May-Thurner Syndrome In Patients Research Articles

Optimization of Arterial Stents for May-Thurner Syndrome Management in West Java: Experience and Outcome

Abstract Context: May-Thurner syndrome (MTS) is an anatomical defect where the right common iliac artery overrides and compresses the left iliofemoral vein. MTS causes deep vein thrombosis (DVT) but is often underdiagnosed. As anticoagulant management (warfarin) rarely achieves target INR, endovascular management is vital for MTS. Surgical and endovascular management of MTS has known to have similar good outcome. Endovascular management is generally facilitated using a venous stent. However, the unavailability of the venous stent in Indonesia made arterial stent be optimized during vein stenting procedure. Aims: We aim to report our experience. Settings and Design: Consecutive observational study within 26 months in a hospital in West Java including 6 MTS patients. Subjects and Methods: Diagnosis is established by the finding of proximal femoral DVT by ultrasonography further confirmed by computed tomography (CT) angiography. Endovascular management was done using arterial stent placement. After endovascular management, we reviewed the outcome on a follow-up including stent fracture, in-stent restenosis (ISR), and stent patency. These are also monitored by serial imaging by CT Angiography, with periods ranging from 1.5 to 10 months (mean: 4.08 months). Direct oral anticoagulants and antiplatelets are usually given along with compression stockings following the procedure. Statistical Analysis Used: None. Results: No stent fracture, no ISR, and the stent remained patent after follow-up. No patient had complications. Conclusions: Apart from the difference in radial power compared to the venous stent, the arterial stent is feasible to use during MTS endovascular management with good postprocedural results. Prompt management is needed to prevent complication and chronic total occlusion. Comprehensive management should be ensured to optimize patients’ quality of life. We do hope that venous stent will be available in the future.

May Thurner Syndrome: Diagnostic and Therapeutic Outcomes in an Institutional Setting

Introduction: May-Thurner syndrome (MTS), a chronic compression of left common iliac vein (CIV) against the lumbar vertebrae by overlying common iliac artery is an underappreciated contributor to left leg deep venous thrombosis. Even though the estimated prevalence of MTS is high in left-leg deep vein thrombosis (DVT) cases per autopsy studies, the clinical association remains low. Since the screening for MTS in patients with recurrent left-leg DVTs is not a common practice, diagnosis can either be incidental or a combination of clinical presentation and objective testing. Diagnosis is challenging via ultrasound (US) due to the deep anatomical location of iliac veins; therefore, invasive imaging including Contrast venography (CTV) is needed for confirmation. The management of MTS has been reformed over the years with the advances in minimally invasive therapeutic tools. We sought to review the management and outcomes of the MTS adult population by conducting a retrospective review to identify all adult cases of MTS at our academic safety net hospital between 2010 and 2022. Methods: Data was extracted and analyzed for baseline parameters including age, gender, ethnicity, and body mass index (BMI). Presenting symptoms, imaging used for MTS diagnosis (including US Doppler, magnetic resonance venography or CTV), and interventional approaches (catheter or systemic thrombolysis, thrombectomy, balloon angioplasty and/or stent placement) were additionally documented. SAS v9.4 (Cary, NC) was used for statistical analysis. Results: A total of 19 cases, predominantly females 68% (13/19), with a median age of 48 years and a mean BMI of 28.84 kg/m 2 diagnosed with MTS were identified. The predominant initial presentation was left lower extremity edema and pain 36% (7/19) later found to have a DVT, followed by non-healing venous ulcer 15% (3/19) and pelvic congestion syndrome 0.05 % (1/19). Whereas 42% (8/19) of the patients were diagnosed with MTS while undergoing evaluation for chronic and recurrent DVTs. All patients were diagnosed following CTV using transvenous pressures with the formation of collateral veins and a pressure gradient of more than 2 mm Hg across iliofemoral stenosis at rest. Sixteen patients (84%) underwent endovascular stent placement, while one patient underwent Balloon Angioplasty only. One patient refused any intervention for MTS however underwent great saphenous vein ablation for chronic venous wounds. In view of anticoagulation therapy, the initial choice in the most cases was low molecular weight heparin (LMWH), which was later transitioned to other choices, 81 % (10/16) were switched to direct oral anticoagulants, (apixaban= 10, rivaroxaban=3) due to ease of administration and compliance, while 19 % (3/16) were continued on LMWH for patient preference and pregnancy. Post-intervention complications consisted of stent failure in 25% (4/16) patients; related to stent thrombosis and Post-thrombotic Syndrome (PTS) in 12.5 % (2/16) patients. No bleeding complications were seen post any case of endovascular stent placement. Conclusion: This review was a highly educational experience giving us insight into this unacknowledged syndrome. Multiple factors could be contributing to this underdiagnosis, including invasive gold standard imaging for MTS, more easily recognizable risk factors for DVTs that can overshadow MTS, and a smaller number of data and studies. Some authorities have advocated a need to rule out MTS in young women with acute left lower extremity DVT, a clear female predominance was also noted (68%) in our analysis. Post-stent placement, systemic anticoagulation for 3-6 months is recommended, in our review, all patients (100%) who underwent stent placement were started on anticoagulation for at least 3 months. A small sample size, patients lost to follow-up (poor outcomes and complications could have been missed) and a single institutional review were some limitations of our study, however with a rare disease such as MTS with 2-3% prevalence it is difficult to conduct a large size, multi- institutional analysis. This study contributes to the limited literature available on MTS.

