Compression Of Left Iliac Vein Research Articles

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.

Lumbar overlordosis — towards the better understanding of the May-Thurner syndrome pathogenesis

Introduction: May-Thurner Syndrome (MTS) is a condition in which the left common iliac vein is compressed by the right common iliac artery, which together with intraluminal vein changes can lead to clinically symptomatic venous outflow obstruction. Patients having such pathology may suffer from symptoms of venous hypertension as well as lower leg deep venous thrombosis. In most of the MTS cases, static and continuous compression is observed which can also lead to the intraluminal spur formation. According to the literature, among the factors which can influence the severity of iliac vein compression, lumbar spinal degeneration can also be mentioned. Considering the aortic bifurcation anatomical conditions, also other, non — degenerative changes of the lumbar vertebral column segment can be taken into consideration. Aim: This study aimed to reveal the prevalence of the left common iliac vein compression in young healthy individuals as well as to assess the severity of the left iliac vein compression provoked by lumbar hyperlordosis. Material and methods: The study was performed on a group of 207 volunteers of both sexes, aged 21–27 yrs. using ultrasound examination to measure the diameter of the right common iliac vein as well as the diameter of the left common iliac vein in the area of the possible compression by the right iliac artery. In all the patients the measurements were performed in the supine position as well as in the provoked lumbar hyperlordosis position. In all the individuals the presence of the symptoms and signs of the lower leg chronic venous disease were investigated. Results: The mean anterior-posterior diameter of the right common iliac vein in the standard supine position in the whole study group was 5.71 mm (± 0.6 mm). The mean diameter of the left common iliac vein in a normal horizontal position was 4.87 mm (± 0.6 mm) with a range from 3.8 mm to 6.2 mm. In most of the cases, the difference between the left and iliac common vein diameter (when measured in the place of the right iliac artery crossing) did not exceed 20%. In 15.9% of the study subjects, the right and left iliac vein diameter difference ranges between 20–30% and in 2.41% only, the diameter difference over 30% was noticed (in none of the cases the stenosis exceeding 40% of the vein diameter was found). Looking for the effect of the overlordosis on the proclivity to decrease left iliac vein diameter, in the provoked hyperlordosis position the changes of the iliac vein diameter in the range of 21–30% were observed in 15.9% and over 30% in 2.4% of the study subjects. Hyperlordosis presence was also responsible for the shift towards lower left iliac vein diameter — in 36.2% of the patients, the left iliac vein diameter below 4 mm was noticed including 1.9% of individuals with a diameter not exceeding 3 mm. In the analysis, there was no statistically significant correlation between the presence of the reported CVD symptoms in the left leg and the reported diameter reduction between the right and left iliac veins in the population of the studied young individuals. Conclusions: Left common iliac vein compression may be anatomically conditioned at least in some of the young population individuals. Lumbar hyperlordosis influence on the left common iliac vein diameter suggests that also in healthily individuals, an incorrect spinal position can promote the occurrence of the left iliac vein compression. Further studies are needed to assess the haemodynamic influence of these findings on the lower leg venous outflow.

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.

Prevalence of left iliac vein compression in an asymptomatic population and patients with left iliofemoral deep vein thrombosis: A multicenter cross-sectional study in southern China.

Population-based epidemiological data on left common iliac vein (LCIV) compression is scarce. This study aimed to investigate the prevalence of LCIV compression in an asymptomatic population and patients with left iliofemoral deep vein thrombosis (IF-DVT). Nonprobability sampling method was used in this multicenter cross-sectional study. The minimum diameter of LCIV and right common iliac vein minimum were measured. The percentage of LCIV compression (LCIV-CP) was calculated. Compression severity (CS) was classified as mild (CP ≤ 50%), moderate (50% < CP ≤ 70%), and severe (CP > 70%). In all, 896 subjects constituted the asymptomatic population and 93 patients constituted the IF-DVT population. In the asymptomatic population, LCIV-CP ranged from 1.1% to 89.9% (mean 44.0%), and people with mild, moderate, and severe CS accounted for 62.3%, 28.2%, and 9.5%, respectively. In the IF-DVT population, the mean LCIV-CP was 71.1% (range 42.2%-95.2%), and patients with severe CS accounted for 75.3%. Gender and age differences in LCIV-CP and CS distribution were observed in the asymptomatic population. Females, the young- and middle-aged group had higher LCIV-CPs. In the population with moderate-severe CS, the middle-aged group accounted for a larger proportion. Middle-aged females comprised the highest percentage of patients with moderate or severe CS. Sex and age affected the LCIV-CP and CS distribution. No gender and age differences were observed in the IF-DVT population. LCIV compression is common in population. Middle-aged females are the predominant population with moderate-severe compression. Overlapping of LCIV-CP in the asymptomatic and IF-DVT population is significant and other risk factors should be integrated into the consideration when assessing the risk of IF-DVT secondary to LCIV compression.

