chapter 13: duplex ultrasound of upper extremity arteries

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upper extremity arterial disease occurs much — frequently than lower extremity

causes of upper extremity arterial disease

• mechanical obstruction (thoracic outlet syndrome, TOS.)

• embolism

• trauma

• digital artery vasospasm (raynaud’s disease)

• digital artery occlusion

brachial artery aka innominate artery

first major branch of the aortic arch

subclavian

the innominate artery divides into right common carotid & — arteries

• rarely, right subclavian will originate directly from aorta

  • may arise distal to left subclavian and cause difficulty swallowing or laryngeal nerve palsy

left subclavian

arises directly from aortic arch as 3rd major branch

vertebral arteries

first major branch from both subclavian arteries

other subclavian artery branches

• thyrocervical trunk

• costocervical trunk

thoracic outlet

subclavian arteries exist chest through —

areas of potential compression of the subclavian arteries

• over first rib between anterior and middle scalene muscles (scalene triangle)

• costoclavicular space bound by clavicle and first rib

• pectoralis minor space (infrequently involved)

compression of the subclavian arteries may cause

stenosis, aneurysmal dilation, laminar thrombosis, and dynamic compression with arm abduction

axillary artery

• originates at the lateral margin of the first rib between anterior

• lies deep to pectoralis major and minor muscles

brachial artery

• axillary transitions to — at the level of the inferno lateral border of the teres major muscle

• courses more superficial in medial arm

recurrent arteries that branch from the brachial artery

deep brachial, radial, and ulnar

• they are important collaterals

anatomic variants of brachial artery

• high takeoff of radial artery

• accessory or duplicated —

• origin of ulnar artery in upper arm (less common)

elbow

at — level, brachial artery divides into radial, ulnar, and interosseous arteries

radial artery

continues to wrist deep to flexor muscles

• courses along radius

superficial and deep palmer arches

the radial artery branches into the —

ulnar artery

• gives rise to interosseous artery

• passes deep to forearm flexor muscles

• courses toward wrist following ulna

metacarpal and digital

branches from palmar arches (superficial more than deep) give rise to — arteries

superficial palmar arch

the ulnar artery terminates as the —

45-60

using optimal — angle in longitudinal plane when recording PSV

anteroposterior (AP)

document diameter (— and lateral) when aneurysm is present

windows for the subclavian artery

• sternal notch

  • may require lower frequency transducer with smaller footprint

• supraclavicular

• infraclavicular

• followed as it courses under clavicle and over first rib

pectoralis major

axillary artery identified from anterior approach deep to — and minor muscles

teres major muscle

brachial artery begins as artery crosses —

• courses more superficial in medial arm between biceps and triceps muscles

physiologic testing

is often included to help identify arterial insufficiency in the limb

qualities

multilevel pressures and/or waveforms provide — assessment of global perfusion

impediments to complete physiologic testing exam

• wounds/dressings

• intravenous catheters

• orthopedic fixation devices

normal upper extremity waveform

• normal

• sharp systolic peak

• brief period of diastolic flow

• minimal continues forward flow in diastole

normal PSV in subclavian

varies from 80 to 120 cm/s

normal PSV in brachial, radial, and ulnar arteries

40-60 cm/s

abnormal waveform findings

• elevated pSV

• poststenotic turbulence

• dampened distal waveforms with loss of end systolic flow reversal

• waveform changes and brachial blood pressures can help determine stenosis significance

>50% stenosis

general guidelines suggest velocity ratio >2 is consistent with —

aneurysm

permanent localized dilation resulting in 50% increase in diameter of an artery compared to adjacent normal artery

TOS

aneurysms often occur in subclavian artery in association with —

other causes of aneurysms

atherosclerosis and trauma

• associated more with axillary, brachial, radial, and ulnar arteries

  • not common

  • may present as a pulsatile mass

hypothenar hammer syndrome

arterial degreneration of ulnar artery as it passes deep to hook of hamate bone

• associated with repeated use of palm of hand as a hammer

raynaud’s syndrome

intermittent digital ischemia from cold exposure or emotional stimuli

primary raynaud’s syndrome

• abnormal digital artery vasospasm

• results in pain and color changes (white, blue, red)

  • color order matters (worst-better)

• anatomically, digital arteries appear normal

• rarely results in tissue damage

secondary raynaud’s syndrome

underlying disease process responsible for symptoms

• patients tend to develop occlusive lesions

• associated with tissues necrosis

possible causes of secondary raynaud’s syndrome

• autoimmune disorder (scleroderma)

• mixed connective tissue disease

• systemic lupus erythematosus

• rheumatoid arthritis

• drug induced vasospasm

• cancer

proximal source

duplex ultrasound can be used to help determine if digital occlusive disease is caused secondarily from —

• aneurysms

• stenosis lesions

• fibromuscular disease of forearm arteries

thoracic outlet syndrome

impingement of the neuromuscular bundle at the thoracic outlet

compressions

TOS — may be secondary to cervical ribs, abnormal fibrous bands, or hypertrophy of the scalene muscles

neurogenic

duplex ultrasound may be used to confirm — TOS; however, evidence is not supportive of this conclusion

20%

— of normal individuals can demonstrate subclavian artery compression with provocative maneuvers

younger patients

major arterial thoracic outlet syndrome occurs primarily in —

the subclavian artery

TOS results in compression and damage to —

high

ultrasound has — sensitivity and specificity for locating arterial trauma

proximal

significant atherosclerotic disease in the upper extremity usually involves the — subclavian artery

arterial occlusive disease

• occurs most often in left subclavian

• often an extension of atherosclerotic involvement of the aortic arch

• rarely produces symptoms in upper extremity but may result in subclavian steal syndrome

  • reversal of flow in ipsilateral vertebral artery

takayasu’s arteritis

autoimmune disorder that affects the arteries of the aortic arch and visceral abdominal aorta

• most common in women in their 20s and 30s

• results in long segment occlusion or stenosis of affected arteries

• acutely, associated with fever, malaise, arthralgias, and myalgias