Aortic Trauma, Dissections, Ulcers Flashcards

1
Q

What are indications for emergent throacotomy in the setting of trauma?

A

Shock with penetrating injury, CT output >1500 or >350 cc/hr for 3 hr.

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2
Q

Name 5 exposures and their uses for vascular thorax trauma

A

1- left anterolateral, most expedient for patients in extremis, can’t access posterior structures 2 - posterolateral - optimal for elective thorax, descending thorax, but often not versatile enough for trauma 3 - sternotomy - access heart/great vessels and is versatile 4 - “trap door” - rarely used because left sided thoracic vessels can be approached with sternotomy extension 5 - Clamshell

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3
Q

What are the 4 grades of BTAI?

A

1 - intimal tear 2 - intramural hematoma 3 - pseudoaneurysm 4 - free rupture

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4
Q

What are anatomic restrictions that would preclude TEVAR for BTAI

A

Inadequate seal zone Diseased iliofemoral vessels < 7mm

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5
Q

What type of thoracotomy would you use for a BTAI?

A

Left posterolateral - gives access to most common site of injury - the isthmus

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6
Q

When performing an open thoracic aortic repair, what is the most expedient way to preserve distal aortic perfusion?

A

Left heart bypass - cannulation of left inferior pulmonary vein and distal aorta

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7
Q

What is the cut off between “acute”, “subacute” vs “chronic” aortic dissections?

A

2 weeks - 75% of patients who die from aortic dissections do so in the first 14 days >3 months - chronic, length of time required for flap to become stiff and fibrotic

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8
Q

How frequent are type A vs B dissections?

A

A - 60% B - 40%

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9
Q

What are 10 risk factors for aortic dissection?

A

Age, HTN, male, bicuspid aortic valve, annulaortic ectasia, turner, noonan syndrome, arch hypoplasia, Marfan, Ehlers-Danlos, cocaine, pregnancy

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10
Q

Which vessels typically arise from true vs false lumen in type B dissection?

A

Left renal - false Right renal, SMA, celiac - true

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11
Q

What pathologic vessel wall process is associated with increased risk of aortic dissection?

A

Medial degeneration - cystic medial necrosis of collagen/elastin in media by elastolysis

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12
Q

Why does the false lumen expand to a larger diameter than the true in a dissection?

A

Laplace law: wall tension is proportional to vessel radius for a given pressure - wall tension = p x r/w where r = radius of vessel and w = wall thickness. Wall thickness of false lumen lower (only adventitial layer) therefore radius has to grow to accomodate the same wall tension at a given BP. True lumen has most of the elastic components of aortic wall and undergoes radial elastic collapse

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13
Q

What are presenting symptoms of aortic dissection

A

Pain most common HTN - often refractory Neurologic symptoms - syncope (stretching of baroreceptors in aortic wall cause vasovagal), spinal cord ischemia 10% or type b, parasthesias, hoarseness (compression of recurrent laryngeal), Horner syndrome (compression of sympathetic ganglion) Peripheral Vasc - arch vessels and ilieofem compromise

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14
Q

Why do pleural effusions occur in patients with type b dissection?

A

Inflammatory reaction of mediastinal pleura

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15
Q

What constitutes standard medical therapy for acute dissection?

A

Beta blocker and vasodilator (nitroprusside). Beta blocker first because direct vasodilator can have reflex sympathetic stimulation and cause catecholamine release and increase dP/dt

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16
Q

What is the mortality of uncomplicated type b dissection with medical management?

A

10%

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17
Q

What were the main results of the INSTEAD trial?

A

No survival advantage of TEVAR over med therapy at 2 years but survival advantage at 5 years on. IRAD data supports this too.

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18
Q

What are hard signs of extremity arterial injury?

A

Pulsatile bleeding, expanding hematoma, absent distal pulse, thrill/bruit

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19
Q

What are soft signs of arterial extremity injury?

A

Diminished distal pulse, history of hemorrhage, proximity to named vessel, neurologic deficit

20
Q

Which imaging modality would you use to evaluate extremity arterial trauma?

A

CTA, duplex not very useful

21
Q

Which imaging features suggest an arterial extremity injury can be watched?

A

No active hemorrhage, no distal ischemia. E.g. intimal tears, pseudoaneurysm, AV fistula

22
Q

What is the rationale for harvesting the uninjured leg when revascularizing extremity trauma?

