Learning objectives
Key terminology
Preprocedure considerations

Signs and symptoms of upper limb venous thrombosis and indications for mapping procedures:

Upper limb venous scan

• Pain and swelling of arm or neck
• Pulmonary embolus
• Dilated superficial veins of arm or shoulder
• Palpable subcutaneous cord in arm
• Infusion difficulty with indwelling IV line

Mapping procedure

• Preoperative planning for:
  • Arteriovenous fistula formation
  • Sclerotherapy
  • Incompetent perforator or varicose vein surgery
  • Radial artery harvest
  • Suitability for venous bypass graft and marking

We acknowledge that there may be variations in the technique presented.

You should perform this procedure under the supervision of an appropriately skilled supervisor until you are confident and competent enough to do it on your own.

Before using any medication or equipment in this procedure, please read the approved product information for instructions, contraindications, adverse effects, and warnings. Familiarize yourself with the equipment. The equipment or medication available to you may differ from what is used in this demonstration. You must inquire with a supervisor or instructor if there are variations or questions related to the equipment, medication, or procedures.

Be sure that all required equipment is plugged in and turned on before beginning with the patient. Typically, ultrasound machines, gel warmers, and power beds are left plugged in at the end of the day. The gel warmer and power bed should be left on. This keeps the gel warm and the bed operational.

Plug in and turn on the computer system, workstation, and printer.

Ensure that there is enough linen on the bed for the procedure, and a good supply of towels and cloths.

Obtain a sonographer's worksheet on which to write the preliminary report.

Select the transducer appropriate to upper limb venous and mapping procedures.

Select the correct ultrasound preset for mapping procedures.

Enter the patient's details into the ultrasound machine.

Introduce yourself to the patient. Ensure the patient is appropriately dressed for the examination.

Confirm the patient's details, clinical information, and the area to be examined. Briefly explain the procedure to the patient, indicating how long the scan is expected to take, and obtain verbal consent.

Obtain a brief medical history:

• Enquire about the type of surgical procedure that is being planned and confirm the type of examination required
• Past history of previous vein surgery or vein-artery harvesting
• Enquire whether the patient has had any previous mapping procedures

Ask the patient to lie on the bed in the supine position.

Supine position

Dim the lights in the room (to prevent light reflecting on the monitor, thus improving the view of the ultrasound images).

Take standard precautions.

Stand or sit on the patient's right-hand side (patient supine), with the ultrasound machine to the left-upper end of the bed.

• Lower limb procedures
  Have the patient lie on the bed in the supine position with their feet resting on the footrest. Explain the tilting mechanism carefully (and demonstrate it for anxious patients). Most patients find it more comfortable if the limb is slightly flexed and externally rotated with the knee supported. The opposite limb is placed carefully on the footrest to support the weight of the body and the bed is tilted, with the head raised up to 30 to 45 degrees in a reverse Trendelenburg position.
  Reverse
  Trendelenburg
  position

• Upper limb procedures
  Have the patient lie on the bed in the supine position with pillows or other supports for comfort. The limb being examined is supinated (turned so that the palm faces up) and abducted (drawn away from the midline of the body). It may be helpful to slightly elevate the head of the bed to assist the patient's breathing and enable some venous distension of forearm veins.

  Note that shoulder veins (subclavian and axillary) may drain and appear to collapse due to extrinsic compression if the patient is sitting or is too upright.
  Upper limb position

Expose the limb and apply gel to the region of interest along the anatomical line of the vessels being examined.

Apply gel

Select the appropriate high or mid range linear multi-frequency transducer.

Mid and high linear
multi-frequency
transducers

Confirm the correct transducer selection and preset on the ultrasound machine.

Have the patient lie supine on a hospital bed or examination table in the reverse Trendelenburg (head elevated) position, to promote venous distension and optimize visualization. Externally rotate and supinate the limb with additional support from pillows and foam supports as required.

There are a number of scan planes that will be appropriate but it is recommended to start with a lateral approach.

