Vascular Exam 2: Arterial & Venous Physiologic, Non-Atherosclerotic Pathology

Atherosclerosis

Plaque buildup

Arteriosclerosis

Hardening of Arteries

Gangrene

Tissue death due to loss of blood supply

Intermittent Claudication

Occurs with exercise, stops with rest

Spinal Stenosis

Occurs with sitting/moving spine

Herniated Disk

Pain radiates down leg

Osteoarthritis

Can be associated with exercise

Elevation Pallor

Pale skin

Dependent Rubor

Red skin

Bruit

Low frequency

May not always be heard

Graded on strength and duration

Absence does not rule out disease - 90% disappear

Can strengthen with poor cardiac output

Bruit Grading

1+ = mild

2+ = moderate

3+ = severe -> extends through diastole

Uncontrollable Risk Factors of Arterial Disease

Age

Family history

Gender

Controllable Risk Factors of Arterial Disease

Smoking

Type 2 diabetes

Hypertension

Hyperlipidemia

Obesity

Stress

Symptoms of Acute Arterial Disease

Pain (sudden)

Pallor

Pulselessness

Paresthesias

Paralysis

Symptoms of Chronic Arterial Disease

Claudication

Shiny skin

Loss of hair on legs/toes

Cold to touch

Arterial ulcers

Common Sites of Lower Extremity Arterial Disease

Any bifurcation

Larger vessels

Aorta

Iliacs

Common femoral

Popliteal

Newer in literature:

Anterior tibial/dorsalis pedis

Posterior tibial

Peroneal

Direct Arterial Testing

Arterial duplex

Indirect Arterial Testing

ABI

Segmental pressures

PVR

PPG

CW Doppler

Indications for Lower Extremity Arterial Physiologic Testing

Claudication

Difficulty walking

Atherosclerosis in other locations

Cold limbs

Tingling/numbness

Ulcers

Contraindications for Lower Extremity Arterial Physiologic Testing

Recent graft placement

Suspected venous thrombosis

Arm with shunt or dialysis graft

Information Provided by Physiologic Studies

Presence of arterial disease

Level & severity of blockage

Collateralization

Healing potential

Revascularization improvement

Graft patency

Information Not Provided by Physiologic Studies

Exact location of disease

Patient Prep for Arterial Physiologic Exam

At rest for at least 10-15 min - get history, physical, and place cuffs

Warm room - reduces vasospasm

Restrict nicotine or caffeine - reduces vasoconstriction

Arterial Physiologic Exam Sequence

History

Physical exam

Palpate pulses

CW Doppler tracings

PVR/PPG

Segmental pressures

Stress test (if indicated)

Patient History

Smoking

Hypertension

Hyperlipidemia

TIA or CVA

MI or CAD

Vascular surgery

Diabetes (I or II)

Back pain

Claudication - how long can they walk/exercise

Rest pain

Trauma

Hx. of disease

Previous testing

Family history

Physical Examination

Arterial ulcers

Trophic changes - thickened nails, hair loss (toes, foot), shiny skin

Skin Changes - cool skin temp, color changes (cyanosis/pallor), dependency changes (rubor/pallor), Livedo reticularis (purple patches on foot)

Absent pulses

Dry skin

Bruits

Gangrene

Loss of sub-cutaneous fat

Gangrene

Capillary filling (> 3sec = decreased perfusion)

Where to Palpate Pulses in Lower Extremity

Common femoral

Popliteal

Dorsalis pedis

Post tibial

Pulse Grading System

0 = absent

1+ = weak

2+ = good

3+ = strong

4+ = bounding (aneurysmal)

CW Doppler Signals in Lower Extremity

CFA

SFA (lab dependent)

POP A

DPA

Posterior Tibial

CW Doppler Techniques

Gel

Probe at 45º angle to skin

Hold probe steady

Do not apply too much pressure

Make sure the pass-filter is appropriate

Normal CW Doppler Signal in Lower Extremity

Multiphasic - high resistance, two beats in the antegrade direction

Strong late systolic forward flow

Reversal of flow in early diastole (peripheral resistance)

Forward flow in late diastole (compliance)

Dicrotic Notch

Recoil/contraction of distended arterial walls

Size of notch determined by level of arterial compliance

Incisura

Downward pressure contour on waveform

Start of ventricular diastole

Results in velocity decrease in forward flow

Multiphasic With High Resistance

2 phases

2 forward antegrade beats

Normal

Monophasic with Low Resistance

Mild disease

Monophasic without Diastolic Flow

Moderate disease

Monophasic with Low Resistance - Tardus Parvus

Severe proximal disease

Occluded CW Doppler Signal

Pulse Volume Recordings (PVR)

Assesses overall limb perfusion based on pressure changes

Records change in volume of blood in a limb as blood moves through

Used to measure limb volume related to cardiac cycle-pulsing changes in limb volume - girth of limb increases and air in the cuff is displaced

Ways to Obtain a PVR

Air-filled cuffs - volume changes

Strain gauge - electrical resistance

Impedance - voltage difference

Photoelectric - infrared light

Techniques for PVR Cuff Inflation

Fill cuffs with 55-60 mmHg

Take bilateral brachial PVR first

Begin at ankles and move up

Normal PVR Waveform

Biphasic - always above baseline

Rapid upstroke in systole

Sharp & defined peak

Delayed downstroke

Flat dicrotic notch - on downstroke

PVR Waveform of Mild Disease

Monophasic flow (looks like tardus parvus)

Loss of dicrotic notch

Slightly delayed upstroke

Downstroke bows away from baseline

Sharp peak

May decrease in amplitude

PVR Waveform of Moderate Disease

Delayed upstroke

Rounded

Decreased amplitude

PVR Waveform of Severe Disease

Significant delay in upstroke

Absent or low-amplitude

Equal upslope and down slope time

PVR Waveform of Critical Disease

Almost becomes flat line

Seen in severe dz or acute arterial occlusion

Differentiate from increased venous flow

Where is disease on an abnormal PVR waveform?

