Three-Year Outcomes, Risk Factors for Restenosis After Stenting for DVT Combined with Iliac Vein Compression Syndrome.

This study aimed to evaluate the safety and efficacy of pharmacomechanical catheter-directed thrombolysis (PCDT) and stenting for treating acute iliofemoral deep venous thrombosis (DVT) combined with iliac vein compression syndrome (IVCS), and to identify the predictors of stent restenosis. Patients with acute proximal DVT combined with IVCS underwent PCDT and stenting from January 2017 to December 2022 were enrolled. Primary and secondary patency were assessed by duplex ultrasound (DUS). The morbidity of postthrombotic syndrome (PTS) was assessed by the Villalta score. Risk factors for stent restenosis were assessed using univariate and multivariate Cox regression models. Total of 254 patients were included. The mean follow-up time was 36.06 ± 17.66 months. The primary patency rates at 1 year, 3 years, and 5 years were 92.5%±1.7%, 85.4%±2.4%, and 82.4%±2.9%, respectively. The incidence of stent restenosis was 14.2%. Discontinuation of anticoagulants within one year [hazard ratio (HR) = 5.03; P = .048] was the factor associated with acute in-stent thrombosis. Previous DVT history (HR =2.29; P = .037) and stent placement across the inguinal ligament (HR =6.70; P < .001) were identified as independent risk factors significantly associated with stent restenosis. The overall PTS rate was 19.3%. PCDT with stenting is safe and effective for patients with iliofemoral DVT secondary to IVCS, leading to low rates of PTS. Previous DVT history and stents placed across the inguinal ligament may be predictors of stent restenosis. Furthermore, stent restenosis typically occurs within one year and is mainly caused by acute thrombosis due to discontinuation of anticoagulants.

[Successful endovascular treatment of proximal deep vein thrombosis following May-Thurner syndrome]. / Uspeshnoe lechenie proksimal'nogo tromboza glubokikh ven nizhnikh konechnostei na fone sindroma Meya-Ternera endovaskulyarnymi tekhnologiyami.

We present two clinical cases of successful endovascular treatment of proximal deep vein thrombosis following May-Thurner syndrome. In the first case, 2-day regional catheter thrombolysis, percutaneous mechanical thrombectomy and venous stenting were required to restore hemodynamics in the left lower limb. In the second case, regional catheter thrombolysis continued for 3 days with subsequent thrombotic mass lysis. However, iliac vein was severely narrowed that required venous stenting. Long-term results were favorable in both cases. Venous outflow has become almost normal after endovascular treatment. The patients' ability to work has been restored.

Impact of lower limb movements on iliac vein stenting in iliac vein compression syndrome patients: insights from computational modeling.

Purpose: Iliac vein stenting is the primary treatment for patients with iliac vein compression syndrome (IVCS). However, post-stent placement, patients often experience in-stent restenosis and thrombosis. Despite this, the role of lower limb movements in the functioning of stents and veins in IVCS patients remains unclear. This study aimed to address this knowledge gap by developing a computational model using medical imaging techniques to simulate IVCS after stent placement. Methods: This research used a patient-specific model to analyze the effects of lower extremity exercises on hemodynamics post-stent placement. We conducted a comprehensive analysis to evaluate the impact of specific lower limb movements, including hip flexion, ankle movement and pneumatic compression on the hemo-dynamic characteristics within the treated vein. The analysis assessed parameters such as wall shear stress (WSS), oscillatory shear index (OSI), and residence time (RRT). Results: The results demonstrated that hip flexion significantly disrupts blood flow dynamics at the iliac vein bifurcation after stenting. Bilateral and left hip flexion were associated with pronounced regions of low WSS and high OSI at the iliac-vena junction and the stent segment. Additionally, active ankle exercise (AAE) and intermittent pump compression (IPC) therapy were found to enhance the occurrence of low WSS regions along the venous wall, potentially reducing the risk of thrombosis post-stent placement. Consequently, both active joint movements (hip and ankle) and passive movements have the potential to influence the local blood flow environment within the iliac vein after stenting. Conclusions: The exploration of the impact of lower limb movements on hemodynamics provides valuable insights for mitigating adverse effects associated with lower limb movements post iliac-stenting. Bilateral and left hip flexions negatively impacted blood flow, increasing thrombosis risk. However, active ankle exercise and intermittent pump compression therapies effectively improve the patency.

