E2147. Occluded Blood Vessels: Thrombus, the Biggest Culprit
  1. Jose Del Aguila; Hospital General San Juan De Dios
  2. Douglas Henry; Hospital General San Juan De Dios
Acute vascular thrombosis occurs when a blood clot obstructs a vein or artery. Blockages in these vessels can slow or even stop blood flow and cause serious consequences. Different types of vascular thrombosis occur in different parts of the body.

Educational Goals / Teaching Points
Know the epidemiology and pathophysiology of thrombosis and its most common occlusive blood vessels. Doppler ultrasound as the gold standard for thrombosis and to analyze the characteristics of the blood vessel and thrombus, and if this is acute or chronic. Investigate whether the vessel occluded by the thrombus has immediate or late complications. Report radiological findings in a timely, accurate and clear way to have an accurate treatment.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
"Virchow’s Triad” is a term for three broad categories of risk factors that predispose to thrombosis. The factors are abnormalities in the vessel wall, reduced blood flow, and an increase in the coagulability of the blood. The triad considers the following factors: inflammation, endothelial dysfunction, and atherosclerosis, abnormalities of flow, for example turbulence at bifurcations and stenotic regions, and abnormalities in platelet function, coagulation, fibrinolysis, and metabolic or hormonal factors. Today, endothelial dysfunction is regarded as the most important component of the triad. Findings of venous thrombosis The primary criterion for the diagnosis of venous thrombosis is lack of coaptation of the vein walls with compression. They present general characteristics such as loss of phasic flow in the Valsalva maneuver, color flow absent if completely occlusive, and increased flow in superficial veins Portal vein thrombosis, this complication is found in a fibrotic liver, this causes the flow rate to be slow, producing flow stasis, damage to the portal vein and hypercoagulability. Findings of artery thrombosis The absence of signal in the artery, the indirect signs such as abnormal waveforms in arteries and collateral flow, Computed tomography with contrast detect filling defect within the vessel. It is important to detect the exact place of occlusion and extension in the artery, since irrigation may be little or absent, causing distal tissues and organs to be permanently ischemic, causing infarcts or necrosis. The echogenicity of the thrombus explains the time of chronicity. Acute thrombi are markedly hypoechoic, they are not observable in B-mode, therefore they are detected with color and spectral Doppler (signal absent). These are the most dangerous as they can break off and go elsewhere. The more hyperechogenic the thrombus, the greater the chronicity, and these are stable thrombi. Complications can be diverse, from extensive edema, pain, and paleness due to venous occlusion, to ischemia and necrosis due to arterial occlusion.

Occlusive thrombosis is a very common pathology, and they are found in different blood vessels, it is important to know it to suspect it in patients, to be able to look for it in different diagnostic imaging methods (US as the gold standard), analyze its characteristics and report it correctly for the vascular surgeon.