Iliac vein compression syndrome: Clinical, imaging and pathologic findings

Rare presentation of May-Thurner syndrome in childhood with lower abdominal ectopic kidney

We report a case of a child who presented clinically with features of nephrotic syndrome and May-Thurner syndrome consecutively in the first decade of life. Initially, the nephrotic syndrome was diagnosed and treated. May-Thurner syndrome was suspected clinically in later childhood when there was remission of nephrotic syndrome with persistent left lower leg swelling. The specific imaging modalities are used to document the mechanical compression of the left common iliac vein by the lower abdominal ectopic left kidney before definite management. Our discussion highlights the role of various imaging modalities in the diagnosis of May-Thurner syndrome.

Under pressure: a head-to-toe review of vascular compression syndromes

Vascular compression syndromes are a group of conditions resulting from mechanical compression of blood vessels by adjacent structures leading to compromised blood flow and various associated symptoms. They frequently affect young, otherwise healthy individuals and are often underdiagnosed due to their rarity and vague clinical manifestations. Achieving an accurate diagnosis depends on the integration of clinical presentation and imaging findings. Imaging modalities including color doppler ultrasound, computed tomography angiography, magnetic resonance angiography, and catheter-directed digital subtraction angiography are essential for diagnosis and management. Dynamic imaging is crucial in eliciting findings due to the positional nature of many of these syndromes. In this paper, we will present a "head-to-toe" overview of vascular compression syndromes including Vascular Eagle Syndrome, Vascular Thoracic Outlet Syndrome, Quadrilateral Space Syndrome, Hypothenar Hammer Syndrome, Median Arcuate Ligament Syndrome, Renal Artery Entrapment Syndrome, Left Renal Vein Compression/Nutcracker Syndrome, May-Thurner Syndrome, Adductor Canal Syndrome, and Popliteal Artery Entrapment Syndrome. Treatment is variable but typically involves a combination of conservative and surgical management. Surgical approaches focus on decompression of affected neurovascular structures. Endovascular treatment alone is rarely recommended. We aim to equip general radiologists with the knowledge needed to accurately diagnose patients with vascular compression syndromes, allowing for timely treatment.

Review of Mixed Arterial Venous Leg Ulcers (MAVLU) Disease in Contemporary Practice

BACKGROUND

Mixed Arterial and Venous Leg Ulcers (MAVLU) are challenging. Clinical evidence specific to MAVLU management is scarce. We evaluated our recent experience with MAVLU patients and reviewed current data regarding MAVLU epidemiology, aetiology, diagnostic assessment and management options.

METHODS

A prospective leg ulcer database was retrospectively interrogated to determine the prevalence and clinical outcome of MAVLU over 2-year period (2021-2022). The literature was reviewed to determine if optimal treatment strategies.

RESULTS

307 patients attended the ulcer clinic over a 2-year period. Most were venous leg ulcers (71%), 24% were arterial and 5% were MAVLU. The highest healing rate was in MAVLU (93%), followed by (74%) and (41%), in arterial and venous leg ulcer groups, respectively.

CONCLUSION

Evidence-based guidelines for MAVLU remain lacking. Well-developed randomised controlled trials are warranted to guide current clinical practice.

Cardiac Arrest Due to Pulmonary Embolism Without Clinical Features of Deep Vein Thrombosis in a Young Female: A Rare Presentation of May-Thurner Syndrome

Deep vein thrombosis (DVT) is a serious condition with a high disease burden. Pulmonary embolism is one of the disastrous complications of DVT. The etiology of DVT includes factors responsible for hypercoagulation, venous injury, and factors causing stasis in the deep veins. May-Thurner syndrome (MTS) is one of the rarely thought of causes of DVT. MTS is an anatomical variant where the right common iliac artery compresses the left common iliac vein against the lumbar vertebrae. This leads to thrombus formation and stenosis in the left common iliac vein at the site of cross-over, resulting in an iliofemoral DVT. We present a case of a young female who presented with acute bilateral pulmonary embolism and subsequent cardiac arrest. She was treated with mechanical thrombectomy, angioplasty, and stent placement under the umbrella of anticoagulant agents. We aim to present this case to highlight that MTS should be considered a differential etiological condition in iliofemoral DVT. MTS is a rarely considered condition by clinicians while evaluating patients with lower limb DVT. When unaddressed, MTS can lead to recurrent DVT, post-thrombotic syndrome, and fatal complications like pulmonary embolism. Clinicians should investigate for possible MTS in patients with left lower extremity venous thrombotic events, irrespective of the presence of other risk factors.

Efficacy of ultrasound in the evaluation of iliac vein stenting

Objectives: The current study evaluated the efficacy of iliac and IVC ultrasound alone for follow-up evaluation of iliac vein stents in patients with pelvic venous disorders or iliac occlusion from chronic deep vein thrombosis. Methods: A retrospective single site cohort study was conducted by evaluating the most recent 100 iliac vein and inferior vena cava ultrasounds in patients who had undergone iliac vein stenting. Inclusion criteria included a history of iliac vein stent placement. Exclusion criteria included patients under 18-years-old, duplicates of the same patient, and pregnancy at the time of ultrasound. The degree of visualization for color flow, gray scale, and phasicity were determined and classified into the following categories: complete, partial, or none. In addition, each chart was assessed for external compression, in-stent narrowing, and requirements for further imaging. Results: Of the 100 iliac vein and IVC ultrasounds assessed in this review, 99 of the ultrasounds were sufficient for evaluation during follow-up visits without requiring further investigation. Within this study cohort, the average follow-up time was 22 months. The average participant body mass index was 27.6. One iliac vein and IVC ultrasound was considered inadequate for follow-up evaluation and required further imaging. Conclusion: The use of iliac and IVC venous doppler ultrasound alone in the follow-up evaluation of iliac stent patency is effective and noninvasive and avoids unnecessary radiation exposure and cost.

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.

Unveiling May-Thurner Syndrome in a Case of Recurrent Deep Venous Thrombosis With Bilateral Pulmonary Embolism

May-Thurner syndrome (MTS) is a rare cause of deep venous thrombosis (DVT), characterized by the external compression of the left common iliac vein by the right common iliac artery against bony structures. Risk factors for MTS include female sex (postpartum, multiparous, and using oral contraceptive pills), spinal abnormalities like scoliosis, prior aortoiliac vascular stent placement, dehydration, and hypercoagulability. MTS patients with partial obstruction can be asymptomatic, but progression to extensive symptomatic DVT and/or chronic venous insufficiency can occur. MTS can be diagnosed by non-invasive imaging studies including ultrasound (US), computed tomography (CT) scan, magnetic resonance imaging (MRI), venogram, catheter-based venogram, and intravascular US. For MTS patients with moderate to severe symptoms, we suggest thrombectomy, angioplasty, and stenting of the affected segment. In this case report, we highlight a 44-year-old male with a recent diagnosis of left-sided DVT on apixaban who presented with worsening leg swelling. DVT, pulmonary embolism (PE), and MTS were diagnosed with a lower extremity US, chest CT angiography, and abdominal/pelvic CT scan and venography, respectively. The patient underwent interventional radiology-guided local thrombolysis, thrombectomy, and venoplasty along with stent placement in the left common iliac vein. Subsequently, the patient was discharged on rivaroxaban.

