Endovascular Management of May-Thurner Syndrome in Adolescents: A Single-Center Experience

Abdominal vascular compression syndromes: A pictorial review

Abdominal vascular compression syndromes (AVCS) refer to the entrapment of blood vessels between surfaces in a restricted space, a phenomenon that may cause clinical manifestations and can be identified using imaging methods. Although uncommon, their hemodynamic repercussions may lead to potential morbidity and should therefore be recognized by radiologists, who play a crucial role in diagnosing these conditions. Contrast-enhanced computed tomography (CECT) is the imaging modality of choice, primarily valued for its precision in identifying anatomical abnormalities, thereby facilitating appropriate management and reducing the risk of subsequent complications. Follow-up may range from conservative to invasive approaches, including surgical and endovascular procedures. This pictorial review focuses on the main imaging patterns of AVCS. Our objective is to enhance radiologists' ability to discern abdominal vascular anatomy, its interrelations with neighboring structures and its variants, and assist in the analysis of potential etiologies and pathophysiological mechanisms associated with these anomalies.

Improvement of quality of life in women ≤ 25-years-old with chronic pelvic pain following stenting of nonthrombotic iliac vein compression

ObjectivesStenting of nonthrombotic iliac vein compression for chronic pelvic pain (CPP) is controversial, especially in young populations. The current study evaluated the effects of iliac vein stenting on CPP through the assessment of quality-of-life (QoL) and pain scores in female patients ≤25-year-old.MethodsA retrospective single site cohort study was conducted for 30 female patients who were treated with left common iliac vein (LCIV) stenting for CPP. QoL was assessed before and after stenting using the following assessments: International Pelvic Pain Society (IPPS), Pelvic Congestion Syndrome (PCS), Pelvic Pain and Urinary Urgency Frequency (PUF), Rome III IBS, ancillary symptoms assessment, and pain scores. Secondary evaluation of the accuracy of radiologic interpretations of iliac vein compression on CT and MRI was also performed. Finally, commonly associated comorbidities within this population were assessed.ResultsPatient reported outcomes in 30 iliac vein stent patients demonstrated improvements in QoL post-stenting as demonstrated through significant reductions in IPPS, PCS, and pain scores (p = .0103, .0156, and .0092, respectively). Many of the cross-sectional imaging studies that were read by the interpreting radiologist as normal or mild compression were later identified as moderate or severe by the interventional radiologist clinically evaluating the patient. These patients went on to show significant compression on venography and intravascular ultrasound with associated clinical improvement after stenting.ConclusionSignificant improvements in QoL were identified in young women with CPP after LCIV stenting. Similarities in the clinical presentation of common comorbidities and misinterpretation of cross-sectional imaging studies may make the identification of pelvic venous disease more challenging. Our findings endorse the need for further research on stenting in young women with venous origin CPP through comparative outcomes studies and blinded randomized controlled trials.

Selective iliofemoral stent placement for complex pediatric cases: a decade of institutional experience

BACKGROUND

Pediatric iliofemoral venous thromboembolism that is resistant to conventional treatments poses significant management challenges. Stent placement represents a potentially underutilized strategy in children when stenosis or thrombosis persists intraprocedurally or recurs postoperatively, despite treatments such as venoplasty, lysis, and thrombectomy.

OBJECTIVE

This study aims to report our institutional experience with iliofemoral stenting in 17 pediatric patients with recurrent iliofemoral venous thromboembolism or stenosis.

MATERIALS AND METHODS

We performed an IRB-approved retrospective review of pediatric patients (<18 years of age) who underwent iliofemoral venous stenting for recurrent stenosis or thrombosis between January 2012 and December 2022 at a single tertiary care institution. Patient demographics, risk factors for venous thromboembolism, presenting symptoms, and procedural characteristics were recorded. The primary outcome was stent patency rates at interval imaging follow-up.

RESULTS

Seventeen patients with mean age of 14.6 years (range 7-17) and mean BMI of 27.7 were stented during the study period. Sixteen of 17 patients presented with evidence of May-Thurner anatomy. 14/17 patients presented with acute iliofemoral venous thromboembolism, 2/17 with chronic venous thromboembolism, and 1/17 with left lower extremity swelling without thrombosis. Seventy-three total angiographic procedures were performed, which included angioplasty, lysis, and thrombectomy, and 23 stent placements. Patients underwent an average of 3 procedures (range 1-9) over a mean of 2.8 months (range 0-17 months) prior to undergoing stent placement. Stents were deployed successfully in all patients. The median follow-up was 18 months (range, 1-77 months). Primary and secondary patency rates were 13/17 (76%) and 14/14 (100%) at 12 months and 12/17 (71%) and 14/14 (100%) at 24 months, respectively.