May-Thurner Syndrome: a case of unilateral left lower limb deep vein thrombosis

The May–Thurner Syndrome (MTS) is a rare anatomical condition in which the compression of the left common iliac vein by the right common iliac artery causes an outflow obstruction, presenting frequently as chronic venous insufficiency or deep venous thrombosis (DVT). This variant is rarely considered when investigating DVT, especially in patients with other risk factors. MTS requires careful workup and management to avoid complications such as chronic venous insufficiency, post-thrombotic syndrome, and primary lymphedema. The authors present a 63-year-old woman admitted to the emergency department with a 24-hour history of left lower limb pain and edema. Initial assessment, with computed tomography of the lower left limb and pelvis, showed compression of the left common iliac vein with an extensive thrombus of the left common iliac and external iliac veins, as well as femoral and popliteal left veins, consistent with MTS. Therapeutic enoxaparin initially implemented, was then switched to oral anticoagulation. At 6 months reevaluation, venous duplex ultrasound showed only partial recanalization of the femoral vein. Investigation for May-Thurner Syndrome in patients with left lower limb venous thrombotic events, regardless of risk factors, should always be present since the establishment of an effective therapeutic plan and eventually, endovascular treatment can minimize the long-term sequelae of deep vein thrombosis.

May-Thurner Syndrome and Lymphedema Reconstruction.

Background:May-Thurner syndrome (MTS) is an anatomical variant that results in compression of the left common iliac vein by the right common iliac artery. Although often asymptomatic, lower extremity swelling/edema, deep venous thrombosis, post-thrombotic syndrome, and eventual lymphedema (due to long-standing venous obstruction) can develop. The clinical management of patients presenting for lymphedema surgery with concomitant or undiagnosed MTS is not well described.Methods:This review investigates two patients who were evaluated for unilateral lower extremity lymphedema, both of whom were subsequently diagnosed with MTS. Standard imaging (including lymphoscintigraphy, indocyanine green lymphangiography, and magnetic resonance venography) were performed to identify proximal venous obstruction. Treatment was accomplished using vascular surgical management, including stenting of the iliac vein before lymphedema reconstruction with vascularized lymph node transfer and multiple lymphovenous bypass.Results:Both patients we examined in this review had improvement of lymphedema with vascular surgical management. Literature review reveals that MTS has an incidence as high as 20% in the population, although commonly unidentified due to lack of symptomatology.Conclusions:There are no studies documenting the incidence of MTS in patients referred for lymphedema surgical management. Routine studies should be obtained to screen for proximal venous obstruction in patients presenting for surgical management of lower extremity lymphedema. Additional research is needed regarding the approach to managing patients with both MTS and lymphedema. Careful observational and prospective studies may elucidate the appropriate time interval between venous stenting and lymphedema microsurgical reconstruction.

The Prevalence of May Thurner Syndrome in Children with Ileo-Femoral Deep Vein Thrombosis- Does It Take 2 to Tango?

