Chapter 20, part 2 Flashcards Preview

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Flashcards in Chapter 20, part 2 Deck (73):
1

Etiology of acute lower extremity ischemia

either embolism of a clot or plaque from a proximal source or local development of thrombus

2

What are the six Ps of acute lower extremity ischemia?

Pain
Pallor
Paresthesias
Pulselessness
Poikilothermia
Paralysis

3

What is the most common presenting symptom of acute lower extremity ischemia?

Pain

4

Paralysis in acute LE ischemia?

A late finding and is indicative of advanced ischemia

5

Systemic effects of tissue necrosis

Acidosis
Hyperkalemia
Myoglobinuria
Renal failure
Sepsis
Death

6

What should occur once the clinical dx has been made?

It is more advantageous to proceed directly to arteriography and definitive management to maximize the likelihood of limb salvage

7

Management of acute lower extremity ischemia

Systemic anticoagulation with heparin should be instituted immediately
First step in dx and intervention is arteriography

8

Complications of acute lower extremity ischemia

Compartment syndrome- 2%
Minor catheter-related bleeding
Bleeding requiring transfusion
Hemorrhagic stroke

9

Characteristics of compartment syndrome

Pain with passive stretch of the muscles and increased compartment pressures (>20 to 30 mm Hg)

10

Dx of compartment syndrome

Made by hx, PE, and a high index of suspicion

11

Tx of compartment syndrome

Four-compartment fasciotomy of the leg

12

Most common sx of chronic lower extremity ischemia

Intermittent claudication
Rest pain
Ischemic ulcers
Frank gangrene

13

What will most pts report in chronic lower extremity ischemia?

Heart dz
DM
Kidney dz
HTN

14

PE of chronic lower extremity ischemia

Diminished peripheral pulses
Hair loss
Skin atrophy
Nail hypertrophy
Elevation pallor
Dependent rubor

15

What is typically the initial symptom of chronic lower extremity ischemia?

Intermittent claudication

16

Claudication

Extremity discomfort, pain or weakness consistently produced by exercise and promptly relieved by rest.
Sx generally occur one level below the area of disease

17

What are the most common conflicting diagnoses of claudication?

Neurogenic leg pain caused by spinal stenosis, nerve compression, and diabetic neuropathy.

18

Critical limb ischemia

The presence of ischemic rest pain, the presence of tissue loss, or gangrene secondary to arterial insufficiency

19

Ischemic ulcers

Usually result from minor traumatic injuries, which fail to heal because of lack of adequate blood supply
They are most common in areas of focal pressure on the foot are usually dry and punctate

20

Ulcers of venous insufficiency

Mostly located superior to the medial malleolus and are often moist, superficial, and diffuse
Also associated with hemosiderin skin pigmentation and venous varicosities

21

Gangrene

Characterized by cyanotic, anesthetic tissue associated with necrosis d/t inability of the arterial blood supply to meet minimal metabolic requirements

22

Classification of gangrene

Can be classified as dry or wet
Dry is more common in pts with atherosclerotic dz and frequently results from embolization to the toes or forefoot
Elective amputation is required
Wet gangrene is more common in diabetic pts who sustain unrecognized trauma to the foot
Mandates either complete debridement of infected, nonviable tissue or guillotine amputation

23

Diagnostic tests for chronic lower extremity ischemia

Measurement of segmental systolic blood pressures
ABI
Pulse volume recordings (PVRs)

24

What ABI is considered nl?

>1.0

25

Difference in management between PAD and chronic limb ischemia

PAD warrant medical therapy
-Initial management is antiplatelet therapy and risk factor modification
-Exercise therapy
Revascularization is indicated for all functional pts

26

Tx of aortoiliac occlusive dz

Endovascular therapy for single stenoses of the common iliac artery or external iliac artery shorter than 3 cm
Surgical revascularization for more complex lesions

27

In pts with hostile abdomen or high surgical risk who cannot be revascularized with an endovascular approach for aortoiliac occlusive dz, what is the tx?

Axillobifemoral bypass grafting

28

For pts with unilateral iliac dz not amenable to endovascular therapy, what is the tx?

Unilateral aortofemoral grafting

29

How is endovascular therapy for infrainguinal dz different from aortoiliac dz?

The patency rates are lower
No more than two focal stenoses less than 3 cm in length should be treated
The role of primary stenting is unclear
Bypass grafting is indicated when endovascular therapy is inappropriate or inadequate

30

What is the option of choice for tibial-peroneal dz?

Femoral-distal bypass

31

What are the three common time points that bypass grafts fail?

Early: <30 days
Intermediate (30 days to 2 yrs)
Late (>2 yrs)

32

Causes of early bypass graft failure

Assumed to be related to a technical or judgement error, though infection and hypercoagulability are also possible

33

Causes of intermediate bypass graft failure

Most often caused by neointimal hyperplasia within a vein graft or at anastomotic sites

34

Causes of late bypass graft failure

Natural progression of atherosclerotic dz

35

Exam of bypass graft

Perioperatively
6 wks
3-mo intervals
for 2 yrs and every 6 mos after

36

Complications of interventions for chronic lower extremity ischemia

Two categories: those related to concomitant systemic illnesses and those related to surgery
First category examples: MI and renal failure
Surgical complications: pseudoaneurysm resulting from arterial puncture, compartment syndrome, and graft infection

37

RFs for AAA

Advanced age
Atherosclerosis
HTN
Smoking hx
Men
First-degree FHx

38

Sx of AAA

Usually asymptomatic
Presence of sx such as abdominal or back pain signifies impending or active rupture

39

Presentation of rupture of AAA

Severe abdominal or back pain with associated hypotension, tachycardia, and shock

40

PE of AAA

May reveal a pulsatile abdominal mass, but only 30-40% of aneurysms are noted on PE

41

Dx of AAA

Often dxed accidentally by u/s or abd CT
CT is preferred

42

How to decide whether to operate in pts with asymptomatic AAA

Decision is largely driven by diameter criterion
Aneurysms greater than or equal to 5.5 cm should be electively repaired

43

What are the most common early complications of open AAA repair?