CONCLUSION

In our experience of 17 patients, stent placement appears to be a durable option for children with iliofemoral venous thromboembolism following failure to establish vessel patency or development of recurrent thrombosis/stenosis postoperatively.

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.

Antithrombotic Therapy after Deep Venous Intervention

Chronic deep venous disease (CVD) can result in significant morbidity and impact on quality of life due to a spectrum of symptoms, including lower extremity edema, venous claudication, and venous ulcers. CVD can be secondary to both thrombotic and nonthrombotic disease processes, including postthrombotic syndrome from prior deep vein thrombosis (DVT) or iliac vein compression syndrome. Endovascular therapy has become a mainstay therapy for CVD patients, with venous stent placement frequently performed. However, the management of anticoagulation following venous stent placement is not well-studied, with no large trials or consensus guidelines establishing an optimal regimen. The current knowledge gap in antithrombotic therapy is magnified by heterogeneity in practice and data collection, along with incomplete reporting in available studies. Furthermore, most published datasets are antiquated in the setting of rapid evolution in technique and technology available for deep venous intervention. Herein, we summarize the current available literature and offer an approach to anticoagulation and antiplatelet management following deep venous intervention for CVD.

Clinical outcomes of AngioJet rheolytic thrombectomy in the treatment of May-Thurner syndrome-related deep venous thrombosis

Objective

May–Thurner syndrome (MTS) is an anatomic stenotic variation associated with deep vein thrombosis (DVT) of the left leg. The classical DVT treatment strategy is medical treatment without thrombus removal. This study was performed to assess the clinical outcomes of the combination of AngioJet™ rheolytic thrombectomy and stenting for treatment of MTS-related DVT.

Methods

We conducted a retrospective cohort study of patients treated for MTS-related DVT from January 2017 to June 2020 at a single institution.

Results

Fourteen patients (nine women) underwent AngioJet™ rheolytic thrombectomy for MTS-related DVT during the study period. The median DVT onset time was 8 days (interquartile range (IQR), 3–21 days). The median procedure time was 130 minutes (IQR, 91–189 minutes), and the median hospital stay was 7 days (IQR, 5–26 days). One patient had a residual thrombus and occluded iliac stent and underwent adjuvant catheter-directed thrombolysis for revascularization. The primary patency rate for the iliac stent was 92.9% at 12 months.

Conclusion

Concomitant AngioJet™ rheolytic thrombectomy and stenting of MTS-induced lesions may be beneficial for patients with MTS-related DVT.

[Diagnosis of arteriovenous compression in small pelvic varicose veins]

AIM

The study was aimed at assessing the incidence of arteriovenous compression in women with chronic venous insufficiency of the inferior vena cava and at developing an optimal diagnostic algorithm.

PATIENTS AND METHODS

During the period 2019-2020, we performed a cross-sectional study including a total of sixty-six 18-to-55-year-old (mean 33.5±5.0) women with clinical manifestations of chronic venous insufficiency of the basin of the inferior vena cava. A diagnostic algorithm included questionnaire, transvaginal ultrasound examination, multislice computed tomography, direct phlebography in combination with phlebotonometry.

RESULTS

Chronic venous insufficiency of lower limbs was diagnosed in 66 (100%) cases and was presented by the following clinical classes according to the CEAP classification: C0 - 4.5%, C1 - 60.6%, C2 - 27.2%, C3 - 3%. Symptoms of pelvic venous plethora were revealed in 36 (55.5%) examined patients. Arteriovenous compression syndrome according to the findings of multislice computed tomography was verified in 16 (24%) women, including May-Turner syndrome in 5 (7.6%), aortomesenteric compression syndrome in 8 (12%) women, with a combination of both syndromes observed in 3 cases; the frequency of their detection did not differ statistically in subgroups of women with and without clinical signs pelvic varicose veins. Direct phlebography in combination with phlebotonometry was performed in 9 women, the diagnosis of arteriovenous compression (May-Thurner syndrome) was confirmed in 1 case only.

CONCLUSION

In women with signs of chronic venous insufficiency in the system of the inferior vena cava the frequency of detecting arteriovenous compression on multislice computed tomography may reach 24% and does not depend on the presence of symptoms of pelvic venous plethora. The proportion of arteriovenous compression according to the findings of direct phlebography and phlebotonometry in the structure of causes of the development of pelvic varicose veins did not exceed 11%. An algorithm for diagnosing arteriovenous compression syndromes should obligatorily include multislice computed tomography, direct phlebography and phlebotonometry.