Introduction:May-Thurner syndrome (MTS) is characterised by compression of the left external iliac vein by overriding right common iliac artery resulting in venous stasis. It carries a higher risk of left iliofemoral deep vein thrombosis (DVT), however the prevalence and management guidelines are unclear in pediatrics. We reviewed the prevalence of MTS in children diagnosed with left iliofemoral DVT at our center, associated prothrombotic risk factors and their clinical outcomes.Methods:This is a retrospective audit of pediatric patients (<18 years) with left iliofemoral DVT treated at the IWK Health Center from January 1 2008 to December 31 2020.Results:Twelve pediatric patients with left iliofemoral DVT were identified at our center and all patients except one had MRV/CTV during their course of anticoagulation to evaluate for MTS. MTS was diagnosed on imaging in 8 of the eleven evaluable patients with DVT and one patient had an incidental diagnosis of MTS with no DVT. The median age at diagnosis of MTS was 15 years (13-16), male:female ratio of 1:8. The overall prevalence rate was of MTS was 72.72% (8/11) in patients with left iliofemoral DVT. All patients with iliofemoral DVT and MTS had at least one other prothrombotic risk factor- initiation of estrogen containing contraceptive pills in the preceding 3 months of the DVT (n=5), inherited thrombophilia (n=2) and obesity (n=2).All patients with MTS were referred to vascular surgery. Only one patient required catheter directed thrombolysis and stenting at presentation of DVT, the remaining 7 patients were managed with anticoagulation alone. Complete (n=1) or partial (n=7) resolution of the thrombus was seen in all 8 patients. Median duration of follow up was 3 years. Recurrent DVT was seen in 1 patient and two patients came off anticoagulation at 6 months post therapy. Post thrombotic syndrome was seen in 4 patients, mild in 3 and moderate in 1; as per modified Villalta score.Conclusion:We observed a high prevalence of MTS in patients with left iliofemoral DVT which may be due our screening approachwith upfront radiographic evaluation for MTS in all patients with left iliofemoral DVT. A second pro-thrombotic risk factor was identified in all patients, which raises the possibility of a “two hit theory” for the occurrence of DVT in MTS. Compared to published adult studies, majority of our pediatric patients were managed conservatively with anticoagulation therapy alone. DisclosuresNo relevant conflicts of interest to declare.

Outcomes and Risk Factors Associated with Thrombosis Recurrence and Post-Thrombotic Syndrome in Children and Adolescents with May-Thurner Syndrome

Introduction : May-Thurner syndrome (MTS) is a condition in which the right iliac artery compresses the left iliac vein, predisposing affected individuals to venous outflow obstruction and deep vein thrombosis (DVT). Despite the frequency of this anatomic variant, found in 20-25% of adults, not everyone with this variant will develop a DVT. Adults with MTS are treated with catheter-directed thrombolysis (CDT), anticoagulation, and often iliac vein stent placement. There is no standard of care established for pediatric MTS patients. The aims of this study are to 1) describe risk factors, clinical factors, and outcomes (complications of CDT, recurrence rate, post-thrombotic syndrome) in a pediatric MTS cohort and 2) determine what factors are associated with thrombus resolution, recurrence, and development of post-thrombotic syndrome (PTS).Methods : A retrospective cohort of children (0-21 years) diagnosed with MTS and DVT were identified between January 1, 2012 and July 15, 2017. MTS was confirmed by CT venogram, MR venogram, intravascular ultrasound, and/or conventional endovascular venography. Patient demographic, clinical, and thrombophilic risk factors, clinical outcomes (resolution, recurrence, PTS using modified Villalta scale), and bleeding complications were abstracted from review of the electronic medical record. Bleeding complications were defined by ISTH definitions for pediatric trials. Student's t test, Wilcoxon rank sum test, Chi square test and logistic regression analysis were used for statistical analysis (SAS v9.4, Cary, NC, USA).Results : The cohort was comprised of 23 subjects, 65% of them female (n=15), with a median age at presentation of 16.1 years (9.9-19.7 years). The median follow-up time was 505 days. The most frequent risk factor was thrombophilia (n=10), which included Factor V Leiden mutation (n=6), antithrombin deficiency (n=3), protein S deficiency (n=3), lupus anticoagulant (n=3), prothrombin gene mutation (n=1), protein C deficiency (n=1), or more than one thrombophilia (n=3). Other risk factors included hormone therapy (n=8), obesity (n=7), family history of DVT (n=6), immobility (n=5), central line (n=2), lupus (n=1), pregnancy (n=1), trauma (n=1), surgery (n=1), nephrotic syndrome (n=1), and retroperitoneal fibrosis (n=1). One subject had no risk factor, while 14 (61%) had multiple risk factors. Among the subjects, 78% underwent CDT (n=18) and 83% had stent placement (n=19). The remaining subjects will have future stent placement. Following CDT, there were no major bleeding complications (1 minor and 1 clinically relevant non-major bleeding complication). Other complications included pain (n=8), hemolysis (n=7), hemoglobinuria (n=2), hypofibrinogenemia requiring cryoprecipitate infusion (n=2), and transient increase in creatinine (n=1). Primary patency, defined as >90% patency of vessel diameter in the first week after CDT, was achieved in 91% (n=21). Thrombosis resolution was seen in 91% (n=21) of the cohort. Anticoagulant treatment prescribed included enoxaparin (65%), rivaroxaban (30%) and warfarin (26%). In univariate analyses, the only factor associated with thrombus resolution was primary patency (p=0.0012). DVT recurred in 13% (n=3), with a median time of 32 days off anticoagulation. The only factor associated with recurrence was antithrombin deficiency (p=0.048). Ten subjects (43%) had no evidence of PTS and 13 had mild PTS (57%). There were no significant factors associated with the development of PTS.Conclusions : To our knowledge, this is the largest retrospective cohort of pediatric subjects with MTS and DVT. Underlying thrombophilia was the most common risk factor found, suggesting that patients diagnosed with MTS warrant thrombophilia evaluation. Bleeding complications associated with CDT were minimal and non-bleeding complications were transient, demonstrating that CDT is safe in the pediatric population. Efficacy of CDT in this population is supported by the finding that primary patency is an important factor for thrombosis resolution. Lastly, thrombosis recurrence was not uncommon (13%) and was likely to occur soon after stopping anticoagulation. These findings demonstrate that multicenter studies are needed in children with MTS to evaluate the efficacy of CDT to achieve thrombus resolution, and that evaluation of thrombophilic risk factors should be considered. DisclosuresNo relevant conflicts of interest to declare.

