Ultrasound assessment of the upper extremity Harry Hulbert

Ultrasound assessment of the upper extremity Harry Hulbert Holdorf Ph. D, MPA, RDMS, RVT, LRT(AS)

Contents Vascular Technology Lecture 6 Ultrasound Assessment of the Upper Extremity �Anatomy of the upper extremity including palmar arches �Doppler Segmental Pressures of the upper extremity �The Allen Test �Duplex/Color Flow Imaging (UE) �Upper Extremity Arterial Doppler Protocol

Upper extremity arterial examination. Point of origin

Arteries of the Upper Extremity

Arteries of the Upper extremity

Arteries of the Upper Extremity

Upper Extremity Arteries � 1. Subclavian artery • Runs laterally to outer border of 1 st rib becoming the axillary artery • Some branches: vertebral, thyrocervical, costocervical. � 2. Axillary artery • After giving off several branches, becomes brachial artery � 3. Brachial artery • Branches into the radial and ulnar arteries a the inner aspect of the elbow (AKA the antecubital fossa)

� 4. Radial artery • Travels down lateral side of forearm into hand, branching to form: �Superficial palmer (volar) arch �Terminates in deep palmer arch by joining deep branch of ulnar artery � 5. Ulnar artery • Travels down medial side of forearm into hand, branching to form: �Deep palmar (volar) branch �Terminates in superficial palmar arch �Predominate source of blood flow to the hand

� 6. Superficial palmar (volar) arch includes: • Distal portion of the ulnar artery • Branch of the radial artery � 7. Deep palmar arch includes: • Deep palmar arch of the ulnar artery • Distal portion of the radial artery � 8. Digital arteries arise from the palmar arches and extend into the fingers dividing into lateral and medial branches.

Doppler Segmental Pressures of the upper extremity Patient positioning: • Supine with arms relaxed at the patient’s side • Cuffs should be on snug, but not too tight. Technique: • • 12 x 40 cm cuff placed snugly on the upper arm: 10 x 40 cuff on the forearm bilaterally Brachial artery used to obtain upper arm BP; Radial and ulnar arteries used to obtain the forearm pressure.

�Pressures are combined with Doppler velocity wave forms from the sites previously describe.

upper extremity segmental pressure � � � 1) Bilateral brachial arm pressures no more than 20 mm. Hg 2) Finger/Brachial Index a. Normal >0. 75 b. Abnormal <0. 75 3) Pressure measurements between adjacent cuff sites on the same arm should not differ by more than 10 mm. Hg (brachial and forearm) 4) Pressure measurements differences at the same cuff level on opposite arms should not exceed 20 mm. Hg 5) The pressures in the radial and ulnar arteries should be within 5 -10 mm. Hg of one another. A pressure difference >= 20 mm. HG indicates obstruction in the vessel with the lower pressure

What mm/Hg difference from arm to arm constitutes an abnormal upper extremity segmental pressure? �Pressure measurements differences at the same cuff level on opposite arms should not exceed 20 mm. Hg.

Doppler Segmental Pressures of the Upper Extremity � What is the Allen Test and how is it performed? The test is performed to estimate palmar arch patency. A technologist compresses the radial artery while patient closes ipsilateral fist to cause pallor, but in the meantime, this action will increase resistance. � What mm/Hg difference from arm to arm constitutes an abnormal upper extremity segmental pressure? The differences of pressure measurements at the cuff level on the other arms should not go over than 20 mm. Hg.

The Allen Test �Only done to evaluate patency of the palmer arch

The Allen test �The hand is normally supplied by blood from the ulnar and radial arteries. �The arteries undergo anastomosis in the hand. Thus, if the blood supply from one of the arteries is cut off, the other artery can supply adequate blood to the hand. �A small amount of people lack this dual blood supply.

� 1) The hand is elevated and the patient/person is asked to make a fist for about 30 seconds. � 2) Pressure is applied over the ulnar and the radial arteries so as to occlude both of them. � 3) Still elevated, the hand is then opened. It should appear blanched (pallor can be observed at the finger nails). � 4) Ulnar pressure is released and the color should return in 7 seconds. � Inference: Ulnar artery supply to the hand is sufficient and it is safe to cannulate/prick the radial � If color does not return or returns after 7– 10 seconds, the test is considered positive and the ulnar artery supply to the hand is not sufficient. The radial artery therefore cannot be safely pricked/cannulated.