Left common iliac vein diameter in patients referred for lower limb venous duplex ultrasound

INTRODUCTION

Evidence regarding ultrasound assessment of left common iliac vein diameter (LCIV) is limited. Extensive work is currently being undertaken worldwide on non-thrombotic iliac vein lesions to identify patients who may benefit from intervention to alleviate symptoms of chronic venous obstruction. Interventions include long-term stent implantation to improve vein diameter stenosis. This study aimed to assess a cohort of symptomatic venous patients and the diameter of the LCIV in these patients.

METHODS

: Retrospective medical records review of all patients attending a tertiary vascular surgery centre who underwent a venous duplex ultrasound assessment between April 2017 and February 2018 were analysed for assessment of LCIV. Medical records of those patients with documented LCIV diameter were assessed over 18 months of follow-up.

RESULTS

: A total of 672 (271 males, 401 females) LCIV diameter measurements were collected. The age of the patients ranged from 21 to 95 years (mean = 56.38). Median LCIV diameter overall was 7.64 mm (IQR 5.80mm-9.00 mm). 40 patients (6%) were reported to have a LCIV diameter measurement of < 4 mm, 8 (20%) male and 32 female (80%). 17 of these 40 patients (47.5%) were treated conservatively. Median LCIV diameter was 3.4 mm (IQR 2.5-3.7). 21 of these 40 patients (52.5%) underwent superficial venous intervention only, with a median LCIV diameter of 3.5 mm (IQR 3.2-3.7) and 2 out of these 40 patients (5%) underwent deep venous stenting (2/2 female - 100%), with a median LCIV diameter of 2.9 (IQR 2.9-2.9). No patients underwent both superficial and deep venous treatment in this 40 patient cohort. In those undergoing superficial venous intervention, 4 (19%) underwent repeat treatment. The two deep venous stenting patients underwent magnetic resonance venogram and venogram with intravascular ultrasound to allow stent placement, which confirmed a narrowed left common iliac vein. Primary stent patency at 18 months was 100%.

CONCLUSION

In this large study cohort of venous duplex assessments the median vein diameter was 7.64 mm and 40 patients out of 672 had a vein diameter smaller than 4 mm. 2 patients underwent deep venous stenting with primary patency of 100%.

Vascular compression syndromes in the abdomen and pelvis: a concise pictorial review

Vascular compression syndromes are a diverse group of pathologies that can manifest asymptomatically and incidentally in otherwise healthy individuals or symptomatically with a spectrum of presentations. Due to their relative rarity, these syndromes are often poorly understood and overlooked. Early identification of these syndromes can have a significant impact on subsequent clinical management. This pictorial review provides a concise summary of seven vascular compression syndromes within the abdomen and pelvis including median arcuate ligament (MAL) syndrome, superior mesenteric artery (SMA) syndrome, nutcracker syndrome (NCS), May-Thurner syndrome (MTS), ureteropelvic junction obstruction (UPJO), vascular compression of the ureter, and portal biliopathy. The demographics, pathophysiology, predisposing factors, and expected treatment for each compression syndrome are reviewed. Salient imaging features of each entity are illustrated through imaging examples using multiple modalities including ultrasound, fluoroscopy, CT, and MRI.

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

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: A case of extensive unprovoked left lower extremity deep vein thrombosis (DVT)

May-Thurner syndrome (MTS) also known as iliac vein compression syndrome, is a congenital anatomical variant, that results from the extrinsic compression of the left common iliac vein by the right iliac artery with resultant formation of left venous thrombosis. We report a case of a young man with recurrent unprovoked left lower extremity DVT in the setting of May Thurner syndrome who required endovascular intervention and was discharged on oral anticoagulation.

Ilio-Iliac Arteriovenous Fistula with May-Thurner Syndrome: A Case Report

An ilio-iliac arteriovenous fistula (AVF) is rare. Common factors leading to ilio-iliac AVF include congenital malformations, iatrogeny, and trauma. There is limited documentation in the literature of cases involving ilio-iliac AVF with May-Thurner syndrome. Here, we present a case of an ilio-iliac AVF with May-Thurner syndrome in an 80-year-old male. CT and angiography confirmed extensive ilio-iliac AVF. Successful endovascular procedures for ilio-iliac AVF were performed using several variable-sized coils and 1400-2000 µm gelatin particles. After embolization, follow-up abdominopelvic CT revealed an improvement in edema in the left leg.

Technical Feasibility and Clinical Efficacy of Iliac Vein Stent Placement in Adolescents and Young Adults with May-Thurner Syndrome

PURPOSE

To report technical feasibility and clinical efficacy of iliac vein stent placement in adolescent patients with May-Thurner Syndrome (MTS).

MATERIALS AND METHODS

Single-institution retrospective review of the medical record between 2014 and 2021 found 63 symptomatic patients (F = 40/63; mean age 16.1 years, 12-20 years) who underwent left common iliac vein (LCIV) stent placement for treatment of LCIV compression from an overriding right common iliac artery, or equivalent (n = 1, left IVC). 32/63 (50.7%) patients presented with non-thrombotic iliac vein lesions (NIVL). 31/63 (49.2%) patients presented with deep vein thrombosis of the lower extremity and required catheter-directed thrombolysis after stent placement (tMTS). Outcomes include technically successful stent placement with resolution of anatomic compression and symptom improvement. Stent patency was monitored with Kaplan-Meier analysis at 3, 6, 12, 24, and 36 months. Anticoagulation and antiplatelet (AC/AP) regimens were reported.

RESULTS

Technical success rate was 98.4%. 74 bare-metal self-expanding stents were placed in 63 patients. Primary patency at 12, and 24-months was 93.5%, and 88.9% for the NIVL group and 84.4% and 84.4% for the tMTS group for the same period. Overall patency for the same time intervals was 100%, and 95.4% for the NIVL group and 96.9%, and 96.9% for the tMTS group. Procedural complication rate was 3.2% (2/63) with no thrombolysis-related bleeding complications. Clinical success was achieved in 30/32 (93.8%) and 29/31 (93.5%) patients with tMTS and NIVL groups, respectively.

CONCLUSION

CIV stent placement in the setting of tMTS and NIVL is technically feasible and clinically efficacious in young patients with excellent patency rates and a favorable safety profile.

