What is Subclavian steal syndrome? What are the symptoms? How is it diagnosed? How is it managed?
- Rare atherosclerotic stenotic plaque at the origin of the subclavian
- Allows enough blood supply to the arm for normal activity, but not for exercise
- The arm sucks blood from the brain via vertebral artery when exercised.
- Sx include claudication of the arm and posterior neurologic signs (visual and equilibrium problems)
- DO NOT confuse with thoracic outlet syndrome (same vascular sx but no neurologic sx)
- Dx by duplex scanning (reversal of flow)
- Cured with bypass surgery
Which is the most common sx of AAA?
Typically asymptomatic
How are AAA usually found?
- On exam as a pulsatile mass between the xiphoid process and the umbilicus
- Incidentally on XR, CT, Sonograms scans done for another purpose
How are AAA managed?
- If 5-6 cm: elective repair
- If it grows 1 cm/year or faster: elective repair
What technique can be used to treat AAA? What caveats are found?
- Endovascular stent inserted percutaneously
- good 10 year outcome
- AAA should be unruptured and should have a 2.5 cm neck
When is immediate/emergency repair of AAA indicated?
- When AAA is tender: may rupture within 1-2 days
- Excruciating back pain in patient with large AAA: Leakage, retroperitoneal hematoma, blowout into the peritoneal cavity only minutes away
When is surgery indicated in atherosclerotic disease of lower extremities?
-Only to relieve disabling symptoms or to save extremity from impending necrosis
How does atherosclerotic disease of lower extremities present clinically?
-Pain brought about by walking and relived by rest (intermittent Claudication)
What is the treatment for intermittent claudication?
- No workup is indicated if it does not interfere significantly with the patients lifestyle
- Smoking cessation, exercise program, cilostazol can help
What is the treatment for disabling intermittent claudication?
- Disabling claudication required doppler studies to look for pressure gradient.
- If no gradient is found, then the disease is in the small vessels surgery cannot be performed.
- IF there’s a significant gradient then CT angio and MRI angio are done to identify stenosis/obstruction
- Angioplasty and stenting is done is short stenotic segments are found
- Bypass grafts, sequential stents of longer stents may be needed for long stenotic segments
- Aortobifemoral graft are sone with prosthetic materal
- In distal vessels a reverse saphenous vein graft is used
What are the stages of atherosclerotic disease of lower extremities?
- Asymptomatic
- Intermittent claudication
- Disabling intermittent claudication
- Rest pain
- Ulceration
- Gangrene
How does Rest pain present?
-Patient complains that “s/he cannot sleep” (caused by calf pain)
What do patients with rest pain notice?
Sitting up and dangling the legs helps resolve the pain. Soon after the legs become purple
What does PE shoe with rest pain?
Shiny atrophic skin without hair, no peripheral pulses. Work up and therapy is the same as that of disabling claudication
In which patients is arterial embolization of distal source seen?
In those with Afib or with recent MI which release thrombus from the atrial appendage and the ventricle wall, respectively
What are the symptoms seen in patients with arterial embolization of distal source ?
How is it managed?
Sudden onset of the 6P’s:
- Painful, pale, poikilothermic (cold), pulseless, paresthetic and paralytic lower extremity
- Evaluation and treatment should start within 6 hour from sx onset.
- Doppler can locate site of thrombosis
- clot busters can tx early incomplete occlusion
- Fogerty catheter is used to tx complete obstructions
- Fasciotomy should be done if several hour have passed before revascularization (Prevents compartment syndrome)
How does a dissecting aneurysm of the thoracic aorta present?
Similar to an MI: sudden onset of severe and tearing chest pain, radiating to the back and migrating down.
-unequal pulses in upper extremities and wide mediastinum
-
In what patients are aortic dissections common?
Poorly controlled hypertensives
How should aortic dissection be managed?
- EKG and trops to r/o MI
- Spiral CT scan is best choice for dx (MRA and TEE may be used)
How are dissection of ascending aorta treated?
Surgery
How are dissection of descending aorta treated?
Medically by controlling hypertension in the ICU
When a vascular bypass graft fails within 30 days what is the most likely the cause?
Technical failure
When a vascular bypass graft fails within 2 yrs what is the most likely reason?
Intimal hyperplasia
When a vascular bypass graft fails after 2 yrs what is the most likely reason?
Recurrent atherosclerotic disease
