Lecture 16: PAD Part 2 Flashcards
What are the essentials of diagnosing an acute arterial occlusion of a limb?
- Sudden pain in limb + absent limb pulses
- Neurologic dysfunction with numbness, weakness, or complete paralysis
- Loss of light touch = need to revascularize within 3 hours!!!!
What is a thrombus?
- Stable atheroma with fibrous cap ruptures
- Hx of intermittent claudication
- Usually collateral development is present, so not as dramatic
The actual clot on the wall.
What is an embolus?
- Anything that is too large to pass through its vessel
- MCC: Afib
What are the 6 Ps of circulation?
- Pallor
- Pain
- Pulseless
- Paralysis
- Polar/Poikilothermia
- Paresthesias
Poikilothermia = inability to regulate temperature
How do we diagnose an acute occlusion of a limb and what is the best imaging if light touch is compromised?
- Clinical diagnosis
- Doppler is first-line.
When is CTA/MRA primarily used in evaluating acute occlusion of a limb?
In the OR
Takes a while so we don’t want to do it first.
What is the preferred imaging study to evaluate for an embolic source after treating an acute occulsion of a limb?
TEE with bubble study to check for a PFO
How soon do we need to revascularize a symptomatic arterial thrombosis?
3 hours!!
Once we have diagnosed acute arterial occlusion, what is the first step to begin managing it?
A/C using IV heparin bolus
Done after doppler probably
What is the next step in management of a stable arterial occlusion?
Determining whether is it is a PAD thrombus or an embolus
When is a AAA palpable and what is the treatment threshold?
- 80% of 5cm ones are palpable.
- Treat at 5.5cm
How does an AAA present prior to rupture usually?
Asymptomatic
What are the 3 primary symptoms/signs of a ruptured AAA?
- Massive abd pain radiating to the back
- Severe hypotension
- Palpable abdominal mass
When is an AAA considered an actual aneurysm?
Must be greater than 3 cm
Normal aorta is 2cm
Who is AAA MC in, and where is it MC found specifically?
- Men
- Below the renal arteries, at the aortic bifurcation
- Often includes common iliac arteries
What are the primary risk factors for developing an AAA?
- Male
- Smoker
- FMHx
- Age
What are the two major groups of AAAs?
- Fusiform: Circumferential expansion of the aorta
- Saccular: Outpouching of a segment.
How do we find most AAAs?
Incidentally
What is the first presenting symptom of an AAA?
Abdominal pain that is mild to severe and radiating to the back
It will hurt when u press it even a little
Why is an AAA rupture lethal?
Blood into the peritoneal cavity = PAIN
What is the diagnostic study of choice for initial screening to detect an aneurysm?
Abdominal US
When is CT scan indicated for AAA evaluation?
- When you want to treat it because it may be near the 5.5cm threshold.
- Helps with surgical planning once you add contrast.
Once it is approximately 5cm, do a CTA
What scan is typically done to routinely monitor AAA growth?
US
When is AAA screening recommended per the USPSTF?
2023
- Single screening at 65-75 for men with ANY smoking history
- Consider screening if they have significant family hx/risk factors even if no smoking
Recommendation grade B
How often do you screen AAAs?
- 3-3.4 = 2y
- 3.5-4.4 = 1y
- 4.5-5.4 = q6 months + vascular referral
Via US
When is elective repair of an AAA indicated?
- > 5.5cm
- Rapid expansion (> 0.5cm in 6 months)
- Extreme symptoms regardless of diameter
What are the indications for surgery to fix AAAs or aortic inflammation?
- > 5.5cm
- Compression of retroperitoneal structures
- Pain with palpation
What are the pros/cons of open repair vs endovascular repair of an AAA?
- Open: Good long-term results, more complications and longer recovery.
- Endovascular: Better short-term, less complications, but leaks can occur more often.
What is the leading cause of death post-AAA repair?
MI
What are the essentials of diagnosis of a thoracic aortic aneurysm?
- Widened mediastinum on CXR
- Rupture presents as sudden onset CP radiating to the back
What is the primary underlying etiology for a thoracic aortic aneurysm? Rare etiologies?
