requirement for more attention to PE.

Endovascular intervention for iliac vein thrombosis after simultaneous kidney-pancreas transplant

May–Thurner syndrome (MTS) is an anatomic variant where the overlying right common iliac artery compresses and chronically obstructs the left common iliac vein, leading to thrombosis. Interventions for symptomatic MTS include endovascular thrombectomy and stenting. Occluding venous thrombus can be fatal to transplanted allografts. No guidelines exist for patients with MTS after simultaneous kidney-pancreas transplant. A 57-year-old female with ESRD and diabetes mellitus underwent a kidney-pancreas transplant. Post-operative imaging revealed a compressed left CIV with an occlusive thrombus threatening the renal graft. Thrombectomy with stent placement was performed, maintaining patency of both allograft venous outflows. Post-intervention the patient has demonstrated preserved kidney and pancreas allograft function through 1 year of follow-up. Interventions for MTS in patients after transplant are challenging given the complex allograft vascular reconstruction. We present a case which demonstrates that angiographic interventions for MTS can be safely performed after simultaneous kidney-pancreas transplant.

Slippery Stents: A Case Report and Review of the Literature Describing Patients with May-Thurner Syndrome That Experienced Stent Migration

Endovascular stent placement is an effective treatment for relieving chronic venous obstruction in patients with May-Thurner Syndrome (MTS) with or without the presence of thrombotic lesions. Stent migration is a rare but potentially life-threatening complication of endovascular stenting. Herein, we describe a case of stent migration from the left common iliac vein into the right heart, requiring open-heart surgery. We also completed a literature review of MTS patients with stent migration in hopes of raising awareness of this rare and life-threatening complication.

Prevalence, risk factors, and evaluation of iliocaval obstruction in advanced chronic venous insufficiency

OBJECTIVE

The aim of this study was to investigate the prevalence and clinical predictors of >50% iliocaval venous obstruction (ICVO) in Thai patients with lipodermatosclerosis and healed or active venous ulcers and the diagnostic accuracy of duplex ultrasound (DUS) compared with computed tomography venography (CTV).

METHODS

Limbs with lipodermatosclerosis, healed venous leg ulceration, or active venous leg ulceration were prospectively evaluated by DUS and CTV. Loss of respiratory variation in the common femoral vein (CFV) and reversed flow in the superficial epigastric vein (SEV) were evaluated by DUS. Percentage of venous obstruction was measured by CTV. The prevalence and clinical predictors of >50% ICVO were determined, and the accuracy of DUS for diagnosis of >50% ICVO was compared with the diagnostic accuracy of CTV.

RESULTS

A total of 106 patients (135 limbs) were enrolled. The mean age was 58 ± 12 years, and 57 (54%) patients were female. Previous history of deep venous thrombosis (DVT) in the symptomatic leg was documented in 21 (15.6%) limbs; >50% ICVO by CTV was found in 38 (28.1%) limbs. Independent predictors of >50% ICVO included left leg (P = .001) and previous history of DVT in the affected leg (P = .001). For diagnosis of >50% ICVO, the sensitivity and specificity of loss of respiratory variation in the CFV were 23.7% and 100%, respectively; the sensitivity and specificity of reversed flow in the SEV were 7.9% and 100%, respectively.

CONCLUSIONS

Limbs with lipodermatosclerosis or with healed or active venous ulceration, especially in the left limb or in limbs with a history of DVT in the affected limb, had a high prevalence of ICVO; these limbs should be routinely studied with DUS. Limbs with an abnormal finding on DUS, including loss of respiratory variation in the CFV or reversed flow in the SEV, should be routed for venous intervention, and those with normal DUS findings should be referred for CTV.

Occult Left Common Iliac Vein Compression Increases Postoperative Venous Thromboembolism Risk Following Total Hip Arthroplasty

BACKGROUND

Left common iliac vein (LCIV) compression by the right or left common iliac artery (RCIA, LCIA) is known to cause venous thromboembolism (VTE), but the extent to which occult LCIV compression synergizes with lower extremity orthopedic surgery is unknown. We hypothesize that occult LCIV compression is associated with increased VTE risk following total hip or knee arthroplasty (THA, TKA).

