Vascular Flashcards
Suspect this in a pt w/ leg claudication (“angina of the leg”), pain in the leg with ambulation. On PE, they have shiny skin or loss of hair. Decreased pulses and cool extremity distal to pain.
Peripheral vascular disease (AKA Arteriosclerotic occlusive disease of the lower extremities by Pestana’s)
Symptoms of severe peripheral vascular disease
Non-healing wounds, rest pain, or color change when pt moves their feet.
Workup for peripheral vascular disease
Ankle-Brachial Index (ABI). If too high (i.e. not possible) do a toe-brachial index (TBI).
If ABI confirms peripheral vascular disease, what further workup should you do?
Ultrasound Doppler to find the point of pressure gradient drop. If the plan is to intervene, do a CT angiogram to identify collaterals and the lesion itself.
Surgical treatments for peripheral vascular disease.
Angioplasty, stent, or bypass. Stent lesions above the knee or <3cm, bypass lesions below the knee, or that are >3cm.
Conservative medical management for PVD.
Control of risk factors, smoking cessation, exercise classes, anti-platelets (aspirin, clopidogrel if stented), Cilostazole or pentoxyphillene to tx symptoms.
Risk factors for PVD
SMOKING, hypertension, diabetes, high cholesterol.
Pathophysiology of Acute Limb Ischemia
Obstruction of blood flow to an extremity, which occurs fast enough that collateral circulation did not have time to develop. This blockage can be due to aFib, CHOLESTEROL embolism (think this in a pt who had a cath put in, or an angiogram or something), acute thrombosis.
6 P’s of acute limb ischemia
Pulseless Pallor Poikilothermia Pain Paresthesia Paralysis
Tx of acute limb ischemia
Embolectomy, localized tPA, or heparin. Keep a watchful eye on them for compartment syndrome. Want to treat within 6 hours.
Dx of acute limb ischemia
U/S w/ doppler, or arteriogram
Ankle-Brachial Index - values!
Calcified: >1.4 Normal: 1.0 - 1.4 Equivocal: 0.9 - 1.0 Mild PVD: 0.8 - 0.9 Moderate PVD: 0.4 - 0.8
Suspect this in a patient who describes claudication of the arm (coldness, tingling, muscle pain) and posterior neurologic signs (visual symptoms, equilibrium problems) when the arm is exercised
Subclavian steal syndrome.
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 does not allow 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 in the vertebral.
Dx and tx of subclavian steal syndrome
Duplex scanning is diagnostic when it shows reversal of flow. Bypass surgery cures it.
Typical characteristics of Abdominal Aortic Aneurysms
Typically asymptomatic, found as a pulsatile abdominal mass on examination (between the xiphoid and the umbilicus) or found on x-rays, sonograms, or CT scans done for another diagnostic purpose, usually in an older man.
Management of abdominal aortic aneurysms
<5cm and asymptomatic, you can watch carefully. >5 cm, or growing 1 cm per year, surgical intervention is recommended. If symptomatic or ruptured, emergency surgery.
Most common surgical treatment for abdominal aortic aneurysm
Endovascular stents inserted percutaneously
Suspect this in a patient who seeks help because he “cannot sleep.” It turns out that pain in the calf is what keeps him from falling asleep. He has learned that sitting up and dangling the leg helps the pain, and a few minutes after he does so, the leg that used to be very pale becomes deep purple. Physical exam shows shiny atrophic skin without hair, and no peripheral pulses.
The pain is described as “Rest Pain”, and is the penultimate stage of Peripheral Vascular Disease. The only stage after this is ulceration and gangrene.
Suspect this in a patient with sudden onset of extremely severe, tearing chest pain that radiates to the back and migrates down shortly after its onset. There may be unequal pulses in the upper extremities, and x-ray shows a wide mediastinum.
Aortic dissection
Best option to image an aortic dissection
Ultrasound, and CT
Suspect this in a patient with temporary blindness in one eye that resolves spontaneously in a few minutes. What is the name of this symptom? What might you find on physical exam?