Correlation of Imaging and Hemodynamic Findings with Clinical Outcomes for Diagnosis of Left Renal Vein Compression Syndrome.

PURPOSE: Left renal vein compression syndrome (LRVCS) remains a challenging diagnosis. This study aimed to correlate imaging and hemodynamic findings with clinical outcomes for patients with LRVCS. MATERIALS AND METHODS: A retrospective review of 66 renal venography procedures with or without intravascular ultrasound (IVUS) was performed from 2017 to 2023 at a single institution. Patients with prior LRVCS treatment or other indications were excluded (n = 11). Primary outcome measure was correlation of catheter-based endovascular (CBE) findings with clinical outcomes (n = 55). Secondary outcome measures included correlation of CBE findings and LRV (i.e., beak) angle > 32°, beak sign, aortomesenteric angle (AMA < 41°), and hilar-to-aortomesenteric ratio (HTAMR ≥ 4.9) on cross sectional imaging. Descriptive statistics, chi-square testing, and ROC analyses were used. RESULTS: Of the 55 patients, 52 (94.5%) were females (median age 31, range 14-72) and 56.4% (n = 31) had a diagnosis of LRVCS on CBE evaluation. A renocaval pressure gradient of ≥ 3 mmHg, presence of collaterals, and > 50% area stenosis on IVUS were significantly associated with CBE diagnosis of LRVCS (p < 0.001). Surgical treatment (renal autotransplantation or LRV transposition) was recommended to all patients with CBE diagnosis of LRVCS (n = 31). 81.2% (18/22) of patients who underwent surgery reported symptom resolution or improvement. When the cross sectional imaging measurements were compared with CBE evaluation, AMA was the most sensitive (100%), HTAMR and beak sign were highly specific (93.3%), and beak angle was the most predictive (77.4% sensitivity; 86.7% specificity). CONCLUSION: CBE diagnosis of LRVCS was highly predictive of surgical candidacy and post-surgical symptom resolution. The presence of collaterals, > 50% area stenosis on IVUS, or a renocaval pressure gradient ≥ 3 mmHg had a significant association with a CBE diagnosis of LRVCS.

Venous Compressive Disorders.

Venous compressive disorders are a heterogenous group of vascular syndromes characterized by extrinsic venous compression that can lead to complications of venous hypertension or venous thrombosis. Endovascular damage secondary to deep venous thrombosis (DVT) can result in post-thrombotic syndrome (PTS), a potentially debilitating condition that can be associated with significant morbidity in the pediatric population. Here we discuss 4 venous compressive disorders: iliac vein compression (May-Thurner syndrome [MTS]); subclavian vein compression at the venous thoracic inlet (Paget-Schroetter syndrome); left renal vein compression (nutcracker syndrome); and popliteal vein compression (popliteal entrapment syndrome) with a focus on clinical evaluation and diagnostic methods. Where endovascular therapy is appropriate, specific procedural considerations including procedure indications, equipment, procedural steps, technical challenges, complications, clinical follow-up and expected outcomes are discussed.

Initial experience with the ambulatory management of acute iliofemoral deep vein thrombosis with May-Thurner syndrome with percutaneous mechanical thrombectomy, angioplasty and stenting.

