Chapter 100 Acute limb ischemia evaluation and decision making

Question 1

Causes of acute limb ischemia

Answer 1

1) Trauma 2) Iatrogenic 3) Arterial embolism 4) Thrombosis

Question 2

Origin of the word embolism

Answer 2

Greek: “plug”

Question 3

Define saddle emboli

Answer 3

At aortic bifurcation

Question 4

Most common location of emboli in lower extremity

Answer 4

1) CFA 2) Popliteal

Question 5

Most common location of emboli in upper extremity

Answer 5

1) brachial bifurcation 2) brachial artery at take off of profunda brachialis

Question 6

Characteristic of secondary thrombus

Answer 6

Plum colored and obstructs distal small vessels

Question 7

Causes of emboli

Answer 7

1) Cardiac (atrial or ventricular) 2) Paradoxical from DVT via foramen ovale 3) Bacterial endocarditis 4) Cardiac tumor (atrial myxoma)

Question 8

Classic patient with paradoxical emboli

Answer 8

young patient with DVT and concurrent acute ischemia

Question 9

Cases of cardiac thrombus

Answer 9

1) Afib 2) Mural thrombus secondary to MI 3) Valve disease

Question 10

Non-cardiac embolism

Answer 10

1) Atheroembolism from vessel itself 2) aortic mural thrombus

Question 11

Atheroembolism types

Answer 11

1) Platelet rich thrombus 2) Atheromatous plaque (hard to remove)

Question 12

Causes of atheroembolism

Answer 12

1) Spontaneous 2) iatrogenic

Question 13

Aortic mural thrombus characteristics

Answer 13

1) Absence of aortic pathology 2) hypercoagulable state 3) normal cardiac exam

Question 14

Causes of acute thrombosis

Answer 14

1) Atheroclerotic obstruction 2) Hypercoagulable state 3) Vasospasm 4) Aortic dissection 5) Bypass graft occlusion

Question 15

Treatment of acute vasospasm (secondary raynauds)

Answer 15

1) Anticoagulation to prevent secondary thrombosis 2) tpa 3) vasodilator 4) prostanoid

Question 16

Clinical presentation stages of acute limb ischemia

Answer 16

1) Sensory nerve loss 2) muscle nerve loss (weakness) 3) skin ischemia (vasodilation blanchable to capillary disruption non-blanchable) 4) Muscle death = tender and rigor

Question 17

Changing demographic pattern of acute limb

Answer 17

used to be more valve now afib older patients with more chronic disease

Question 18

Time to irreversible necrosis

Answer 18

6-8 hours

Question 19

6 P’s of acute limb ischemia

Answer 19

Pallor Pain Pulselessness Paralysis Parasthesia Polar

Question 20

Transatlantic Inter-society Consensus 2007 definition of ALI

Answer 20

Sudden decrease in limb perfusion causing threat to viability

Question 21

Classification of acute limb ischemia

Answer 21

Question 22

Management consideration for aortoiliac occlusion (acute)

Answer 22

Needs urgent surgery

High risk to renal injury either

1) primary insult
2) due to reperfusion

Question 23

Water-hammer pulse

Answer 23

Most common at CFA due to distal CFA embolism/thrombosis

Question 24

Imaging modalities in acute limb ischemia

Answer 24

U/S

CTA

Angio

Question 25

Considerations around Echo in acute limb ischemia

Answer 25

Debated usefulness given no change in management

Use it in young patient where cardiac diagnosis suspected and may change management regarding life long anticoagulation

Question 26

Initial treatment in acute limb ischemia

Answer 26

1) anticoagulation to treat secondary thrombosis
2) O2 to give increase skin perfusion
3) IVF to hydrate and to prevent contrast-induced nephropathy
4) Analgesia: avoid intramuscular injection due to TPA bleed

Question 27

Usefulness of anticoagulation alone in treating acute limb ischemia

Answer 27

Ok in Class I and Class III

Stabilizes clot and prevents further secondary thrombosis

Question 28

History of balloon embolectomy

Answer 28

1963 Fogarty

Question 29

Management options of Class IIb

Answer 29

1) Surgery
2) percutaneous endovascular thrombetomy
3) accelerated tpa

Question 30

Management of Class IIa

Answer 30

1) Surgery
2) tpa +/- mechanical thrombectomy

Question 31

Prognosis following acute limb ischemia

Answer 31

Poor especially in setting of cancer; life expectancy 6 months

Question 32

Indication to perform surgery urgently in acute limb ischemia without needing additional information

Answer 32

1) Class IIb
2) obvious embolic source
3) pulse in contralateral leg

Question 33

Causes of upper extremity limb ischemia

Answer 33

1) Cardiac embolism
2) TOS
3) proximal subclavian aneurysm

Question 34

Indication to treat upper extremity acute limb ischemia

Answer 34

1) prevent future fatigue with use
2) prevent pain (50% of patients)
3) prevent contracture/amputation in future

Question 35

Mortality with acute upper extremity ischemia

Answer 35

20% mortality from index event

5 year survival 60%

Question 36

Age of upper extremity ischemia pateints compared to lower

Answer 36

4 years older for upper extremity