A rare case of left inferior vena cava presenting with May-Thurner syndrome

BackgroundMay–Thurner anomaly is characterized as external venous compression by the arterial framework against hard bony structures. This chronic anatomical lesion infrequently leads to deep vein thrombosis in the lower extremity, and it may lead to leg swelling as a long-term post-thrombotic complication. Left iliac vein compression may not be as uncommon as was previously thought, and it typically occurs in women more than men. Congenital anomalies of venous tree are not rare; they exist in 8.7% of the general population.Case-presentationWe herein present the first case of right-sided May Thurner Syndrome in a patient with IVC anomalies. In our patient, both common iliac veins formed the left-sided IVC, which extended to the hemiazygos vein and the superior vena cava. Additionally, there was a right-sided suprarenal IVC, which extended to the right atrium.ConclusionUnderstanding the proper anatomy in May-Thurner syndrome helps in better decision making for management of disease pathophysiology.

Severe compression of left iliac vein is a protective factor for the risk of inferior vena cava thrombosis

ObjectiveThe purpose of this study is to evaluate the association between left iliac vein (LIV) compression and inferior vena cava thrombosis (IVCT) in patients with LIV involvement of deep vein thrombosis (DVT). MethodsA total of 263 consecutive patients with DVT were reviewed retrospectively and divided into a group with IVCT and a group without IVCT. The influences of LIV smallest diameter and percentage compression on the risk of IVCT were investigated using logistic regression analysis. ResultsThe mean age of patients with IVCT was significantly younger than that of patients without IVCT (55.5 ± 1.8 vs 62.7 ± 1.1; P = .001). The percentage of provoked DVT in patients with IVCT was higher than that in patients without IVCT (67.1% vs 48.2%; P = .01). The smallest diameter of the LIV in patients with ICVT was larger than that in patients without IVCT (4.1 ± 0.3 vs 2.5 ± 0.2; P < .001). The mean percentage compression of LIV in patients with IVCT was significantly lower than that in patients without IVCT (63.5 ± 2.2 vs 74.3 ± 1.3; P < .001). Age was associated with a decreased odds of ICVT (odds ratio [OR], 0.965; 95% confidence interval [CI], 0.965-0.985; P = .001). Provoked DVT was associated with an increased odds of ICVT (OR, 2.011; 95% CI, 1.070-3.782; P = .03). LIV compression was associated with a decreased odds of ICVT for each 1-mm decrease in smallest diameter of the LIV (OR, 0.717; 95% CI, 0.627-0.820; P < .001), and for each 10% increase in percentage compression of the LIV (OR, 0.715; 95% CI, 0.612-0.835; P < .001). ConclusionsFor LIV involvement in patients with DVT, patients without IVCT had more severe LIV compression than patients with IVCT. Severe LIV compression may be a protective factor for the risk of IVCT.

Efficacy of one-stop endovascular intervention in treatment of left iliac vein compression syndrome complicated with deep venous thrombosis of lower limbs.