OBJECTIVE: Patients undergoing intervention for acute iliofemoral deep vein thrombosis (IFDVT) with May-Thurner syndrome (MTS) typically require inpatient (IP) hospitalization for initial treatment with anticoagulation and management with pharmacomechanical thrombectomy. Direct oral anticoagulants and percutaneous mechanical thrombectomy (PMT) devices offer the opportunity for outpatient (OP) management. We describe our approach with these patients. METHODS: Patients receiving intervention for acute IFDVT from January 2020 through October 2022 were retrospectively reviewed. Patients undergoing unilateral thrombectomy, venous angioplasty, and stenting for IFDVT with MTS comprised the study population and were divided into two groups: (1) patients admitted to the hospital and treated as IPs and (2) patients who underwent therapy as OPs. The two groups were compared regarding demographics, risk factors, procedural success, complications, and follow-up. RESULTS: A total of 92 patients were treated for IFDVT with thrombectomy, angioplasty, and stenting of whom 58 comprised the IP group and 34 the OP group. All 92 patients underwent PMT using the Inari ClotTriever (Inari Medical), intravascular ultrasound, angioplasty, and stenting with 100% technical success. Three patients in the IP group required adjuvant thrombolysis. There was no difference in primary patency of the treated IFDVT segment at 12 months between the two groups (IP, 73.5%; OP, 86.7%; P = .21, log-rank test). CONCLUSIONS: Patients with acute IFDVT and MTS deemed appropriate for thrombectomy and iliac revascularization can be managed with initiation of ambulatory direct oral anticoagulant therapy and subsequent return for ambulatory PMT, angioplasty, and stenting. This approach avoids the expense of IP care and allows for effective use of resources at a time when staffing and supply chain shortages have led to inefficiencies in the provision of IP care for nonemergent conditions.

Three-Year Outcomes of the Abre Venous Self-Expanding Stent System in Patients with Symptomatic Iliofemoral Venous Outflow Obstruction.

PURPOSE: To report 36-month outcomes and subgroup analysis of the ABRE study evaluating the safety and effectiveness of the Abre venous self-expanding stent system for the treatment of symptomatic iliofemoral venous outflow obstruction disease. METHODS: The ABRE study was a prospective, multicenter, nonrandomized study that enrolled and implanted Abre venous stents in 200 participants (mean age 51.5 years [SD ± 15.9], 66.5% women) with symptomatic iliofemoral venous outflow obstruction at 24 global sites. Outcomes assessed through 36 months included patency, major adverse events, stent migration, stent fracture, and quality-of-life changes. Adverse events and imaging studies were adjudicated by independent clinical events committee and core laboratories, respectively. RESULTS: Primary, primary-assisted, and secondary patency through 36 months by Kaplan-Meier estimates were 81.6%, 84.8%, and 86.3%, respectively. The cumulative incidence of major adverse events through 36 months was 10.2%, mainly driven by 12 thrombosis events. Subgroup analyses demonstrated a primary patency of 76.5% in the acute deep vein thrombosis group, 70.4% in the postthrombotic syndrome group, and 97.1% in the nonthrombotic iliac vein lesion group through 36 months. The overall mean lesion length was 112.4 mm (SD ± 66.1). There were no stent fractures or migrations in this study. Quality of life and venous functional assessments demonstrated significant improvements from baseline to 36 months across all patient subsets. CONCLUSIONS: Results from the ABRE study demonstrated sustained patency with a good safety profile after implantation of a dedicated venous stent in patients with symptomatic iliofemoral venous outflow obstruction disease.

Spontaneous Extraperitoneal Hematoma Related to May-Thurner Syndrome.

In this report, we describe a rare case: deep vein thrombosis due to May-Thurner syndrome with a spontaneous pelvic extraperitoneal hematoma. This unique challenge highlights balancing thrombosis treatment and bleeding risk. Endovascular treatment with delayed anticoagulation may be an alternative to surgery for stable retroperitoneal hematoma in May-Thurner syndrome patients.

Technical Feasibility and Clinical Efficacy of Iliac Vein Stent Placement in Adolescents and Young Adults with May-Thurner Syndrome.

PURPOSE: To report technical feasibility and clinical efficacy of iliac vein stent placement in adolescent patients with May-Thurner Syndrome (MTS). MATERIALS AND METHODS: Single-institution retrospective review of the medical record between 2014 and 2021 found 63 symptomatic patients (F = 40/63; mean age 16.1 years, 12-20 years) who underwent left common iliac vein (LCIV) stent placement for treatment of LCIV compression from an overriding right common iliac artery, or equivalent (n = 1, left IVC). 32/63 (50.7%) patients presented with non-thrombotic iliac vein lesions (NIVL). 31/63 (49.2%) patients presented with deep vein thrombosis of the lower extremity and required catheter-directed thrombolysis after stent placement (tMTS). Outcomes include technically successful stent placement with resolution of anatomic compression and symptom improvement. Stent patency was monitored with Kaplan-Meier analysis at 3, 6, 12, 24, and 36 months. Anticoagulation and antiplatelet (AC/AP) regimens were reported. RESULTS: Technical success rate was 98.4%. 74 bare-metal self-expanding stents were placed in 63 patients. Primary patency at 12, and 24-months was 93.5%, and 88.9% for the NIVL group and 84.4% and 84.4% for the tMTS group for the same period. Overall patency for the same time intervals was 100%, and 95.4% for the NIVL group and 96.9%, and 96.9% for the tMTS group. Procedural complication rate was 3.2% (2/63) with no thrombolysis-related bleeding complications. Clinical success was achieved in 30/32 (93.8%) and 29/31 (93.5%) patients with tMTS and NIVL groups, respectively. CONCLUSION: CIV stent placement in the setting of tMTS and NIVL is technically feasible and clinically efficacious in young patients with excellent patency rates and a favorable safety profile.

