Prevalência de marcadores de trombofilia em pacientes portadores da síndrome de May-Thurner e trombose de veia ilíaca comum esquerda

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.

Iliac vein compression syndrome: literature review

Iliac vein compression syndrome is a clinical condition in which the right common iliac artery extrinsically compresses the left common iliac vein. The syndrome predominantly affects young women between their 2nd and 4th decades of life. In view of the syndrome's potential complications, it should be recognized/diagnosed and treated in symptomatic patients before it causes irreversible damage to patients' venous systems. Noninvasive methods, such as venous color Doppler US are reasonable screening methods, but angiotomography and magnetic resonance angiography are more reliable diagnostic tools and the method of choice for confirmation of diagnosis remains multi-plane phlebography with measurement of pressure gradients. Endovascular treatment (angioplasty with placement of self-expanding stents) is safe and effective and can replace open surgical reconstruction and/or anticoagulation alone.