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

OBJECTIVE: This study aimed to investigate the association between common iliac vein (CIV) compression and pulmonary embolism (PE) in lower extremity deep vein thrombosis (DVT). METHODS: 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. RESULTS: 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%. CONCLUSION: 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.

A Comprehensive Review of the Pathophysiology and Clinical Importance of Iliac Vein Obstruction.

OBJECTIVE: The purpose of this comprehensive review is to give a historical account of iliac vein compression and to analyse the pathophysiological aspects and their clinical implications. METHODS: An extensive search of the databases was performed from inception until 2019. The patterns, length and site of compression, wall and luminal changes, and anatomical variations were some of the factors recorded and analysed. RESULTS: Twenty-seven studies were included in this review, divided into cadaveric, histological, and imaging. According to the literature 22%-32% of the asymptomatic population shows "spurs" at the origin of the left common iliac vein (LCIV). Imaging studies also show the presence of direct and indirect compression signs such as the presence of collateral venous flow in axial, transpelvic, or ascending lumbar collaterals, and >50% compression in 37%-44% of the asymptomatic population. In patients without thrombosis it is unknown what produces the signs and symptoms, as the obstruction pre-exists their development. Haemodynamic evaluation is found in only a few studies often including patients with previous deep vein thrombosis. Furthermore, most of the tests are performed with the patient in the supine position and therefore the haemodynamic information is relatively poor. CONCLUSION: Patients with venous obstruction have various clinical presentations from being asymptomatic to having venous claudication and skin damage. Obstruction should be placed into clinical context, together with other contributing factors. Proper evaluation and clinical judgement are important in selecting patients for treatment. Given that such selection is not always clear, further work is needed.

Best practices in diagnosis and treatment of chronic iliac vein obstruction.

Iliac vein obstruction occurs in 20-30% of the general population. In patients with severe chronic venous insufficiency, this prevalence can be even higher, reaching 50-90% when the obstruction is investigated using intravascular ultrasound. Less invasive methods, such as venous Duplex Scanning, and even invasive ones such as venography may fail to diagnose the condition. Endovascular treatment of these obstructions is effective, safe, and associated with excellent clinical outcomes and stent patency rates, provided that fundamental anatomical and technical principles are considered and applied.

Spontaneous rupture of the iliac vein.

Spontaneous iliac vein rupture is a rare diagnosis with less than 40 cases documented worldwide. There are certain similarities between many of the previously reported cases described in the literature and there are various proposed theories as to why patients develop a spontaneous rupture. A delay in diagnosis is not uncommon and the mainstay of treatment is laparotomy. Here, we report a case of a 51-year-old female with lower extremity swelling for 2days who subsequently developed hemorrhagic shock and had to be taken emergently to surgery, where a rupture of the common and external iliac veins was identified. After multiple blood products, vasopressors, and continuous renal replacement therapy the patient expired on day 3 of hospitalization.

A comparative study of altered hemodynamics in iliac vein compression syndrome.

Introduction: Iliac vein compression syndrome (IVCS) is present in over 20% of the population and is associated with left leg pain, swelling, and thrombosis. IVCS symptoms are thought to be induced by altered pelvic hemodynamics, however, there currently exists a knowledge gap on the hemodynamic differences between IVCS and healthy patients. To elucidate those differences, we carried out a patient-specific, computational modeling comparative study. Methods: Computed tomography and ultrasound velocity and area data were used to build and validate computational models for a cohort of IVCS (N = 4, Subject group) and control (N = 4, Control group) patients. Flow, cross-sectional area, and shear rate were compared between the right common iliac vein (RCIV) and left common iliac vein (LCIV) for each group and between the Subject and Control groups for the same vessel. Results: For the IVCS patients, LCIV mean shear rate was higher than RCIV mean shear rate (550 ± 103 s-1 vs. 113 ± 48 s-1, p = 0.0009). Furthermore, LCIV mean shear rate was higher in the Subject group than in the Control group (550 ± 103 s-1 vs. 75 ± 37 s-1, p = 0.0001). Lastly, the LCIV/RCIV shear rate ratio was 4.6 times greater in the Subject group than in the Control group (6.56 ± 0.9 vs. 1.43 ± 0.6, p = 0.00008). Discussion: Our analyses revealed that IVCS patients have elevated shear rates which may explain a higher thrombosis risk and suggest that their thrombus initiation process may share aspects of arterial thrombosis. We have identified hemodynamic metrics that revealed profound differences between IVCS patients and Controls, and between RCIV and LCIV in the IVCS patients. Based on these metrics, we propose that non-invasive measurement of shear rate may aid with stratification of patients with moderate compression in which treatment is highly variable. More investigation is needed to assess the prognostic value of shear rate and shear rate ratio as clinical metrics and to understand the mechanisms of thrombus formation in IVCS patients.