Ultrasound characteristics of abdominal vascular compression syndromes

Abdominal vascular compression syndrome (AVCS) is caused by the compression of abdominal blood vessels by adjacent structures or the compression of abdominal organs by neighboring blood vessels. Such compressions can result in a variety of clinical symptoms. They are not commonly seen in ultrasound practices, and their presence may have been underrecognized and underdiagnosed. This article reviews the clinical features, ultrasound characteristics, and diagnostic criteria of four types of AVCS, namely, celiac artery compression syndrome, renal vein compression syndrome, iliac vein compression syndrome, and superior mesenteric artery syndrome to increase awareness of these conditions among ultrasound practitioners. The ultrasound criteria for AVCS are primarily based on studies with small sample sizes, and therefore, it is important to exercise caution if these criteria are used.

A Case Report on May-Thurner Syndrome: Beyond the Usual Suspects

May-Thurner syndrome (MTS), also known as iliocaval venous compression syndrome, is a vascular condition characterized by extrinsic venous compression within the iliocaval territory. While traditionally considered a condition predominantly affecting women, this case report presents an atypical presentation in a middle-aged male patient. The patient initially presented with left lower extremity pain and swelling, which was attributed to deep venous thrombosis (DVT) in the left calf and femoral vein. Despite anticoagulation therapy, his symptoms persisted, leading to further diagnostic evaluation and the identification of MTS. This report highlights the clinical presentation, diagnostic challenges, and successful management of MTS in a male patient. Endovascular interventions, including balloon dilation and stent placement, were employed to address refractory stenosis and thrombus burden. The case emphasizes the importance of considering MTS as a potential diagnosis in patients with unexplained lower limb symptoms, irrespective of traditional risk factors or gender. Early identification and appropriate interventions can lead to symptom relief, obstruction resolution, and improved long-term outcomes for patients with MTS. This case underscores the need for heightened clinician awareness regarding MTS and its potential impact on patient care.

Iliac vein compression syndrome by lumbar degenerative changes is associated with deep vein thrombosis after total knee arthroplasty

INTRODUCTION

This study aimed to identify whether iliac vein compression syndrome(IVCS) is associated with deep vein thrombosis(DVT) after total knee arthroplasty(TKA) and whether lower lumbar degenerative changes were risk factors for IVCS.

MATERIALS AND METHODS

A total of 259 consecutive patients who underwent TKA from January 2019 to March 2022 was retrospectively reviewed. Preoperative plain radiographs of lumbar spines and CT venography (CTV) for DVT diagnosis at postoperative 7 days were performed in all patients. Imaging findings of lower lumbar degenerative changes were analyzed on plain radiograph including lateral osteophytes, scoliosis, lateralolisthesis, retrolisthesis, anterolisthesis, and lower lumbar lordosis angle (LLLA). Percent compression at the left common iliac vein (LCIV) and right common iliac vein (RCIV) as well as DVT were evaluated on CTV. Moreover, IVCS was defined as greater than 50% of compression of the iliac vein on CTV.

RESULTS

DVT occurred in 79 patients (30.5%) after TKA. The overall occurrence of DVT was significantly higher in patients with IVCS of LCIV (52.8%) than those without (18.8%, P < 0.001). When DVT was further subdivided, compared to non-IVCS, IVCS of LCIV was significantly associated with bilateral DVT (P < 0.001, both), especially distal DVT (P < 0.001, both), and IVCS of RCIV was significantly associated with right-side DVT (P = 0.031), especially popliteal (P = 0.008) and distal DVT(P = 0.011). Female patients (OR: 3.945, P = 0.039), presence of left osteophyte (OR: 2.348, P = 0.006), and higher LLLA (OR: 1.082, P < 0.001) were significantly associated with IVCS of LCIV, and presence of right osteophyte (OR: 3.494, P = 0.017) was significantly associated with IVCS of RCIV.

CONCLUSION

IVCS was significantly associated with DVT after TKA and lumbar degenerative changes with lateral osteophytes and hyperlordosis were significant risk factors for IVCS.

The utility of computed tomography venography in the routine evaluation of patients who present to a lymphedema center with lower extremity edema

OBJECTIVE

Computed tomography venography (CTV) is not routinely used to screen patients presenting with a presumed lower extremity lymphedema diagnosis for left iliac vein obstruction (IVO) or May-Thurner syndrome (MTS). The objective of this study is to determine the utility of routine CTV screening for these patients by evaluating the proportion presenting with clinically significant CTV-identified left IVO.

METHODS

We retrospectively reviewed 121 patients who had presented to our lymphedema center with lower extremity edema between November 2020 and May 2022. Information regarding demographics, comorbidities, lymphedema characteristics, and imaging reports was collected. Cases of IVO present on CTV were reviewed by a multidisciplinary team to determine the clinical significance of the CTV findings.

RESULTS

Of the patients with complete imaging studies, 49% (n = 25) had abnormal lymphoscintigraphy findings, 45% (n = 46) had reflux on ultrasound, and 11.4% (n = 9) had IVO on CTV. Seven patients (6%) had CTV findings of IVO and edema of either the isolated left (n = 4) or bilateral (n = 3) lower extremities. Cases of IVO on CTV were determined by the multidisciplinary team to be the predominant cause of lower extremity edema for three of these seven cases (43%; or 2.5% of all 121 patients).

CONCLUSIONS

Six percent of patients presenting to a lymphedema center with lower extremity edema had left-sided IVO on CTV suggestive of MTS. However, the cases of IVO were determined to be clinically significant <50% of the time or for 2.5% of all patients. CTV should be reserved for patients with isolated left-sided or bilateral lower extremity edema with a greater left-sided component and a history of findings that raise clinical suspicion for MTS.

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.

Effect of stent treatment on hemodynamics in iliac vein compression syndrome with collateral vein

BACKGROUND

Iliac vein compression syndrome (IVCS) leads to blood flow obstruction in the lower extremities and is usually treated with stents, but stenting may worsen the hemodynamics and increase the risk of thrombosis in the iliac vein. The present work evaluates the advantages and disadvantages of the stent on IVCS with a collateral vein.

METHODS

The computational fluid dynamics method is adopted to analyze the preoperative and postoperative flow fields in a typical IVCS. The geometric models of the iliac vein are constructed from medical imaging data. The porous model is used to simulate the flow obstruction in IVCS.

RESULTS

The preoperative and postoperative hemodynamic characteristics in the iliac vein are obtained, e.g., the pressure gradient at two ends of the compressive region and the wall shear stress. It is found that the stenting restores the blood flow in the left iliac vein.

CONCLUSION

Impacts of the stent are classified into short-term and long-term effects. The short-term effects are beneficial in relieving IVCS, i.e., shortening the blood stasis and reducing the pressure gradient. The long-term effects increase the risk of thrombosis in the stent, i.e., enlarging wall shear stress due to a large corner and a diameter constriction in the distal vessel, and suggests the need to develop a venous stent for IVCS.

