Microvascular Thrombosis (MT)

Microvascular Thrombosis (MT): Understanding Causes, Symptoms, and Treatment
Microvascular thrombosis (MT) refers to the formation of blood clots in small blood vessels (arterioles, capillaries, and venules), leading to impaired blood flow and tissue ischemia. Unlike large-vessel thrombosis, microvascular clots often occur due to endothelial dysfunction, inflammation, or systemic conditions and can affect multiple organs. This condition is central to several life-threatening disorders, including thrombotic microangiopathies (TMAs) and sepsis-associated complications.
Mechanisms and Causes
- Endothelial Activation/Damage:
Inflammatory mediators (e.g., TNF-α, IL-1) or toxins (e.g., Shiga toxin) activate endothelial cells, promoting adhesion of platelets and leukocytes. This triggers fibrin deposition and clot formation56. - Inflammation and Sepsis:
Sepsis-induced endothelial injury disrupts anticoagulant pathways, leading to microthrombi that exacerbate organ dysfunction5. - Thrombotic Microangiopathies (TMAs):
Conditions like atypical hemolytic-uremic syndrome (aHUS) or thrombotic thrombocytopenic purpura (TTP) involve dysregulation of complement proteins or ADAMTS13, causing platelet-rich microthrombi6. - Small Vessel Disease:
Coronary microvascular dysfunction, seen in small vessel disease, reduces blood flow to the heart, causing angina and ischemia without major artery blockages2.
Symptoms
Symptoms vary by affected organs:
- Neurological: Confusion, seizures, or stroke-like symptoms (e.g., slurred speech, numbness)13.
- Renal: Acute kidney injury, hematuria, or proteinuria6.
- Cardiac: Chest pain, shortness of breath, or fatigue (resembling angina)2.
- Systemic: Fever, thrombocytopenia, and hemolytic anemia with schistocytes (fragmented red blood cells)6.
Critical Indicators:
- Sudden organ dysfunction (e.g., renal failure, altered mental status).
- Hemolytic anemia with schistocytes on blood smear6.
Diagnosis
- Lab Tests:
- Complete blood count (thrombocytopenia, schistocytes).
- Lactate dehydrogenase (elevated in hemolysis).
- ADAMTS13 activity (to rule out TTP)6.
- Imaging:
- Coronary angiography for small vessel disease (may show no major artery blockages)2.
- Biopsy:
Treatment
- Address Underlying Cause:
- Sepsis: Antibiotics, supportive care, and anticoagulants5.
- TMAs:
- Plasma exchange (TTP).
- Complement inhibitors (eculizumab for aHUS)6.
- Anticoagulation:
Heparin or direct oral anticoagulants to prevent clot propagation37. - Supportive Care:
- Dialysis for renal failure.
- Blood transfusions for severe anemia6.
Clinical Implications
- Challenges: Microvascular thrombosis is often underdiagnosed due to nonspecific symptoms and normal imaging in small vessel disease26.
- Prognosis: Rapid treatment improves outcomes, but delays can lead to irreversible organ damage56.
Consult with Our Team of Experts Now!
At DrStemCellsThailand (DRSCT)‘s Anti-Aging and Regenerative Medicine Center of Thailand, we specialize in advanced diagnostics and personalized therapies of Cellular Therapy and Stem Cells for complex vascular conditions. If you have concerns about microvascular thrombosis or related disorders, consult our experts for tailored care.