Embolus from the internal carotid artery (ICA) that occludes the ophthalmic artery, leading to temporary retinal ischemia. The name of the symptom is Amaurosis fugax. You may find a bruit over the ipsilateral carotid artery.
In a patient who you suspect an embolus from the carotid artery caused temporary blindness, what can you find on fundoscopic exam that would confirm a carotid source?
Hollenhorst plaques: cholesterol microemboli seen within the retinal arterioles that have a bright, yellow, and refractile appearance. They are considered highly suggestive of embolization from a plaque at the carotid bifurcation
How do you distinguish a TIA from a stroke?
The symptoms of a stroke persist >24 hours. Though in general, since most TIAs last less than an hour, symptoms lasting beyond that time are highly suggestive of a stroke.
What vessel should you worry about if a patient describes symptoms of Right Arm and Leg Weakness and Numbness?
The contralateral middle cerebral artery, which feeds the left motor cortex.
Risk factors for carotid stenosis
Older age, male gender, hypertension, smoking, hypercholesterolemia, diabetes, and obesity.
Branches of the internal carotid, and branches of the external carotid arteries.
Internal carotid has no branches in the neck. Ophthalmic artery.
External carotid: “some attendings like freaking out potential medical students”. Superior thyroid, Ascending pharyngeal, Lingual, Facial, Occipital, Posterior auricular, Maxillary, and Superficial temporal
Two main categories of stroke
Strokes are broadly categorized into ischemic and hemorrhagic types. Ischemic stroke occurs (80%) when there is a blockage to the blood supply to the brain, whereas hemorrhagic stroke occurs when an artery ruptures and bleeds.
Two main causes of hemorrhagic stroke
Intracerebral hemorrhage due to poorly controlled hypertension, trauma, congenital arteriovenous malformations, and subarachnoid hemorrhage due to a ruptured intracranial aneurysm.
Main causes of Ischemic stroke
Emboli (clot from somewhere else) and thrombosis (clot forming within the intracranial arteries).
Main sources of cerebral emboli
Emboli arise from the rupture of plaque in the internal carotid artery (ICA) at the carotid bifurcation and from the heart (left atrial thrombus in association with atrial fibrillation, mural thrombus in association with acute myocardial infarction, endocarditis). Less commonly plaque from the aortic arch can embolize.
What is a lacunar stroke?
A lacunar stroke is an ischemic stroke that is caused by an occlusion of the deep penetrating arteries. The main risks are severe hypertension and diabetes. Lacunar infarcts are not generally thought to be due to large vessel (carotid) or cardiac embolization.
If a Patient has Had Multiple TIAs, with the Same Symptom Each Time, What Is the Most Likely Source of the TIA?
Carotid artery
Diagnostic test of choice for carotid stenosis
Carotid duplex scan (ultrasound with doppler). Follow up with CT Angio.
Three management options for symptomatic carotid stenosis
Medical management alone (aspirin {ASA}, clopidogrel, and statin), carotid endarterectomy (CEA), and carotid artery stenting (CAS).
Is CEA better for men or women? For more or less occluded carotid arteries?
Men. More occluded (80-99%).
What is more common, anterior or posterior circulation ischemic stroke?
Anterior (70%)
For what patient is CEA the MOST beneficial?
Men, symptomatic, 70-99% occluded ICA
Suspect this in a person with a history of these three things: (1) pain in the leg with walking, (2) relieved within a few
minutes of rest, and (3) reproducible at the same walking distance each time.
Claudication. Due to peripheral arterial disease (PAD).
Risk factors for Peripheral arterial disease
Smoking, diabetes, hypertension, hypercholesterolemia, advanced age, male gender, obesity, sedentary lifestyle, family history of vascular disease, heart attack, and stroke
What do you call it when a patient complains that his foot turns pale after it is elevated (usually for 1–2 min). Once the patient sits up and dangles the foot down, it becomes ruborous (like a cooked lobster). Also, why does it happen and what is the diagnosis?
Buerger’s sign. It’s due to artery dilation from chronic severe ischemia, causing reactive hyperemia. The diagnosis is peripheral arterial disease, and is usually accompanied with ischemic rest pain.