In situ management of late thrombosis of a renal graft vein in a patient with Cockett syndrome / Prise en charge in situ d'une thrombose tardive de la veine d'un greffon rénal chez une patiente avec un syndrome de Cockett

Late thrombosis of the renal graft vein is a rare complication that results in graft loss in the majority of cases. We describe the case of a 57-year-old female patient who had a kidney transplant 32 years ago and developed a late thrombosis of the graft vein, accompanied by extensive thrombosis in the common femoral and iliac veins. Risk factors included severe malnutrition, chronic inflammation due to an anal fistula, and Cockett syndrome. The treatment consisted of mechanical thrombectomy of the iliac vein, placement of a stent in the common iliac vein, partial thromboaspiration of the renal vein thrombus with local thrombolysis, followed by systemic anticoagulation. With this approach, renal function fully recovered without major complications.

La thrombose tardive de la veine du greffon rénal est une complication rare qui conduit à la perte du greffon dans la majorité des cas. Nous présentons le cas d'une femme de 57 ans, transplantée depuis 32 ans, qui a développé une thrombose de la veine du greffon, se manifestant par une insuffisance rénale aiguë anurique. Cette thrombose compliquait une thrombose extensive débutant dans la veine fémorale superficielle et s'étendant dans les veines fémorale commune et iliaque. La patiente présentait plusieurs facteurs de risque de thrombose veineuse, tels qu'un état de malnutrition sévère, une inflammation chronique due à une fistule anale chronique et un syndrome de Cockett. La patiente a été traitée en plusieurs étapes successives : une thrombectomie mécanique de toute la veine iliaque a d'abord été réalisée, suivie de la mise en place d'un stent dans la veine iliaque commune gauche en raison du syndrome de Cockett, puis d'une thrombo-aspiration partielle du thrombus de la veine rénale combinée à une thrombolyse locale (par urokinase) de la veine rénale via un cathéter, et enfin d'une anticoagulation systémique. Cette approche a permis une récupération complète de la fonction rénale sans complication notable. Nous rapportons cette prise en charge in situ d'une thrombose tardive de la veine d'un greffon rénal chez une patiente avec un syndrome de Cockett, ayant permis une issue favorable.

Venous compression syndromes in females: A descriptive review.

Venous compression syndromes have been described, yet the role of sex is poorly understood. Although iliac vein compression has been discussed more often with the advent of newer technologies, research has fallen short on defining epidemiology, best practices for evaluation and treatment, and differences in responses to treatment between men and females. The authors report on iliac vein compression, nonthrombotic renal vein compression, and other venous compression syndromes in females. Literature searches of PubMed were performed using the following keywords: females/females and May Thurner, venous stenting, venous outcomes, deep venous disease, deep venous compression, venous stenting, renal vein compression, renal vein surgery/stent, popliteal vein entrapment, venous thoracic vein entrapment, and popliteal vein entrapment. The articles prompted the authors to research further as the referenced articles were reviewed. Sex representation has not been addressed adequately in the research of venous compression syndromes, making the discussion of best treatment options and long-term outcomes difficult. More specific understanding of epidemiology and response to interventions will only come from research that addresses these issues directly, understanding that some of these syndromes occur rarely.

An ultrasound imaging and computational fluid dynamics protocol to assess hemodynamics in iliac vein compression syndrome.

