Chapter 7 - Vascular Surgery Flashcards
What is subclavian steal syndrome?
An arteriosclerotic stenotic plaque at the origin of the subclavian (before the takeoff of the vertebral) allows enough blood supply to reach the arm for normal activity, but not enough to meet higher demands when the arm is exercised. When that happens, the arm sucks blood away from the brain by reversing the flow fo the vertebral.
Presentation of subclavian steal syndrome?
Claudication of the arm (coldness, tingling, muscle pain), posterior neurologic signs (visual symptoms, equilibrium problems) when the arm is exercised
Claudication of the arm without neurologic signs indicates what?
Thoracic outlet syndrome
Dx and Rx subclavian steal syndrome?
Dx - duplex scanning (shows reversal of flow)
Rx - bypass surgery cures
Presentation of AAA?
Typically asymptomatic, found as a pulsatile abdominal mass on exam between xiphoid and umbilicus or XR, U/S, CT done for another dx purpose in an older man.
Management of AAA?
Size is the key
If found on physical, sonogram or CT are needed for precise measurements
4cm or less: safe to observe, chance of rupture is almost 0
5-6cm or larger: elective repair because the chance of rupture is very high
Aneurysms that grow >1 cm/year or faster also need elective repair.
Traditionally done by open laparotomy, but about 70% of them are now performed by perc inserted vascular stents
Prognosis and management of tender AAA?
Going to rupture in a day or two - immediate repair is indicated
Prognosis and management of excruciating back pain in a patient with a large AAA?
Aneurysm is already leaking
Retroperitoneal hematoma is already forming
Blowout into the peritoneal cavity is only minutes or hours away
Emergency surgery is required
Why is there no role for prophylactic surgery in arteriosclerotic occlusive disease of the lower extremities?
It has an unpredictable natural history (except for the predictable negative impact of smoking)
When is surgery indicated in arteriosclerotic occlusive disease of the lower extremities?
To relieve disabling symptoms or to save the extremity from impending necrosis
Management of arteriosclerotic occlusive disease of the lower extremities?
Smoking cessation
Exercise program
Cilostazol
If intermittent claudication does not interfere significantly with a patient’s lifestyle, no work-up is indicated. When it is disabling, what is the work-up?
Doppler studies looking for a pressure gradient (ABI)
No gradient (ABI of 1) -> disease is in the small vessels and not amenable to surgery
Significant gradient (ABI of 0.8 or less) -> CT angio or MRI angio to look at anatomy and plan revascularization
What types of interventions are available for disabling intermittent claudication?
Bypasses, for which saphenous vein grafts are harvested from the patient and reversed, remain the most durable option.
Angioplasty and stents, once reserved for short segments, have exploded as the most sophisticated current option for most patients. Stents can be impregnated with medication, hooked to each other, or composed of a nickel alloy with shape memory triggered by temperature. Presurgery, nickel alloy stents are stored in the freezer in the closed position. Once inserted percutaneously where they need to go, the blood warms them and they deploy by themselves.
What are the penultimate and ultimate stages of arteriosclerotic occlusive disease of the lower extremities?
Rest pain (patient cannot sleep 2/2 calf pain, sitting up and dangling the leg helps, color changes from pale to deep purple, exam shows shiny hairless atrophic skin and no peripheral pulses)
Ulceration and gangrene
Arterial embolization from a distant source is seen in what types of patients?
AF (clot breaks off from atrial appendage) Recent MI (mural thrombus)
Presentation of arterial embolization from a distant source?
Painful Pale Poikilothermic (cold) Pulseless Parasthetic Paralytic lower extremity
Management of arterail embolization from a distant source?
Urgent evaluation and rx within 6 hours
Doppler studies will locate the point of obstruction
Early incomplete occlusion -> clot busters
Complete obstruction -> embolectomy with Fogarty catheter
Fasciotomy added if several hours have passed before revascularization
Presentation of dissecting aneurysm of the thoracic aorta?
Poorly controlled hypertension
Similar to MI - sudden onset of extremely severe, tearing chest pain that radiates to the back and migrates down shortly after onset
May be unequal pulses in the upper extremities
CXR with wide mediastinum
Work-up of suspected dissecting aneurysm of the thoracic aorta?
EKG and cardiac enzymes to r/o MI
Non-invasive means to avoid high-pressure injection needed for the aortogram -> MRI angiogram (if available) provides the best diagnostic images.
CT angiogram has often been used, but but should be avoided if limited renal function.
Third option - TEE
Rx dissecting aneurysm of thoracic aorta?
As a rule (riddled with exception) -> surgical management for ascending aorta dissections vs. descending managed medically with control of the HTN in the ICU
Ascending aorta - monitor for aortic valve damage that may require repair
Why is dissecting aneurysm of the descending thoracic aorta managed medically vs. surgery?
Devastating consequences of interrupting bloody supply to the spinal cord make surgery a risky proposition
If we think there is cancer somewhere inside the body, what are the 2 options to prove it? What are the advantages and disadvantages?
- FNA
- Advantages: in office, no local anesthetic, virtually no risk
- Disadvantages: no view of tissue architecture, diagnosis is often not made, not sensitive - Core biopsy
2 circumstances when an FNA is contraindicated?
- Do not do an FNA if you think there is a hemangioma in the liver (could cause fatal bleeding)
- Do not do an FNA of a testicular mass -> almost always malignant, will quickly spread through the needle tract