A

Preserve collateral venous drainage (no evidence)

23
Q

What are 3 ways for getting proximal control in a extremity arterial trauma?

A

Tourniquet, Cut down proximal vessel (e.g. subclavian, iliac), endovascular placement of occlusion balloon

24
Q

Why is prosthetic not a good choice in upper extremity arterial trauma?

A

All wounds considered infected. Also high graft occlusion rate ~5%

25
Q

How long can you place an arterial shunt for an orthopedic repair without systemic heparinization

A

3 hours - 100% reported patency

26
Q

In forearm traumas, when is it safe to ligate the artery?

A

Allen’s test to determine complete palmar arch

27
Q

What percentage of brachial traumas present with a pulse deficit?

A

3/4

28
Q

What exposure do you use for popliteal artery traumas?

A

Above knee and below knee medial incisions

29
Q

Which arterial trauma in the upper or lower extremity has the highest risk of amputation?

A

Popliteal artery

30
Q

What is the mangled extremity severity score?

A
  1. Energy of skeletal/soft tissue injury
  2. Age <30, >50
  3. Shock
  4. Ischemia
31
Q

How do you treat IV drug injuries to upper extremity arteries?

A

Supportive care - usually the digital arteries. IV heparin, IV dexamethasone, elevate arm

32
Q

What is the etiology of penetrating aortic ulcers?

A

Only 50% are atherosclerotic. 25% of Saccular aneurysms degenerate and are associated with PAU.

NOT RELATED TO: trauma, genetic mutations (e.g. Marfans), cystic medial necrosis or seronegative spondyloarthropathies, mycotic

33
Q

What are the differences between mycotic aneurysms and PAU?

A

1 - appearance: mycotic has fluid/stranding

2 - systemic signs of infection: fever, WBC

34
Q

What are 6 risk factors for penetrating aortic ulcers?

A

1 - male (2/3 male, 1/3 female)

2 - old in 70s/80s

3- universally hypertensive

4- smoking common

5-CAD

6-COPD

35
Q

How do patients with penetrating thoracic aortic ulcers present? What about abdominal aortic ulcers?

A

Thoracic is mostly symptomatic - upper back/mid scapular pain

Abdominal mostly asyptomatic and seen as incidental finding

36
Q

How can you clinically tell the difference between aortic dissections and penetrating aortic ulcers (3 types of signs)?

A

1 - Type 1 aortic dissections have aortic valve regurg, PAU does not

2 - AD can have unequal pressure/pulses in upper and extremity, PAU does not.

3 - AD can present with symptoms of malperfusion, PAU does not

37
Q

What other aortic conditions are penetrating aortic ulcers associated with? Which lung condition?

A
  • AAA, intramural hematoma, aortic dissection
  • pleural effusions
38
Q

Does intramural hematoma put penetratic aortic ulcer at more risk?

A

No difference in overall survival, but TEVAR has higher failure rates if the PAU also has IMH.

39
Q

What imaging modalities do you use for penetrating aortic ulcers?

A

CTA gold standard. TEE may also be used and has advantage of simultaneously identifying wall motion abnormalities.

40
Q

How should you manage asymptomatic patients with an incidentally found penetrating aortic ulcer?

A

Annual imaging surveillance (1/3 progress to an aneurysm)

BP control with beta blockate or vasodilators.

In a study of thoracic PAU - 80% of patients had a resolution of their ulcer within 6 months (?!?)

41
Q

Name 6 indications for intervention for a penetrating aortic ulcer

A

1- symptomatic/rupture

2- recurrent/refractory pain

3-signs of impending rupture (contained rupture, rapid growth, hematoma, hemothorax, pleural effusions)

4-expanding IMH

5-evolving aortic dissecion

6- distal embolization

42
Q

What are 6 limitations of endovascular repair for penetrating aortic ulcers?

A

1 - adjacent aneurysm

2- proximity to branch and mesenteric vessels

3-steep angulation

4-insufficient landing zones

5- more proximal aortic pathology

6-heavy burden of atherosclerotic disease

43
Q

How long should the landing zones be for a endovascular repair of a penetrating aortic ulcer?

A

20 mm proximal and distal

44
Q

How much do you oversize a endograft for penetrating aortic ulcer?

A

10-20% very little

45
Q

What is the overall mortality of TEVAR for PAU?

A

4%