To evaluate the clinical effect and safety of one-stop endovascular intervention in treatment of left iliac vein compression syndrome (IVCS) complicated with deep venous thrombosis (DVT) of lower limbs. Clinical data of 26 patients with secondary DVT due to IVCS admitted in the Department of Vascular Surgery, Hebei General Hospital from January 2018 to December 2021 were retrospectively analyzed. All patients underwent one-stop endovascular intervention procedure, including ultrasound-guided deep venipuncture, Angiojet catheter aspiration, iliac vein balloon dilation, stent implantation and simultaneous filter retrieval. The operation time and catheter aspiration time were documented; the preoperative and postoperative left lower extremity deep vein venous patency, circumferences of bilateral limbs at 15 cm above the knee and 10 cm below the knee, and the levels of hemoglobin, creatinine, alanine aminotransferase (ALT), aspertate aminotransferase (AST), total bilirubin and indirect bilirubin were measured. The incidence of post-thrombotic syndrome (PTS) and iliac vein stent patency were recorded through follow-up. The one-stop endovascular intervention was successfully performed in 26 patients, with the operation time of (171±35) min and the thrombolysis time of (263±89) s. After treatment, the left lower extremity deep vein venous patency, circumferences of bilateral limbs at 15 cm above the knee and 10 cm below the knee were decreased (all P<0.01); the hemoglobin level were decreased, the creatinine, ALT, AST, total bilirubin and indirect bilirubin levels were increased (all P<0.01). Patients were followed up for 1-12 months. Stent thrombosis occurred in 1 patient 7 months after procedure, and the symptoms were improved after conservative treatment; the stents were unobstructed in all patients, 1 patient had stent mural thrombosis, in whom the stent blood flow was not affected. No PTS was observed during the follow-up. The one-stop endovascular interventional treatment of IVCS complicated with DVT of left lower limb is safe and effective. Attention should be paid to the changes of liver and kidney function caused by catheter aspiration during the treatment, and corresponding intervention should be given in time to avoid the occurrence of related complications.

May-Thurner Syndrome in Pregnancy: A Case Report

May-Thurner Syndrome, left iliac vein compression by the right iliac artery, is a congenital permissive lesion that requires an additional insult prior to the onset of symptoms. We present a case of a 31-year-old gravida 1 para 0 at 28.6 weeks who presented to the emergency room with a 2-month history of progressive lower left leg swelling since 21.2 weeks’ gestation. The patient endorsed incidence of domestic violence at 17 weeks’ gestation. The patient had a twin sister who was also pregnant and had not experienced these symptoms. Physical exam revealed 3+ pitting edema in the left lower extremity from ankle to groin. There was left calf tenderness with negative Homan’s sign bilaterally. Overall finding on magnetic resonance angiography revealed severe compression of the upper left common iliac vein and lower inferior vena cava by gravid uterus. Conservative management and anticoagulation is instrumental in preventing veno-thromboembolic events in pregnancies complicated by MTS.

Synergistic effect of May–Thurner syndrome and COVID-19

May–Thurner syndrome (MTS) is also called Cockett syndrome or iliocaval syndrome is described as compression of the left iliofemoral vein by the right common iliac artery against the vertebral body. We present a rare case of MTS in a 31-year-old female in the left lower extremity complicated after COVID-19. Screening magnetic resonance imaging pelvis showed compression of left common iliac vein by right common iliac artery over L5 lumbar vertebra suggestive of MTS. Findings were confirmed by a lower limb computed tomography venogram. A high degree of clinical suspicion of COVID-19 post sequela is needed for early diagnosis in this era.

May-Thurner Anatomy in Patients With Chronic Thromboembolic Pulmonary Hypertension: An Important Clinical Association.

The aim of this study was to investigate the incidence of May-Thurner anatomy (MTA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and identify its predictors. MTA is an anatomical variant characterized by compression of left common iliac vein by the overlying right iliac artery. Over time, this leads to venous intimal scarring, blood flow stasis, and the development of deep vein thrombosis (DVT). DVT is a known risk factor for the development of CTEPH. The prevalence of this anatomical variation in patients with CTEPH is unknown. A retrospective chart review was conducted in patients referred to Temple University Hospital's cardiac catheterization laboratory for the evaluation of CTEPH between January 2016 and June 2020. Among these patients, those who underwent invasive venography were evaluated for the presence of angiographic MTA. Multivariate regression was used to identify factors associated with presence of MTA. A total of 193 patients with CTEPH were referred for pulmonary angiography, of whom 148 patients underwent invasive venography. MTA was identified in 44 patients (29.7%). Factors associated with the presence of MTA were lower extremity DVT (odds ratio: 3.5; 95% confidence interval: 1.58-7.8; P=0.002), and left lower extremity post-thrombotic syndrome (odds ratio: 2.0; 95% confidence interval: 0.98-4.1; P=0.05). Patients with MTA were more likely to undergo pulmonary thromboendarterectomy than patients without MTA (79.5% vs 58.7%; P=0.015). MTA is very common in patients with CTEPH. History of lower extremity DVT and or left lowerextremity post-thrombotic syndrome was associated with the presence of MTA.

