Compression Of Common Iliac Vein Research Articles

Venous Stasis Ulceration due to Massive Splenomegaly Causing Iliac Vein Compression From Secondary Myelofibrosis.

Venous stasis ulcers are nonhealing lesions due to venous hypertension secondary to valvular dysfunction or deep venous outflow obstruction. We describe a case of a 71-year-old male with a history of polycythemia vera, secondary myelofibrosis, and massive splenomegaly up to 38cm who presented with chronic, perimalleolar venous stasis ulcers and pain on the left lower extremity. CT showed significant compression of the left common iliac vein due to mass effect from the spleen. He was managed medically while being evaluated for partial splenic artery embolization but expired due to other chronic conditions before any intervention could be performed. Partial splenic artery embolization may be considered as a treatment option for patients with symptomatic iliac vein compression due to massive splenomegaly secondary to myelofibrosis, as long as extramedullary hematopoiesis is not compromised.

A Systematic Review of Radiological Diagnosis and Management of May–Thurner Syndrome

ABSTRACT May–Thurner syndrome (MTS) is an anatomical condition of external luminal compression of common iliac vein due to a partial obstruction of the common iliac vein between common iliac artery and lumbar vertebra causes deep-vein thrombosis, venous hypertension, and chronic venous insufficiencies. In this article, we review present evidence of the clinical diagnosis and management of MTS. Here, we conducted a literature review of studies on MTS. We also reviewed different clinical features, presentation, diagnostic methods, and therapeutic procedure for this condition. Most studies mentioned the diagnosis of this condition is performed by color Doppler, computed tomographic angiography, venography, and problem-solving cases by intravascular ultrasound technique. Nonsurgical methods of management are first line, and vascular surgery is reserved for refractory cases. Multiple modalities are required to reach the diagnosis of MTS, and noninvasive intervention radiology methods are the first line of management. This review highlights the presentations of MTS and outlines diagnostic procedure and management.

May–Thurner syndrome: The unexplored

Abstract May–Thurner syndrome (MTS) is the pathologic compression of the left common iliac vein by the right common iliac artery, resulting in left lower extremity pain, swelling, and deep venous thrombosis. MTS is missed by many interventionists as there is no standard criteria to establish the diagnosis. Imaging plays an integral part in screening patients for MTS. Here, we present a series of cases of MTS, which may help clinicians to diagnose and treat MTS.

A Case Series of May-Thurner Syndrome: An Anatomical Variation Leading to a Life-threatening Condition

May-Thurner syndrome is a rare clinical condition resulting from anatomical variation, where patients present with unilateral left lower limb swelling due to a thrombus in the left common iliac vein. This occurs as a result of compression of the left common iliac vein by the right common iliac artery. The condition is more commonly observed in females and can lead to life-threatening pulmonary thromboembolism. Early diagnosis and interventional management, such as stenting and placement of an Inferior Vena Cava (IVC) filter, can help prevent pulmonary embolism. In the present case series, four patients were included. Two of them presented with the classical clinical history of unilateral left lower limb oedema and calf muscle tenderness. One of these patients underwent stenting of the left common iliac vein and placement of an IVC filter. In the other two patients, abdominal complaints prompted the performance of Multidetected Computed Tomography (MDCT), and incidentally, left common iliac vein thrombus secondary to May-Thurner syndrome was detected.

Patient reported outcome measures (PROMS) and patient reported experience measures (PREMS): Measuring outcomes in pelvic venous disorders

Pelvic venous disorders (PeVD) present with a range of heterogenous symptoms that arise from altered venous hemodynamics in the pelvis. Many of these symptoms lead to mental health and quality of life issues and are not limited to the pelvic region. The nutcracker phenomenon causing left renal vein compression and left ovarian venous hypertension as well as the compression of the left common iliac vein by the overlying right common iliac artery are often stated as the common underlying pathologies. As a result, there has been a sudden increase in the number of ovarian vein coil embolizations and iliac vein stents placed. In truth however, the altered venous hemodynamics in PeVD is more complex. There appears to be little correlation between the symptoms patients experience and the obvious image detected anatomical lesions being treated. In addition, these anatomical lesions are very commonly seen in asymptomatic and especially muti-parous women as well. To compare outcomes of these and other more extensive procedures being performed for these commonly seen anatomical changes in the pelvic veins, objective assessments of the outcomes as seen from the symptom relief they bring to patients treated is essential. Validated Patient-reported outcome measures (PROMS) can be an important tool to compare outcomes across interventions for PeVD. However, as the impact of similar symptoms on different patients’ quality of life (QoL) can vary, developing a validated PROM that can be used to compare procedural outcomes in PeVD is a challenge. On the other hand, complications and procedural success as reported by physician do not assess the effect on a patient’s QoL. This paper provides a narrative review of PROMs, patient reported experience measures (PREMs) and individualized-PROMs. It also suggests a process for how a validated PROM for comparing procedural outcomes in PeVD may be developed. This could provide a framework that incorporates the recently adopted Symptoms-Varices-Pathophysiology (SVP) classification of pelvic venous disorders into the PROM development process to ensure that a like-for-like comparison is made between procedures being performed on a very heterogenous, but long-suffering group of patients.

