Rotthromben

Rotthromben, often referred to as red thrombi, are a type of thrombus characterized by a high content of erythrocytes embedded in a fibrin network, giving the clot a reddish appearance. They form predominantly in veins or in low-flow regions where blood moves slowly, allowing fibrin to trap red blood cells. In contrast to white thrombi, which are platelet-rich and form under high shear in arteries, rotthromben have relatively more red cells and fewer platelets.

Formation and location: They develop under conditions of venous stasis, hypercoagulability, or endothelial injury—summarized as Virchow's triad. Common sites include the deep veins of the legs and pelvis. They may propagate and become adherent to the venous wall and can dislodge, leading to pulmonary embolism.

Histology and characteristics: The thrombus shows a dense fibrin network with entrapped erythrocytes; platelets are present but less prominent. The erythrocyte-rich core can exhibit layered patterns reflecting flow and thrombin activity.

Clinical relevance: Rotthromben are central to the pathophysiology of deep vein thrombosis and pulmonary embolism. They may be asymptomatic or cause leg swelling, pain, and, if chronic, post-thrombotic syndrome.

Diagnosis and treatment: Diagnosis relies on clinical assessment and imaging, especially Doppler ultrasound, with D-dimer testing as an adjunct. Management includes anticoagulation to prevent growth and embolization, with options such as heparin, direct oral anticoagulants, or, in selected cases, thrombolysis or surgical thrombectomy. Prevention focuses on mobility, compression, and addressing risk factors.