Scan in the following planes:

• Transverse - for survey scan, compression views, and diameter measurements
• Longitudinal - for color flow and spectral Doppler views

  Longitudinal scan plane

  Transverse scan plane

For lower limb mapping procedures:

• Longitudinal color Doppler with spectral trace and augmentation of the following lower limb deep veins:
  • Common femoral vein
  • Deep femoral vein
  • Femoral vein
  • Popliteal vein
• Longitudinal color Doppler with spectral trace and augmentation of the following superficial lower limb veins:
  • Saphenofemoral junction
  • Great saphenous vein
  • Saphenopopliteal junction
  • Small saphenous vein
• Transverse compression views of the major veins
• Measurement of the diameters of the saphenofemoral and saphenopopliteal junctions
• Measurement of the diameters of vessels for harvest or to be used as a conduit

For upper limb veins and upper limb mapping procedures:

• Longitudinal color Doppler with spectral trace and augmentation of the following deep upper limb veins:
  • Internal jugular
  • Subclavian
  • Axillary
  • Brachial
  • Radial
  • Ulnar
• Longitudinal color Doppler with spectral trace and augmentation of the following superficial upper limb veins:
  • Cephalic
  • Basilic
• Longitudinal color Doppler with spectral trace and augmentation of the following upper limb arteries:
  • Subclavian
  • Brachial
  • Radial
  • Ulnar
• Transverse compression views of the major veins
• Views to demonstrate proximal and distal extent of thrombus (if present)
• Measurement of the diameters of vessels for harvest or to be used as a conduit

The following annotations are required for the mapping and upper limb venous protocols:

• Scan plane:
  • Longitudinal
  • Transverse
• Structure scanned:
  • Common femoral vein (CFV)
  • Femoral vein (FV)
  • Deep femoral vein (DFV)
  • Popliteal vein (PV)
  • Great saphenous vein (GSV)
  • Small saphenous vein (SSV)
  • Subclavian vein (SV)
  • Axillary vein (AV)
  • Brachial vein (BrV)
  • Radial vein (RV)
  • Ulnar vein (UV)
  • Cephalic vein (CV)
  • Basilic vein (BV)
  • Radial artery (RA)
• Patient position:
  • Supine
  • Upright
  
  Properly annotated
  image

The landmarks for veins:

• Deep veins - are almost always paired with an artery and are located in a deep compartment that contains muscles and is bounded by fascia
• Superficial veins - are located in superficial fascia bounded deeply by muscular fascia and superficially by the dermis. In addition, saphenous veins lie within a separate saphenous compartment

Sonographic features of normal veins:

• Thin smooth walls
• Anechoic lumen
• Vessel walls collapse with light or moderate transducer pressure
• Spontaneous phasic low-velocity Doppler signals augment with distal limb compression

• Great saphenous vein may be duplicated in the thigh, 65% of patients have a single GSV
• Small saphenous vein in popliteal fossa may vary in its insertion to the popliteal vein, 80% of patients have a saphenopopliteal junction
• Thigh extension of the SSV (formerly known as the Vein of Giacomini) will vary considerably in many patients and may be a source of incompetence
  Saphenous vein
  anatomical variants

• Compare sides:
  The superior vena cava, innominate, and proximal subclavian veins may not be clearly visualized in many patients due to habitus (physical characteristics of the individual patient). Scanning the opposite limb will confirm if there is an access related difficulty. Comparing waveforms will establish a normal waveform for that patient.

  Venous pulsatility in the proximal arm veins can resemble arterial flow. To avoid confusion, compare a waveform from both the vein and its accompanying artery.

  Subclavian vein flow

  Subclavian artery flow

  If veins are not identified, change the position of the patient. Extrinsic axillary vein compression due to the first and second ribs may suggest an occlusion. Patency can be confirmed by varying patient position from supine to reverse Trendelenburg or to a sitting position; and by varying the amount of abduction of the patient's arm.
• Internal and external jugular vein reverse flow collateral pathways:
  When there are proximal occlusions, both the internal and external jugular veins and their branches quickly form large collaterals that could be mistaken for the subclavian vein. External jugular vein collaterals will lie anterior to the clavicle.
• Transducer pressure:
  Superficial veins are very responsive to even slight transducer pressure. While concentrating on identifying veins, it is easy to unintentionally increase pressure, causing the appearance of an occlusion.
  Superficial vein
  pressure

• Vein mapping versus suitability:
  When patients present for preoperative scans of their superficial veins, it is worthwhile checking the proposed date of surgery. If the scan is for suitability there is no need to mark the veins; but if a definite date for surgery is scheduled, marking can be performed up to two days before surgery.