High fibrinogen and mixed proximal and distal thrombosis are associated with the risk of residual venous thrombosis in patients with posttraumatic deep vein thrombosis

Background

The risk factors for residual venous thrombosis (RVT) in patients with post-trauma deep vein thrombosis (DVT) are unknown.

Methods

We evaluated 127 patients with DVT after trauma, all of whom were treated with conventional anticoagulation and assessed for the presence of RVT with venous compression ultrasound (CUS), using an internal diameter of the venous lumen ≥ 4 mm after compression as the criterion.

Results

RVT was present in 59 (46%) patients, and complete thrombus dissolution was present in 68 (54%) patients. Among them, mixed proximal and distal thrombosis (OR, 4.292; 95% CI, 1.253-14.707), diabetes (OR, 6.345; 95% CI, 1.125-35.786), fibrinogen > 4.145 g/L (OR, 2.858; 95% CI, 1.034-7.897), the time between detection of thrombus and initiation of antithrombotic therapy > 2.5 days (OR, 3.470; 95% CI, 1.085-11.094) was an independent risk factor for RVT in patients with posttraumatic DVT.

Conclusion

A mixed proximal and distal thrombosis, diabetes mellitus, late initiation of antithrombotic therapy, and high fibrinogen levels increase the risk of RVT in patients with posttraumatic DVT. Therefore, treatment regimens for patients with posttraumatic DVT can be adjusted according to the site of thrombosis, the presence of diabetes mellitus, and the level of fibrinogen, and antithrombotic therapy can be started as early as possible after the detection of thrombosis to prevent the development of RVT and its serious complications.

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.

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

OBJECTIVE

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).

MATERIALS AND METHODS

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%).

RESULTS

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.

CONCLUSIONS

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.

Diagnostic Value of the Iliac Vein Stenosis Percentage Combined With Indicators of Venous Reflux for Iliac Vein Compression Syndrome With Computed Tomography Venography

OBJECTIVES

To identify a cutoff value of iliac vein stenosis in computed tomography venography (CTV) for assisting in the diagnosis of iliac vein compression syndrome (IVCS). Meanwhile, determining whether the inclusion of venous return and collateral imaging findings could further enhance the diagnostic performance.

METHODS

We conducted a retrospective study on 264 patients suspected of IVCS who underwent both CTV and digital subtraction venography (DSV) from January 2016 to December 2020; they were assigned to either a control group (n = 101) or an IVCS group (n = 163) based on the DSV results. The narrowest anteroposterior diameter of the common iliac vein and the anteroposterior diameter of the distal end were measured to calculate the percentage of iliac vein stenosis. Receiver operating characteristic curve analysis was performed to determine the predictive accuracy of the percentage of iliac vein stenosis for IVCS and whether the inclusion of venous reflux indicators can further improve the diagnostic accuracy.

RESULTS

With respect to the DSV results, the area under the curve was 0.797 (P < 0.001). The best cutoff value was 46.67%, corresponding to a sensitivity of 83.44% and a specificity of 69.31% for predicting IVCS. Moreover, the combination diagnostic method had higher sensitivity and accuracy (94.48% vs 83.44% [P = 0.01] and 84.85% vs 78.03% [P = 0.04], respectively).

CONCLUSIONS

The best cutoff percentage of iliac vein stenosis to diagnose IVCS was 46.67% with CTV. The sensitivity and accuracy of the combined diagnostic method were higher than those of the iliac vein stenosis ratio diagnostic method.

A systematic review of current trends in pharmacologic management after stent placement in nonthrombotic iliac vein lesions

Objective

Stenting of the iliac vein is increasingly recognized as a treatment for chronic venous insufficiency (CVI). However, the pharmacologic management after stent placement is unclear. This review was conducted to illustrate recent trends in anticoagulation and antiplatelet regimens following stent placement for nonthrombotic iliac vein lesions (NIVL).

Methods

The MEDLINE database was searched using the term “iliac vein stent.” Retrieval of articles was limited to studies conducted on humans and published in English between 2010 and 2020. Studies were included that described iliac vein stent placement. Studies were excluded that contained fewer than 25 patients, performed procedures other than stent placement, did not specify the postoperative anticoagulant used, or treated lesions of thrombotic origin.

Results

12 articles were included in this review, yielding a total of 2782 patients with a male-to-female ratio of 0.77. The predominant CEAP classification encountered was C3. The most common stent used in the included studies was the Wallstent (9/12), and the most common pharmacologic regimen was 3 months of clopidogrel (6/12). Warfarin, aspirin, cilostazol, and rivaroxaban were among other agents used. Primary stent patency ranged from 63.1 to 98.3%. There was no apparent correlation between pharmacologic agent used and stent patency or subjective patient outcomes.

Conclusion

Multiple different approaches are being taken to pharmacologically manage patients following stent placement for NIVL. There is no consensus on which agent is best, nor is there a formal algorithmic approach for making this decision. Additionally, the findings in this study call into question whether anticoagulation following stenting for NIVL is necessary at all, given the similar outcomes among the different agents utilized. This review underscores the potential value of undertaking a multi-institutional prospective study to determine what is the best pharmacologic therapy following venous stent placement for NIVL.

A Curious Presentation of May-Thurner Syndrome With Isolated Iliofemoral Deep Vein Thrombosis

May-Thurner syndrome, which has been called by many names, including Cockett syndrome, iliocaval compression syndrome, and iliac vein compression syndrome, is an anatomic variation where there is extrinsic venous compression by the arterial system against the bony structure of the axial skeleton, most commonly right common iliac artery compressing the left iliac vein against the fifth lumbar vertebra. The persistent right common iliac pulsation results in endothelial irritation of the venous system and at the same time reduces venous return, hence satisfying two factors in Virchow's triad for the formation of venous thrombosis. Here we present a rare case of a patient who presented with multiple risk factors that could propagate the formation of deep vein thrombosis with the underlying anatomic variation of May-Thurner syndrome in the setting of dehydration, systemic infection, failure to thrive, and psychiatric decompensation. Treatment required fluid hydration, antibiotic therapy, and mechanical thrombectomy in conjunction with local infusion of thrombolytics. Subsequent stent placement was performed to prevent re-thrombosis and stenosis of the affected area with long-term oral anticoagulation.

Black-blood Venous Imaging (BBVI): A Contrast-Free and High-Resolution Magnetic Resonance Approach for Diagnosing IVCS - a Proof of Concept Study

Background

Iliac vein compression syndrome (IVCS) diagnosis heavily relies on an imaging test. However, non-invasive and contrast-free imaging test for the diagnosis of IVCS remains a big challenge. To address this issue, this prospective study aimed to assess the image quality and diagnostic performance of a magnetic resonance imaging technique, black-blood venous imaging (BBVI), in detecting IVCS by comparing it with contrast-enhanced computed tomography venography (CTV) and using invasive digital subtraction angiography (DSA) as the reference.