Atypical iliac vein compression in patients with symptomatic May-Thurner syndrome.

We aimed to investigate the incidence, etiology, treatment, and clinical course of atypical iliac vein compressions (AIVCs) among patients with May-Thurner syndrome (MTS). A total of 173 patients who presented with MTS were retrospectively analyzed at a single center. Computed tomographic venography (CTV) was used to diagnose MTS. An AIVC was defined as the compression of the left common iliac vein (LCIV) by structures other than the right common iliac artery (RCIA) or the compression of other venous structures in the pelvic cavity instead of the LCIV. The patients with AIVC were categorized into the LCIV compression group (category A) and non-LCIV compression group (category B). Ten patients with AIVC were identified (5.8%; male/female, 5/5), five in category A and five in category B. The median age of patients was 76 years (range, 51-94 years), and the median follow-up duration was 388 days (range, 12-4694 days). In category A, the LCIVs were compressed by the left common iliac artery (LCIA) (n=2), uterine leiomyoma (n=1), LCIA aneurysm (n=1), and RCIA aneurysm (n=1). In category B, the right common iliac veins were compressed by the RCIA (n=4) and L5 osteophyte (n=1). Endovascular treatment, including balloon angioplasty and stent placement, was performed in six patients, three from each group. Three patients underwent conservative treatment due to their advanced age and comorbidities. Endovascular aneurysm repair was performed in one patient with RCIA aneurysm. Follow-up images were available for six patients, and all of them had patent venous flow. The AIVC had an incidence of 5.8% (10/173) among symptomatic MTS patients and wide spectrum of etiologies. Pathogenesis-tailored endovascular treatments are safe and effective.

May\u2013Thurner syndrome, a diagnosis to consider in young males with no risk factors: a case report and review of the literature

BackgroundMay–Thurner syndrome is an anatomical condition characterized by compression of the left common iliac vein by the right common iliac artery, causing venous outflow obstruction. It is an uncommon cause of deep vein thrombosis and is more prevalent among women. This paper highlights the importance of considering May–Thurner syndrome in young males without risk factors presenting with left lower limb pain, as endovascular treatment may be required.Case presentationA 23 year-old Caucasian male presented with a 1-week history of left lower limb pain, edema, and pallor. He was found to have an unprovoked deep vein thrombosis on Doppler ultrasound involving the left fibular, soleus, gastrocnemius, popliteal, femoral, common femoral, and external iliac veins. A heparin infusion was commenced as the initial treatment for deep vein thrombosis. Further investigation with computer tomography pulmonary angiogram and computer tomography venography of the abdomen and pelvis showed bilateral pulmonary emboli and left common iliac vein compression with left common, internal, and external iliac vein thrombosis. He was diagnosed with May–Thurner syndrome despite having no risk factors. A retrievable Cook Celect Platinum inferior vena cava filter was placed, and thrombus of the left common femoral, external, and common iliac veins was treated successfully with AngioJet thrombectomy, thrombolysis using 200,000 units of urokinase, angioplasty and stenting using two Cook Zilver Vena venous self-expanding stents. Therapeutic enoxaparin was commenced on discharge. His filter was removed after 10 weeks. Hematological follow-up 4 months later showed an overall negative thrombophilia screen, and anticoagulation was switched to apixaban. He has had no recurrent thrombosis.ConclusionsClinicians should have a low threshold to investigate for May-Thurner syndrome in patients with left lower limb venous thrombotic events regardless of risk factors, as endovascular treatment may be required to minimize the long-term sequelae of deep vein thrombosis. Duplex ultrasound can be used initially for diagnosis, and computer tomography venography used subsequently if the common iliac vein is not visualized on ultrasound. Endovascular treatment is preferred over anticoagulation alone, especially in otherwise fit patients presenting early, the aim being to reduce the chances of chronic venous hypertension in the lower limb.