May-Thurner Syndrome Should be Explored As a Possible Existing Risk Factor in Pediatric Patients Presenting with Non-Central Venous Line Associated Deep Vein Thrombosis

Background: The compression of the left common Iliac vein (LCIV) by the right common iliac artery is called May-Thurner Syndrome (MTS). The incidence of this anatomic variance is unknown, though it is estimated to be 18-49%. It is currently established that the chronic compression of the iliac vein outflow results in various clinical symptoms including edema, pain, discoloration, skin ulcers and venous thromboembolism. Deep vein thrombosis (DVT) of the LCIV is the most reported presentation of MTS in pediatrics. DVTs in pediatric patients are rare and often provoked by a central venous line (CVL). Patients without a CVL in the context of left lower extremity (LLE) DVT often do not undergo MTS work-up if the DVT does not include the LCIV. To assess if MTS is a risk factor for LLE DVT distally to the LCIV, we describe an institutional incidence of MTS in two pediatric patient populations: those with non CVL-associated LLE DVTs and a control group composed of pediatric patients undergoing imaging that includes the LLE vasculature for unrelated reasons. Methods: This was a single center retrospective study. We identified patients with a non CVL-associated LLE DVT seen at our institution using ICD-10 codes as well as a cohort of patients who received imaging of the LLE vasculature for reasons other than DVT using radiology MRI protocol codes.Electronic medical records were reviewed for demographic variables such as age and gender. Patients without DVTs had imaging reviewed for the incidental finding of MTS. Those with DVTs had information collected regarding clinical characteristics such as coagulation panels, thrombosis risk factors (thrombophilic states, oral contraceptive use, obesity), and therapy received. All images were reviewed by a pediatric radiologist. Results: A total of 35 patients with non CVL-associated LLE DVTs, and 752 patients without CVL and without LLE DVTs were identified. Of those with LLE DVTs, 19 (54%) were found to have MTS. Of these 19 patients, 5 (26%) were obese, 14 (74%) were on oral contraceptive pills, and 8 (42%) reported prothrombotic risks (7 heterozygous for Factor V Leiden, 1 heterozygous for protein C deficiency). Two patients (10%) had no additional risk factors for thrombosis. Of those without LLE DVTs, 6 patients (0.01%) were incidentally diagnosed with MTS. Interestingly we also described one patient with non CVL-associated LLE DVT distally to the LCIV with MTS. Conclusions: In our study, the presence of MTS was significantly higher in the non CVL-associated LLE DVT group than in the control group. This study suggests that MTS should be considered, and associated imaging performed, in pediatric patients with a non CVL-associated LLE DVT, considering the incidence revealed by this single institutional case series. The presence of MTS in pediatric patients may significantly impact the life-long risk of DVT recurrence. Given that aging adversely impacts lower limb venous return (exacerbated by central obesity, sedentary lifestyle, and other risk factors) and that pregnancy is a known trigger of DVT in patients with MTS, knowledge of prior MTS may impact patient care over the lifespan.

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.