• With the patient's head turned away from the affected side, evaluate the internal jugular vein using transverse compression views
• Record longitudinal color and spectral Doppler views of internal jugular vein flow
  Longitudinal internal
  jugular vein

• Using a supraclavicular approach, evaluate proximal subclavian veins in the longitudinal view with color and spectral Doppler
  Supraclavicular
  approach

• From an infraclavicular approach and a transverse view evaluate the distal subclavian and axillary veins using compression
  Infraclavicular
  approach

• Record longitudinal color and spectral Doppler views of the distal subclavian and axillary vein

• Normal flow should be spontaneous, pulsatile (due to transmission of right atrial pulsation), phasic and responsive to Valsalva

  
  Normal spontaneous,
  phasic, pulsatile flow

• With the arm abducted and externally rotated, use transverse compression views to assess the brachial, cephalic, and basilic veins in the upper arm
  Upper limb venous
  compression

• Record augmented color and spectral Doppler images of the brachial, cephalic, and basilic veins in the upper, mid, and distal portions of the upper arm
  Ultrasound image of
  upper limb veins

• Assess the forearm veins in a similar way with transverse compression, longitudinal color, and spectral Doppler views of the radial, ulnar, cephalic, and basilic veins in the upper, mid, and distal forearm
  Ultrasound image of
  forearm veins

• Thrombosis:
  The pathogenesis of thrombosis consists of interactions between an injured vessel, stasis, and increased coagulability of blood. Stasis and local acceleration of the coagulation process are the most important factors in thrombus formation.

  Venous thrombi (plural of "thrombus") form under conditions of low flow. They are composed of erythrocytes and fibrin with relatively few platelets. Most thrombi begin as platelet aggregates in valve pockets.

Clinical signs and symptoms

• Pain and swelling of arm or neck
• Pulmonary embolus
• Dilated superficial veins of arm or shoulder
• Palpable subcutaneous cord in arm
• Infusion difficulty with indwelling IV line

Sonographic findings

• Acute venous thrombosis - first 14 days after thrombus forms:
  • Low echogenicity - recently formed thrombus generates low-level echoes and may be virtually anechoic
  • Venous distension - recently thrombosed veins are generally distended. Distension persists through the acute period and into the subacute phase
  • Loss of compressibility - lack of compressibility is the single most reliable finding that distinguishes thrombosed from normal veins
  • Free-floating thrombus - the proximal end of an acute thrombus, representing the most recently formed, may not adhere to the vein wall
  • Doppler signal abnormality - in the presence of thrombus flow, augmentation is diminished or absent proximal to the thrombosed segment. Distal to the thrombosed segment, flow is continuous rather than phasic and Valsalva response is diminished or absent
  • Collateralization - collateral venous channels enlarge rapidly during the acute phase. Collaterals are typically smaller and more tortuous than the normal vein
  
  Acute venous
  thrombosis

• Subacute venous thrombosis - More than two weeks and potentially up to six months after initial thrombus formation:
  • Increased echogenicity - thrombus becomes more echogenic during the subacute phase but this change is variable and not a reliable indicator of precise age
  • Decreased thrombus and vein size - retraction and lysis cause a notable reduction in size of the veins during the subacute phase. This is particularly noticed on serial examinations
  • Adherence of thrombus - free floating thrombus becomes attached during the acute phase and is not free floating in the subacute phase
  • Resumption of flow - with thrombus retraction and lysis, patency may be restored and flow may resume
  • Collateralization - collateral channels will continue to enlarge during this phase
  