OBJECTIVE: Elevated shear rates are known to play a role in arterial thrombosis; however, shear rates have not been thoroughly investigated in patients with iliac vein compression syndrome (IVCS) owing to imaging limitations and assumptions on the low shear nature of venous flows. This study was undertaken to develop a standardized protocol that quantifies IVCS shear rates and can aid in the diagnosis and treatment of patients with moderate yet symptomatic compression. METHODS: Study patients with and without IVCS had their iliac vein hemodynamics measured via duplex ultrasound (US) at two of the following three vessel locations: infrarenal inferior vena cava (IVC), right common iliac vein, and left common iliac vein, in addition to acquiring data at the right and left external iliac veins. US velocity spectra were multiplied by a weighted cross-sectional area calculated from US and computed tomography (CT) data to create flow waveforms. Flow waveforms were then scaled to enforce conservation of flow across the IVC and common iliac veins. A three-dimensional (3D), patient-specific model of the iliac vein anatomy was constructed from CT and US examination. Flow waveforms and the 3D model were used as a basis to run a computational fluid dynamics (CFD) simulation. Owing to collateral vessel flow and discrepancies between CT and US area measurements, flows in internal iliac veins and cross-sectional areas of the common iliac veins were calibrated iteratively against target common iliac flow. Simulation results on mean velocity were validated against US data at measurement locations. Simulation results were postprocessed to derive spatial and temporal values of quantities such as velocity and shear rate. RESULTS: Using our modeling protocol, we were able to build CFD models of the iliac veins that matched common iliac flow splits within 2% and measured US velocities within 10%. Proof-of-concept analyses (1 subject, 1 control) have revealed that patients with IVCS may experience elevated shear rates in the compressed left common iliac vein, more typical of the arterial rather than the venous circulation. These results encourage us to extend this protocol to a larger group of patients with IVCS and controls. CONCLUSIONS: We developed a protocol that obtains hemodynamic measurements of the IVC and iliac veins from US, creates patient-specific 3D reconstructions of the venous anatomy using CT and US examinations, and computes shear rates using calibrated CFD methods. Proof-of-concept results have indicated that patients with IVCS may experience elevated shear rates in the compressed left common iliac vein. Larger cohorts are needed to assess the relationship between venous compression and shear rates in patients with IVCS as compared with controls with noncompressed iliac veins. Further studies using this protocol may also give promising insights into whether or not to treat patients with moderate, yet symptomatic compression.

Spontaneous iliac vein rupture and thrombosis in patients with May-Thurner syndrome: A narrative review.

Spontaneous iliac vein rupture (SIVR) is extremely rare and can lead to serious complications, including death. Etiologies include inflammatory processes and hormonal and mechanical triggers, with concomitant May-Thurner syndrome (MTS) being a rare cause. Management can be challenging due to the difficult balance between reducing thrombotic burden and life-threatening hemorrhage that can result from aggressive anticoagulation. Furthermore, surgical interventions are associated with high mortality, making conservative management more desirable. We report a case of SIVR with retroperitoneal hematoma and concurrent MTS that was successfully managed using conservative measures. We further provide a narrative review of the current literature addressing the diagnosis, management, and outcome of SIVR focusing on cases with concurrent MTS.

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.

Predictors of long-term outcomes after catheter-directed thrombolysis combined with stent implantation in acute deep vein thrombosis secondary to iliac vein compression.

The purpose of this study is to analyze predictive factors for long-term clinical outcomes after catheter-directed thrombolysis (CDT) combined with stent implantation for acute deep vein thrombosis (DVT) secondary to iliac vein compression (IVC). A retrospective analysis was performed to review clinical data and follow-up information on 52 patients who underwent CDT combined with stent implantation for acute DVT secondary to IVC from June 2015 to March 2020. Clinical outcomes including stent patency and incidence of postthrombotic syndrome (PTS) were investigated using Kaplan-Meier analysis. All included patients were categorized into 2 groups according to the presence of PTS. Potential risk factors, including age, gender, degree of iliac vein stenosis, time from onset to treatment, dosage of thrombolytic agent, stent extending below the inguinal ligament, and duration of anticoagulation for PTS were evaluated using multivariate logistic regression analysis. Over a median follow-up of 24 months, 4 individuals underwent reintervention due to in-stent stenosis or stent compression. Primary stent patency was 98.1% at 1 month, 94.2% at 6 months, 90.4% at 12 months, and 88.5% at 24 months. Freedom from PTS was 98.1% at 6 months, 84.6% at 12 months, and 75% at 24 months. No treatment-related mortality or morbidity was observed. Based on the development of PTS, 13 patients with PTS were classified into group A and 39 patients without PTS were regarded as group B. Upon multivariate logistic regression analysis, key prognostic factors for PTS were degree of iliac vein stenosis and time from onset to treatment. CDT combined with stent implantation is safe and effective for acute DVT secondary to IVC in the long-term perspective. Severe iliac vein stenosis and longer period from onset to treatment may be associated with a higher risk of PTS.