Abstract 12297: A Rare Case of May-Thurner Syndrome Due to External Compression of the Right and Left Common Iliac Veins

Description of Case: A 54yr male with HTN and CKD stage IIIa presented with asymmetric right greater than left lower extremity (LE) edema. Vital signs were normal. His exam showed asymmetric right greater than left LE edema to the mid-thighs. ECG revealed sinus rhythm. Medical therapy with increasing titration of diuretics was unsuccessful in resolving his asymmetric LE edema. A TTE showed EF of 55-60% with normal bi-ventricular size and function and no significant valve abnormalities. Bilateral duplex US showed no DVT. CT abdomen pelvis showed no hydronephrosis or compressive masses. Right heart catheterization revealed normal bi-ventricular filling pressures. Bilateral peripheral venogram showed bilateral common iliac vein stenosis (Figure 1A). IVUS showed external compression of the right common iliac vein (RCIV) between the right external and internal iliac arteries with external compression of the left common iliac vein (LCIV) by the right common iliac artery (RCIA) against the lumbar spine (Figure 1A). A diagram of the compression observed in this case is included (Figure 1B). The RCIV had an 18mmHg gradient with no significant gradient on the LCIV. The RCIV was stented using an 18x60mm self-expanding stent and balloon dilation. Final IVUS and venogram showed no residual stenosis, edge dissection or perforation (Figure 1D). The patient was discharged on dual-antiplatelet therapy for three months and aspirin thereafter with continued diuretics. He had significant reduction in asymmetric LE edema with marked improvement in ambulation capacity and no further LE asymmetry at the 30-day follow-up visit. Discussion: Here we present a rare case of May-Thurner Syndrome via compression of the LCIV by the RCIA and RCIV by the right internal and external iliac arteries with successful management. We also illustrate the importance of a broad differential diagnosis in patients with persistent asymmetric LE edema refractory to diuretic management

Prevalence and predictors of radiological left common iliac vein compression in asymptomatic patients

ObjectiveThe aim of this study was to investigate the prevalence of radiological left common iliac vein (LCIV) compression among the asymptomatic population and identify possible predictors. MethodsContrast-enhanced abdominal and/or pelvic computed tomography scans of eligible asymptomatic patients were examined. The LCIV diameter was measured from different horizontal planes in the venous phase using PACSView. Degree of LCIV compression (Dc) was calculated by a predefined formula and graded as insignificant (Dc < 25%), mild (≥25% Dc < 50%), moderate (≥50% Dc <75%), and severe (Dc ≥ 75%). Venous stenosis was defined as a Dc of ≥50%. Comparison of variables, including gender, age, body mass index (BMI), and comorbidities was performed between the different grades of LCIV compression. ResultsBetween November 2019 and July 2022, 1698 eligible asymptomatic patients (53.1% females; mean age, 39.3 ± 11.8 years; mean BMI, 22.9 ± 3.6 kg/m2) were reviewed. The mean Dc was 46.2% (range, 0.29%-90.4%). Insignificant, mild, moderate, and severe compression were distributed in 14.5%, 38.0%, 42.2%, and 5.2% of the cohort population, respectively. Prevalence of venous stenosis was higher in females than males (58.1% vs 42.2%; χ2 = 15.52; P < .001). Females aged ≥25 and <35 years accounted for the highest proportion of venous stenosis than other age groups and was a significant predictor (odds ratio [OR], 3.18; 95% confidence interval [CI], 1.74-7.79; P < .001). In the Asian BMI classification group, being underweight is associated with venous stenosis (OR, 4.69; 95% CI, 2.70-8.14; P < .001) and obesity may be a protective factor (OR, 0.38; 95% CI, 0.23-0.64; P < .001). There is an inverse relationship between Dc and age and BMI. ConclusionsThe prevalence of radiological LCIV compression on computed tomography scans was high, but all patients were asymptomatic. Female gender, especially those aged ≥25 and <35 years, and underweight were possible predictors for venous stenosis.

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

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

Ilio-caval venous stenting for the treatment of severe post-thrombotic syndrome due to multiple sites of iliac vein compression

Classical May-Thurner Syndrome describes compression of the left common iliac vein. However, multiple sites of venous compression can occur. This report describes a case of ilio-caval venous thrombosis from multiple sites of iliac vein compression

Common Iliac Vein Compression, Our Own Pulmonary Embolism Saving Filter

Common Iliac Vein Compression, Our Own Pulmonary Embolism Saving Filter

PD18-09 THE INCIDENCE OF LEFT COMMON ILIAC VEIN COMPRESSION IN MEN WITH A VARICOCELE. IMPLICATIONS FOR ETIOLOGY AND MANAGEMENT

