Venous Compression Syndromes: a Review

Venous compression syndromes in females: A descriptive review

Venous compression syndromes have been described, yet the role of sex is poorly understood. Although iliac vein compression has been discussed more often with the advent of newer technologies, research has fallen short on defining epidemiology, best practices for evaluation and treatment, and differences in responses to treatment between men and females. The authors report on iliac vein compression, nonthrombotic renal vein compression, and other venous compression syndromes in females. Literature searches of PubMed were performed using the following keywords: females/females and May Thurner, venous stenting, venous outcomes, deep venous disease, deep venous compression, venous stenting, renal vein compression, renal vein surgery/stent, popliteal vein entrapment, venous thoracic vein entrapment, and popliteal vein entrapment. The articles prompted the authors to research further as the referenced articles were reviewed. Sex representation has not been addressed adequately in the research of venous compression syndromes, making the discussion of best treatment options and long-term outcomes difficult. More specific understanding of epidemiology and response to interventions will only come from research that addresses these issues directly, understanding that some of these syndromes occur rarely.

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.

Extrinsic venous compression secondary to spine osteophytes

OBJECTIVE

This study aims to report two cases of symptomatic extrinsic compression of the inferior vena cava and left iliac vein caused by vertebral osteophytes.

METHODS

We present two case reports of extrinsic venous compression by vertebral osteophytes. Both cases were endovascularly treated, with a successful outcome. A review of the literature of this unusual condition is also presented.

RESULTS

The first patient is an 80-year-old woman who presented to the vascular surgery clinic with bilateral lower extremity edema and pain. A computed-tomography angiography (CTA) revealed extrinsic compression of the inferior vena cava from enlarged osteophytes. Venography and intravascular ultrasound were performed, confirming the diagnosis. A self-expanding venous stent was successfully deployed in the inferior vena cava relieving the extrinsic compression. The edema resolved the following day and was discharged without complications. The second patient is a 61-year-old male that presented to the emergency department with a left iliofemoral deep venous thrombosis. CTA showed left iliac vein compression by a lumbar osteophyte. Percutaneous thrombectomy was successfully achieved and an expanding stent was deployed covering the entire lesion. One month after the procedure the patient died from COVID-19-associated respiratory failure.

CONCLUSION

Osteophytes must be considered when dealing with extrinsic venous compression, especially in elderly people.

Current Status and Prospect of Stent Placement for May-Thurner Syndrome

Stent implantation has been proven to be safe and has become the first-line intervention for May-Thurner syndrome (MTS), with satisfactory mid-term patency rates and clinical outcomes. Recent research has demonstrated that catheter-directed thrombolysis is the preferred strategy when MTS is combined with deep vein thrombosis after self-expanding stent placement. However, the stent used for the venous system was developed based on the experience obtained in the treatment of arterial disease. Consequently, relatively common corresponding complications may come along later, which include stent displacement, deformation, and obstruction. Different measures such as adopting a stent with a larger diameter, improving stent flexibility, and increasing stent strength have been employed in order to prevent these complications. The ideal venous stent is presently being evaluated and will be introduced in detail in this review.

Venous popliteal entrapment syndrome

Popliteal entrapment syndrome (PES) describes a set of symptoms related to compression of the neurovascular bundle in the popliteal fossa, with popliteal artery involvement the most widely recognized variation. Popliteal vein entrapment is a rare variation which can easily go undiagnosed. This is most commonly due to an anomaly of the medial head of the gastrocnemius muscle, but other etiologies include excess adipose tissue or cysts within the popliteal fossa, popliteal artery aneurysm, fibrous bands, thickened perivenous fascia, compression by the popliteus muscle or muscular hypertrophy independent of anomalous anatomy, or variant origin of the short saphenous vein. However, with improving awareness, it is a condition which should be increasingly considered in patients presenting with unexplained lower extremity swelling or other symptoms of lower extremity thrombosis. The initial test of choice is typically ultrasound with flexion and extension maneuvers. Venography is the gold standard for diagnosis, but MRI offers a noninvasive option for both diagnosis and evaluation of etiology and should be considered in the work-up of popliteal venous entrapment. Management is based on severity and type of symptoms, ranging from conservative management with compression stockings to surgical management if there is popliteal artery involvement or more severe symptoms. Endovascular therapy such as angioplasty or stenting has also been reported with good results.