May-Thurner syndrome with inferior mesenteric vein drainage and porta system - Case report

We present the case of a 12-year-old girl with a history of vascular anomalies in the lower pelvic limbs and back, who developed unilateral deep vein thrombosis of the left lower limb after her pubertal development, she was diagnosed with May-Thurner syndrome with an abnormal venous drainage of the pelvic structures through the superior hemorrhoidal veins to the inferior mesenteric vein towards the porta system, this being a chronic manifestation. This kind of behavior has not been documented in the reviewed medical literature. Secondarily, balloon angioplasty was performed without breaking the stenotic ring. As a second attempt, it was decided to place the venous stent, with satisfactory resolution of the symptoms. There are controversies about the indications for the use of anticoagulants and antiplatelet agents, or the indications to place a venous stent in children. We must consider an approach to for effective therapeutic treatment in these cases is to control bleeding, the main goal being trying to avoid ulcerations in the lower limb due to venous insufficiency with irreversible affectation of the valvular system.

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.

Diagnosis, Clinical Characteristics, and Treatment Modalities of Adolescent May-Thurner Syndrome-associated Deep Venous Thrombosis

May-Thurner syndrome (MTS) predisposes individuals to develop lower extremity deep venous thrombosis (DVT) because of compression of the left common iliac vein. Diagnosis of the anatomic obstruction is critical for effective therapy, as treatment by interventional radiology is often required in addition to anticoagulation to prevent thrombus progression and recurrence. The authors performed a retrospective review of adolescent patients who presented with MTS-associated DVT at a pediatric tertiary care center from 2009 to 2018 to assess for delays in MTS diagnosis after the presentation. Fourteen patients (median age 16.5 y, range, 13.8 to 17.9 y) were included, no DVTs were provoked by a central venous catheter. The median time from DVT to MTS diagnosis was 0.65 months (range, 0 to 21.5 mo). The initial imaging modalities used for DVT diagnosis were not able to diagnosis MTS. All patients were treated with anticoagulation and 13 underwent interventional therapy. Four patients had thrombus progression or recurrence, whereas 6 had complete thrombus resolution on follow-up imaging. Three patients who had a delayed MTS diagnosis had clinical worsening despite therapeutic anticoagulation requiring rehospitalization. Adolescent patients with "unprovoked" left lower extremity DVT should undergo appropriate imaging to diagnose MTS to allow for adequate medical and interventional therapy.

Novel typing of iliac vein compression in asymptomatic individuals evaluated by contrast enhanced CT

Purpose

Compression of the iliac vein between the iliac artery and lumbosacral vertebra can cause iliac vein compression syndrome (IVCS). The purpose of this study is to assess compression characteristics and establish a new sub-typing in asymptomatic IVCS individuals using contrast-enhanced CT.

Methods

A retrospective analysis of abdomen contrast-enhanced CT images from 195 asymptomatic subjects with iliac vein compressed was investigated. Patients had no history of venous pathology, and images were collected from June 2018 to January 2019. Qualitative and quantitative characteristics of compression were examined including the location, pattern, minor diameter, area, and the percentage compression on an orthogonal section by the post-processing of multiple planar reconstruction and volume rendering.

Results

There were 107 females and 88 males with age range 18–92 years. The most common site of iliac vein compression was localized to the left common iliac vein (LCIV) (178/195, 91.3%). Notably, four compression types (type I–IV) were established according to the compression location, with type II being the most common. The four compression types had differences in the upper limit and fluctuation range of compression. It was found that the average level of iliac vein compression was below 25%. The compression degree of the left common iliac vein in type II was relatively concentrated, and the upper limit of compression was close to 70%.

Conclusion

Asymptomatic iliac vein compression was categorized according to compression location. The proposal of four types might help clinicians to predict which IVCS patients would benefit from interventional therapy.

Clinical Outcomes of May-Thurner Syndrome in Pediatric Patients: A Single Institutional Experience