METHODS

This case-control study involves all patients at our institution who underwent primary or revision THA or TKA from 2009 to 2017 who had computed tomography or magnetic resonance imaging of the abdomen or pelvis available preoperatively. VTE cases (pulmonary embolism or left-sided deep vein thrombosis) within 30 days of surgery were matched to a control by age, gender, body mass index, Charlson Comorbidity Index, surgical site, and hypercoagulable risk factors. LCIV compression by the right common iliac artery and/or the left common iliac artery was measured in a blinded fashion and was considered present at 50% diameter reduction.

RESULTS

One hundred twelve patients (22 cases, 90 controls) were included for analysis. Nineteen (86.4%) cases and 46 (51.1%) controls demonstrated LCIV compression. The overall sample odds ratio of postoperative VTE in the presence of LCIV compression was 5.97 (95% confidence interval 1.59-33.67, P = .003). In patients who underwent THA (n = 75), LCIV compression was highly predictive of VTE (odds ratio ∞, 95% confidence interval 2.83-∞, P < .001). Compression in the TKA patients did not significantly predict VTE.

CONCLUSION

Compression of the LCIV significantly increases odds of developing postoperative VTE following THA. This effect may suggest a new method of stratifying VTE risk in the orthopedic population to reduce VTE-associated morbidity and mortality.

[Antithrombotic therapy after venous stenting]

Presented herein is a literature review considering the problems of using antithrombotic therapy after venous stenting. Described herein are the literature data according to which the authors give preference to anticoagulant therapy (low-molecular-weight heparins, vitamin K antagonists, direct oral anticoagulants). This is followed by considering the problems of duration of treatment depending on various clinical situations. According to the presented data, the problem of prescribing disaggregants in a combination with anticoagulants after stenting of veins remains disputable, finding however many supporters. Analysed in the article are the results of the first International Delphi Consensus dedicated to antithrombotic therapy after venous stenting. Participating in the study were 106 independent experts practicing stenting in 78 centres of 28 countries of the world. Nonthrombotic iliac vein lesions, having appeared as May-Thurner syndrome due to extravasal compression and residual obstruction after thrombolysis, as well as the presence of postthrombotic syndrome were the main 'scenarios' for our study. The study resulted in working out provisions considering the policy of antithrombotic therapy in various obstructive lesions of deep veins. According to the presented data, anticoagulant therapy is preferable during 6-12 months after stenting in nonthrombotic iliac vein lesions. Low-molecular-weight heparins appear to be a method of choice in treatment during the first 2-6 weeks. Life-long administration of anticoagulants is recommended after multiple deep vein thromboses. Discontinuation of anticoagulants after 6-12 months is indicated after venous stenting in one episode of deep vein thrombosis. No consensus was achieved regarding the role of prolonged disaggregant therapy. Underlined in the article is the importance of a meticulous individual approach to choosing optimal policy of antithrombotic therapy and determining therapeutic policy together with a haematologist.

Application of computed tomography venography in the diagnosis and severity assessment of iliac vein compression syndrome: A retrospective study

The objectives are to evaluate the application of computed tomography venography (CTV) in the diagnosis of iliac vein compression syndrome (IVCS), and to assess the factors related to the incidence and development of IVCS and the recurrence of varicose veins.Imaging data of 120 patients with chronic venous disease (CVD) of the lower extremity and 68 subjects without CVD (control) were retrospectively reviewed by radiologists blinded to the groups. CTV, conventional venography, and Doppler ultrasound were compared in the diagnosis and contributing factors for IVCS were also analyzed.CTV required less procedure time than venography or color ultrasonography (P < .001). The rate of iliac venous compression diagnosed by CTV was higher in the CVD group (53.3%) than in the control group (22.1%) (χ = 17.425, P < .001). Risk factors for IVCS included gender, hyperlipidemia, and course of disease (P < .05). Development of femoral vein collateral was more common in patients with IVCS (P < .05). The duration of disease was positively associated with the severity of iliac vein compression (r = 0.321, P < .001). IVCS was an important contributing factor for varicose vein recurrence (51.2%). In patients with IVCS and venous ulcer (C5-C6), the healing time of the ulcer treated with stent was significantly shorter compared with those without stent treatment (P < .001).CTV is accurate for the diagnosis and severity evaluation of IVCS. IVCS might be a contributing factor for varicose vein recurrence. Iliac vein stent implantation as a safe and effective interventional therapy promotes the healing of venous ulcer caused by IVCS.