Duplex Scanning

What should you evaluate for noninvasive arterial testing?

• arterial disease

• pulsatile masses

• suspected arterial trauma

• angioplasty/stent placement

What should you do before the operative reconstruction?

baseline study

With postoperative follow up include?

bypass graft surveillance  

Aid in diagnosis of exercise induced pain caused by

occlusive arterial disease

Supplement clinical judgment regarding healing of

foot ulcers and amputation sites

Lower Extremity:

aorta through entire limb

Upper Extremity:

innominate through entire limb

What are the limitations of the lower extremity arterial imaging examination?

-nonvisualization of iliac system because of bowel gas or obesity

-shadowing because of calcification

-imaging of popliteal trifurcation/anomalies

-difficulty evaluating lesions distal to tight stenoses because of low velocities in these segments

Scanning technique:

-document grayscale, color doppler, and spectral doppler

-assist with localization and tracking of vessels

-rapid assessment of flow dynamics

-placement of doppler sample volume

-power doppler useful in low flow states or vessel occlusion

What would a normal artery look like in 2D and color doppler?

anechoic, nice smooth walls, want the artery to cover whole screen, have the color doppler fill wall to wall red

What can be useful for determining intervention planning?

evaluation of arterial size, length, and degree of narrowing plus plaque characterisitics, is also useful

Normal color flow should?

completely fill the vessel lumen

Color should be

uniform and limited to lumen only

What are abnormal color findings?

-aliasing

-reduced flow channel

-color bruit (because of turbulence)

Spectral Doppler used as primary tool to categorize disease:

-record PSV in all major vessels

-when disease is present (stenosis), record velocities

-proximal to the stenosis

-in the stenosis (higher velocity)

-distal to the stenosis (turbulent flow then tardus parvus more distal)

Normal findings of spectral doppler is:

• PSV that does not increase

• Normal, high resistance spectral waveform

• triphasic

Velocity rations can be used to

help classify disease severity

3 major changes in the arterial waveform

-increase in PSVs >100%

-spectral broadening and turbulence

-loss of reversal of flow 

Abnormal findings include:

focal velocity increases

• PSV velocity ratio >2 = >50% stenosis

• PSV velocity ratio >3 = >70% stenosis

• PSV >300 cm/s suggest a severe stenosis

What can influence patient management?

hemodynamic information

What is the distal to a hemodynamically significant stenosis waveform? 

-more low resistance characteristic (flow throughout diastole)

-delayed rise to peak systole 

An abnormal waveform illustrating constant forward flow throughout the cardiac cycle in addition to a delayed upstroke. This is observed…….

distal to a high-grade stenosis or occlusion

What is the waveform proximal to an occlusion?

-very high resistance pattern

-anterograde flow component only during systole

-no flow during diastole

For contrast arteriography still consider the?

gold standard for diagnosis of arterial stenosis

-can be used when duplex imaging is limited

Aim to ______ patient symptoms and improve prognosis by preventing the risk of further cardiovascular events

decrease

Treatments can be categorized into 3 types:

-medical management/conservative

-endovascular

-surgical

Management:

-control risk factors

-exercise

-pharmaceutical agents

Endovascular:

-revascularize limbs

-endovascular procedures

• angioplasty

• endografts

• atherectomy

• thrombin injections

What is the most common surgical treatment for PAD?

bypass graft surgery

Surgical:

-thrombectomy

-endarterectomy (cut open vessel to clean out the plaque)

What is an atherectomy?

a procedure that utilizes a catheter with a sharp blade on the end to remove plaque from a blood vessel

What is a stent?

a tiny expandable mesh tube that can be inserted into a blocked passageway to keep it open