Prevalence of May-Thurner Syndrome in Patients with Deep Vein Thrombosis at a Large Medical Referral Center.

We set out to investigate the prevalence of May-Thurner syndrome (MTS) in a cohort of patients diagnosed with iliofemoral deep vein thrombosis at a large medical referral center. We retrospectively analyzed a cohort of 496 patients who were referred to the emergency unit of a large medical referral center with suspected venous thromboembolism (VTE) and were diagnosed with deep vein thrombosis of the iliac veins and/or the thigh on ultrasound. We retrospectively assessed the presence of MTS in the primary ultrasound examination and on additional imaging (available in n = 193 patients). Across all 496 patients with iliofemoral deep vein thrombosis, the median age was 70 years. 238 patients (48 %) were female. The thrombosis was left-sided in 263cases (53 %), right-sided in 208 cases (42 %) and bilateral in 24 cases (5 %). In the subgroup of patients with left-sided and bilateral thrombosis, the growth pattern was classified as ascending in 142 patients (50 %), descending in 104 patients (36 %) and unclear in 41 patients (14 %). Additional imaging tests were available in 193 patients: 119 patients (41 %) underwent CT, 18 patients (6 %) MRI and 30 patients (10 %) underwent phlebography. Within the subgroup of patients with left-sided and bilateral thrombosis, MTS was confirmed in 88 patients (31 %), and the imaging findings in 17 patients (6 %) were highly suspicious of MTS. Differentiation was not possible in 86 patients (30 %) and MTS was excluded in 96 patients (33 %). Underlying MTS is not uncommon in the selected cohort of patients with deep iliofemoral vein thrombosis at a large referral center and should be excluded by imaging. · May-Thurner syndrome (MTS) is a relatively frequent cause of deep vein thrombosis.. · MTS should be excluded in patients with left-sided or bilateral iliofemoral thrombosis.. · Cross-sectional imaging is helpful in this setting.. · Approximately one third of patients in this subgroup show signs of MTS.. · Heller T, Teichert C, Hafer J et al. Prevalence of May-Thurner Syndrome in Patients with Deep Vein Thrombosis at a Large Medical Referral Center. Fortschr Röntgenstr 2019; 191: 1107 - 1117.

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.

4:12 PM Abstract No. 359 Single-session flow restoration in May-Thurner syndrome with secondary acute iliofemoral deep venous thrombosis

Catheter-directed thrombolysis (CDT) for iliofemoral deep venous thrombosis (DVT) associated with May-Thurner syndrome (MTS) traditionally requires lytic infusion in an intensive care unit (ICU) and multi-day procedures. The advent of venous-specific thrombolytic devices has improved procedural efficiency. We aim to evaluate the efficacy of single-session therapy utilizing rheolytic pharmacomechanical thrombectomy (PMT) followed by stent placement for MTS with secondary acute DVT. MTS patients treated in a single-session were retrospectively analyzed. All procedures were performed utilizing 8Fr rheolytic PMT with power-pulse administration of 10 mg of alteplase into thrombosed segments, 30-minute dwell time, followed by thrombectomy mode. Additional balloon angioplasty/suction thrombectomy was employed as necessary; 14 mm iliac vein self-expanding stents were placed in all patients. Pre- and postprocedure venous clinical severity scores (VCSS) were calculated and paired t-test was performed; significance was determined at p<0.05. From 7/2016 to present, 6 patients (4M:2F, mean age 51) with acute left iliofemoral DVT secondary to MTS were identified; initial diagnosis was via venous duplex exam. All patients presented with lower extremity edema/pain; mean symptom duration was 3 (range, 1-7) days. Rheolytic PMT with total run time confined to less than 240 seconds, followed by suction thrombectomy (4/6 patients), balloon angioplasty (2/6 patients), and stent placement was performed. Single-session flow restoration with symptomatic relief was achieved in all patients; VCSS decreased from a mean of 6 ± 0.8 (SEM) to 1.8 ± 0.8 (p = 0.002) postprocedure. Patients were followed up by computed tomographic venography (CTV) at approximately 1 month, all patients demonstrated stent patency. Single-session treatment appears effective for MTS with secondary acute DVT when 8Fr rheolytic PMT is used with local lytic administration, potentially improving DVT thrombolysis safety profile by limiting prolonged lytic exposure and avoiding ICU observation. Further study is necessary to confirm the long-term efficacy of this protocol.