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

We sought to evaluate the safety and feasibility of single-stage treatment with left iliac vein stenting and saphenous stripping in patients with left iliac vein compression (LIVC) and left great saphenous vein (GSV) incompetence. s: We conducted a prospective cohort study of 72 patients diagnosed with LIVC and left GSV incompetence between June 2012 to Oct 2018. We evaluated the periprocedural, 30-day, and 1-year outcomes of venous clinical severity score (VCSS), Chronic Venous Insufficiency Questionnaire 2 (CIVIQ2), the success rate of stent placement, duration of intervention, length of hospital stay, duplex recurrence, and clinically visible recurrence. There were 43 patients in the two-staged group and 29 patients in the single-staged group. The clinical characteristics of the two groups were similar. There were no differences between the two groups in the technical success rate, perioperative mortality, and surgical morbidity. There was no significant difference in the duplex and clinically visible recurrence. The length of hospital stay was significantly lower in the single-staged group. The single-staged group was associated with a higher complication rate of ecchymosis. There was no death, pulmonary embolism, or contrast-induced nephropathy among the patients. The 1-year primary patency rate was similar. Both treatment approaches were equally effective and had a high technical success rate. The single-staged group had a higher complication rate of ecchymosis due to heparin applying during the procedure.

May-Thurner syndrome: modern methods of diagnosis and treatment

May-Turner syndrome is a condition where the left common iliac vein is compressed between the lumbar spine and the overlying right common iliac artery. Left iliac vein compression is common (up to 24%) in the general population, but clinical manifestations occur in a few patients. This syndrome should be considered in case of unexplained edema of the left lower extremity since routine duplex ultrasound does not possess optimal sensitivity and specificity in the study of the iliac veins and the inferior vena cava. Intravascular ultrasound is the most accurate diagnostic method. However, the advent of computed tomography angiography and magnetic resonance angiography providing high-quality images of the vasculature have become a promising alternative to invasive intravascular ultrasound. Treatment for May-Turner syndrome usually involves stenting of the left common iliac vein along with medical therapy, including antithrombotic (anticoagulant and antiplatelet) therapy combined with phlebotonics. Our review reports modern methods of diagnosis and treatment of May-Turner syndrome.

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

BackgroundBalloon dilatation with stent implantation has been proved to be an effective option for left iliac vein compression syndrome (LIVCS), but thrombosis may still occur after the operation. Currently, warfarin is used for anticoagulant therapy, but long-term monitoring is required, while rivaroxaban does not need laboratory monitoring, which can simplify treatment. Therefore, this study aimed to compare the efficacy and safety of rivaroxaban and warfarin in anticoagulation.MethodsThis study is a multicenter, randomized controlled trial. We will recruit 224 patients with thrombotic LIVCS from 9 hospitals. Moreover, these patients will be randomized to either the experimental group (rivaroxaban) or the control group (warfarin plus nadroparin). The primary outcome is stent occlusion rate. Secondary outcomes are quality of life scale survey results, all-cause mortality, anticoagulation-related mortality, and the proportion of participants with stent displacement/fracture, thrombosis, hemorrhage, and other vascular events.DiscussionThis study will provide reliable, evidence-based clinical evidence for the efficacy and safety of rivaroxaban antithrombotic therapy after stent implantation.Trial registrationClinicalTrials.gov NCT04067505. Registered on August 26, 2019.

Endovascular therapy for floating thrombus in the inferior vena cava.