Venous Thromboembolism (VTE) in May-Thurner Syndrome: Decision-Making Related to Long-Term Anticoagulation.

May-Thurner syndrome (MTS) involves the compression of the left iliac vein between the right iliac artery anteriorly and the lumbar vertebrae posteriorly. Patients may remain asymptomatic throughout their lives or experience unilateral lower limb swelling and symptoms of deep vein thrombosis (DVT), such as redness and pain in the limb, or features of its complication (pulmonary embolism) such as chest pain or shortness of breath. We present the case of a 34-year-old female exhibiting acute pain and tightness in her left leg, due to DVT of the left common femoral vein, extending up to the pelvic veins, which, on further diagnostic imaging, was found to be due to MTS. The patient was initiated on lifelong anticoagulation to prevent further complications. The rising incidence of MTS, coupled with frequent delays in its diagnosis, highlights the need to raise awareness among healthcare providers, especially acute medics (who are often the first point of contact for the patient) to expand their diagnostic umbrella of differentials to include MTS as a potential cause of such presentations and to look and think beyond DVT of the lower limb. This is especially important in females presenting with non-specific DVT symptoms, as early suspicion and referral to the respective medical teams including vascular medicine, can improve diagnostic accuracy and provide more management options, thereby improving long-term outcomes.

Multi-factor analysis of failure for modified single-session Angiojet rheolytic thrombectomy in treatment of acute iliofemoral venous thrombosis from iliac vein compression syndrome.

PURPOSE: To explore the risk factors of failure for modified single-session Angiojet rheolytic thrombectomy combined with directed iliac vein stenting, directed filter retrieval in the treatment of iliac vein compression with iliofemoral vein thrombosis. METHODS: During September 2017 to September 2021, 278 patients with DVT were retrospectively analyzed and 203 were eligible for inclusion. All patients were tried to take modified single-session Angiojet rheolytic thrombectomy combined with directed iliac vein stenting, directed filter retrieval treatment. The perioperative factors were analyzed between groups: group 1-modified single-session therapy succeed, and group 2-modified single-session therapy failed. The high risk factors of failure group were evaluated by logistic regression analysis. RESULTS: 48 patients failed in modified single-session therapy, up to 23.64%. Single factor analysis indicated that there were five independent risk factors related with the failure (p < 0.05), including course of disease longer than 7 days, lumbar degeneration-related iliac vein compression syndrome (dIVCS), antegrade vein access, balloon-assisted cracking thrombus, and suction time. Logistic regression analysis indicated that course of disease longer than 7 days (OR = 19.642.95%CI:6.776∼56.933), dIVCS (OR = 11.586.95%CI:4.016∼33.427) were high risk factors for modified single-session therapy failed, antegrade vein access (OR = 0.171.95%CI:0.047∼0.614) and balloon-assisted cracking thrombus (OR = 0.157.95%CI:0.045∼0.542) were protective factors for therapy failure (p < 0.05). CONCLUSIONS: Long course of disease and dIVCS are the high risk factors for failure of modified single-session Angiojet rheolytic thrombectomy combined with directed iliac vein stenting, directed filter retrieval in the treatment of iliac vein compression syndrome (IVCS). But, antegrade vein access and balloon-assisted cracking thrombus intraoperatively may improve the success rate of modified single-session treatment.

Preliminary application of three-dimensional venography and fusion navigation technique in May-Thurner syndrome.