Most common area in the leg to develop atherosclerotic plaque? How about most common vessel to get arterial emboli?
Atherosclerotic plaque = SFA
Emboli = Common femoral
What is dependent rubor?
Sign of advanced chronic ischemia. Dermal arterioles and capillaries no longer constrict w/ increased hydrostatic pressure. The arterioles in the foot become vasodilated in an effort to maximize blood and oxygen delivery, which results in pooling of blood in the foot when in a dependent position.
What is Buerger’s disease?
AKA thromboangiitis obliterans. Seen in YOUNG SMOKERS. It’s an inflammatory and thrombotic process that causes occlusion of distal arteries (tibial) below the knee in the hands, as well as venous thrombosis. The only effective treatment is smoking cessation.
How Does the Location of the Muscle Affected Correlate with the Location of the Disease?
The muscle groups affected by claudication are generally supplied by the arteries one level above. (e.g. buttock claudication means aorta or common iliac arteries; calf claudication is due to superficial femoral artery disease; foot claudication is extremely rare and is most often due to isolated tibial artery disease)
Suspect this in a patient with this triad of symptoms: (1) buttock and thigh claudication, (2) absent femoral pulses, and (3) impotence
Leriche syndrome, a chronic, slowly developing occlusion of the infrarenal aorta
The only two drugs approved to treat peripheral arterial disease. Also two other drugs that help with this condition.
Cilostazole (vasodilator, platelet aggregation inhibitor; considered more effective), and Pentoxifyllene (lowers blood viscosity, helps RBC deformability to pass through occluded vessels).
Give statins, too, to stabilize the plaques.
Also aspirin, to prevent stroke and MI.
Suspect this in a pt who complains of right thigh pain during walking; on PE, he has a small pulsatile mass in the right groin area.
femoral artery aneurysm
If a patient has an AAA, what other vessels should you worry about having an aneurysm?
Femoral and Popliteal
Normal diameter for infra-renal aorta, and at what measurement is it considered an aneurysm?
2 cm in men, 1.8 cm in women. At 1.5x normal it’s considered an aneurysm (e.g. in a man w/ a 2 cm aorta, a 3 cm segment is considered an aneurysm)
Normal aneurysm growth rate, and rapid growth rate that a person should get it repaired.
Normal: 2-4 mm / year
Rapid: >5 mm / 6 months
Fun fact: what disease is actually protective from AAA?
Diabetes.
Most common place for AAA to rupture into
Retroperitoneum, mostly to the left
Recommended imaging in a stable pt w/ suspected ruptured AAA, and why. In an unstable patient?
CT Angio, because it helps confirm whether there really is a ruptured AAA, and whether it can be repaired endovascularly. In an unstable patient, no CT just go straight to the OR for an Ex Lap
Two surgical options for repair of asymptomatic or ruptured AAA
Open repair and Endovascular Aneurysm Repair (EVAR)
After repair of an AAA, how should patients be monitored moving forward?
Annual CT, evaluating for endoleak
Who should be screened for AAA?
Men 65-75 with any smoking history, OR anyone with a first-degree family member with an AAA
Most common cause of death in people who repaired an AAA
MI
Most common cause of arterial emboli
Atrial fibrillation
How long can tissue stand ischemia before irreversible damage occurs?
Irreversible damage starts at 3 hours, is complete in 6 hours.
Tests to evaluate acute limb ischemia
Doppler, or duplex scanning. For chronic ischemia, Ankle-brachial index (ABI)
Three most important initial management steps for acute limb ischemia
1) Anticoagulation with heparin to stop embolus propagation while the body’s own fibrolytics dissolve some of the clot
2) Place the limb in a dependent position to improve blood flow
3) Start IV fluids to help optimize collateral blood flow.
What should you do if muscle / limb damage from acute limb ischemia has become irreversible?
Amputation. Repairing it can cause reperfusion syndrome. Think rhabdomyolysis leading to renal failure, or hyperkalemia leading to heart failure.
Time cutoff for acute vs chronic limb ischemia
2 weeks. Less is acute, more is chronic.