ObjectiveWe aimed to summarize the clinical characteristics of floating thrombus in the inferior vena cava (IVC).MethodsFrom January 2014 to June 2019, four patients with floating thrombus in the IVC were admitted to our hospital and underwent intracavitary therapy. Diagnosis, therapy, and clinical characteristics of floating thrombus were summarized.ResultsThree patients presented with pulmonary embolism. Three of the patients had a floating thrombus discovered by inferior venacavography and one was found by contrast-enhanced computed tomography. Two patients had deep venous thrombosis in the lower extremities. One patient had a double IVC, one had left iliac vein compression syndrome, and one had right renal phlebothrombosis. The four patients underwent implantation of a temporary IVC filter and were treated with anti-coagulation, debulking, and thrombolysis. All four patients achieved satisfactory results.ConclusionsFloating thrombus in the IVC is often caused by spread of branch vein thrombosis, and is more likely to lead to pulmonary embolism. Anti-coagulant therapy and debulking under the protection of filters can achieve satisfactory clinical results.

AN ATYPICAL VARIANT OF MAY-THURNER SYNDROME TREATED SUCCESSFULLY WITH ENDOVASCULAR STENT PLACEMENT

May-Thurner syndrome (MTS) is a rare disorder caused by compression of left common iliac vein by right common iliac artery. Here we report a rare case of MTS with compression of right common iliac vein (R-CIV) by tortuous right common iliac artery (R-CIA). A 59 year obese male presented with

Prevalence of left iliac vein compression on computed tomography scans from a population.

BackgroundMay-Thurner syndrome (MTS) is defined as compression of the left iliac vein between the right iliac artery and the lumbar vertebral body in the presence of signs and symptoms of unilateral left chronic venous insufficiency. However, imaging findings of compression are not manifest in symptoms of the syndrome in all subjects.ObjectivesTo evaluate findings of compression in an asymptomatic population.MethodsComputed tomography angiographies or venous phase computed tomographies were analyzed. Demographic data and reason for the exam were recorded. Vein diameter was measured at the site of greatest compression and distal of the compression and the ratio between the two diameters was calculated.ResultsFrom January to July of 2016, 590 computed tomography scans were analyzed (357 women and 233 men). Left iliac compression was found in 14.74% of patients. Patients with a left iliac diameter below the 5mm threshold had a mean diameter at the site of greatest iliac vein compression of 4.4 mm (range: 2.67 mm-4.97 mm). The ratio between the two measurements was < 0.5 in 30% of patients.ConclusionsOur study suggests that iliac vein compression is common among random patients who have had computed tomography for any other reason. This indicates that compression found on tomography images is not the only finding to consider when treating a patient.

Case of Deep Venous Thrombosis Secondary to May-Thurner Syndrome

May-Thurner syndrome (MTS) remains an underdiagnosed cause of venous thromboembolism (VTE) because most individuals with MTS anatomy are asymptomatic. The most common variant of MTS is due to compression of the left iliac vein between the overlying right common iliac artery and the fifth lumbar vertebrae. Clinical features include chronic venous hypertension that usually presents as lower extremity pain and swelling. Acute VTE almost exclusively affects the left lower extremity. In cases of acute VTE of an unknown etiology, MTS should be considered when other more common pathologies have been ruled out. A 65-year-old African American gentleman with past medical history of hypertension and coronary artery disease presented with left lower extremity pain and swelling of the leg for five days. He had no history of leg trauma, recent surgery, bed rest, travel, malignancy, previous clotting episodes or family history of hypercoagulable disorders. Patient regularly ambulates. He is a lifetime non-smoker and does not take any medication. His left lower extremity was swollen from the calf down to the ankle and foot, tense, erythematous and tender to palpation. Dorsalis pedis and posterior tibial pulses were weakly palpable. Homan’s sign was appreciated while the rest of the physical exam was unremarkable. Duplex ultrasound of the left lower extremity showed thrombi in the left popliteal, posterior tibial and peroneal veins. CT abdomen and pelvis with IV contrast demonstrated significant compression of the left common iliac vein as it crosses posterior to the left internal iliac artery, consistent with MTS. Spiral chest CT was significant for subsegmental emboli in the bilateral lobe pulmonary arteries. Patient was started on anticoagulation, then he was referred to an advanced vascular center to consider the need for angioplasty and stenting and for possible thrombolysis. MTS was first described in 1908 by Virchow, who observed that iliofemoral vein thrombosis was five times more likely to occur in the left leg than in the right leg. May and Thurner discovered an anatomical variant where the right iliac artery compressed the left iliac vein against the fifth lumbar vertebra. Clinicians should have a high index of suspicion for MTS in the presence of unprovoked DVT in the left lower extremity, and/or signs of chronic venous hypertension. Angioplasty and stenting of the affected lesion is the definitive treatment for MTS, while anticoagulation management is similar to patients with provoked VTE. Therefore, it can be argued that in patients with an unexplained cause of VTE, investigation for MTS if clinically suspected can impact management decisions.