OBJECTIVE: The purpose of this study was to report a technique for intraprocedural guidance of endovascular iliac vein stenting procedures using three-dimensional (3D) venography images as an overlay on live biplanar fluoroscopy. METHODS: Using 3D venography and a fusion navigation technique, percutaneous transluminal angioplasty and stent placement were performed to evaluate the feasibility of using 3D venography images and the fusion navigation technique to treat MTS compared with traditional digital subtraction angiography. The general epidemiologic data (ie, age, gender), clinical manifestations (ie, major symptoms, affected extremity, CEAP [clinical, etiology, anatomy, pathophysiology] classification, comorbidity, stenosis rate), intraoperative findings (ie, stent type, stent count, stent to inferior vena cava distance, procedure time, radiation dose, contrast agent dosage), and postoperative recovery were obtained and analyzed. RESULTS: A total of 30 consecutive patients with symptomatic MTS from our institution were enrolled in the present study. Of the 30 patients, 12 (group A) were treated using 3D venography images and fusion navigation and 18 (group B) were treated with two-dimensional venography images during endovascular management. Significant differences were observed between the two groups with respect to the procedure time (64.42 ± 4.35 minutes vs 76.61 ± 3.47 minutes; P = .04), radiation dose (2152 ± 124.7 mGy vs 2561 ± 105.6 mGy; P = .02), and contrast agent dosage (71.42 ± 4.87 mL vs 86.17 ± 4.14 mL; P = .03). CONCLUSIONS: 3D venography and its fusion navigation technique can improve prediction of the coverage area of the stent. Its use can also shorten the procedure time and reduce the contrast agent dose and radiation exposure, making it a valuable tool for both the diagnosis and the treatment of symptomatic MTS.

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

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

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

Staged Treatment of Phlegmasia Cerulea Dolens in a Patient with Iliac Vein Compression Syndrome and Deep Vein Thrombosis: A Case Report.

Iliac vein compression syndrome (IVCS) is defined as extrinsic compression of the left common iliac vein (LCIV) between the overlying right common iliac artery and the lumbar vertebra. The most severe complication is phlegmasia cerulea dolens (PCD), a medical emergency that requires quick intervention to prevent irreversible limb ischemia. This article reports the case of a patient with PCD as the first manifestation of IVCS. The treatment included embolectomy and fasciotomy. Bilateral femoral iliac axis phlebography and cavography were performed 48 hours after the procedure. The IVCS was identified, and balloon predilatation of the lesions followed by implantation of self-expanding stents from the confluence of the LCIV with the inferior vena cava to the middle portion of the left external iliac vein was performed. Postprocedure phlebography demonstrated satisfactory final results, and a 12-month follow-up image showed patent stents and minimal intimal hyperplasia.

Management of May Thurner Syndrome in Pregnant Patients.

May Thurner Syndrome contributes to thromboembolic disease and can cause significant morbidity in pregnant patients secondary to exaggerated anatomic relationships and physiologic changes in the hematologic system favoring thrombogenesis. Because this condition is both underrecognized and underreported, management in pregnant and postpartum patients is based on expert opinion without any formal evidence-based guidance. Herein, we review five pregnancies in four patients with May Thurner Syndrome and general management strategies. Through collaborative and multidisciplinary care, patients with May Thurner Syndrome can be safely and successfully managed during pregnancy and the postpartum period with appropriate anticoagulation.

May-Thurner Syndrome in an Elderly Man.

May-Thurner syndrome (MTS) is a rare cause of deep vein thrombosis (DVT). This diagnosis is seldomly included in the differential diagnosis. The disease is defined as extraluminal iliac vein compression by the arterial system against bony structures in the iliocaval area. This occurs more commonly on the left side due to the unfortunate position of the proximal left iliac vein that runs between the right common iliac artery and spine. MTS is commonly presented in younger female patients with left unilateral proximal DVT. However, MTS is rarely reported in elderly patients. We present a case of a 69-year-old man with a diagnosis of MTS and further management with a venous stent.

May-Thurner syndrome.

May-Thurner syndrome (MTS) is a venous compression syndrome in which the left common iliac vein (LCIV) is compressed between the lower lumbar spine and the right common iliac artery (RCIA). Variations are known where in the right lower limb can be affected. While most of the cases are asymptomatic, it can cause severe morbidity in symptomatic individuals, most commonly deep vein thrombosis and post thrombotic sequelae. In this article, we review the key clinical features, multimodality imaging findings and treatment options of this disorder. Our goal is to raise awareness of this under-diagnosed condition among clinicians in order to promote early detection and recognition to enhance positive and expedited outcomes.

Association between deep vein thrombosis and stent patency in symptomatic iliac vein compression syndrome: Systematic review and meta-analysis.

