Aortic Dissection Affecting Blood Flow to a Leg

Key Clinical Manifestations

Pulse deficits in the affected leg are found in up to 20% of patients with acute aortic dissection, though this finding may be transient due to the changing position of the intimal flap 1, 2
Limb ischemia occurs when the peripheral vessel origin is involved in the dissection or when the true lumen is obliterated by an expanding false lumen 2, 3
If the iliac bifurcation is completely obstructed, Leriche's syndrome with pulse loss in both legs may occur, which is typically painless 1
Pain in the affected limb due to acute ischemia 1, 3
Pallor (paleness) of the affected limb compared to the contralateral side 3
Paresthesia (abnormal sensations such as tingling or numbness) in the affected limb 3
Paralysis or weakness of the affected limb in severe cases 1, 3
Poikilothermia (coolness) of the affected limb compared to the contralateral side 3

Severe chest or back pain is typically the initial presenting symptom of aortic dissection, often described as tearing or ripping in nature 4, 5
The pain is usually abrupt in onset and at maximum intensity from the beginning, unlike myocardial infarction pain which typically builds gradually 4
Hypertension is commonly present, especially in distal (Type B) dissections 4
Syncope may occur in up to 20% of patients, even without a history of typical pain 2, 4

Pulse phenomena in the legs may be transient due to the intimal flap's changing position 1
The symptoms may fluctuate as the dissection progresses or as the position of the intimal flap changes 1, 3
Bilateral leg symptoms (Leriche's syndrome) indicate complete obstruction of the iliac bifurcation 1
Malperfusion of the lower extremity is one of the complications that requires immediate intervention in both Type A and Type B dissections 6

Pulse deficits may be absent in up to 80% of patients with aortic dissection, so their absence does not rule out the diagnosis 1, 2
Symptoms may mimic other conditions such as acute arterial embolism or thrombosis 3
The clinical presentation can be dynamic and changing as the dissection progresses or the intimal flap position shifts 1, 2

Emergency intervention (surgical or endovascular) is recommended for aortic dissection complicated by lower extremity malperfusion 6
For Type B dissection with limb ischemia, TEVAR (Thoracic Endovascular Aortic Repair) or other percutaneous malperfusion repair is the preferred approach 6, 7
If lower extremity malperfusion persists despite initial interventions, extra-anatomic bypass should be considered 6