Paralytic ileus
Coronary ischemia
Cardiac arrhythmias
Renal dysfunction
PNA

44

What are the less common early complications of open AAA repair?

Ischemic colitis
Impotence
Paralysis
Graft infection
Pseudoaneurysm

45

Late complications of AAA open repair

Incisional hernia
Pseudoaneurysm development
Atherosclerotic graft occlusion
Graft thrombosis
Aortoenteric fistula

46

Device-related complications of endovascular aneurysm repair

Kinking
Occlusion
Thrombosis
Endoleak

47

Non-device related complications of endovascular aneurysm repair

Dissection or thrombosis of the access vessels
Contrast-induced nephropathy
Wound complications

48

Origin of aneurysmal disease that occurs in the renal, hepatic, and splenic arteries

Usually not of atherosclerotic etiology and tend to occur in younger pts

49

Tx of visceral aneurysms

Renal and hepatic aneurysms should be repaired when discovered
Closely monitor splenic aneurysms
-Those in pregnant women or women who may become pregnant and those larger than 2 cm in diameter should be repaired
Renal, hepatic and splenic aneurysms are treated with exclusion and bypass grafting

50

Tx of iliac artery aneurysms

Should be repaired if they are symptomatic, larger than 3 cm, or mycotic either endovascularly with a covered stenth or through open surgical bypass graft with exclusion of the aneurysm

51

Tx of femoral artery aneurysms

Should be repaired if they are symptomatic, larger than 2.5 cm, or mycotic
Exclusion of the aneurysm and bypass graft

52

Tx of popliteal artery aneurysms

Repaired if they are symptomatic, larger than 2 cm, or mycotic
Exclusion and bypass with saphenous vein graft, although recently stent grafting has gained support, especially in high-risk pts

53

Where are most upper extremity vascular dz lesions?

Proximal

54

What is the most commonly affected vessel of upper extremity vascular dz?

The subclavian artery

55

Subclavian steal syndrome

Occurs in the presence of a proximal stenosis or occlusion of the subclavian artery
The delivery of arterial blood to the ipsilateral extremity thus depends on reversed flow through the ipsilateral vertebral artery via the circle of Willis

56

Thoracic outlet syndrome

A constellation of vascular and/or neurologic sx, often without any physical findings and most commonly without an anatomic correlate
Caused by compression of the subclavian artery, vein, or branches of the brachial plexus

57

Pt complaints in thoracic outlet syndrome

Weakness
Numbness
Paresthesias
Pain
Swelling of the extremity

58

Where do the brachial plexus and subclavian artery pass through?

Through the narrow triangle formed by the anterior scalene muscle, the middle scalene muscle and the first rib (the scalene triangle)

59

What can cause compression of the brachial plexus, subclavian artery, and/or subclavian vein?

Presence of an anomalous cervical rib or hypertrophy of the anterior scalene muscle

60

Complaints of neurologic thoracic outlet syndrome

Weakness
Paresthesias and numbness typically occur in the hand and medial forearm
Pain in the subscapular, scapular and cervical regions

61

Physical findings of neurologic thoracic outlet syndrome

Weakness and atrophy of the triceps muscle, the intrinsic muscles of the hand, and the wrist flexors

62

Dx of neurologic thoracic outlet syndrome

Often based on hx, PE, and exclusion of other conditions

63

What is the mainstay of tx of neurologic thoracic outlet syndrome?

Conservative, with exercise and physical therapy providing symptomatic relief
Surgical tx of neurologic TOS should be reserved for refractory cases because major neurovascular complications are not uncommon

64

What does subclavian artery compression usually result from?

Hypertrophy of the anterior scalene muscle in athletes but may also be caused by the presence of a cervical rib.

65

Surgery for subclavian artery compression

Involves release of the scalene muscles and resection of bony abnormalities

66

Presentation of compression of subclavian vein in TOS

Presents as effort-induced thrombosis (Paget-von Schrotter disease)
Common in young men with a hx of strenuous upper extremity activity, with painful swelling of the affected arm

67

Dx of compression of subclavian vein

Venous duplex studies and venography

68

Tx of compression of subclavian vein

Recanalizing the subclavian vein with thombolytics and anticoagulation

69

What does acute embolic occlusion usually affect

The SMA and the embolus is typically from a cardiac source

70

What is the most common site for an embolus to lodge

At the origin of the middle colic artery, distal to the first jejunal branches

71

Classic finding of mesenteric ischemia

Pain out of proportion to physical examination

72

Common sx of mesenteric ischemia

Sudden onset of periumbilical pain
Diarrhea
vomiting
GI bleeding

73

Diagnostic test for mesenteric ischemia

If dx suspected before onset of peritoneal signs, mesenteric angiography is the procedure of choice
If embolism present, laparotomy should be performed immediately, with embolectomy of the SMA and resection of nonviable bowel