You have accessJournal of UrologyCME1 Apr 2023PD18-09 THE INCIDENCE OF LEFT COMMON ILIAC VEIN COMPRESSION IN MEN WITH A VARICOCELE. IMPLICATIONS FOR ETIOLOGY AND MANAGEMENT Peter Chin and Laurencia Villalba Peter ChinPeter Chin More articles by this author and Laurencia VillalbaLaurencia Villalba More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003273.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The etiology of varicocele is thought to be related to incompetence of the gonadal vein. Epidemiological studies have shown that Left Common Iliac Vein Compression (LCIVC) ≥25% occurs in 22-35% of the general population. The objective of this study was to compare the incidence and severity of LCIVC in men with a varicocele with the published incidence in asymptomatic men, document the incidence of left gonadal incompetence and provide a possible explanation for varicocele treatment failure. METHODS: Men presenting at our practice with a varicocele were enrolled into this study. Ethics approval was obtained. All participants underwent a Duplex Ultrasound of the pelvic veins. The degree of LCIVC was grouped into ≥25% (significant compression) and ≥50% (severe compression). The results were compared to a vascular epidemiological study of 272 asymptomatic men (Cheng et al 2017), by Chi-squared analyses. Degree of compression was analyzed for association with Grade of varicocele by Kruskal-Wallis ANOVA test. RESULTS: 80 men with varicoceles completed the investigations. Mean age of the cohort was 39.5 years. In our study group, 91.2% men had a LCIVC ≥25% (73/80) compared to the expected incidence in asymptomatic men of 29.4% (80/272) [χ2=96.2; p<0.001]. The study also showed that 67.5%% (54/80) had LCIVC ≥50% (severe) compared to the expected incidence in asymptomatic men of 6.9% (19/272) [χ2=137; p<0.0001]. Only 23% of men had incompetent gonadal veins (19/80). 16% of men with varicoceles had retrograde flow through the left internal iliac vein. 8.8% (7/80) men presented with recurrent varicocele and all had severe LCIV compression ≥50%. There was no significant correlation between WHO varicocele grade and degree of compression (Kruskal-Wallis one-way ANOVA H=3.26, p=0.196). CONCLUSIONS: This is the largest study to show that men with varicoceles have a significantly higher incidence of LCIVC ≥25% (significant) and LCIVC ≥50% (severe) than asymptomatic men. Increased pelvic venous pressure from LCIVC can lead to retrograde flow through the left internal iliac vein (16%). The high incidence of LCIVC in men with a varicocele suggests that a varicocele is an “escape” vessel for increased pelvic venous pressure. The majority of men in our cohort did not have a demonstrable incompetent gonadal vein (23%). This would make embolization difficult, and ligation unlikely to provide long term benefit if there was a separate pelvic feeding vessel. Severe LCIV compression (≥50%) is associated with DVT and pelvic venous congestion. Men with varicoceles should be further investigated with a pelvic duplex ultrasound. All of the men presenting with recurrent varicocele after embolization had severe LCIV compression. Although these results are significant, larger studies are needed to confirm these findings. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e506 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Peter Chin More articles by this author Laurencia Villalba More articles by this author Expand All Advertisement PDF downloadLoading ...

Impact of Common Iliac Vein Compression on the Incidence of Pulmonary Embolism in Patients with Acute Deep Vein Thrombosis

This study aimed to investigate the association between common iliac vein (CIV) compression and pulmonary embolism (PE) in lower extremity deep vein thrombosis (DVT). This was a single centre retrospective study. Between January 2016 and December 2021, DVT patients with enhanced computed tomography of the iliac vein and pulmonary artery were included. Patient demographics, comorbidities, risk factors, and degree of CIV compression were collected and analysed. Logistic regression was performed to evaluate the odds ratio (OR) with a 95% confidence interval (CI) of PE in relation to compression severity groups. The association between PE and compression degree was evaluated with restricted cubic splines (RCS) based on an adjusted logistic regression model. Two hundred and twenty-six DVT patients (left side, n= 153; right side, n= 73) were included. Univariable analyses suggested that symptomatic or asymptomatic PE (54.4%, 123/226) was more common in men (p= .048) and right side DVT (p= .046) patients. Compared with no CIV compression, multivariable analyses suggested that mild compression did not statistically significantly reduce the PE risk, whereas moderate (adjusted OR 0.36; 95% CI 0.15 - 0.88; p= .025) and severe (adjusted OR 0.18; 95% CI 0.06 - 0.54; p= .002) compression statistically significantly reduced the risk. RCS showed that a smaller minimum diameter or greater compression percentage was correlated with continuously decreasing PE risk at a minimum diameter of < 6.77 mm or compression > 42.9%. PE is more common in men and right side DVT patients. An increasing severity of CIV compression is consistently associated with a decreasing risk of PE when the minimum diameter is < 6.77 mm or the compression is > 42.9%, indicating that it is a protective factor against PE.