  Subacute venous
  thrombosis

• Chronic venous thrombosis - longer than six months after the acute episode:
  • Wall thickening - diffuse wall thickening with scarring and caliber reduction is common after six months
  • Echogenic intraluminal material - post-thrombotic fibrous scars may produce focal plaque-like areas, webs, or fibrous bands
  • Fibrous cord - if a vein lumen does not recanalize and remains occluded or substantially narrowed it may reduce to an echogenic cord of smaller diameter than the normal vein
  • Valve abnormality - valve damage is common in the presence of incomplete lysis and subsequent fibrosis. Valve damage may appear as:
    • Thickening of cusps
    • Adherence of cusps to vein walls
    • Failure of complete valve closure in the center of the vein
  • Doppler flow abnormalities - in addition to reflux, there may be:
    • Lack of spontaneous flow
    • Lack of phasicity
    • Absence of Valsalva response
    • Subnormal or absent augmentation
  
  Chronic venous
  thrombosis

Differential diagnosis

• Extrinsic compression
  Extrinsic
  compression

• Cellulitis, lymphedema

An arteriovenous fistula is surgically created (usually in the arm) for patients who are undergoing hemodialysis for renal failure. Typically the radial artery and the cephalic vein at the wrist are used. The procedure results in an increased flow in the cephalic vein, which becomes enlarged and consequently visible and easily palpable in the forearm. Hemodialysis catheters can be positioned at this site. The mapping procedure ensures that both the radial artery and the cephalic vein are suitable for use in the procedure and that there is continuity around the newly created pathway.

• The veins and arteries of the upper limb are scanned with the transducer in a transverse plane to assess and determine the diameter and wall thickness of the vessels
• Transverse compression views are used to determine the patency of the veins
  Upper limb venous
  compression
• Longitudinal color and spectral Doppler views are used to record the patency of arteries
• The depth from the skin surface to the anterior wall of the cephalic vein is measured in the forearm to assess suitability for access during hemodialysis, because sometimes superficial veins are too far from the skin surface to allow the placement of the hemodialysis catheters
  Cephalic vein to skin
  measurement
• The veins and arteries of the forearm are assessed to determine their suitability for a forearm graft placement:
  • The non-dominant forearm should be assessed first
  • The patient may sit with their arm supinated on a pillow
    Arteriovenous fistula
    mapping position
  • The radial artery needs to measure at least 2 mm in diameter at the wrist to be useful as a graft
    Radial artery
  • Apply a light tourniquet just below the elbow and measure the forearm cephalic vein in the proximal, mid, and distal forearm. The cephalic vein must measure at least 2.5 mm in diameter with a continuous vein channel identified all the way up the arm
    Apply a light
    tourniquet to the
    forearm
  • If the cephalic vein is not suitable (too small, absent, thrombosed, or thick walled), assess the basilic vein in the same way
• The upper arm vessels are a second choice
  • Assess the brachial artery diameter using a transverse view in the mid portion of the upper arm
  • Apply a light tourniquet at the axilla
    Apply a light
    tourniquet to the
    upper arm
  • Measure the cephalic and basilic vein diameters from the proximal, mid, and distal portions of the upper arm in a transverse plane
    Measure upper arm
    vein
  • Remove the tourniquet, and assess continuity with deep veins by following the superficial veins up to the axilla using transverse compression and longitudinal color views
  • Longitudinal color and spectral Doppler views of the subclavian vein and internal jugular vein are recorded, to confirm patency

Sclerotherapy is usually performed after a formal lower limb venous incompetence study has been completed and immediately prior to treatment. Accurate location of the veins that have been selected for treatment will greatly assist the physician and will improve the outcome and lessen the time taken for the procedure.