Acute left iliofemoral vein thrombosis: Comparison between simple and bony May-Thurner syndrome in CT venography.

OBJECTIVES: To explore the etiology of May-Thurner syndrome (MTS) with acute iliofemoral deep vein thrombosis (DVT) regarding imaging findings and clinical features. METHODS: We retrospectively analyzed 57 patients with acute left iliofemoral DVT from 2015 to 2020. The diameter of left common iliac vein (LCIV) at the maximal compression site and its percent compression regarding the average diameter of the uncompressed iliac vein were recorded in central and distal portions of the LCIV according to the location in the quadrant of lumbar vertebral body. Compression was categorized into simple and bony MTS; Simple MTS as LCIV compressed by the right common iliac artery (RCIA) versus Bony MTS as LCIV by lower lumbar degenerative changes regardless of RCIA compression. Initial computed tomographic venography (CTV) regarding chronic change of LCIV such as fibrotic atrophy or cordlike obliteration, extent of thrombus, and lumbar degenerative changes were evaluated. Therapeutic effect after initial therapy was assessed in follow-up CTVs after 3-6 months. RESULTS: All patients showed LCIV compression with 19 simple MTS (mean age, 42.8 ± 14.1 years [23-67 years]; 12 females; symptom for 4.4 ± 5.5 days) and 38 bony MTS (mean age, 73.0 ± 10.2 years [49-85 years]; 26 females; symptom for 5.5 ± 4.8 days). There was significant difference in age (p < .001) and no significant difference in sex or symptom duration between two groups (p = .691 and 0.415, respectively). All simple MTS showed compression only in the central LCIV and half of bony MTS showed compression in both central and distal LCIV (p < .001). Among the lumbar degenerative changes, symmetric anterolateral osteophyte (p < .001) and asymmetric osteophyte (p < .001) were significantly associated with bony MTS, but not scoliosis (p = .799), compared to simple MTS. Although there was no significant difference in chronic change of LCIV, thrombosis extent, and therapeutic effect between two groups (p > .05), chronic change of LCIV showed significant difference between single and dual compression (23.7% vs. 57.9%, p = .024) and residual thrombus after initial therapy was occurred in 21.1% of single compression and 47.4% in dual compression with non-significant trend (p = .082). CONCLUSION: Bony MTS related to lumbar degenerative changes with acute iliofemoral DVT occurs in older patients, presenting more than one stenosis at LCIV, inducing more chronic change with possibly weaker therapeutic effect than simple MTS.

Intravascular Ultrasound in Treating Iliac Vein Compression With Endovascular Stenting: A Necessary Tool for Optimal Outcomes.

Symptomatic compression of the left common iliac vein between the right common iliac artery and spinal vertebrae is referred to as May-Thurner Syndrome (MTS). Atypical cases of MTS including compression of the left external iliac vein, right iliac vein or the inferior vena cava can also coexist and cause double vein compression. Current literature suggests that endovascular treatment including thrombolysis, thrombectomy, venoplasty and stent placement to correct the mechanical obstruction together with anticoagulation therapy is safe and a reasonable management for patients with MTS. Intravascular ultrasound (IVUS) can aid in the diagnosis and the operative planning of MTS, especially regarding sizing and precise deployment of venous stents. Here we present 2 unique atypical cases of MTS with double left iliac vein compression treated endovascularly with stent placement along the common and external iliac vein with the assistance of IVUS.

Imaging Signs of May-Thurner Syndrome in Asymptomatic Patients: Computed Tomography Angiography Analysis of Kidney Donors.