Abstract TP160: May-Thurner Syndrome is Associated With Stroke Due to Paradoxical Embolism

Background: May-Thurner Syndrome (MTS) is a potential risk factor for cryptogenic stroke (CS). While retrospective reports have found important association with MTS in CS, prospective data has been lacking. In this study, we prospectively explored the epidemiology and clinical correlates of MTS patients with cryptogenic stroke. Method: Eligible patients were prospectively recruited in accordance with an IRB-approved protocol. All patients underwent full evaluation of etiopathogenesis of stroke such as MRI/MRA, long-term cardiac telemetry (&gt;30 days), echocardiography, and extensive thrombophilia screen (AT3, FV Leiden, Proteins C and S; prothrombin gene mutations, APLAbs, lipoprotein(a), homocysteine) and 1.5T pelvic MRV. Results: We prospectively recruited 1,131 acute ischemic stroke patients, with 59 patients with PFO-related CS; 15 (40.5%) had May-Thurner anatomy (MTA), and 6 (16.2%) had MTS. MTS pts are younger (36.33±9.95 vs. 53.35±14.78, p=0.011), with a lower trend for BMI (24.40±4.87 V.S. 31.13±8.75, p=0.051, table 1). Lower BMI is predictive of MTS in CS (&lt;=22) with high specificity 93.3% (AUC=0.756, p=0.007). Conclusion: In this prospective study, we found MTA and MTS to be very common in PFO CS patients - especially in younger patients with lower BMI and without traditional stroke risk factors. MTS is a novel risk factor that may aide in the diagnosis of PFO CS, and needs further study.

Contemporary outcomes after venography-guided treatment of patients with May-Thurner syndrome.

Patients with May-Thurner syndrome (MTS) present with a spectrum of findings ranging from mild left leg edema to extensive iliofemoral deep venous thrombosis (DVT). Whereas asymptomatic left common iliac vein (LCIV) compression can be seen in a high proportion of normal individuals on axial imaging, the percentage of these persons with symptomatic compression is small, and debate exists about the optimal clinical and diagnostic criteria to treat these lesions in patients with symptomatic venous disease. We evaluated our approach to venography-guided therapy for individuals with symptomatic LCIV compression and report the outcomes. All patients with suspected May-Thurner compression of the LCIV between 2008 and 2015 were analyzed retrospectively. Patients with chronic iliocaval lesions not associated with compression of the LCIV were excluded from analysis. Criteria for intervention included LCIV compression in the setting of (1) leg edema/venous claudication with associated venographic findings (collateralization, iliac contrast stagnation, and contralateral cross cross-filling), or (2) left leg deep venous thrombosis. Outcome measures included presenting Clinical, Etiology, Anatomy, Pathophysiology (CEAP) score, postintervention CEAP score, primary patency, and secondary patency. Technical success was defined as successful stent implantation without intraoperative device complications, establishment of in-line central venous flow, and less than 30% residual LCIV stenosis. Of the 63 patients evaluated, 32 (51%) had nonthrombotic MTS and presented with leg edema (100%) or venous claudication (47%). Thirty-one patients (49%) had thrombotic MTS and presented with acute (26%) or chronic (71%) DVT, leg edema (100%), or venous claudication (74%). The mean presenting CEAP score was 3.06 and 3.23 for nonthrombotic and thrombotic MTS, respectively. Forty-four patients (70%) underwent successful intervention with primary stenting (70%) or thrombolysis and stenting (30%); 14 nonthrombotic MTS patients were treated conservatively with compression therapy alone, and 5 thrombotic MTS patients were treated with lysis or angioplasty alone. Clinical improvement and decrease in CEAP score occurred in 95% and 77% of stented patients compared with 58% and 32% of nonstented patients. Complete symptom resolution was achieved in 48% of patients overall, or 64% of stented patients and only 21% of nonstented patients. Complications included two early reocclusions. Primary and secondary 2-year patency rates were 93% and 97% (mean follow-up, 20.3 months) for stented patients. Venography-guided treatment of MTS is associated with excellent 1-year patency rates and a significant reduction in symptoms and CEAP score. Treating symptomatic MTS patients on the basis of physiologically relevant venographic findings rather than by intravascular ultrasound imaging alone results in excellent long-term patency and clinical outcomes but may result in undertreatment of some patients who could benefit from stent implantation.

3:39 PM, Abstract No. 307 - Incidence of May-Thurner syndrome (MTS) in patients under evaluation of lower extremity venous reflux: implications for treatment

3:39 PM, Abstract No. 307 - Incidence of May-Thurner syndrome (MTS) in patients under evaluation of lower extremity venous reflux: implications for treatment

Endovascular Treatment of Iliac Vein Compression (May-Thurner) Syndrome: Angioplasty and Stenting with or without Manual Aspiration Thrombectomy and Catheter-Directed Thrombolysis.