BACKGROUND: The study intended to evaluate stent primary patency rates for patients with iliac vein obstruction related with iliac vein compression syndrome according to clinic presentation. METHODS: A systematic review and meta-analysis was conducted of studies that compared: unexposed patients with nonthrombotic iliac vein lesion (NIVL, group 1) vs exposed patients with iliac acute deep vein thrombosis (DVT, group 2); and NIVL (group 1) vs exposed patients with iliac vein obstruction and post-thrombotic syndrome (PTS, group 3). The following databases were searched: EMBASE, PubMed, Web of Science, Scopus, SciELO, and LILACS. Two reviewers independently selected the potential studies and extracted data. The pooled odds ratio (OR) and 95% confidence interval (95% CI) are shown for each outcome. RESULTS: Five studies with a total of 1050 participants and 1169 lower limbs were included. Five hundred eighty-eight lower limbs presented NIVL (50.3%), 91 lower limbs presented acute DVT (7.7%), and 490 lower limbs presented PTS (42%). The endovascular technical success rate of stenting did not differ in any of the groups: 99.6% in NIVL, 94.5% in acute DVT, and 96.5% in PTS (P = .0632). The primary stent patency rates in the 6-month follow-up were 98.3% in NIVL vs 90.9% in PTS, with a statistical difference showing reduced stent patency rates in PTS (OR, 0.17; 95% CI, 0.06-0.48; P = .0008; I2 = 0%), and 100% in the NIVL group vs 91.6% in acute DVT, with no statistical difference (OR, 0.30; 95% CI, 0.06-2.32; P = .30; I2 = 0%). The primary stent patency rates in the 12-month follow-up were 94.6% in NIVL vs 84.1% in PTS, with a statistical difference showing decreases stent patency rates in the PTS group (OR, 0.29; 95% CI, 0.14-0.63; P = .0008; I2 = 0%), and 91.1% in NIVL vs 90.9% in acute DVT, with no statistical difference (OR, 1.03; 95% CI, 0.26-4.07; P = .96; I2 = 0%). CONCLUSIONS: There is no statistical difference for the stent primary patency rates when the treatment is conducted in NIVL as compared with acute DVT lower limbs (at 6 and 12 months); therefore, other criteria must be considered for the indication of this treatment in NIVL patients. However, because there were better results of stent primary patency rates for NIVL vs PTS patients, this finding favors the treatment of acute DVT instead of PTS in lower limbs, once PTS renders smaller stent patency rates at 6 and 12 months.

Comparison of computed tomography venography and intravascular ultrasound in screening and classification of iliac vein obstruction in patients with chronic venous disease.

OBJECTIVE: To investigate power of computed tomography venography (CTV) to identify and characterize iliac vein obstruction (IVO) compared with intravascular ultrasound (IVUS) examination in highly symptomatic patients with chronic venous disease (CVD). METHODS: CVD CEAP C3-6 limbs with visual analog scale for pain score of greater than 3 and/or Venous Clinical Severity Scale of greater than 8 were prospectively investigated with CTV and IVUS examination. The segment of maximum IVO was verified and categorically classified: group I, 0% to 49%; group II, 50% to 79%; and group III, 80% or greater. The CTV's screening power to detect the point and degree of maximum IVO was compared with IVUS. RESULTS: The CTV point of maximum IVO was 80% in the left limb, 10% in the right limb, 10% bilaterally; 2% in the inferior vena cava; 91% in the common iliac vein (CIV) confluence (41.6% below the CIV confluence, 34.5 at the CIV confluence, and 23.9% above the CIV confluence); 7% at the external iliac vein (kappa index 0.841; P < .001, when compared with IVUS). The distal venous segment considered free of obstruction was above inguinal ligament: 68% (CIV, 47%; external iliac vein, 21%) 32% below the inguinal ligament (common femoral vein, 26%; deep femoral vein, 6%) (kappa index 0.671; P = .023, when compared with IVUS). The power of CTV to detect an IVO of 50% or greater (groups II and III) when compared with IVUS achieved a sensitivity and specificity ratio of 94.0% and 79.2%, respectively. The positive predictive value was 94%, the negative predictive value was 79.1%, accuracy was 86.7% (kappa, 0.733), and interobserver agreement was 92.1% (95% confidence interval, 87.1-97.7; kappa, 0.899). CONCLUSIONS: CTV is a powerful screening method in determining the precise point of compression and classifying IVO in limbs with symptomatic CVD when compared with IVUS. The prevalence of an obstruction above the iliac vein confluence is significant and should be considered in iliac vein stenting treatment strategy. The tomographic classification system proposed here may help to define the optimum technique of treatment, prognosis, and comparison of outcome results.