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.

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.

The association between iliac vein compression degree and characteristics of first diagnosed left lower extremity deep vein thrombosis.

This study aimed to investigate the association between the left common iliac vein (CIV) compression degree and characteristics of first diagnosed left lower extremity deep vein thrombosis (DVT). This was a single-center retrospective observational study. Between January 2015 and June 2022, first diagnosed left lower extremity DVT patients with enhanced computed tomography of lower extremities were included. Patient demographics, comorbidities, risk factors, DVT characteristics, and CIV compression degree were collected and analyzed. Logistic regressions were performed to evaluate the odds ratio (OR) with a 95% confidence interval (CI) of iliofemoral or mixed DVT vs. compression percentage. The association between compression percentage and iliofemoral or mixed DVT was evaluated on a continuous scale with restricted cubic splines (RCS). The association between compression percentage and thrombus burden was evaluated using the Spearman test. A total of 196 (mean age, 61.8 ± 16.1 years; 86 males) patients were included. The median CIV compression percentage in iliofemoral or mixed DVT patients was significantly greater than in non-iliofemoral or non-mixed DVT, respectively (64.4 vs. 46.6%, p < 0.001; 67.8 vs. 54.8%, p = 0.004). CIV compression >50% was associated with significantly increased morbidity of iliofemoral DVT (adjusted OR, 2.96; 95% CI, 1.58-5.52; p = 0.001) or mixed DVT (adjusted OR, 2.39; 95% CI, 1.19-4.81; p = 0.014). RCS showed that a greater compression percentage was associated with a continuously increased OR of iliofemoral DVT (overall p = 0.003, non-linear p = 0.577) or mixed DVT (overall p = 0.020, non-linear p = 0.771). CIV compression percentage had a positive correlation with thrombus burden (rs = 0.284, p < 0.001). A greater left CIV compression percentage may be associated with increasing likelihood of more proximal location and severe clot extent in first diagnosed left lower extremity DVT.

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.

Risk factors for stent occlusion after catheter-directed thrombolysis and iliac vein stenting in the treatment of May-Thurner syndrome with iliofemoral deep vein thrombosis: a retrospective cohort study.

This study aimed to identify the risk factors for stent occlusion in patients with iliofemoral deep vein thrombosis (DVT) secondary to May-Thurner syndrome (MTS) who underwent catheter-directed thrombolysis (CDT) and iliac vein stenting. A retrospective analysis was performed on 44 patients who underwent CDT and iliac vein stenting for MTS with iliofemoral DVT between October 2001 and March 2018. MTS was diagnosed based on extrinsic compression of the left common iliac vein (CIV) by the overlying right common iliac artery (CIA) on computed tomography (CT). Clinical records of the study population were reviewed to collect baseline data, procedural characteristics, and outcomes. Final venograms showing diffuse and irregular wall thickening in the iliofemoral vein were considered to indicate a chronic post-thrombotic lesion. The stent position was categorized as follows: confluence coverage without touching the contralateral inferior vena cava (IVC) wall, IVC extension contacting the contralateral IVC wall, or distal to the iliocaval junction. Stent patency was assessed using duplex ultrasonography. Risk factors for stent occlusion were assessed using univariate and multivariate Cox proportional hazard models. The median duplex ultrasound follow-up period was 25 months (range, 1-196 months). The overall cumulative patency rate at 12 months was 70.0%. In the univariate Cox regression, factors significantly associated with stent occlusion included symptom duration >2 weeks before CDT, partial thrombolysis (50-99% of thrombus removal), chronic post-thrombotic lesions, and stent position. Multivariate Cox regression showed that chronic post-thrombotic lesions [hazard ratio (HR) =7.15; 95% confidence interval (CI): 1.32-38.81; P=0.023] and a stent distal to the iliocaval junction (HR =5.59; 95% CI: 1.46-21.38; P=0.012) were significantly associated with stent occlusion. Chronic post-thrombotic lesion and a stent distal to the iliocaval junction were important risk factors for stent occlusion in patients who underwent CDT and iliac vein stenting.

Controversies in the management of proximal deep vein thrombosis.

Controversies in the management of proximal deep vein thrombosis.