Chapter 108

Question 1

What is the management approach for a claudicant?

Answer 1

1- Recognize the presence of lower extremity ischemia. 2- Quantify the extent of the local and systemic disease.

3- Determine the degree of functional impairment related to PAD.

4- Identify and control modifiable risk factors.

5- Establish a comperhensive treatment plan.

Question 2

What is the pathophysiology of the ischemic pain?

Answer 2

1- Ischemic neuropathy involving small unmyelinated A delta and C sensory fibers.

2-Local intramuscular acidosis from anaerobic metabolism enhanced by the release of substance P.

Question 3

What is the definition of Intermittent Claudication?

Answer 3

• It is an ischemia related symptom that varies from fatigue to pain most commonly affecting the calf muscles but it might affect the thigh or the buttock.
• Intermittent in nature.
• Reproducible with the same walking distance.
• Relieved by rest.

Question 4

What are the major patterns of arterial obstruction/ stenosis?

Answer 4

1- Inflow disease.

2- Outflow disease.

3- combination of both.

Question 5

What is the definition of Inflow disease?

Answer 5

It refers to lesions in the suprainguinal vessels:

1- Infrarenal aorta.

2- Iliac arteries.

Question 6

What is the classic presentation of patients with inflow disease?

Answer 6

• Commonly leads to buttock and thigh claudication.
• In men, if the stenosis or occlusions are bilateral and are proximal to the origins of the internal iliac arteries, vasculogenic erectile dysfunction may be present as well.
• Although buttock and thigh claudication may be the first symptoms, with continued ambulation, these patients may exhibit classic symptoms of intermittent calf claudication.

Question 7

Which group of patients tend to have an inflow disease?

Answer 7

1- Male patients.

2- Smokers.

Question 8

What is the definition of Outflow disease?

Answer 8

It refers to lesions in the infrainguinal vessels, from the common femoral artery to the pedal vessels.

Question 9

What is the classic presentation of patients with outflow disease?

Answer 9

• Superficial femoral artery stenosis or occlusion is
  associated with intermittent calf claudication with no specific thigh or foot symptoms.
• Popliteal and tibial artery occlusions are more commonly associated with limb-threatening ischemia.

Question 10

What is the most common lesion associated with intermittent claudication of the calf muscles?

Answer 10

Superficial femoral artery stenosis or occlusion.

Question 11

Why isolated superficial femoral artery occlusion without distal disease is rarely the cause of critical leg ischemia?

Answer 11

Because the deep femoral artery provides
collateral circulation and reconstitution of the popliteal
artery.

Question 12

Why Popliteal and tibial artery occlusions are more commonly associated with limb-threatening ischemia?

Answer 12

owing to the paucity of collateral vascular pathways beyond these lesions.

Question 13

Which group of patients tend to have an outflow disease?

Answer 13

1- Elderly.

2- Diabetics.

3- End stage renal disease.

4- Long-term corticosteroid therapy.

Question 14

What is the classic presentation of patients with a combination of inflow and outflow disease?

Answer 14

• They may have widespread symptoms of IC affecting the buttock, hip, thigh, and calf.
• These symptoms frequently begin in the buttock and thigh and then involve the calf muscles with continued ambulation; however, they may appear in reverse order if the distal disease is more severe than the inflow disease.
• Severe combined inflow-outflow disease may result in limb-threatening ischemia.

Question 15

What are the Nonatherosclerotic Causes of Claudication?

Answer 15

Question 16

Waht is the pathopysiological mechanism of the pain caused by chronic compartment syndrome?

Answer 16

• Chronic compartment syndrome causes exercise-related discomfort only in the anterolateral aspect of the calf.
• The cellular basis for the anterior compartment muscular pain associated with chronic compartment syndrome is ischemia resulting from diminution of the muscular arteriovenous pressure difference owing to venous congestion and compartment tissue hypertension.

Question 17

What is the definition of Critical limb ischemia (CLI)?

Answer 17

It is the most severe form of PAD and represents approximately 1% of the total number of patients with PAD.

Question 18

How does the natural history of CLI differs significantly
from that of claudication?

Answer 18

CLI is associated with a higher risk of limb loss in the absence of revascularization, whereas claudication rarely progresses to the point of requiring
amputation.

Question 19

What are the manifestattions of CLI?

Answer 19

1. Rest pain.
2. Ischemic ulceration of the forefoot or toes.
3. Ischemic Gangrene of the forefoot or toes.

Question 20

What does CLI represent?

Answer 20

It represents a reduction in distal tissue perfusion below the resting metabolic requirements.

Question 21

What is Rest pain?

Answer 21

• It is a burning sensation or an uncomfortable coldness or paresthesia of sufficient intensity to interfere with sleep.
• The ischemic neuropathy in CLI may also cause numbness, which is diffucult to distinguish in patients with diabetic neuropathy.

Question 22

Why does rest pain worsen by leg elevation?

Answer 22

Because of the loss of the gravitational pull of blood to
the foot; and that is why it is relieved by placing the limb in a dependent position, such as dangling it off the side of the bed.