• Carefully interpret the previous lower limb venous scan and become familiar with the specific findings. These findings will guide the physician treating the patient and they become the basis for the mapping procedure
• Scan the fascia - carefully identify the fascia separating the deep compartment from the superficial compartment and surrounding the saphenous vein in the region of interest indicated from the initial scan. Using a transverse plane and then longitudinal or oblique planes, follow the fascia looking for a clear break in the echogenic line of the fascia that might indicate the incompetent perforating vein
  B-mode image of
  perforator
• Assess and record competence using color flow and spectral Doppler
• Measure the diameter of incompetent perforators as the vein passes through the fascia. The threshold diameter for treatable incompetent perforators will vary. Incompetent perforators are generally greater than 3 mm in diameter
  Measure perforator
  diameter
• Select an appropriate technique for marking the location of suitable veins - generally a two-step procedure is recommended. First mark the skin with a temporary marker (eg, a straw, ball-point pen, or artist's watercolor pencil, which writes in gel). Then wipe off the gel and apply a more permanent mark

Perforator and varicosity marking follows a very similar technique to sclerotherapy marking as described in Step 7. It is usually performed after a formal lower limb venous incompetence study and prior to surgery. Accurate marking of the appropriate veins will significantly improve the outcome of surgery.

• As with sclerotherapy, carefully interpret the previous lower limb venous scan and become familiar with the specific findings. These findings will have guided the physician treating the patient and become the basis for the mapping procedure
• Measure the diameter of saphenofemoral and or saphenopopliteal junctions as required. Using a longitudinal view and B-mode, identify the saphenofemoral junction in the groin and the saphenopopliteal junction in the popliteal fossa. Apply measuring calipers to measure the diameter of the junction

  Measure saphenofemoral junction

  Measure saphenopopliteal junction

• Scan the fascia: carefully identify the fascia separating the deep compartment from the superficial compartment and surrounding the saphenous veins, using initially a transverse plane and then longitudinal or oblique planes as necessary. Follow the fascia looking for a clear break in the echogenic line of the fascia that might indicate a perforating vein
  B-mode image of
  perforator

• Assess and record competence using color flow and spectral Doppler
• Measure the diameter of incompetent perforators as the vein passes through the fascia. The threshold diameter for treatable incompetent perforators will vary. Incompetent perforators are generally greater than 3 mm in diameter
  Measure perforator
  diameter

• Select an appropriate technique for marking the location of suitable veins  - generally a two-step procedure is recommended. First mark the skin with a temporary mark (eg, a straw, ball-point pen, or artist's watercolor pencil, which writes in gel). Then wipe off the gel and apply a more permanent mark
• Varicose veins may be incompetent, tortuous, dilated segments of saphenous veins, accessory saphenous veins or, commonly, a combination of both
• As a general principle, the varicosities that are very visible on the skin surface do not require marking but may be associated with an atypical incompetent perforator lying beneath them that may require marking
• Varicosities that lie deeper or in atypical anatomical positions may be marked using the marking technique described for the saphenous vein or perforators

The decision to use the radial artery for a graft conduit is usually related to coronary bypass graft surgery when it has been determined that the great saphenous, small saphenous, cephalic, and basilic veins are not suitable.

• Generally the radial artery from the non-dominant arm will be used
• Before scanning takes place, a physiologic assessment will be performed. This may include:
  • Bilateral systolic brachial artery pressure measurements
  • Allen's test - performed by the referring physician
  • Modified Allen's test, to assess the patency of the palmar arch - performed by the vascular sonographer
    • The digital waveforms are recorded with photoplethysmography and the radial and ulnar arteries are alternately compressed
    • Decreased waveforms during compression indicate that the arch is incomplete and radial artery harvest may be contraindicated
• Identify the origin of the radial artery at the elbow
  Radial artery origin
  at the elbow

• With a transverse view, measure the diameter of the radial artery just below the elbow, mid forearm, and at the wrist. Ideally, the radial artery measures more than 2.5 mm, with 2 mm as the minimum diameter
• Use a longitudinal view with color and spectral Doppler to assess patency and to look for any possible stenosis
• Contradictions for radial harvest include:
  • Ischemic digits
  • Raynaud's syndrome
  • Ipsilateral athero-occlusive disease in the arm
  • Incomplete palmar arch

Sonographic findings related to radial artery harvest

• Sclerotic, atresic, or occluded radial artery
  Occluded radial
  artery

• It may be possible to mistake low flow for occlusion in a small distal artery. Ensure the ultrasound machine has been optimized for low flow with increased color gain and decreased pulse repetition frequency
• Pay careful attention to transducer pressure. As with all small superficial vessels it is possible to accidentally occlude the vessel with too much pressure

Superficial vein mapping is used to determine the suitability and location of veins for use as a bypass graft. Mapping is generally performed before lower extremity bypass or coronary bypass surgery. Accurate mapping of the location of the vein that is to be used for the graft avoids exposing inadequate veins, decreases the time taken for the operation, and lessens the possibility of wound complications.