Introduction  May-Thurner syndrome (MTS) is a vascular anatomic variant resulting in compression of the left common iliac vein by the right common iliac artery, affecting approximately 22% of the population. In adults, following acute deep vein thrombosis (DVT) of the iliofemoral veins, the incidence of postthrombotic syndrome (PTS) and recurrent DVT are high if treated with anticoagulation alone, warranting adjunctive treatment with thrombolysis and stent placement. However, there is paucity of literature documenting the course of treatment and associated outcomes in pediatric patients with MTS. Methods  A retrospective chart review of pediatric patients (≤ 18 years of age) with radiologic confirmation of MTS with or without DVT evaluated and/or treated at our institution from January 1, 2005 through December 31, 2015 was conducted. Results  Seventeen patients (4 male; 13 female) were identified. Median age was 15.4 years (range 8.8-17.1 years) with a median follow-up of 1.2 years (range 0.4-7.5 years). Thirteen (76.5%) patients presented with left lower extremity DVT. Management included catheter-directed thrombolysis ( n  = 5), systemic thrombolysis ( n  = 1), and mechanical thrombectomy ( n  = 1). Fifteen patients were treated with anticoagulation including two patients with endovascular stents without DVT. Median duration of anticoagulation was 6.3 months (range 3.2-18.7 months). Ten patients (59%) underwent stent placements. Complete and partial thrombus resolution was noted in six patients each and no resolution in one patient. Four patients had recurrence/progression of thrombus ( n  = 3 with stents) at a median time of 29 days (range 12-495 days). No bleeding complications were observed. Clinically documented or self-reported PTS was noted in 8 patients (62%). Conclusion  There are no clear guidelines for MTS management in children and adolescents. In our cohort, thrombolysis, anticoagulation, or stent placements were not associated with bleeding risks, with recurrence/progression of DVT and signs and symptoms of PTS noted in 30 and 62%, respectively. Further studies are needed to determine a standardized treatment approach of the pediatric patient with MTS with or without thrombosis.

A review into the management of May-Thurner syndrome in adolescents

OBJECTIVE

To investigate the presentation, etiology, management and outcomes of May-Thurner syndrome (MTS) in adolescents aged under 18.

METHODS

We searched electronic bibliographic databases to identify published reports of MTS in patients under 18 years of age. We conducted our review according to the PRISMA statement standards.

RESULTS

Ten studies encompassing 22 patients treated for MTS in adolescent cases were identified. The mean age of patients was 15 years (range, 10-18 years). Of the 22 patients, 12 (55%) were confirmed to have proximal deep vein thrombosis as the primary indication for intervention. Treatment methods included catheter-directed thrombolysis and iliac vein stenting (41%), pharmacomechanical thrombolysis and iliac vein stenting (18%), iliac vein stenting alone (27%), open surgery (14%), catheter-directed thrombolysis (5%), and anticoagulation alone (5%). Complications were infrequent. All studies reported subjective improvements in clinical symptoms with only two studies using validate outcome measures. In total, 9 of 22 patients (41%) had addition risk factors that may precipitate thrombosis.

CONCLUSIONS

As in adults, the most common form of treatment seen in the literature is a combination of catheter direct thrombolysis, followed by iliac vein stenting with subsequent anticoagulation. Complications from interventions were low. It is unclear how these interventions affect symptomology and the long-term sequalae associated endovascular surgery and stenting in adolescents. Further research is needed in well-designed studies with adequate follow-up.

[A case of successful endovascular treatment of a patient with chronic pelvic pain and recurrent varicocele]

Described in the article is a clinical case report regarding diagnosis and treatment of pelvic varicose veins in a 34-year-old male patient presenting with compressive stenosis of the left common iliac vein (May-Thurner syndrome). The man had developed clinical symptoms of the disease as varicocele when he was 17 years old. Multiple surgical interventions on the veins of the spermatic cord failed to result in significant success. The diagnosis was verified by means of ultrasound examination and contrast X-ray phlebography. The patient was subjected to balloon angioplasty and stenting of the compressive stenosis of the left common iliac vein. The endovascular treatment performed was followed by the patient's improved condition, confirmed by methods of instrumental diagnosis, as well as by regression of clinical symptomatology.

A case of May-Thurner Syndrome: An old anomaly but, a new suggestion: A case report

May-Thurner syndrome (MTS) is an anatomical condition resulting in compression of the left common iliac vein between the right common iliac artery and the underlying spine. MTS is rarely diagnosed because diagnostic workup is seldom continued once the diagnosis of a deep vein thrombosis (DVT) has been established. Furthermore, patients with DVT generally have several well-known confounding risk factors. We report a 16-year-old girl with a history of left leg swelling who was incidentally diagnosed with MTS. We hope that our case report will create awareness of vascular abnormalities in sports medicine and suggest that routine venous Doppler ultrasound screening may help to detect MTS or associated anatomical prior to the formation of early thrombosis.

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.

Lower extremity endovenous reconstruction for symptomatic occlusive disease in pediatric patients: techniques, clinical outcomes, and long-term stent patencies

BACKGROUND

Endovascular stent reconstruction is the standard of care for chronic venous occlusive disease in adults, but it has not been reported in pediatric patients.

OBJECTIVE

This study reports the technical success, complications, clinical outcomes, and stent patency of iliocaval stent reconstruction for chronic iliocaval thrombosis in pediatric patients.