Allen Test Interpretations �Normal • Reappearance of the normal color to indicate the ulnar artery is providing flow to the palmar arch �Abnormal • Color does not reappear to indicate an ulnar artery occlusion or palmar arch obstruction

Allen Test Limitations �Excessive dorsiflexion of wrist may compress radial and ulnar arteries leading to a false positive test. �If hand is opened, fingers forcibly extended; the skin over palm can be stretched, which could lead to pallor due to compression of small vessels

Allen Test documentation �Use a PPG (photoplethysomography) on the index finger to document arterial pulsations before and after the “clinched fist”. �Although more difficult to compress, the ulnar artery can be evaluated similarly to assess radial artery flow.

Duplex Color Flow Imaging (UE) �Capabilities • Localize stenosis/occlusion; evaluate degree of stenosis • Determine the presence/absence of aneurysm • Post-op study: hemodialysis access or arterial bypass graft • Direct Artero- Venous fistula (AVF) or other unusual abnormality

�Limitations • Limited access to extremity (e. g. , ) dressings, skin staples or sutures, open wounds IV site… • Pertaining to hemodialysis access grafts: �Graft angulation �Difficult to adequately evaluate the outflow vein in an obese patient �Patient positioning • Patient is supine with small pillow under head • Extremity close to examiner • Arm is at a 45 degree angle from the body, and extremity rotated “Pledge Position”

�Physical Principles • Duplex scanning: combination of real-time B-mode imaging (gray scale evaluation) and Doppler spectral analysis • Doppler Color Flow Imaging: Doppler information is displayed on image after evaluated for phase (direction toward or away from the transducer) and its frequency content (hue or shade of the color) • Sample size for acquiring pulsed Doppler information is usually 1 -1. 5 mm. Size is increased incrementally if needed.

�Technique: Native Arteries • Utilize a 7 or 5 MHz linear array transducer • Neck vessels identified with attention to innominate artery on the right. The LCCA braches off the Arch. • Color / duplex scanning is also used to evaluate the following: �Subclavian �Axillary �Brachial �Radial �Ulnar �Palmar arch (if needed)

Example of an UE Arterial Signal

�NOTE: It is uncommon for arteries in the upper extremities to become stenotic. Main indication for ultrasound assessment is for evaluation of dialysis access grafts.

Dialysis access is an entranceway into the bloodstream that lies completely beneath the skin and is easy to use. The access is usually in the arm, but sometimes in the leg, and allows blood to be removed and returned quickly, efficiently, and safely during dialysis or, less commonly, for other procedures requiring frequent access to the circulation.

Access Grafts Technique �Hemodialysis Access • Auscultate the access for bruit and or palpate for a “thrill” (vibration). A patent dialysis access, as well as a stenotic one can produce a “thrill. ” • Utilize a 7 or 5 MHz linear array transducer

Evaluate dialysis access grafts as follows: �Inflow artery �Arterial anastomosis �Continue through the body of the graft �Observe of aneurysm, puncture sites, perigraft fluid �If color available, observe the image for flow changes, turbulence, flow channel changes �Venous anastomosis �Outflow vein

�NOTE: Dialysis access (e. g. Brescia. Cimino fistula) assessment sites include: inflow artery, anastomosis, outflow vein

Brescia-Cimino Access

Upper Extremity Arterial Doppler Protocol �Includes an evaluation of bilateral extremity arterial waveforms of the common carotid, subclavian, brachial, ulnar, and radial arteries utilizing spectral Doppler. The goal is to document any hemodynamic changes related to vessel narrowing or stenosis

�Patient Prep: None �Patient is instructed to remove clothing from the waist up- gown open in the front Transducer: � • The highest frequency linear transducer possible - usually 5 to 15 MHz. � Continuous wave “Pencil-Probe is transducer of choice. Paperwork: Fill out Upper Extremity Arterial Doppler Worksheet completely (Department specific). Document reason for exam and all pertinent history. Record all measurements and fill in comments. Obtain reports of previous exams or other pertinent studies.

Protocol � Patient is instructed to relax spine on the bed. A blood pressure cuff is placed above the brachial artery on the upper arm. The cuff is inflated and a systolic pressure of the brachial artery is obtained. This number is documented. The brachial artery spectral waveform is evaluated for flow characteristics (Triphasic, biphasic, or monophasic). Pressure differences are compared segmentally and contra laterally.

�A blood pressure cuff is placed on the forearm and systolic pressures are obtained of the radial and ulnar arteries. Once again, flow characteristics are evaluated and ratios are calculated using the brachial pressure. �Examination is repeated on the contralateral arm.

Doppler Waveform Analysis �The following spectral Doppler images must be obtained during the procedure: • • • Right Carotid Right Subclavian Right Axillary Right Brachial Right Radial Right Ulnar • Waveform analysis is repeated on the left arm