PAD pt 2 Flashcards
Acute Occlusion is a result of?
THROMBUS or EMBOLUS
stable atheroma with fibrous cap suffers plaque rupture leading to ___ development and acute occlusion
thombus
Pt has hx of intermittent claudication
Presentation may not be as dramatic if h/o chronic PAD due to development of collaterals
large emboli MC come from where?
the heart
MCC of embolus
Afib
Atherosclerosis of larger vessels may suffer plaque rupture, creating a thrombus, which can break off and travel to smaller vessels (embolus)
presentation of acute occlusion
6 P’s:
* Pallor
* Pain
* Pulseless
* Paralysis
* Polar / Poikilothermia
* Paresthesias
diagnostics for acute occlusion
- CLINICAL dx
- Doppler - little/no flow in distal vessels
-
AVOID: Acute imaging (CTA or MRA) if light touch sensation compromised
- Causes a delay in therapy
- Often used to examine extent of arterial occlusion in OR - EKG - determine if pt is in Afib
- CBC, PT/INR, PTT - pre-op
-
Echo - done LATER if embolic source is suspected
- TEE with bubble study preferred - BMP, ABG - met acidosis, hyperkalemia, rhabdomyolysis, AKI
management for acute occlusion
-
Immediate revascularization for all sx acute arterial thrombosis
- within 3 hrs of sx -
Emergent vascular surgery consult is VITAL!
- IV Heparin bolus ASAP and continuous infusion - Endovascular or open-surgical approaches are taken to revascularize the limb
- Once stable, source must be determined → thrombus vs embolus
- If thrombus - treat as you do other PAD pts
- If embolus - determine source and tx underlying - Most require warfarin x +3 mo, goal of INR of 2.0 to 3.0
causes of AAA
- Dilatation of infrarenal aorta is a nml part of aging
- aorta normally measures 2 cm
- AAA = > 3 cm
- Rare to rupture under 5 cm - MC men over 55 years of age
- MC below renal arteries
- Aneurysms usually involve aortic bifurcation and often involve common iliac arteries
RF for AAA
- Male
- Smoking history
- Family History
- Increasing Age
classification of AAA
- Fusiform: circumferential expansion of the aorta
- Saccular: outpouching of a segment of the aorta
presentation of AAA
- Asx - Most are incidental findings on imaging
- Symptomatic → PAIN!
- mild-severe, located over the mid-abd, and radiating to lower back
- May be constant or intermittent
- Exacerbated by even gentle pressure on aneurysm sack
- Most have thick layer of thrombus lining aneurysmal sac - Distal embolization of thrombus is rare - Symptomatic → RUPTURE!
- severe pain, palpable abd mass, and hypotension.
- Free rupture into peritoneal cavity is lethal
diagnostics for AAA
- Labs - only if undergoing surgical repair
- CBC, BMP, PT/INR, PTT - Abd US - initial screening for presence of aneurysm
-
CT - more reliable assessment of diameter
- Done when aneurysm nears 5.5 cm diameter threshold for tx
- Contrast-enhanced CT show arteries above and below aneurysm, which is essential for surgical planning - Once aneurysm is identified, routine f/u + US will determine size and growth rate
- Frequency of imaging depends on size of aneurysm
- aneurysm at 5 cm, = CTA + contrast
Screening for AAA
- USPSTF Recommendations (B):
- One-time screening US for men 65-75 y/o who have ever smoked
- Could also consider screening men 65-75 who have never smoked but with considerable risk factors and family history (C) -
What if you find an aneurysm? - Continue to screen by US depending on size
- 3.0 - 3.4 cm : every 2 years
- 3.5 - 4.4 cm: every 12 months
- 4.5 - 5.4 cm: every 6 months = Should be referred to Vascular Surgery at this point
management for AAA
-
elective repair
- Indicated for aneurysms ≥ 5.5 cm OR rapid expansion (>0.5 cm growth in 6 mo)
- sx (pain, tenderness) may precipitate urgent surgical intervention regardless of diameter -
rupture - EMERGENT ENDOVASCULAR REPAIR
- Lethal if not repaired -
Aortic Inflammation/Inflammatory Aneurysm
- tx cause (vasculitis, infection, retroperitoneal fibrosis)
- Surgical indications: aneurysms ≥5.5 cm, compression of retroperitoneal structures (ureter), or pain w/ palpation
2 AAA surgical repair mechanisms
-
Open Repair
- Excellent long-term results
- Higher complication rates
- 1-5% mortality
Up to 10% risk of post-op MI
- Long recovery -
Endovascular Repair
- Decreased 30 day mortality (0.5 - 2%)
- Decreased perioperative systemic complications
- increased need for secondary procedures d/t leaks (up to 10% of pts per year)
prognosis of AAA
- survived surgical repair - 60% are alive at 5 yrs
- Long-term survival (≥ 5 years) is equivalent for open and endovascular repair - Untreated aneurysm mortality rate varies with aneurysm diameter
- > 6 cm = 12% annual risk of rupture
- > 7 cm = 25% annual risk of rupture - aortic aneurysm >5.5 cm have 3x high risk of dying from rupture > surgical resection
MCC of death from AAA surgical repair
MI is the leading cause of death
causes of Thoracic Aneurysm
- MCC by atherosclerosis
- Disorders of connective tissue (Ehlers-Danlos and Marfan syndromes) are rare causes but are important to note
- Bicuspid aortic valve disease is also a rare cause
- < 10% of aortic aneurysms occur in the thoracic aorta
presentation of thoracic aneurysm
- Most asx
- sx depend on size & position of aneurysm
- Substernal back or neck pain
- Pressure on the trachea, esophagus, or superior vena cava can result in dyspnea, stridor, or brassy cough; dysphagia; and edema in the neck and arms as well as distended neck veins
- Stretching of L recurrent laryngeal nerve = hoarseness
- With aneurysms of the ascending aorta, aortic regurgitation may be present due to dilation of the aortic valve annulus.