May-Thurner syndrome (MTS) is a rare clinical entity featuring venous obstruction of the left lower extremity. The aim of the present study was to report our experience with MTS and to evaluate the utility of treatment using endovascular techniques. We retrospectively analyzed data on 23 MTS patients (21 females, two males; mean age 44 ± 15 years). Eighteen patients presented with deep vein thrombosis (DVT) and five with symptoms associated with chronic venous hypertension (CVH). DVT patients were treated via thromboaspiration, catheter-directed thrombolysis, and angioplasty; followed by stent placement. CVH patients were treated with angioplasty and stent placement alone. All patients were followed-up using Doppler ultrasonography and computed tomography venography. Complete left common iliac vein patency was achieved in 21 of the 23 patients (technical success rate: 91,3%). Complete thrombolysis was attained by 14 of the 18 DVT patients (77.7%). The mean clinical and radiological follow-up time was 15.2 ± 16.1 months. Upon follow-up, complete symptomatic regression was observed in 19 of the 23 patients (82.6%). Stent patency was complete in 19 of the 21 patients (90.4%) who received stents. Restenosis occurred in two patients. No treatment-related mortality or morbidity was observed. Endovascular treatment of MTS is safe and effective and reduces symptoms in most patients, associated with high medium-term patency rates.

Outcomes of endovascular intervention for May-Thurner syndrome.

Endovascular interventions for May-Thurner syndrome (MTS) have become first-line therapy, often performed in a young patient population despite the lack of robust supportive data. This article reports on long-term outcomes from a large series of patients treated in the setting of de novo or postthrombotic presentation. A retrospective review of MTS patients treated between 2006 and 2010 was conducted at two institutions. Patients who presented with acute iliofemoral deep vein thrombosis (DVT) were treated with either catheter-directed thrombolysis (CDT) and/or pharmacomechanical thrombolysis and identified as having a venous stenosis by venogram orintravascular ultrasound (IVUS). Patients who presented with chronic venous insufficiency symptoms or recalcitrant ulceration but no DVT and evidence of MTS on duplex ultrasound, magnetic resonance venography, or computerized tomography venography were evaluated by venography. IVUS was selectively utilized. Stenting of the iliocaval junction was performed in all patients with a >50% diameter stenosis by IVUS or venogram. Seventy patients with MTS underwent 77 lower extremity interventions. They were divided into two groups: postthrombotic (group 1) and de novo presentation of chronic swelling/pain or ulceration but no DVT (group 2). There were 56 extremities in group 1 and 21 extremities in group 2. Both groups were comparable in terms of gender distribution and comorbidities, but hypercoagulable state was more common in group 1 (P= .014), and average CEAP and Villalta scores on presentation were higher in group 2 (P< .001). There were left-sided symptoms in 40 (78%) patients in group 1 and 15 (79%) in group 2 (P= 1.00). Female patients were more likely to have left-sided symptoms compared with male patients (odds ratio, 4.88; 95% confidence interval, 1.49-15.89; P= .014). The average stent size was significantly different among the groups (P< .027), with different types used in each group. There was one patient in group 1 who had significant periprocedural bleeding (1 unit transfused) during the CDT portion of the procedure. Mean follow up was 29.7months in group 1 (range, 18.4-58.3 months) and 22.4months in group 2 (range, 17.1-42 months). Complete or partial symptom relief was reported for 52 (92.9%) extremities in group 1 and 20 (95.2%) extremities in group 2 (P= 1.00). The overall primary patency of group 1 at 36 months by life-table analysis was 91% with a secondary patency of 95%. The primary and secondary patency for group 2 was 91% at 36months. Stenting of MTS has proven to be safe, efficacious, and durable for up to 36 months in both the postthrombotic patient as well as those treated for edema alone.