Diagnosis and Treatment of Nonthrombotic Right Iliac Vein Compression Syndrome

The anatomical etiology of right iliac vein compression syndrome (RIVCS) differs from that of left iliac vein compression syndrome. This study aimed to investigate the clinical features and therapeutic characteristics of RIVCS. Sixteen patients with nonthrombotic RIVCS were admitted to our hospital from May 2013 to July 2017. All patients underwent computed tomography venography (CTV) examinations of the right lower limb, which indicated that the right iliac veins were compressed by extrinsic structures. RIVCS was divided into 3 types according to the CTV findings. Stenting was conducted in patients with the appropriate indications. The superficial varicose veins in the lower limbs were simultaneously treated during endovascular treatment in a compound operating room. Antiplatelet therapy was administered after discharge. Most RIVCS cases were types II and III, and the most frequently compressed segments were the middle and distal parts of the iliac vein. Most stents did not require stretching into the inferior vena cava and therefore seldom affected contralateral blood flow. Fifteen patients required stenting; the diameters of the stents ranged from 10 to 16mm. All symptoms were alleviated, and the ulcers healed postoperatively. The remaining single patient with superficial varicose veins did not have an indication for endovascular therapy. During follow-up, all patients were symptom free, and the stents showed excellent patency. CTV is a simple, accurate, and important method for diagnosing RIVCS. Endovascular therapy is an effective therapeutic method for RIVCS. Compared with the left side, stent implantation for RIVCS is safer and has fewer effects on contralateral blood flow.

A Rare Cause of May-Thurner Syndrome Postarterial Intervention

AbstractMay-Thurner syndrome (MTS) is rare condition thought to occur due to an anatomical variation. In MTS, there is left iliac vein compression by the right iliac artery and lumbar spine resulting in left lower limb deep venous thrombosis. The authors report a rare cause of MTS postarterial intervention. They describe the unusual case of an Asian man who presented with acute left lower limb deep venous thrombosis 5 days following left common iliac artery angioplasty and stent insertion. Computed tomographic (CT) venogram demonstrated the left iliac vein compression by the left iliac artery stent. Successful recanalization of the thrombosed iliac vein was achieved with a combination of pulse spray thrombolysis and rheolytic mechanical thrombectomy, followed by angioplasty and stent placement in the iliac vein. There was rapid and complete resolution of symptoms. This report illustrates the use of complementary imaging modalities and a multidisciplinary team approach to achieve a successful technical and clinical outcome following an unusual case of MTS postarterial intervention and the subsequent successful endovascular management.

Management of Nonthrombotic May-Thurner Syndrome

Venous outflow pathology of the lower extremity may be categorized into thrombotic or nonthrombotic etiology. This chapter focuses on the nonthrombotic etiology that results from the compression of the left iliac vein or May-Thurner syndrome (MTS). MTS is an anatomic variant condition associated with venous outflow stenosis due to extrinsic compression of the iliocaval venous segment. The most common cause of the partial obstruction is left iliac vein compression by the overlying right common iliac artery, although other anatomic varieties of MTS do exist. Partial or complete impedance to the venous outflow in the iliocaval venous segment may lead to extensive deep vein thrombosis of the ipsilateral extremity. Clinical presentations may include, but are not limited to, pain, extensive lower-extremity swelling, venous stasis ulcers, and skin discolorations. Treatment is based entirely on the clinical presentation; normally for nonthrombotic MTS, angioplasty and stenting of the diseased iliac vein segment are usually sufficient after defining the location and extent of stenosis. In this review, we (1) describe and define MTS, (2) highlight variable presentations of MTS, and (3) outline the possible management strategies within the current Society for Vascular Surgery updated consensus guidelines. This review contains 3 Figures, 2 Videos, 3 Tables and 66 references Key Words: angioplasty, artery compression, deep venous thrombosis, iliac vein, iliofemoral stenosis, May-Thurner syndrome, spur, stent, venogram, venous hypertension