BACKGROUND: The current study aimed to evaluate the distance between the right common iliac artery (RCIA) and lumbar vertebra in asymptomatic patients in order to determine whether such distance was statistically correlated with the left common iliac vein (LCIV) diameter (LCIVD) and to investigate if both measures were related to demographic characteristics and anthropometric data, such as sex, age, height, and body mass index (BMI). METHODS: In this descriptive and uncontrolled anatomic study, data from high-definition computed tomography (CT) angiography images of living kidney donors without a medical history of chronic venous insufficiency or past deep vein thrombosis (DVT) were analyzed. The RCIA crossed over the LCIV in 311 individuals, who were then included in this study. CT scans were reviewed to measure (1) the narrowest space between the RCIA and fifth lumbar vertebral body and (2) the LCIVD. Measures were subjected to normality tests and were divided according to the sex of the study population. Correlations of measures with age, BMI, and height were calculated. RESULTS: Of the 311 patients analyzed, 66.6% (n = 207) were female. The mean lumbar vertebral body-iliac artery distance (LVBIAD) was 7.2 mm, whereas the mean LCIVD was 8.5 mm; both were higher in men (P < 0.001). The statistical analysis of LVBIAD and LCIVD distributions revealed no normality pattern (P < 0.05). The analysis of the correlation between them showed a weak statistically significant relationship with age. A linear regression model considering the normality percentile interval indicated a strong positive correlation between LVBIAD and LCIVD (R2 = 0.884). CONCLUSIONS: The LVBIAD was <5 mm and <3 mm in 25% and 5% of asymptomatic individuals, respectively. The LCIVD correlated with the space between the RCIA and lumbar vertebra. The distance between the RCIA and lumbar vertebra and the LCIVD were higher in male subjects and older patients, but did not correlate with BMI and height.

Seizures, deep vein thrombosis, and pulmonary emboli in a severe case of May-Thurner syndrome: a case report.

BACKGROUND: May-Thurner syndrome is a vascular disorder caused by the right common iliac artery compressing the left common iliac vein against the lumbar spine, causing distal venous stasis and potentially leading to fibrous change in the venous wall structure. Although May-Thurner syndrome is most commonly discovered in females upon investigation of new-onset deep vein thrombosis, we present the case of an otherwise healthy 29-year-old male with severe May-Thurner syndrome who presented with seizures, bilateral deep vein thrombosis, and diffuse pulmonary emboli. Seizures constituted the earliest presenting symptoms for the patient. Although it is difficult to prove that the patient's seizures were related to the May-Thurner syndrome, this possible association renders this case extraordinary. CASE PRESENTATION: This report describes the case of a 29-year-old previously healthy white male with a severe case of left-sided May-Thurner syndrome that required extensive medical and interventional treatment. The patient experienced two seizures, one month apart, both of which occurred while residing at high altitude. The patient had no prior history of seizures, and epilepsy was ruled out. Three weeks after the second seizure, he presented to the emergency room with hemoptysis, dyspnea, and severe leg pain. Sites of thrombus were confirmed in both legs and diffusely in the lungs. Etiological work-up after treatment with intravenous tissue plasminogen activator revealed May-Thurner syndrome. Hematology workup including genetic testing showed no evidence of coagulopathy. Bilateral common iliac venous stents were placed to attempt definitive treatment. Despite stenting, the patient had another thrombotic event with associated sequelae after discontinuation of anticoagulation. The patient has not had another seizure since the stents were placed. Despite the negative testing, the patient remains on lifelong chemoprophylaxis in the event of an undiscovered hypercoagulopathy. CONCLUSIONS: The care team theorizes that the seizures resulted from hypoxia due to May-Thurner syndrome-induced hemostasis and associated thrombotic events, the high-altitude location of his residence at the time he experienced the seizures, and shallow breathing during sleep. For patients with lower limb venous thrombosis, May-Thurner syndrome should be considered in the differential diagnosis. Endovascular treatment followed by extended prophylactic anticoagulation therapy until the patient is determined to be no longer at risk for thrombosis is recommended. Post-venoplasty thrombosis is a common complication of endovascular treatment of May-Thurner syndrome and should be carefully monitored.