vasoocclusion

Vasoocclusion refers to the obstruction of a blood vessel that impairs or halts blood flow. It can affect arteries, veins, or capillaries and may arise from thrombosis (clot formation), embolism (a detached fragment traveling to a narrower vessel), external compression, vasospasm (sudden narrowing of the vessel), or inflammation that leads to swelling and narrowing. The clinical impact depends on the vessel involved and the duration of the blockage, with potential tissue ischemia and injury.

Common mechanisms include clot formation, sudden constriction of vessels, or blockage by abnormal blood cells, fat, air, or plaque. In certain conditions, such as sickle cell disease, small-vessel occlusion is driven by abnormally shaped red blood cells that obstruct microcirculation, often triggered by dehydration, infection, or acidosis. Recurrent or extensive vasoocclusion can cause chronic tissue damage.

Vasoocclusion can occur in many organs. In the eye, it may lead to retinal vascular occlusions with vision impairment; in the brain, it can cause transient ischemic attacks or strokes; in the heart, kidneys, or limbs, ischemia and pain may result. The presentation ranges from sudden severe pain to gradual organ dysfunction, depending on the site and extent of blockage.

Diagnosis typically uses clinical assessment supported by imaging and laboratory studies. Imaging modalities may include Doppler ultrasound, CT or MR angiography, and, when appropriate, tissue biopsy. Treatment aims to restore perfusion, address the underlying cause, and prevent recurrence. This may involve fluids, analgesia, oxygen, antiplatelet or anticoagulant therapy in selected cases, thrombolysis or surgical intervention for acute arterial occlusion, and disease-specific measures such as transfusion or disease-modifying therapy in sickle cell disease.

Prognosis depends on the vessel involved and promptness of reperfusion. Prevention focuses on managing underlying risk factors and, where applicable, disease-specific strategies to reduce recurrent occlusion.