Rupture is catastrophic - bleeding is rarely contained, allowing no time for emergent repair
diagnostics for thoracic aneurysms
-
CXR - widened mediastinum
- Can also show a calcified outline - CT w/ contrast (1st line) - demonstrate anatomy and size of aneurysm
- MRA - r/o conditions (neoplasms, substernal goiter)
- Cardiac cath & echo - determine relationship of coronary vessels aneurysm of ascending aorta, as well as look at aortic valve (bicuspid AV or for aortic regurgitation)
management for thoracic aneurysm
-
Surgical Repair
- Aneurysms measuring >5.5-6 cm
- Aneurysms of descending thoracic aorta - endovascular grafting
- involvement of proximal aortic arch or ascending aorta - more complicated
indications for thoracic aneurysm repair depend on:
location of dilation
rate of growth
associated symptoms
overall patient condition
screening for thoracic aneurysm
- No current guidelines on screening for thoracic aortic aneurysm
-
Referral to CT surgeon or vascular surgeon at time of dx
- Monitor size with TTE / CT chest x 6-24 mo depending on size and rate of growth - Controlling RF and BP is important to lower risk of growth and rupture
occurs when a spontaneous intimal tear develops and blood dissects into the media of the aorta
Aortic dissection
how are Aortic dissections classified
by entry point and distal extent
- Type A dissection - involves arch proximal to L subclavian artery
- Type B dissection- occurs in proximal descending thoracic aorta typically just beyond L subclavian artery
aortic dissection is MC in who?
men >50
presentation of aortic dissection
-
Chest pain
- Severe and persistent, Sudden onset
- Radiates to back and possibly neck - hypertensive
-
disrupted perfusion
- Syncope, hemiplegia, or paralysis of the lower extremities may occur
- Intestinal ischemia
- Renal insufficiency
- Peripheral pulses may be diminished or unequal. - diastolic murmur - a dissection in ascending aorta close to AV = valvular regurg, HF, and cardiac tamponade
diagnostics of aortic dissection
- EKG - LVH
- CXR - widened mediastinum
- A multiplanar CT scan chest & abdomen w/ contrast - immediate diagnostic imaging modality of choice
- Must have low threshold for obtaining a CT scan in any HTN pt w/ CP and equivocal findings on ECG - TEE - excellent, typically takes longer to obtain
management for aortic dissection
-
BP control
- Aggressive measures before dx studies have been completed
- Lower SBP to 100–120 mmHg and lower pulse pressure
- Labetalol → alpha- and beta-blocker; lowers pulse pressure and achieves rapid blood pressure control
- Alt: esmolol
- Add IV CCBs (nicardipine) or nitroprusside if BP not to goal - Pain: Morphine
-
Surgical Intervention
- Required for all type A dissections
- Type B dissections + signs of malperfusion of target tissues too
Segmental, inflammatory, thrombotic processes that occur in the small distal arteries and occasionally veins of extremities - NOT ATHEROSCLEROSIS
Cause is unknown
Pathology examination reveals arteritis
Buergers
Buergers MC starts where?
Starts with toes/feet and with disease progression
MC plantar and digital vessels of foot/leg
Can see hand/finger involvement in advances stages
Buergers is MC in who?
male smokers <40 y/o
presentation of Beurgers
-
MC distal ischemic rest pain or ischemic ulcerations on toes, feet, or fingers
- Claudication is less common - Superficial thrombophlebitis may occur
- Progression of the disease may lead to involvement of more proximal arteries, but involvement of large arteries is unusual
- Can have intermittent episodes
diagnostics for Buergers
Most to r/o other thromboembolic sources for the distal ischemia
1. CBC, CMP, Coagulation studies
1. TEE
1. Rheumatologic testing (DDx includes other vasculitides)
Arterial duplex
CTA or MRA - corkscrew!
management for Buergers
- tobacco cessation is only effective tx!
-
Revascularization of occluded vessels is rarely an option as there are no good distal targets
- Amputation required for ischemic areas - Pain - NSAIDs/opioids
- All other forms of pharm have been generally ineffective - Steroids, calcium-channel blockers, vasodilators, antiplatelet drugs, and anticoagulants
prognosis/complications of Buergers
- Complications: ulcerations, gangrene, infection
- Determining need for amputation:
- pts who stop tobacco use can prevent amputation
- For pts who continue using tobacco, there is an 8-yr amputation rate of approximately 40% - Uncommon cause of death
