Peripheral Artery Disease Part 2 Flashcards
What are the essentials of diagnosis of acute arterial occlusion of a limb?
- Sudden pain in limb + absent limb pulses
- Some degree of neurologic dysfunction with numbness, weakness, or complete paralysis
- Loss of light touch sensation requires revascularization within 3 hours to save limb
What is the etiology of an acute arterial occlusion?
Thrombus or embolus
If a thrombus occurs leading to acute occlusion, what happens?
stable atheroma with fibrous plaque ruptures
What is the presentation of a patient with a thrombus leading to acute occlusion?
- Typically history of intermittent claudication
- May not be as dramatic if hx of PAD due to collaterals
Where do most emboli come from? What is the most common cause?
Heart
* Afib
* Atherosclerosis can also cause plaque rupture leading to thrombus that can break off and become an embolus in smaller vessels
What are the 6 P’s of acute occlusion presentation?
- Pallor
- Pain
- Pulseless
- Paralysis
- Polar/poikilothermia (purple spots)
- Paresthesias
How is diagnosis of acute occlusion made?
- Most often clinical
- Doppler with little to no flow in distal vessles
- Acute imaging (CTA or MRA) avoided if light touch sensation compromised
Would not use acute imaging due to delay in therapy unless in preparation for surgery
What other tests can be considered for acute arterial occlusion?
- EKG (see if pt is in afib)
- CBC, PT/INR, PTT (pre-op assessment)
- Echo (later if embolic source suspected)
- BMP, ABG for metabolic acidosis, hyperkalemia, rhabdomyolysis, AKI
How is acute occlusion managed?
- Immediate revascularization if symptomatic within 3 hours
- Emergent vascular surgery consult for endovascular or open-surgical approach
- Anticoag with IV heparin bolus and continuous infusion
Longer delays carry risk of irreversible tissue damage, up to 100% at 6 hrs
What should you do for a patient with acute arterial occlusion once stable?
Determine source
* If due to PAD thrombus –> treat as other PAD
* Embolus –> determine source and treat underlying cause
* Most require warfarin for 3 + months with INR of 2.0-3.0
What is the prognosis of acute arterial occlusion?
- 10-25% risk of amputation and 25%+ in-hospital mortality rate
What are the essentials of diagnosis of a abdominal aortic aneurysm?
- Most asymptomatic until rupture
- 80% measuring 5 cm are palpable; threshold for treatment is 5.5 cm
- Back or abdominal pain with aneurysmal tenderness may precede rupture
- Rupture causes excruciating abdominal pain that radiates to back and hypotension
What is the etiology of AAA?
- Dilatation of infrarenal aorta is part of aging
- AAA >3 cm (normal aorta = 2 cm)
- MC in men over 55
- Most AAA occur below renal arteries (usually aortic bifurcation and common iliac arteries)
Rarely ruptures under 5 cm
What are risk factors for AAA?
- Male gender
- Family history of AAA
- Smoking history
- Increasing age
What are the 2 major groups of AAA?
- Fusiform: circumferential expansion of aorta
- Saccular: outpouching of a segment of the aorta
What is the presentation of AAA?
- Most asymptomatic found on imaging
- Symptoms: mild to severe pain over mid-abdomen can radiate to lower back
- Constant or intermittent
- Exacerbated by pressure
Most have thrombus lining aneurysm but embolization is rare
What is the presentation of rupture of AAA?
- Severe pain
- Palpable abdominal mass
- Hypotension
- Free rupture into peritoneal cavity is LETHAL :(
How is AAA diagnosed?
- Lab eval only in patients undergoing surgical repair: CBC, BMP, PT/INR, PTT
- ABD US= diagnostic study of choice for initial screening
- CT scans = more reliable assessment of aneurysm diameter
When would a CT scan be done for AAA?
- When aneurysm nears diameter threshold (5.5 cm) for treatment
- For surgical planning: contrast-enhanced CT scans show arteries above and below
What is done once a AAA is identified?
