The left common iliac artery also compresses the left common iliac vein

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.

Double May-Thurner syndrome causing chronic deep vein thrombosis and natural venous femoro-femoral bypass: a description of rare case

May-Thurner syndrome (MTS) belongs to a group of uncommon vascular syndromes. It consists in left common iliac vein (LCIV) compression between the right common iliac artery (RCIA) anteriorly and the lumbar spine posteriorly. A compression of LCIV by the left common iliac artery (LCIA) or by both iliac arteries were described. We present a rare case of "double MTS" which consist in double stenosis of LCIV by both RCIA and LCIA. Double MTS can cause acute or chronic DVT; this latter could be clinical manifest or well compensated. A 58-year-old woman with chronic mild pelvic pain underwent Doppler Ultrasound (US) of the pelvis and lower extremity vessels which showed thrombosis of both LCIV and ipsilateral common femoral vein caused by the extrinsic compression by both common iliac arteries against the spine. CT angiography confirmed the US data and ruled out other causes of compression. CT scan also showed the development of a natural venous femoro-femoral bypass which allowed to counteract the venous stasis and compensate venous drainage. Therefore, we decide for a long-term prophylaxis with anticoagulant drugs and doppler US follow-up at 6 months. In conclusion, doppler US is a non-invasive, low-cost, repeatable and sensitive method which allows to diagnose MTS and associated DVT. It may be considered the first level exam which allows to easily detect pelvic vascular compression syndrome.

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.

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.

Occult Left Common Iliac Vein Compression Increases Postoperative Venous Thromboembolism Risk Following Total Hip Arthroplasty

BACKGROUND

Left common iliac vein (LCIV) compression by the right or left common iliac artery (RCIA, LCIA) is known to cause venous thromboembolism (VTE), but the extent to which occult LCIV compression synergizes with lower extremity orthopedic surgery is unknown. We hypothesize that occult LCIV compression is associated with increased VTE risk following total hip or knee arthroplasty (THA, TKA).

METHODS

This case-control study involves all patients at our institution who underwent primary or revision THA or TKA from 2009 to 2017 who had computed tomography or magnetic resonance imaging of the abdomen or pelvis available preoperatively. VTE cases (pulmonary embolism or left-sided deep vein thrombosis) within 30 days of surgery were matched to a control by age, gender, body mass index, Charlson Comorbidity Index, surgical site, and hypercoagulable risk factors. LCIV compression by the right common iliac artery and/or the left common iliac artery was measured in a blinded fashion and was considered present at 50% diameter reduction.

RESULTS

One hundred twelve patients (22 cases, 90 controls) were included for analysis. Nineteen (86.4%) cases and 46 (51.1%) controls demonstrated LCIV compression. The overall sample odds ratio of postoperative VTE in the presence of LCIV compression was 5.97 (95% confidence interval 1.59-33.67, P = .003). In patients who underwent THA (n = 75), LCIV compression was highly predictive of VTE (odds ratio ∞, 95% confidence interval 2.83-∞, P < .001). Compression in the TKA patients did not significantly predict VTE.

CONCLUSION

Compression of the LCIV significantly increases odds of developing postoperative VTE following THA. This effect may suggest a new method of stratifying VTE risk in the orthopedic population to reduce VTE-associated morbidity and mortality.

Confluence of the right internal iliac vein into a compressed left common iliac vein

The authors describe the abnormal confluence of the right internal iliac vein into a left common iliac vein compressed by the overlying right common iliac artery. The prevalence of this combination of abnormalities, evaluated in cadavers and in living subjects by CT, was 0.9%. The possible obstacle to venous pelvic return by these anomalies is pointed out.

Computed Tomograpy Venography diagnosis of iliocaval venous obstruction in advanced chronic venous insufficiency

Objective:Iliocaval obstruction is associated with venous hypertension symptoms and may predispose to deep venous thrombosis (DVT). Ultrasonography may fail to achieve noninvasive diagnosis of these obstructions. The possibility of using Computed Tomography Venography (CTV) for these diagnoses is under investigation.Methods:Patients with CVI graded at CEAP clinical classes 3 to 6 and previous treatment failure underwent evaluation with CTV. Percentage obstruction was rated by two independent examiners. Obstruction prevalence and its associations with risk factors and CEAP classification were analyzed.Results:A total of 112 limbs were prospectively evaluated. Mean patient age was 55.8 years and 75.4% were women. Obstructions involved the left lower limb in 71.8% of cases and 35.8% of patients reported a medical history of deep venous thrombosis. Overall, 57.1% of imaging studies demonstrated venous obstruction of at least 50% and 10.7% showed obstruction of >80%. The only risk factor that was found to be independently associated with a significantly higher incidence of >50% venous obstruction was a medical history of DVT (p=0.035) (Fisher's exact test). There was a positive relationship between clinical classification (CEAP) and degree of venous obstruction in the limbs studied (Chi-square test for linear trend; p=0.011).Conclusion:Patients with advanced CVI are often affected by obstructions in the iliocaval venous territory and CTV is able to diagnose the degree of obstruction. There is a positive association between degree of obstruction and both previous history of DVT and severity of symptoms of CVI.

Value of magnetic resonance venography and computed tomographic venography in lower extremity chronic venous disease

For the treatment of chronic venous disease (CVD) of the lower extremity, identification of the underlying venous pathologies is essential. Traditionally, the pathologies to detect with imaging have been centred on insufficiency and reflux of the superficial, perforator and deep veins of the leg. More recently, stenosis and obstruction of the deep veins of the pelvis and abdomen (i.e. inferior vena cava, common and external iliac veins) have been identified as significant underlying pathologies in CVD. Accurate detection of stenotic and/or occlusive venous disease expands the treatment options for patients with CVD. In most cases, imaging of venous disease is performed with duplex ultrasound. In this article we discuss the existing evidence and potential value of computed tomographic venography and magnetic resonance venography to contribute in accurately identifying chronic venous disease, in particular chronic venous obstruction.