- Primary: Atherosclerosis
- CT disorders like Ehlers-Danlos or Marfan
- Bicuspid aortic valve
What are the common possible S/S of a thoracic aortic aneurysm?
- Substernal/neck pain
- Dyspnea, stridor, brassy cough, dysphagia
- Distended neck veins
- Hoarseness (left recurrent laryngeal)
- Aortic regurg
Why is a rupture of a thoracic aortic aneurysm catastrophic?
Nearly impossible to contain the bleed.
What is the modality of choice to analyze a thoracic aortic aneurysm?
CT w/ con
What are the backup imaging modalities for a thoracic aortic aneurysm?
- MRA to exclude conditions that mimic thoracic aneurysms
- Cath and echo to determine how other vessels are affected
How large should a thoracic aortic aneurysm be to consider repair? What would make it more complicated? (location)
- If it is descending: 5.5-6cm via endovascular grafting
- Ascending/proximal is more complicated.
What is the first step once a thoracic aneurysm is diagnosed?
Refer to CT/vascular surgery so they can monitor via TTE or CT chest.
Controlling what factors is essential to lowering rupture/growth risk of a thoracic aneurysm?
- Controlling BP
- Managing risk factors (Atherosclerosis)
What are the essentials of diagnosis of an aortic dissection?
- Sudden searing chest pain radiating everywhere in a hypertensive pt
- Widened mediastinum on CXR
- Pulse discrepancy in extremities
- Acute aortic regurg
What is an aortic dissection?
- Sponataneous intimal tear
- Blood dissection into the media of the aorta
What are the 2 aortic dissection types?
- Type A: proximal to left subclavian
- Type B: Proximal descending thoracic aorta BEYOND left subclavian
A for ascending aorta, B for beyond
Who is aortic dissection MC in?
Men ):
What are the risk factors for aortic dissection?
- Age
- Atherosclerosis
- HTN
- Blunt trauma
- Aortic valve defect like AS
- Aortic coarctation
- Pre-existing aortic aneurysm
- Pregnancy
How does aortic dissection present?
- Severe CP of sudden onset that radiates to the back/neck
- Usually hypertensive
- Disrupted perfusion to vital organs
- Diastolic murmur resulting in regurg, HF, and tamponade
What is typically seen on EKG for aortic dissection? CXR?
- EKG: LVH
- CXR: Widened mediastinum
What is the immediate and modality of choice to image for suspected aortic dissection?
CT Chest + Abd w/ con
Low threshold if any HTN pt has CP + LVH
TEE is alternative, but longer to do than a CT
When is BP control indicated for aortic dissection and the goal BP?
- Indicated before diagnostics are completed
- Goal: 100-120 SBP + lowering pulse pressure
What are the first-line therapies for BP control in aortic dissection?
- Labetalol
- Esmolol (If pt may be risky to use BBs in)
- Add-on: CCBs (Nicardipine) or nitroprusside
Esmolol has a short half-life, so it can be used to test BB tolerance.
What is the DOC to manage the pain of aortic dissection?
Morphine
When is surgery indicated for Type A or Type B dissection?
- Type A: always surgery, via grafting
- Type B: surgery if malperfusion of tissue is noted
What are the essentials of diagnosis for thromboangiitis obliterans/Buerger disease?
- Male smokers
- Distal extremity ischemia
- Thrombosis of superficial veins
- SMOKING CESSATION
What exactly is Buerger’s/thromboangiitis obliterans?
Segemental, inflammatory, thrombotic process seen in the small distal arteries and veins of extremities
Unique from atherosclerosis.
Where is Buerger’s MC seen?
Plantar and digital vessels of the foot/leg
What is the primary demographic of Buerger’s?
Male smokers > 40
How do most people present with Buerger’s?
- Distal ischemic rest pain or ischemic ulcerations of lower extremities
- Superficial thrombophlebitis
What is the main goal of testing in Buerger’s?
Ruling out everything else
What is the best and only proven treatment for Buerger’s?
Smoking cessation