- Routine f/up with ultrasound with frequency depending on size
- CTA with contrast once measures 5 cm
What is the 15th leadinng cause of death in the US?
Ruptured AAA
10th leading cause of death in men older than 55
What are screening recommendations by the USPSTF for AAA?
B recommendation:
* One-time screening ultrasound for men 65-75 who have ever smoked
C recommendation:
* Screening men 65-75 who have never smoked with risk factors and family history
How often would you screen by US a aneurysm that is 3-3.4 cm? 3.5-4.4 cm?
- Every 2 years
- Every 12 months
How often should you screen by US an aneurysm that is 4.5-5.4 cm?
Every 6 months
REFER TO VASCULAR SURGERY
When is elective AAA repair indicated?
- Aneurysms >5.5 cm or with rapid expansion
- Pain or tenderness symptoms
How is AAA rupture managed?
Emergent endovascular repair (and 1/2 of those patients survive :()
LETHAL IF NOT REPAIRED
How is abdominal inflammation/inflammatory aneurysm treated?
- Treatment of underlying cause (vasculitis, infection, retroperitoneal fibrosis)
- Surgery if aneurysm >5.5 cm, compression of retroperitoneal structures, or pain with palpation
How can a AAA be repaired?
- Open repair
- Endovascular repair
What are the benefits and risks of open repair of AAA?
- Excellent long-term results
- Higher complication rates
- Risk of post-op MI
- Mortality risk (1-5%)
- Long recovery
What are the benefits and risks of endovascular repair?
- Decreased 30 day mortality (.5-2%)
- Decreased perioperative systemic complications
- Increased need for secondary procedures b/c of leaks
What is the prognosis of AAA post surgical repair?
60% alive at 5 years
What is the leading cause of death post AAA surgical repair?
MI
What are the essentials of diagnosis of a thoracic aortic aneurysm?
- Widened mediastinum on chest radiograph
- With rupture, sudden onset chest pain radiating to the back
What is the etiology of thoracic aneurysm?
- Most due to atherosclerosis
- Disorders of connective tissue (Ehlers-Danlos and Marfan) rare causes
- Bicuspid aortic valve disease rare cause
- Less than 10% AA in thoracic
Thoracic = above diaphragm
What is the presentation of thoracic aneurysms?
- Most asymptomatic
- Symptoms depending on size and position
- Substernal back or neck pain
- If pressure on trachea, esophagus, or superior vena cava: dyspnea, stridor, or brassy cough, dysphagia, edema in neck and arms, distended neck veins
- Stretching of L recurrent laryngeal nerve –> hoarseness
- A of Ascending Aorta–> aortic regurgitation due to dilation of aortic valve annulus
What happens if thoracic aneurysm bursts?
Catastrophic, bleeding rarely contained so no time for repair
How is thoracic aortic aneurysm diagnosed?
- Chest x-ray with widened mediastinum
- CT scan with contrast = modality of choice for anatomy and size
- MRA
- Cardiac catheterization and echo
Why would a MRA be useful for thoracic aortic aneurysms?
Excluse conditions that mimic aneurysms (neoplasms, substernal goiter)
Why is cardiac catheterization and echocardiography helpful?
Determine relationship of coronary vessels aneurysm of ascending aorta and look at aortic valve
How is thoracic aneurysm managed?
Surgical repair
What does surgical repair depend on?
- Location of dilation
- Rate of growth
- Associated symptoms
- Overall patient condition
Which aneurysms should be considered for repair?
- Aneurysms 5.5-6 cm or larger
- Aneurysms of descending thoracic aorta treated by endovascular grafting
- Aneurysms of proximal aortic artch/ascending aorta harder
What are screening guidelines for thoracic aneurysm?
- No current guidelines
- Referral to CT surgeon or vascular surgeon at time of diagnosis and monitor size via TTE or CT every 6-24 months
- Control risk factors and maintain well-controlled BP
epair
What are the essentials of diagnosis of aortic dissection?
- Sudden searing chest pain radiating to back, abdomen, or neck in hypertensive patient
- Widened mediastinum on CXR
- Pulse discrepancy in extremities
- Acute aortic regurg may develop
How is aortic dissection classified?
