Edema, pain and an increasingly discolored leg.
A 56-year-old woman who was diagnosed with a left lower-extremity deep vein thrombosis (DVT) six months ago presents to the emergency department complaining of persistent edema and pain. She now is showing increasing discoloration in the affected leg. The patient has been compliant with the oral anticoagulant therapy as prescribed, but is concerned about the persistence of symptoms and the appearance of her leg, shown below. Which of the following best describes her current pathology?
Question Answer Choices
- Chronic scarring and stenosis of the deep veins
- Chronic soft tissue infection
- Compartment syndrome
- Damage to the venous valves
- Persistent thrombus
Question Explanation
Correct answer: D. Damage to the venous valves
This patient is presenting with symptoms of postthrombotic syndrome (PTS), which can be seen in 20% to 50% of patients following diagnosis with a DVT. Symptoms can vary widely, but often include persistent extremity pain and swelling, as well as redness and dependent cyanosis. Leg ulcers can develop in severe cases. PTS is believed to be caused by local occlusion, local inflammatory changes, and recanalization, all of which damage venous valves that cause chronic venous insufficiency.
Risk of developing PTS is higher in patients with a larger clot burden, more proximal DVTs, and recurrent DVTs. Although use of compression stockings have historically been advocated to reduce the risk of PTS or treatment of PTS, large randomized studies have not shown a preventive role for use of compression stockings. Interventions that may reduce risk of development of PTS after DVT diagnosis include early mobilization and treatment of DVTs with catheter-directed thrombolysis or surgical thrombectomy.
Incorrect answer choices:
The typical findings of PTS — chronic edema, local discoloration, pain and cutaneous ulceration — indicate chronic venous insufficiency due to valvular damage by the thrombus, rather than the presence of a soft-tissue infection (Choice B).
Although PTS is more likely to develop in patients with chronic or recurrent venous obstruction by a thrombus (Choice E), it often develops in patients in whom there is no evidence of persistent thrombus, as a result of chronic damage that occurs to the venous valves. There is no data to suggest that venous scarring or stenosis (Choice A) plays a role in the development of PTS.
Compartment syndrome (Choice C) is a rare complication following DVT. When seen, compartment syndrome following DVT presents with the typical findings of compartment syndrome — pain, pallor, poikilothermia, paresthesias and pulselessness (a very late finding).
Pallor may not be seen in the context of discoloration secondary to the presence of DVT, especially in patients who develop compartment syndrome in the context of phlegmacia cerulea dolens.