Question 23

What are the hemodynamic measurements in a patient with CLI?

Answer 23

• Systolic ankle pressure < 50 mm Hg.
• Toe pressure < 30 mm Hg.
• ABI < 0.40.

Question 24

What are the characteristics of arterial ulceration in non diabetic patients?

Answer 24

It is characterized by a shallow, nonhealing, pallid erosion of the skin in the forefoot and/or toes.

Question 25

What are the characteristics of the pain associated with arterial ulcerations?

Answer 25

* It is described as aching or burning. * It is often unremitting and severe and is occasionally refractory to even high-dose oral narcotic analgesics.

Question 26

What is the pathophysiological mechanism of pain in arterial ulcers?

Answer 26

1. Severe ischemic neuropathy. 2. The actual exposure of the sensory nerves in the skin at the site of the ulcer.

Question 27

What are the categories of diabetic foot ulcerations?

Answer 27

1. Ischemic. 2. Neuroischemic. 3. Neuropathic I

Question 28

What percentage of patients with CLI progress to Gengrene?

Answer 28

Progression to gangrene occurs in 40% of patients with DM, compared with only 9% in nondiabetic patients with CLI.

Question 29

What is the sigificance of ABI?

Answer 29

1. Diagnostic * ABI \> 1.4 _Non compressible_. * 1.4 \>= ABI \>= 1 _Normal._ * 0.99 \> ABI \> 0.9 _Borderline_. * 0.9 \>= ABI \>= 0.4 _mild-moderate PAD._ 1. ABI \< 0.4 _Severe PAD._ 2. Follow- up 3. Prognostic * lower resting ABI values,lower postexercise ABI values, and a greater drop in resting ABI were associated with a higher incidence of death. * Low ABI is a strong marker for the presence of coronary artery disease (CAD) and cerebrovascular disease (CVD). * Abnormal ABI is a significant risk factor for future disability.

Question 30

Why did the ACCF/AHA 2011 writing group recommended ABI diagnostic screening and to whom?

Answer 30

In a cohort of 6880, unselected subjects ≥65 years old who were monitored for over 5 years in the **German Epidemiological Trial on Ankle Brachial Index Study Group.** 836 had **asymptomatic PAD** (ABI \<0.9) and 593 had **symptomatic PAD**. The composite endpoint of **all cause death, myocardial infarction or stroke** was similar in symptomatic and asymptomatic patients with PAD, both of which carried significantly higher risk than subjects without PAD. Because 21% of subjects had symptomatic or asymptomatic PAD, the **ACCF/AHA 2011 writing group** recommended ABI diagnostic screening for patients ≥65 years or for patients ≥50 with a history of smoking or diabetes.

Question 31

What is the prevalence of PAD?

Answer 31

The overall prevalence of PAD (defined as an ABI \<0.90) was **4.3%** (95% confidence interval [CI], 3.1% to 5.5%).

Question 32

What are the relationships of PAD to age, gender, race, and ethnicity?

Answer 32

* Prevalence was slightly higher in men than in women. * The prevalence dramatically increased with age, rising from 0.9% in those younger than 50 years to 14.5% in those 70 years or older. * Non-Hispanic black men and women (19.2% prevalence) and Mexican American women (19.3% prevalence) had a higher prevalence of PAD than did non-Hispanic white men and women (15.6% prevalence).

Question 33

What are the relationships between PAD and CAD in terms of morbidity, mortality and treatment cost?

Answer 33

PAD is associated with equal morbidity and mortality and comparable, or possibly higher, cost compared with coronary heart disease and stroke.

Question 34

What is the natural history of patients with asymptomatic PAD?

Answer 34

Patients with asymptomatic PAD may eventually develop symptoms of claudication or may demonstrate little progression of their disease.

Question 35

What is the natural history of patients with IC?

Answer 35

* The natural history of IC is marked by slow progression to shorter walking distances, but it rarely reaches the level of CLI. * Only about one fourth of patients with IC ever deteriorate significantly, and deterioration is most frequent during the first year after diagnosis (6% to 9%) compared with 2% to 3% per annum thereafter. * This is especially true if risk factors are controlled. * The risk of major amputation is less than 5% over a 5-year period. * the natural histories of asymptomatic PAD and IC are similar and marked by a significantly elevated risk of fatal cardiac and cerebrovascular events, despite the rather small risk of progression to CLI.

Question 36

What are the predictors of progression of IC to CLI?

Answer 36

1. Insulin-requiring DM. 2. Initial low ABI. 3. High pack-years of smoking.

Question 37

What is the impact of IC on patient’s quality of life?

Answer 37

* Reductions in physical function. * Role limitations due to physical dysfunction. * Role limitations due to emotional dysfunction. * Changes in bodily pain, energy, and general health perception. * No effect on social function and mental health.

Question 38

What is the natural history of patients with CLI?

Answer 38

The natural history of CLI is grim; approximately 40% of affected individuals lose their legs and 20% die within 6 months of onset without revascularization.

Question 39

What are the risk factors for Atherosclerosis?

Answer 39