MATERIALS AND METHODS

Fourteen patients, 13 (93%) male with a mean age of 16.4 years (range: 8-20 years), underwent iliocaval stent reconstruction for chronic iliocaval thrombosis. The mean number of prothrombotic risk factors was 2.5 (range: 0-4), including 7 (50%) patients with inferior vena cava atresia. At initial presentation, the Clinical, Etiology, Anatomy, and Pathophysiology classification (CEAP) score was C3 in 2 (14%) patients, C4 in 11 (79%) patients, and C6 in 1 (7.1%) patient. Time course of presenting symptoms included chronic (>4 weeks) (n=7; 50%) and acute worsening of chronic symptoms (2-4 weeks) (n=7; 50%). Aspects of recanalization and reconstruction, stenting technical success, complications, clinical outcomes and stent patency were recorded. Clinical success was defined as a 1-point decrease in the CEAP. Primary, primary-assisted, and secondary patency were defined by Cardiovascular and Interventional Radiological Society of Europe guidelines.

RESULTS

Most procedures employed three access sites (range: 2-4). Intravascular ultrasound was employed in 11 (79%) procedures. Blunt and sharp recanalization techniques were used in 12 (86%) and 2 (14%) patients, respectively. Stenting technical success was 100%. Two (14%) minor adverse events occurred and mean post-procedure hospitalization was 2.8 days (range: 1-8 days). Clinical success rates at 2 weeks, 6 months and 12 months were 85%, 82%, and 83%, respectively. At a mean final clinical follow-up of 88 months (range: 16-231 months), clinical success was 93%. Estimated 6- and 12-month primary stent patencies were 86% and 64%, respectively. Six- and 12-month primary-assisted and secondary stent patency rates were both 100%.

CONCLUSION

Iliocaval stent reconstruction is an effective treatment for symptomatic chronic iliocaval thrombosis in pediatric patients with high rates of technical success, 6- and 12-month clinical success, and 6- and 12-month primary-assisted and secondary patency rates.

May-Thurner syndrome and thrombosis: A systematic review of antithrombotic use after endovascular stent placement

BACKGROUND

May-Thurner Syndrome (MTS) is caused by compression of the left common iliac vein between the right common iliac artery and the pelvis. It likely predisposes an individual to lower extremity deep vein thrombosis (DVT) as well as symptoms of unilateral lower extremity swelling and discomfort in the absence of a known history of thrombosis. In the case of MTS-associated acute thrombosis, there is low-quality evidence to suggest that endovascular intervention including thrombolysis and endovascular stent placement reduces the risk of recurrent thrombosis. However, the optimal type and duration of antithrombotic therapy after stent placement for left iliofemoral vein stenosis is not known.

METHODS

A systematic literature search including studies that evaluated the outcome of endovascular stent occlusion and systemic anticoagulant use in patients with MTS associated DVT was performed. The primary outcome of interest was 12-month risk of endovascular stent occlusion or recurrent DVT.

RESULTS

A total of five studies encompassing 61 patients were included in our study. All studies were retrospective without a comparator group. A variety of anticoagulants and durations were prescribed. Of the 55 patients evaluable, the 12-month rate of endovascular stent occlusion or recurrent DVT ranged from 0% to 40%. The 12-month stent patency rate ranged from 60% to 100%.

CONCLUSIONS

The published evidence regarding antithrombotic treatment for patients with MTS who have undergone stent placement for a DVT is limited. Further high-quality, prospective studies are needed in this setting to inform clinical decision making.

Extensive Intracardiac and Deep Venous Thromboses in a Young Woman with Heparin-Induced Thrombocytopenia and May-Thurner Syndrome

A 38-year-old woman with a history of recurrent deep venous thromboses (DVTs) on chronic anticoagulation presented with acute left leg swelling. The patient was diagnosed with an acute left lower extremity (LLE) DVT in the setting of May-Thurner syndrome for which treatment with unfractionated heparin was started. Her hospital course was complicated by a new diagnosis of heparin-induced thrombocytopenia (HIT), with an incidental discovery of a large tricuspid valve mobile mass on a transthoracic echocardiogram (TTE). Subsequent imaging confirmed multiple right atrial thrombi along with LLE venous stent thrombosis and a new right LE acute DVT. Anticoagulation with argatroban for HIT thrombosis was started. She underwent a right atrial percutaneous thrombectomy and bilateral lower extremity thrombectomy with directed angioplasty and stent placement. This presentation is a rare manifestation of HIT with extensive intracardiac and deep venous thrombi, with successful staged interventions.