Clot Mayhem: A Case of May-Thurner Syndrome.

May-Thurner syndrome (MTS), also known as the iliac vein compression syndrome, is an anatomic anomaly in which the compression of the left common iliac vein by an overlying right common iliac artery leads to blood stasis, which predisposes to deep venous thrombosis (DVT) in the iliofemoral venous system. We present a case of a female with a history of DVT and currently on warfarin with a therapeutic international normalized ratio (INR), admitted with left leg swelling, redness, and intractable pain. Venous Doppler scan confirmed a massive DVT from the level of the left common femoral vein to the popliteal vein. The clot recurred after an unsuccessful trial of argatroban, in-line pharmacokinetic thrombolysis with local catheter-based alteplase infusion, and interventional radiology (IR)-guided mechanical thrombectomy. Subsequently, the patient was diagnosed as MTS with overlying left common iliac vein compression, as evident on venous Doppler ultrasound. She was managed successfully by venous stent placement and ongoing systemic anticoagulation with fondaparinux.

Sciatic Neuralgia Caused by May-Thurner Syndrome.

BACKGROUND: Sciatic neuralgia (SN) is a type of pain commonly associated with lumbosacral radiculopathy. May-Thurner syndrome (MTS) is a disease characterized by venous congestion in the left common iliac vein (LCIV) due to right common iliac artery compression. A case of MTS with SN as the first presenting symptom is described. CASE DESCRIPTION: A 53-year-old man gradually developed left SN; however, radiologic examination showed no causal findings. Conservative medical treatment did not result in satisfactory pain relief. During the follow-up period, edema and brownish skin pigmentation were noted on the left crural region. Follow-up magnetic resonance imaging of lumbar spine revealed vascular enlargement around the spine and compression of the LCIV by the right common iliac artery. Furthermore, the left S1 nerve root was compressed by enlarged veins, which was thought to be the cause of the left S1 radiculopathy and SN. After the stenosed part of the LCIV was expanded, the pain and edema in the left leg disappeared. CONCLUSIONS: This is the first report of SN associated with MTS. MTS should be considered as one of the differential diagnoses of SN. Thus, symptoms such as pain, edema, and skin hyperpigmentation on the left leg should be closely noted.

May-Thurner Syndrome Variant Identified in a Cadaver: First Reported Case.

May-Thurner syndrome (MTS) is defined as the compression of the left common iliac vein by the right common iliac artery. Herein, we describe an unusual case of a male cadaver with right-sided compression of the inferior vena cava and the left and right common iliac veins by the right common iliac artery. This is an unusual variant of this syndrome and the first known case report. We suggest this variant be termed MTS type II due to the additional compression of the inferior vena cava.

O caminho das pedras no diagnóstico e tratamento da síndrome obstrutiva ilíaca venosa crônica / Best practices in diagnosis and treatment of chronic iliac vein obstruction

Resumo A obstrução venosa ilíaca ocorre em 20% a 30% da população. Nos portadores de insuficiência venosa crônica grave, essa prevalência é ainda maior, podendo chegar a 50% a 90% dos pacientes, situação em que essa obstrução é investigada pelo ultrassom intravascular. Métodos diagnósticos menos invasivos, como o Doppler vascular, ou mesmo invasivos, como a flebografia, podem falhar em seu diagnóstico. O tratamento endovascular dessas obstruções tem se demonstrado eficaz, seguro e associado a excelente resultado clínico e de perviedade, desde que princípios anatômicos e técnicos fundamentais sejam considerados e aplicados.

Abstract Iliac vein obstruction occurs in 20-30% of the general population. In patients with severe chronic venous insufficiency, this prevalence can be even higher, reaching 50-90% when the obstruction is investigated using intravascular ultrasound. Less invasive methods, such as venous Duplex Scanning, and even invasive ones such as venography may fail to diagnose the condition. Endovascular treatment of these obstructions is effective, safe, and associated with excellent clinical outcomes and stent patency rates, provided that fundamental anatomical and technical principles are considered and applied.