Methods

We enrolled 105 patients, and all patients underwent BBVI, CTV, and DSA examinations. We compared the consistency of CTV and BBVI image quality and their consistency in diagnosing the rate of iliac vein stenosis in IVCS patients. Using the consensus DSA as a reference, the sensitivity, specificity, positive and negative predictive values, and accuracy of BBVI and CTV and their diagnostic agreement with DSA were calculated.

Results

BBVI demonstrated high sensitivity, specificity, and accuracy for the diagnosis of IVCS, without contrast agents. BBVI and CTV are quite in diagnosis IVCS. Quite SE (67.8% vs 68.3%), SP (94.8% vs 94.8%), PPV (98.0% vs 98.0%), NPV (46.2% vs 46.9%) and ACC (75.3% vs 75.7%) were obtained by BBVI in comparison with CTV.

Conclusion

BBVI has comparable diagnostic performance with CTV. It may be a viable alternative to CTV techniques in screening the IVCS without contrast agents and free of ionizing radiation.

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.

Combined high-resolution 3D CUBE T1-weighted imaging and non-contrast-enhanced magnetic resonance venography for evaluation of vein stenosis in May-Thurner syndrome

PURPOSE

To explore the feasibility of high-resolution MRI 3-dimensional (3D) CUBE T1-weighted magnetic resonance imaging (MRI) in combination with non-contrast-enhanced (NCE) magnetic resonance venography (MRV) for the assessment of lumen stenosis in May-Thurner syndrome.

METHODS

Twenty-nine patients underwent computed tomography venography (CTV) and high-resolution MRI-CUBE T1, and NCE MRV acquisitions. ANOVA and LSD tests were used to compare the stenosis rate and narrowest and distal diameters of the vessel lumen.

RESULTS

There were no significant differences in the estimated stenosis rate between CTV, CUBE T1, and NCE MRV (p = 0.768). However, there were significant differences in the measured stenosis diameters of the left common iliac vein (LCIV), with CTV giving the largest mean diameter and CUBE had the smallest mean diameter (p < 0.05). The measured normal LCIV diameters did not significantly differ between MRV and CUBE (p = 0.075) but were significantly larger on CTV than on MRV and CUBE (p < 0.05).

CONCLUSIONS

Compared with CTV, a combination of CUBE and MRV could provide an improved assessment of the degree of lumen stenosis in May-Thurner syndrome and demonstrate acute thrombosis. MRI underestimates the diameter of the vessel in comparison with CTV. MRI can be a substitute tool for Duplex ultrasound and CTV.

May Thurner syndrome: Sixty years later

May-Thurner syndrome (MTS) was described sixty years ago. Once ignored for several years, it is currently a recognized pathology in the vascular surgery community; but not long ago due to several factors, it was underdiagnosed and sub-optimally treated. In the last 20 years, with renewed interest in venous pathology, technical imaging advances and the recent interventional procedures, it has become a better known disease. On the other hand, nowadays the easiness in diagnosis and treatment of the syndrome has lead to overtreatment of such patients. In this article, we do a historical review and describe the significant advances and current management of May-Thurner syndrome.

Sonographic Evaluation of Pelvic Venous Disorders

ABSTRACT

Pelvic venous disorders are a group of interrelated conditions characterized by venous incompetence. These conditions often manifest with nonspecific symptoms that overlap with many gynecological, gastrointestinal, and urologic diseases. Clinical diagnosis can be difficult, and imaging can play a vital role in differentiating etiology. Sonographic evaluation is often the first step in evaluating these symptoms. Special attention to possible underlying pelvic venous disorders can reveal characteristic findings, support diagnosis, and guide treatment. Here we review pelvic congestion syndrome, nutcracker syndrome, May-Thurner syndrome, and other venous disorders, with a specific focus on sonographic findings and considerations.

Reduced External Iliac Venous Blood Flow Rate Is Associated with Asymptomatic Compression of the Common Iliac Veins

Background and Objectives: Compression of the common iliac veins (CIV) is not always associated with lower extremity symptoms. This study analyzed this issue from the perspective of patient venous blood flow changes using quantitative flow magnetic resonance imaging. Materials and Methods: After we excluded patients with active deep vein thrombosis, the mean flux (MF) and mean velocity (MV) of the popliteal vein, femoral vein, and external iliac vein (EIV) were compared between the left and right sides. Results: Overall, 26 of the patients had unilateral CIV compression, of which 16 patients had symptoms. No significant differences were noted in the MF or MV of the veins between the two sides. However, for the 10 patients without symptoms, the EIV MF of the compression side was significantly lower than the EIV MF of the non-compression side (p = 0.04). The receiver operating characteristic curve and chi-squared analyses showed that when the percentage difference of EIV MF between the compression and non-compression sides was ≤-18.5%, the relative risk of associated lower extremity symptoms was 0.44 (p = 0.016). Conclusions: If a person has compression of the CIV, a decrease in EIV blood flow rate on the compression side reduces the rate of symptom occurrence.

May-Thurner Syndrome: A Case Report and a Concise Review

We report a case of a 31-year-oldman who presented to the hospital with extensive deep vein thrombosis (DVT) complicated by pulmonary embolism (PE) after a recent trauma and prolonged immobilization. He underwent contrast venography that revealed features of May-Thurner syndrome (MTS). He was managed with therapeutic anticoagulation, inferior vena cava filter placement, mechanical clot aspiration, catheter-directed thrombolytic therapy, and left common iliac vein stenting.

MTS is a vascular condition caused by the compression of the left common iliac vein by an overlying right common iliac artery against a vertebral body. This results in indolent endothelial changes secondary to the pulsating nearby artery as well as the compression increasing the susceptibility to venous thrombosis. Females are thought to be more prone to the condition due to the nature of their pelvic anatomy. Most patients are asymptomatic or present with unspecific symptoms, rendering the condition underdiagnosed. The gold standard diagnostic modality is contrast venography that reveals collaterals and a pressure gradient greater than 2 mmHg at rest across the stenotic region. Treatment is revolved around the removal of the thrombus along with the correction of the anatomical defect through interventional or surgical treatment to prevent a recurrence.

Untreated MTS complicated with DVT carries a risk of potentially life-threatening complications, such as PE, iliac vein rupture, retroperitoneal hematoma, or refractory DVT that is difficult to treat. Due to the chronicity of this syndrome, its management plan differs from that of other causes of DVT. Proper identification of MTS carries a positive outcome in treating DVT secondary to MTS. Here we are going to discuss a case diagnosed with MTS complicated by saddle PE outlying the possible pathophysiology, clinical manifestation, diagnostic tools, and management of complicated MTS.