Above the cuff

Uses of Photoplethysmography (PPG)

Digit waveforms

Penile waveforms

Burn sites

Skin lesions

Healing potentials

PPG Techniques

Attached with tape, clip, or pressure cuff

Use same amount of pressure from site to site

LED surface needs to be flat against skin surface

Reseat probe if abnormal signal is seen

PPG Placement

Lower extremity - great toe

Upper extremity - index finger

May need to obtain signals from all digits - Raynaud's or Buerger's disease

Cuff Bladder Width Sizing

Fit snugly and evenly over artery

20% wider than limb diameter

≥ 50% than limb circumference

Cuff Bladder Width too Wide

Underestimates pressures

Cuff Bladder Width too Narrow

Overestimates pressures

Max pressure for segmental pressure cuffs

220 mmHg

3-Cuff Placement

Thigh - 17 cm

Below knee - 12 cm

Ankle - 10 cm

4-Cuff Placement

High thigh - 12 cm

Above knee - 12 cm

Below knee - 10 cm

Ankle - 10 cm

Segmental Pressure Techniques

Start with brachial pressures, then start from ankle and move up the leg

ABI Formula

Highest ankle pressure ÷ highest brachial pressure

Incompressible ABI

> 1.3

Normal ABI

0.9 - 1.3

Mild Disease ABI

0.75 - 0.89

Moderate Disease ABI

0.5 - 0.74

Severe Disease ABI

< 0.5

Ischemia ABI

< 0.35

High Thigh vs. Brachial Pressures in 4-Cuff Method

High thigh should be 30 mHg higher than highest brachial

Thigh vs. Brachial Pressures in 3-Cuff Method

Thigh should be ≥ highest brachial

High Thigh Pressures ≤ Brachial Pressures

Indicates aorta-iliac disease

Pressure Difference Between Adjacent Cuff Sites

< 30 mmHg

Pressure Difference Between Cuff Sites at Same Level on Opposite Legs

< 20 mmHg

Pressure Difference Between Entire Legs

< 40 mmHg

10-15% Pressure Difference Between Brachial Pressures

Positive disease on lower side

When are Toe Pressures More Reliable than Leg Pressures?

Patients with diabetes

Calcified arteries

End stage renal disease

Long-term steroid use

Normal Toe Brachial Index (TBI)

> 0.8

Purpose of Stress Testing

When flow is augmented over the stenosis, distal pressure may drop and reveal the presence of disease

Indications for Stress Testing

Normal study with persistent symptoms

Intermittent claudication

Claudication vs. pseudoclaudication

Presence of collaterals

Contraindications for Stress Testing

Shortness of breath

Hypertension

Cardiac problems

CVA/embolic events

Walking problems

Rest Ischemia

Types of Stress for Stress Testing

Treadmill (slight incline @slow speeds) for 5 min or when symptoms appear

Toe ups (50)

Step ups

Stress Testing Protocol

Take baseline pressures of symptomatic & opposite leg, and one arm

Immediately after exercise

Every 2 minutes for 10-20 minutes or until pressures return to normal

Single Level Stenosis

Pressures return to baseline within 5 minutes

Multi-Level Stenosis

Pressures return to baseline within 10-12 minutes

Ischemic Disease

Pressures remain low for ≥ 15 minutes

Post-Exercise Pressures ≤ 60 mmHg

Confirms vascular etiology of disease

Lower Extremity Venous Anatomy

Upper Extremity Venous Anatomy

Anterior Accessory Vein

Runs parallel and anterior to femoral vein

GSV

Saphenous Eye

Between facial layers

GSV in Calf

Angle Sign

Triangular form between gastrocnemius muscle and tibial bone

Tributary

Outside fascial plane

Perforator

Pass through muscular fascia layers - connect deep system to superficial system

Venous Valves in Lower Extremity

Femoral 1-6 valves

Pop 0-4 valves

GSV 10-12 valves

SSV 7-9 valves

Calf veins 8-19 (every 2 cm)

Perforations 1 each

Veins with No Valves

Soleal

Internal iliac

Common iliac

IVC

Subclavian VV

Innominate

SVC

Distribution of Venous Valves in Deep System

2.1 %

Distribution of Venous Valves in Superficial System

16.8 %

Distribution of Venous Valves in Perforator System

8.4 %

Risk Factors for Leg Swelling

Heart dysfunction (CHF)

Kidney disease

Liver disease

Lymphatic system/Lymphedema

Pulmonary HTN

High BMI

Medications (calcium channel blockers)

Multifactorial

Age

Family History

Obesity

Oral Contraceptive use

Smoking/Tobacco

Pregnancy

History of DVT

Prolonged standing or sitting

Sedentary lifestyle

Gender (women)

Primary Valvular Insufficiency

Congenital absence of veins

Secondary Valvular Insufficiency

Damaged valves caused by thrombotic events

Chronic Venous Insufficiency

Obstruction & valve insufficiency

Chronic Venous Valvular Insufficiency

Impaired superficial or deep flow

Causes venous hypertension

Duplex is primary modality for diagnosing

Symptoms of DVT

Swelling

Shortness of breath - emboli

Redness

Warmth

Painful

Throbbing

Phlebitis/Thrombophlebitis