• It is critical that only light pressure from the transducer is exerted on the skin as superficial veins are easily compressed by pressure
  Light transducer
  pressure

• Commence at the groin with transverse compression views to assess patency of the great saphenous vein
• Measure transverse diameters from the following positions:
  • Proximal, mid, and distal thigh
    Measure saphenous
    vein mid thigh
  • Proximal, mid, and distal calf
    Measure saphenous
    vein mid calf

• If the great saphenous veins are not suitable (too small, absent, or thrombosed), extend the examination to include the small saphenous vein, followed by the cephalic and the basilic veins
  Transducer position
  small saphenous
  vein

• Careful attention is paid to:
  • Size - 3 to 5 mm is ideal (with a minimum of 2.5 mm)
  • Wall thickening
  • Calcification
  • Recanalization
  • Stenotic valves
• Select an appropriate technique for marking the location of suitable veins - generally a two-step procedure is recommended. First mark the skin with a temporary marker (eg, a straw, ball-point pen, or artist's watercolor pencil, which writes in gel). Then wipe off the gel and apply a more permanent mark

Sonographic findings related to lower limb venous mapping and marking

• Unable to identify a suitable vessel
• Absent or occluded veins
• Wall thickening or calcification
  Calcified saphenous
  vein

• Veins too small
• Too much transducer pressure

Before ending the examination, particularly when pathology or atypical anatomy has been found, it may be useful to have the reading physician come into the room and re-scan the areas of interest or concern. This allows the reading physician to clarify the pathology or atypical anatomy for reporting purposes.

End the study on the ultrasound machine (this sends the images to a PACS system or printer).

Give the patient a towel or cloth to wipe off gel.

Remove your gloves.

Postprocedure considerations

References

Guidelines

Caggiati A, Bergan JJ, Gloviczki P, et al. An Interdisciplinary Consensus Committee on Venous Anatomical Terminology. J Vasc Surg. 2002; 36:416-22.

Websites

Online CME courses. GE healthcare website.
Available at: http://www.gehealthcare.com/usen/ultrasound/msucme.html
Accessed March 17, 2009.

Society of Diagnostic Medical Sonographers (SDMS). Industry standards for the Prevention of Work-Related Musculoskeletal Disorders in Sonography. May, 2003.
Available at: http://www.sdms.org/pdf/wrmsd2003.pdf
Accessed December 2, 2008.

The Free Dictionary by Farley.
Available at: http://medical-dictionary.thefreedictionary.com
Accessed April 8, 2009.

U.S. Department of Health & Human Services. Health Information Privacy. The Health Insurance Portability Act of 1996 (HIPPA) Privacy Rule.
Available at: http://www.hhs.gov/ocr/privacy/index.html
Accessed February 27, 2009.

Textbook chapters

Belanger, AC. Vascular Anatomy and Physiology. Pasadena, Ca: Appleton Davies; 1990.

Craig, M. Essentials of Sonography and Patient Care. 2nd ed. St. Louis, Mi: Saunders Elsevier; 2006.

Daigle, RJ. Techniques in Noninvasive Vascular Diagnosis. 2nd ed. Littleton, Co: Summer publishing; 2002.

Dean, RH, Yao JST, Brewster DC, eds. Current Diagnosis & Treatment in Vascular Surgery. East Norwalk, Ct: Appleton & Lange; 1995.

Edelman, SK. Understanding Ultrasound Physics. 3rd ed. Woodlands, Tx: ESP; 2007.

Hagen-Ansert, SL. Textbook of Diagnostic Ultrasonography. 6th ed. St. Louis, Mi: Mosby Elsevier; 2006.

Zwiebel, WJ, Pellerito, JS. Introduction to Vascular Ultrasonography. 5th ed. Philadelphia, Pa: Saunders Elsevier; 2005.