Das May-Thurner-Syndrom – der Beckenvenensporn – in heutiger Zeit

Hintergrund Venensporne in der linken V. iliaca communis sind eine bekannte Entität, insbesondere im Zusammenhang mit schweren tiefen Beckenvenenthrombosen. Allerdings sind fundierte Kenntnisse über diese Sporne nur spärlich vorhanden. Es wurden 5 Formen von Venenspornen beschrieben: zentrale Sporne, Adhäsionen, Brücken, Klappen und Bänder. Dennoch sind sowohl die Lokalisation als auch die Position von venösen Spornen nicht angemessen untersucht worden.

Material/Methoden 101 Körper (68 Frauen, 33 Männer), die dem Institut für Klinisch-Funktionelle Anatomie mit informierter Zustimmung vermacht wurden, wurden untersucht. Ein Individuum musste aufgrund einer Tumorinfiltration ausgeschlossen werden.

Der Startpunkt (mp0) wurde am kaudalsten Teil des Zusammenflusses der beiden gemeinsamen Beckenvenen definiert, der distalste Punkt (mp5) an der Mündung der linken aufsteigenden Lumbalvene. Nach der Teilung der Länge in 4 Viertel wurden Dicke und Umfang an jedem Messpunkt gemessen. Die Klassifizierung der Sporne wurde nach Pinsolle et al. (1982) durchgeführt.

Ergebnisse Die Wanddicke nahm vom Startpunkt (Mittelwert: 0,21 mm) zum ersten Viertel (Mittelwert: 0,16 mm) ab und dann bis zum vierten Viertel (Mittelwert: 0,24 mm) kontinuierlich wieder zu. Der Umfang war am Startpunkt maximal (Mittelwert: 45,45 mm), nahm zum zweiten Viertel hin ab (Mittelwert: 38,14 mm) und nahm dann bis zum vierten Viertel wieder zu (Mittelwert: 39,32 mm).

Insgesamt fanden wir am Zusammenfluss 125 Sporne; im ersten, rechten Viertel 23 Sporne, im zweiten Viertel 18 Sporne, im dritten Viertel 11 Sporne, und im linken, vierten Viertel auch noch 4 Sporne. Zwei Individuen wies keinen venösen Sporn auf.

Schlussfolgerung Zentrale venöse Sporne treten unmittelbar am venösen Zusammenfluss auf. Sie könnten Überreste von ostialen Klappen sein, während die anderen Typen andere Ursachen haben könnten. Zum Beispiel kann eine Verwachsung aus der embryologischen Entwicklung stammen, was durch den Fund unterschiedlicher Wandstärken unterstützt wird. Auch ohne Kompression der linken V. iliaca communis fanden wir erhebliche Umfangsunterschiede, die zu deutlichen Unterschieden in den Kalibern führten. Während der Embryogenese bildet sich der proximale Teil der linken V. iliaca communis als anastomotisches interkardinales Netzwerk kleiner Venen, die im Laufe der weiteren Entwicklung verschmelzen. Die Annahme eines unterschiedlichen embryonalen Ursprungs der verschiedenen Viertel, entweder Kardinalvene oder venöses anastomotisches Netzwerk, wird durch die Unterschiede sowohl in der Dicke der Venenwand als auch im Venenumfang unterstützt. Mit Ausnahme der kaudalen zentralen Sporne am Zusammenfluss stellen sie grundsätzlich ein Strömungshindernis dar und können so einen prädisponierenden Faktor für eine tiefe Venenthrombose darstellen. Diese Strukturen finden sich zudem nicht nur am Zusammenfluss, sondern auch über die ganze Länge der interkardinalen Anastomose. Demnach erscheint ein ursächlicher Zusammenhang mit einer Kompression durch die A. iliaca communis dextra unwahrscheinlich.

Contemporary treatment of May-Thurner Syndrome

Compression of the left common iliac vein by the overlying right common iliac artery is a benign anatomic abnormality in most individuals. However, in patients with significant vein compression, outflow obstruction and chronic intraluminal venous damage may lead to May-Thurner Syndrome. This syndrome commonly manifests as unilateral left leg swelling or acute iliofemoral deep venous thrombosis. In addition to clinical findings, diagnosis is made with ultrasound, computed tomography venography, or magnetic resonance venography. The extent of compression of the iliac vein is best determined by venography with intravascular ultrasound. Symptoms and hemodynamic significance of the compression guides the ideal treatment approach. Iliocaval stenting has become the standard treatment for this condition and has promising patency rates and clinical outcomes. This review paper provides an overview of pathophysiology, and utility and limitations of the existing diagnostic modalities and treatment options in the management of May-Thurner Syndrome.

Comparing the efficacy of endovascular treatment for iliac vein compression syndrome with or without acute deep venous thrombosis: A single-center retrospective study

BACKGROUND

To compare the efficacy of endovascular treatment for iliac vein compression syndrome (IVCS) with or without acute deep venous thrombosis of lower extremity.

METHODS

This study retrospectively analyzed the clinical data of 300 IVCS patients, who received endovascular treatment between January 2013 and December 2017. According to whether IVCS was complicated by deep venous thrombosis or not, these patients were divided into non-thrombotic iliac vein lesion group (NIVL group, n = 127) and post-thrombotic iliac vein lesion group (PIVL group, n = 173). After endovascular treatment, all patients were followed up to assess the symptoms improvement and to evaluate the patency of iliac vein.

RESULTS

The technical success rate was 98% (294/300), and percutaneous transluminal angioplasty with stenting was adopted in 294 cases. The incidence of perioperative complications was 36.33% (109/300), but no severe complications occurred. During a mean follow-up of 22.3 months (range 6-30 months), 9(6.82%, 9/132) patients in PIVL group had recurrence of deep venous thrombosis, but nobody had deep venous thrombosis and varicose veins recurrence in NIVL group. The effective rate of endovascular treatment in NIVL group and PIVL group was 96.88% and 90.15% (P = 0.050), while the cumulative primary patency of iliac vein in NIVL group was significantly higher than that in PIVL group (P = 0.008).

CONCLUSIONS

The endovascular treatment is an effective, feasible, safe method for treating IVCS. There is no difference in the efficacy of IVCS patients with or without deep venous thrombosis, but the medium and long-term patency of patients with deep venous thrombosis is lower than that in patients without deep venous thrombosis.

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

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

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

Background

May–Thurner syndrome is an anatomical condition characterized by compression of the left common iliac vein by the right common iliac artery, causing venous outflow obstruction. It is an uncommon cause of deep vein thrombosis and is more prevalent among women. This paper highlights the importance of considering May–Thurner syndrome in young males without risk factors presenting with left lower limb pain, as endovascular treatment may be required.