Maximal Venous Outflow Velocity: An Index for Iliac Vein Obstruction

Leg swelling is a common cause for vascular surgical evaluation, and iliocaval obstruction due to May-Thurner syndrome (MTS) can be difficult to diagnose. Physical examination and planar radiographic imaging give anatomic information but may miss the fundamental pathophysiology of MTS. Similarly, duplex ultrasonographic examination of the legs gives little information about central impedance of venous return above the inguinal ligament. We have modified the technique of duplex ultrasonography to evaluate the flow characteristics of the leg after tourniquet-induced venous engorgement, with the objective of revealing iliocaval obstruction characteristic of MTS. Twelve patients with signs and symptoms of MTS were compared with healthy control subjects for duplex-derived maximal venous outflow velocity (MVOV) after tourniquet-induced venous engorgement of the leg. The data for healthy control subjects were obtained from a previous study of asymptomatic volunteers using the same MVOV maneuvers. The tourniquet-induced venous engorgement mimics that caused during vigorous exercise. A right-to-left ratio of MVOV was generated for patient comparisons. Patients with clinical evidence of MTS had a mean right-to-left MVOV ratio of 2.0, asymptomatic control subjects had a mean ratio of 1.3, and MTS patients who had undergone endovascular treatment had a poststent mean ratio of 1.2 (P = 0.011). Interestingly, computed tomography and magnetic resonance imaging results, when available, were interpreted as positive in only 53% of the patients with MTS according to both our MVOV criteria and confirmatory venography. After intervention, the right-to-left MVOV ratio in the MTS patients was found to be reduced similar to asymptomatic control subjects, indicating a relief of central venous obstruction by stenting the compressive MTS anatomy. Duplex-derived MVOV measurements are helpful for detection of iliocaval venous obstruction, such as MTS. Right-to-left MVOV ratios and postengorgement spectral analysis are helpful adjuncts to duplex imaging for leg swelling. The MVOV maneuvers are well tolerated by patients and yields physiological data regarding central venous obstruction that computed tomography and magnetic resonance imaging fail to detect.

Abstract No. 34: The incidence of May-Thurner syndrome in patients with multiple sclerosis (MS) undergoing endovascular treatment for chronic cerebrospinal venous insufficiency (CCSVI)

Abstract No. 34: The incidence of May-Thurner syndrome in patients with multiple sclerosis (MS) undergoing endovascular treatment for chronic cerebrospinal venous insufficiency (CCSVI)

An IVUS study of May-Thurner syndrome in patients with cryptogenic stroke and patent foramen ovale

Background: We have previously documented the incidence of MayThurner Syndrome (MTS) in patients with cryptogenic stroke and patent foramen ovale (PFO). We prospectively performed intravascular ultrasound (IVUS) in a cohort of 16 patients undergoing PFO closure in the context of a cryptogenic stroke. Methods: IVUS was performed of the left common iliac vein (CIV) in all patients with documented MTS by magnetic resonance venography using an 8F, 40-MHz transducer (Boston Scientific Corporation, Natick, MA, USA). The transducer was positioned distally in the inferior vena cava and systematically pulled back through the left CIV into the sheath. Studies were recorded and analyzed offline. Results: The patients were predominantly female (88%) with a mean age of 40±12 years. The group represented a low cardiovascular risk group with hypertension (12%), hypercholesterolemia (11%), smokers (27%), and diabetes (17%). All PFOs demonstrated right-to-left shunting on transesophageal echocardiography. Atrial septal aneurysms were present in 16% and hypermobile atrial septae in 17% of patients. IVUS demonstrated N75% lumen area stenosis from the adjacent right common iliac artery in all studied vessels. Intimal venous spurs were observed in two patients, venous stasis with rouleaux formation was observed in 10 patients but no evidence of deep venous thromboses was evident in these vessels. Conclusion: IVUS is a safe and reliable invasive tool for the study of MTS in the context of PFO and cryptogenic stroke. This study further highlights the importance of the association of MTS and PFO in the context of cryptogenic stroke.

May-Thurner Syndrome in Patients With Cryptogenic Stroke and Patent Foramen Ovale

We aimed to investigate the incidence of May-Thurner syndrome in patients with cryptogenic stroke with patent foramen ovale. This was a retrospective study. All consecutive patients with cryptogenic stroke having undergone patent foramen ovale closure from January 1, 2002, to December 31, 2007, at our institute were included in this study. Pelvic magnetic resonance venography studies of all patients were reviewed to determine if features of May-Thurner syndrome were present. Medical records and invasive venography studies of all patients were reviewed when available. All patients with May-Thurner syndrome features on magnetic resonance venography were reviewed by a vascular medicine specialist to define any previous incidence of deep vein thrombosis or any signs of chronic venous insufficiency. All patients also had lower limb venous duplex performed to rule out lower limb venous thrombosis. A total of 470 patients from January 1, 2002, until December 31, 2007, with cryptogenic stroke underwent patent foramen ovale closure at our institute. Thirty patients (6.3%) had features consistent with May-Thurner syndrome on magnetic resonance venography. These patients were predominantly female (80%) with a mean age of 43.6+/-11.9 years. Twelve patients (40%) had abnormalities in their laboratory thrombophilia evaluation and 13 females (54.1%) were taking hormone-related birth control pills. Only 2 patients had a history and signs of chronic venous insufficiency. All patent foramen ovales demonstrated right-to-left shunting on transesophageal echocardiography. Atrial septal aneurysms/hypermobile atrial septa were present in 70% of patients with May-Thurner syndrome. May-Thurner syndrome has an important clinical association with cryptogenic stroke and patent foramen ovale.