Causes of Deep Vein Thrombosis (DVT)
Virchow, in 1856, proposed the triad of ‘venous stasis, endothelial injury, and hypercoagulable state’. This is still the accepted theory for the development of DVT.
Generally if the blood is stagnant it has a tendency to clot. There exists a balance between clot formation and resolution. Significant clotting occurs when this balance is not maintained. The causes can be described under three headings:
1) Venous stasis: Immobility
- Extended travel and sitting. For example long airplane flights, car, or train travel can cause this. Long airplane flights cause the so called "economy class syndrome."
- Prolonged hospitalization
- Injury to the lower leg with or without surgery or casting
2) Hypercoagulable state: i.e. blood coagulates faster than usual
- Certain drugs like birth control pills, estrogen.
- Some individuals are genetically predisposed
- An increased number of red blood cells as in polycythemia
3) Endothelial injury: injury to the inner lining of the vein
- Due to invasive procedures of the vein
- Sabiston Textbook of Surgery, 18th ed.
- Bailey & Love Short Practice of Surgery, 25th ed.