Case presentation

A 23 year-old Caucasian male presented with a 1-week history of left lower limb pain, edema, and pallor. He was found to have an unprovoked deep vein thrombosis on Doppler ultrasound involving the left fibular, soleus, gastrocnemius, popliteal, femoral, common femoral, and external iliac veins. A heparin infusion was commenced as the initial treatment for deep vein thrombosis. Further investigation with computer tomography pulmonary angiogram and computer tomography venography of the abdomen and pelvis showed bilateral pulmonary emboli and left common iliac vein compression with left common, internal, and external iliac vein thrombosis. He was diagnosed with May–Thurner syndrome despite having no risk factors. A retrievable Cook Celect Platinum inferior vena cava filter was placed, and thrombus of the left common femoral, external, and common iliac veins was treated successfully with AngioJet thrombectomy, thrombolysis using 200,000 units of urokinase, angioplasty and stenting using two Cook Zilver Vena venous self-expanding stents. Therapeutic enoxaparin was commenced on discharge. His filter was removed after 10 weeks. Hematological follow-up 4 months later showed an overall negative thrombophilia screen, and anticoagulation was switched to apixaban. He has had no recurrent thrombosis.

Conclusions

Clinicians should have a low threshold to investigate for May-Thurner syndrome in patients with left lower limb venous thrombotic events regardless of risk factors, as endovascular treatment may be required to minimize the long-term sequelae of deep vein thrombosis. Duplex ultrasound can be used initially for diagnosis, and computer tomography venography used subsequently if the common iliac vein is not visualized on ultrasound. Endovascular treatment is preferred over anticoagulation alone, especially in otherwise fit patients presenting early, the aim being to reduce the chances of chronic venous hypertension in the lower limb.

Transabdominal duplex ultrasound and intravascular ultrasound planimetry measures of common iliac vein stenosis are significantly correlated in a symptomatic population

OBJECTIVE

The objectives of the present study were to determine the validity of transabdominal duplex ultrasound (TAUS) against the reference standard of intravascular ultrasound (IVUS) examinations for the detection of iliac vein obstruction (IVO).

METHODS

We analyzed the data from patients at a private vascular laboratory who had undergone IVUS investigation with an intention to treat because of symptoms of chronic venous insufficiency and a high suspicion of IVO. These patients had also previously undergone a TAUS examination at the same location. The TAUS and IVUS planimetry measures of the left common iliac vein (CIV) were correlated. These included the TAUS-measured minimum and maximum diameter and the percentage of stenosis with the IVUS-measured minimum and maximum diameter and area and the percentage of stenosis.

RESULTS

The TAUS and IVUS data from 47 patients (83% female; age, 49.3 ± 17.3 years; 64% obese) were included in the analyses. We found 89% agreement between the TAUS and IVUS findings regarding the identification of left CIV stenosis of ≥50%. The TAUS data had a positive predictive value of 95.5%. The TAUS measures of the minimum diameter and percentage of stenosis correlated significantly with the IVUS measures of the minimum diameter, minimum area, and cross-sectional area of the percentage of stenosis. The strongest correlations were between the TAUS-measured minimum diameter and IVUS-measured minimum area and percentage of the area of stenosis according to the literature-derived value. The TAUS-measured vein diameter of 8 mm equated to an IVUS cross-sectional area of 94.2 mm² (53% stenosis), and an IVUS cross-sectional area of 50% of stenosis equated to a TAUS diameter of 8.56 mm.

CONCLUSIONS

The findings from the present study support the validity of TAUS evaluation as a workup diagnostic tool for the detection of IVO. Our findings also support the use of TAUS planimetry-in particular, the CIV diameter of ≤8 mm as a threshold value-to indicate clinically relevant stenosis and trigger an IVUS investigation with an intention to treat, because this correlated with a cross-sectional area stenosis of ≥50%, as determined by IVUS examination.

The Protégé Nitinol Self-Expanding Stent for the Treatment of Iliofemoral Veno-Occlusive Disease

PURPOSE

To evaluate the safety and effectiveness of the Protégé nitinol self-expanding stent for the treatment of iliofemoral veno-occlusive disease.

MATERIALS AND METHODS

A retrospective review was performed of 376 (284 left, 92 right) Protégé stents in 212 limbs of 183 patients (mean age: 53 ± 17 years, 52% female) treated for iliofemoral veno-occlusive disease between 2011 and 2018. Binary patency was assessed with duplex ultrasound and calculated by Kaplan Meier analysis. Clinical outcomes were evaluated by clinical-etiology-anatomy-pathophysiology (CEAP) classification and Villalta scores. Adverse events were recorded and categorized per Society of Interventional Radiology reporting standards.

RESULTS

Of the 212 limbs, 125 presented with acute thrombosis and 28 with chronic thrombosis requiring thrombectomy (n = 44), catheter directed thrombolysis (n = 32), or both (n = 77). Fifty-nine limbs were non-thrombotic. Mean follow-up time was 11.44 ± 11.37 months. Kaplan Meier analysis revealed a primary limb-level patency of 92.3%, 88.6%, 86.9% and 86.9% at 6, 12, 24 and 36 months, respectively. CEAP and Villalta scores improved from a median of C3 (range: 0-6) to C1 (0-5) (p < 0.001) and from a mean of 13.4 ± 7.5 to 5.3 ± 4.9 (p < 0.001), respectively. Nine minor and 2 major adverse events were recorded.

CONCLUSIONS

Endovascular treatment of iliofemoral veno-occlusive disease with the Protégé self-expanding stent appears to have good mid-term patency.

LEVEL OF EVIDENCE

Level 4, Case Series.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Percutaneous endovenous intervention without vena cava filter for acute proximal deep vein thrombosis secondary to iliac vein compression syndrome: preliminary outcomes

The aim is to report the preliminary outcomes of percutaneous endovenous intervention (PEVI) for acute proximal deep vein thrombosis (DVT) secondary to iliac vein compression syndrome (IVCS) without inferior vena cava filter (IVCF) placement. Acute DVT patients who underwent PEVI without IVCF were analyzed retrospectively. PEVI consisted of catheter-directed thrombolysis, manual aspiration thrombectomy, balloon angioplasty and stenting. CT was used to evaluate the left common iliac vein (LCIV). Sixty-two consecutive patients (17 men and 45 women, mean age, 59.4 ± 15.2 years) were enrolled. The compression percentage of the LCIV ranged from 51.7% to 95.2% (median 83.2%). Iliac DVT was present in 7 patients; iliofemoral, in 30 patients; and iliofemoropopliteal, in 25 patients. Complete technical success and clinical improvement were obtained in all subjects without the occurrence of symptomatic pulmonary embolism (PE). Five patients experienced recurrent thrombosis. The primary patency rates at 12 and 24 months were 93.8% and 91.4%, respectively, which remained stable at 36, 48 and 60 months. The secondary patency rates at 12 and 24 months were 95.7% and 93.3%, respectively, and there was no change at 60 months. Although limited, our preliminary results suggested that PEVI without IVCF placement seemed to be safe and effective for acute proximal DVT secondary to IVCS without inferior vena cava thrombosis or symptomatic PE.