- Entry point and distal extent
- Type A dissection: involves arch proximal to the left subclavian artery
- Type B dissection: occurs in proximal descending thoracic aorta just beyond left subclavian artery
What is the etiology of aortic dissection?
- Spontaneous intimal tear and blood dissects into media of aorta
What is the epidemiology of aortic dissection?
- MC in men over 50
What are risk factors for aortic dissection?
- Aging
- Atherosclerosis
- Increased BP
- Blunt trauma to chest wall
- Aortic valve defect
- Aortic coarctation
- Pre-existing aortic aneurysm
- Pregnancy
What is the presentation of aortic dissection?
- Severe, persistent, sudden pain that radiates to back and possibly neck
- Hypertension (usually)
- S/s of disrupted perfusion to organs
- Diastolic murmur (if in ascending aorta close to aortic valve)
What are signs and symptoms of disrupted perfusion to vital organs that result from aortic dissection?
- Syncope, hemiplegia, or paralysis of lower extremities
- Intestinal ischemia
- Renal insufficiency
- Peripheral pulses may be diminished or unequal
What can a diastolic murmur due to aortic dissection cause?
- Valvular regurgitation
- Heart failure
- Cardiac tamponade
How is aortic dissection diagnosed?
- EKG with LVH
- Chest X Ray with widened mediastinum
- CT scan of chest and abdomen with contrast - diagnostic imaging modality of choice
- TEE (typically takes longer to obtain)
How is aortic dissection managed?
- BP control
- Pain control
- Surgical intervention
What should be used for blood pressure control in aortic dissection?
- Agressive measures if suspected
- Lower to 100-120 mmHg
- Beta-blockers = 1st line (labetolol)
- IV CCBs (nicardipine) or nitroprusside added if not at goal
What beta blockers are usually used in aortic dissection management and why?
- Labetolol = alpha and beta blocker, lowers pulse pressure and achieves rapid BP control
- Esmolol= for patients with asthma, bradycardia, or potential for reaction to beta blockers, has short half life
What is used for pain control with aortic dissection?
Morphine = drug of choice
How is type A dissection managed surgically? Type B?
- Urgent surgical intervention for type A
- Type B may require urgent surgery if signs of malperfusion of target tissues
What are the essentials of diagnosis of thromboangiitis obliterans (Buerger disease)?
- Typical in male cigarette smokers
- Causes severe ischemia of distal extremities progressing to tissue loss
- Thrombosis of superficial veins is possible
- Smoking cessation is essential
What is the etiology of Buerger’s disease?
- Segmental, inflammatory, thrombotic processes in small distal arteries and veins of extremities
- Cause unknown
- Pathology shows arteritis
NOT ATHEROSCLEROSIS
How does Buergers progress?
- Starts with toes/feet MC plantar and digital vessels of foot/leg
- Can see hand/finger involvement in advanced stages
- Severe ischemia can result in tissue loss
What is the epidemiology of Buergers?
- Closely linked to tobacco use
- Male smokers <40 y/o
What is the presentation of Buergers?
- Distal ischemic rest pain or ischemic ulcerations on the toes, feet, or fingers
- Claudication less common
- Superficial thrombophlebitis possible
- May progress to proximal arteries, but rarely large arteries
- Intermittent episodes possible
How is Buergers diagnosed?
R/O other thromboembolic sources for distal ischemia
* CBC, CMP, Coag studies
* TEE
* Rheumatic testing
- Arterial duplex
- CTA or MRA
How is Buergers managed?
- Tobacco cessation is only effective treatment
- Revascularization rarely and option and amputation often required
- NSAIDs/opioids for pain control in acute ischemic events
No other pharm has been shown to be effective :(
What are complications of Buergers?
- Ulcerations
- Gangrene
- Infection
What is the prognosis for Buergers?
- Patients who stop tobacco use can prevent amputation
- Continued tobacco use = 8-year amputation rate of 40%
- Uncommonly causes death