Incidence and severity of postthrombotic syndrome after iliofemoral thrombosis – results of the Iliaca-PTS – Registry

Summary: Background: Deep venous thrombosis (DVT) and in particular, iliofemoral thrombosis (IFT) can lead to recurrent thrombosis and postthrombotic syndrome (PTS). Data on the prevalence, predictors and outcome of IFT are scarce. Patients and methods: We retrospectively searched our database of outpatients who had presented with DVT and IFT including the iliac veins from 2014 until 2017. In addition, we performed a prospective registry in a subgroup of patients with IFT. These patients received duplex ultrasound, magnetic resonance venography and measurement of symptom-free walking distance using a standardized treadmill ergometry. The severity of PTS was analyzed using the Villalta-Scale (VS) and quality of life was assessed using the VEINES-QOL/Sym Questionnaire. Results: 847 patients were retrospectively identified with DVT and 19.7% (167/847) of these presented with IFT. 50.9% (85/167) of the IFT-patients agreed to participate in the prospective registry. The majority of these patients (76.5%: 65/85) presented with left-sided IFT. In 53.8% (35/65) May-Thurner syndrome was suspected. 27.1% (23/85) underwent invasive therapy. Moderate or severe PTS (VS ≥ 10) occurred in 10.6% (9/85). The severity of PTS is correlated with a reduced quality of life (ρ (CI 95%) = −0.63 (−0.76; −0.46); p < 0.01). None of the patients presented with a venous ulcer at any time. A high body mass index was a significant predictor (OR (CI 95%) = 1.18 (1.05; 1.33), p = 0.007) for the development of clinically relevant PTS (VS ≥ 10) and venous claudication. Conclusions: Every fifth patient with DVT presented with an IFT. The majority developed left sided IFT. Every 10th patient developed moderate or severe PTS (VS ≥ 10). A high body mass index was predictive for the development of PTS and venous claudication.

Correlation of venous symptoms with iliac vein stenosis on magnetic resonance imaging

OBJECTIVE

Magnetic resonance imaging (MRI) is used in patients with lower extremity venous disease to screen for iliac vein stenosis. The objective of the present study was to determine the prevalence of iliac vein stenosis and associated lower extremity venous symptoms in consecutive patients undergoing MRI of the pelvis.

METHODS

A retrospective study of all consecutive adult patients who had undergone MRI of the pelvis for various indications from March 2012 to June 2016 was performed. The electronic medical records (EMRs) were reviewed for patient characteristics and, specifically, for the presence and laterality of venous symptoms. All MRI scans were reviewed, and the maximal degree of iliac vein stenosis was recorded. All the patients also responded to a brief telephone survey inquiring about the presence of venous symptoms. Two thresholds of venous stenosis, ≥50% and ≥70%, were used to correlate its presence with the presence of venous symptoms determined from the EMR review and telephone survey results.

RESULTS

A total of 120 patients were included, with a mean age of 53 ± 14 years; 79% were women and 79% were white. The prevalence of iliac vein stenosis ≥50% was significantly greater on the left than on the right (34.2% vs 16.7%; P < .001). The survey demonstrated that 44 of the 120 patients (36.7%) had had venous symptoms compared with only 30 patients (25%) according to the EMR review (P = .001). No differences were found between patients with positive vs negative survey results for venous symptoms and the occurrence of iliac vein stenosis ≥50% on the right (17.2% vs 15.2%; P = .78) or the left (38% vs 26.8%; P = .22). We also found no differences when the occurrence of iliac vein stenosis ≥70% was used as threshold between the right (2.3% vs 3%; P = .99) and the left (10.1% vs 2.4%; P = .16). Analysis of the venous symptoms from the EMR review yielded similar results.

CONCLUSIONS

In our study, iliac vein stenosis was more common on the left and was encountered in up to one third of patients who had undergone MRI of the pelvis. No correlation was found in our study between the presence of iliac vein stenosis and the occurrence of ipsilateral venous symptoms. Venous symptoms were underreported in the EMRs. Further studies are necessary to identify the predictors of pathologic iliac vein stenosis.

Diagnosis and treatment of iliac vein stenosis

Stenosis of the iliac veins is common in patients with chronic venous insufficiency. The article describes the methods for the diagnosis and treatment of iliac vein stenosis. The causes of iliac vein stenosis include extravasal compression or the consequences of ileofemoral thrombosis. Stenosis of the iliac veins exists in 1/4 of the entire adult population, but clinical manifestations do not occur in all patients. Stenosis of the iliac veins should be considered in case of an unknown edema, more often in the left lower extremity, since venous duplex ultrasound of lower extremities is not sensitive and specific enough when examining the veins above the inguinal ligament. The most accurate diagnostic method is intravascular ultrasound (IVUS) but the appeared computed tomography angiography (CTA) and magnetic resonance angiography (MRA) with high-quality images have become a good replacement for IVUS. The main method of treatment of iliac vein stenosis, besides stenting, isindispensable drug therapy consisting of antithrombotic and phlebotonic drugs.

Three-dimensional computed tomography venography reconstruction facilitates identification of atypical radiologic features of May-Thurner syndrome

OBJECTIVE

May-Thurner syndrome (MTS) is typically characterized by compression of the left common iliac vein by the overlying right common iliac artery. The present study evaluated the occurrence of atypical imaging features of MTS using three-dimensional computed tomography venography reconstruction (3D-CTV) and analyzed their correlation with clinical features.

METHODS

We analyzed the data from 268 patients with left lower extremity chronic venous disease (CVD) using 3D-CTV at a single institution from January to June 2019. An area stenosis percentage >50% was defined as significant venous compression. Of the 268 patients, 92 had at least one significant iliac and/or vena cava compression confirmed by 3D-CTV. Of the 92 patients, 89 underwent digital subtraction venography via the left common femoral vein, and the outcomes were compared with their 3D-CTV findings. Different types of venous compression were evaluated using 3D-CTV. The relationship among compression type, sex, age, and CVD symptoms was evaluated.

RESULTS

A total of 106 venous compression sites were found in 92 patients. Atypical compression included inferior vena cava (IVC) compression and partial IVC compression (8.5% and 55.7%, respectively). Multiple compression sites were present in 13 patients (14.1%). The compression sites correlated significantly with clinical symptoms (P = .017) and were related to sex (P = .001). The number of patients with IVC and partial IVC compression but false-negative venography findings was four (33.3%) and six (50%), respectively.

CONCLUSIONS

3D-CTV facilitates the detection of atypical venous compression in patients with MTS with notable chronic symptoms. Patients with multiple compression sites had more severe clinical symptoms and greater false-negative rates with venography. IVC compression was more likely to occur in female patients with MTS.