Lower Extremity Wounds: The role of the vascular technologist

Lower Extremity Wounds: The role of the vascular technologist

Jesse Thomas, RVTUNC Health Care

DISCLOSURES

NO RELEVANT CONFLICTS OF INTEREST TO DECLARE

Objectives

• Review types of wounds• Discuss risk factors• Role of Duplex Imaging• Role as a Technologist

• This presentation will NOT address the use of ultrasound as a wound management and/or treatment tool.

Types of Wounds

•Arterial•Venous•Neuropathic• Small vessel/Vasculitis•Pressure ulcers

Arterial• Ischemic wounds• Result of

inadequate blood supply• Tissue hypoxia and

tissue damage• Most commonly

result of atherosclerotic disease (PAD)

PAD

• Narrowing of arteries to the limbs that reduces blood flow•More common in

LE• Atherosclerosis –

build up of fatty deposits (plaque)

Arterial• Risk Factors• High cholesterol• Aging• HTN• Diabetes• Smoking• Family hx of

cardiovascular disease• Obesity

PAD• Approximately 8

million people in the US• 12-20% in those

>60• Public awareness

around 25%• Associated with

significant morbidity and mortality

Source: National Center for Chronic Disease Prevention and Health Promotion

PAD• May present with

variety of signs/symptoms• Claudication – to

limp• Aching, cramping

pain brought on by exercise and relieved with rest• Calf, thigh, hips or

buttocks

PAD

• Rest pain• Non-healing

ulceration• gangrene

Arterial Ulcers• Characteristics• “punched out”

appearance• Smooth wound edges• Surrounding skin may

exhibit dusky erythema• Cool to touch• Hairless, thin, brittle

with shiny texture

Arterial Ulcers

• Typically lower leg• Lateral foot• Toes• Pressure points

or where injury has occurred

Arterial Ulcers

• Jesse, why do I care what these look like and are you done showing these nasty pictures?

Role of Sonographer

• Patient history• Physical exam• ABI’s• Clues to what is

going on before you put the transducer on the patient

Role of Duplex• Presence or absence of disease• Severity• Physiologic• Anatomic

• Location• Single level• Asymptomatic• claudication

• Multi-level • Claudication• Rest pain• ulcerations

Pressures

• Ankle/Brachial Index (ABI)• 1.0-1.2 Normal• 0.92-0.99 may indicate

presence of arterial obstruction • <0.92 Evidence of

arterial obstruction, claudication• <0.40 associated with

rest pain or tissue loss

Pressures--Toe

• Photoplethysmography (PPG)• Infrared light which

responds to changes in blood content near the surface of the skin• Waveform analysis and

pressure measurement

Pressures--Toe

• Disease from the level of the ankle to the toe• Diabetics•Wound healing

potential• Absolute number

and index

Pressures--Toe• A toe/ankle index >0.60

suggests the absence of hemodynamically significant obstruction between the ankle and the toe

• A toe/brachial index >0.60 suggests the absence of hemodynamically significant obstruction between the heart and the digit

Pressures--Toe

TCPo2• Transcutaneous oxygen tension• Evaluates oxygen delivery to tissue• Indirect measure of local blood flow• Aids in determining wound healing potential

• Patient in supine position• Small electrodes placed at chest, below knee, and 2 over dorsum

of foot• Electrodes in the sensors heat area underneath the skin to dilate

capillaries• Results recorded and measured in mmHg• >30 mmHg – greater success for wound healing• <30 mmHg - suggests high likelihood of wound not healing

Pressures--Segmental

• Typically 3 or 4 cuff system•High thigh, above knee, calf, ankle•Measures pressure at each level• >30mmHg gradient from level to level

is significant• >40mmHg indicates occlusion• >20mmHg from side to side is also

significant

Pressures--Segmental

• Pitfalls include• Medial arterial

calcification• Limb girth• Inappropriate cuff

size• Can be

uncomfortable for patient

Pressures--Segmental

Pulse Volume Recordings (PVR)

•Measures pressure changes in the bladder of the cuff wrapped around the leg• These changes reflect change in cuff

volume•Can use same cuffs as used for

segmental pressures

PVR

•A 1mmHg pressure change detected in the cuff produces a 20mm deflection (amplitude) on the chart recorder•Using appropriate size cuffs, a preset

pressure is obtained•A recording is then obtained

PVR

PVR/Segmental Pressures

• PVR waveforms and segmental pressures are complimentary tests• If differences exist

then a source of error should be investigated

Duplex• Image based

evaluation• Looking for

anatomic disease and physiologic disease

Duplex – Segmental

Duplex

PW Doppler--Duplex

Velocity Ratio (VR) = 6.1

Velocity Ratio = v2/v1

V2= highest peak systolic velocity

V1= proximal normal vessel

Arterial Ulcers• Role of Duplex

essential to understanding presence, location, and severity of disease• Guides intervention

and management• Indicator wound

healing potential

Changing Gears

Venous Ulcers

• Result of sustained venous hypertension (Chronic venous insufficiency)• Incompetent valves or poor calf muscle pump• Local venous dilatation and pooling• Traps leukocytes that may release proteolytic

enzymes that destroy tissues• May also “trap” important growth factors within

vein rendering them unavailable for wound repair

Venous

•70%-90% of chronic wound cases• Estimated 2.5 million patients in the

US•Rarely fatal - can severely diminish

quality of life

Venous Ulcers• CVI Risk factors• > Age• Hx DVT• Surgery• Restricted mobility• CHF• Cancer• Obesity• Smoking• Family hx VTE• Hypercoable state (Factor V Leiden, Protein C/S deficiency, etc.)

• Sedentary lifestyle• Varicosities

Venous Ulcers• Wound characteristics• Gaiter region –

medial malleolus• Superficial, irregular

shape• Skin shiny and tight

(edema)• Brown or purple

discoloration – “stasis skin changes”

Stasis Skin Changes

Varicose Veins

Varicose Veins

Varicose Veins

Varicose Veins • Complications• Swelling• Pain/aching• itching• Leg heaviness• Phlebitis – inflammation of vein• Superficial thrombophlebitis• bleeding• Cosmetic

• Not commonly associated with venous ulcers when isolated to the superficial system

Role of the Sonographer

•Patient history•Physical exam•Clues to what is

going on before you put the transducer on the patient

Role of Duplex• Presence or absence of disease• Severity• Physiologic• Anatomic

• Location• Deep• Superficial

Venous Obstruction

• Presence or absence of deep or superficial venous obstruction• Compression

ultrasound

Venous Obstruction• Thrombus Characteristics• Acute

• Softly echogenic• Spongy• Dilated vein• Smooth borders

• Chronic• Brightly echogenic• Rigid• Contracted vein• Irregular borders• Presence of collaterals

Acute or Chronic?

• These distinguishing characteristics are not absolute• “Can be useful in estimating the age of a

thrombus and the risk of its embolization.” (Techniques of Venous Imaging. Talbot, Oliver. 1992)

Venous Duplex• Complete and careful evaluation• Deep

• CFV• Fv• Pop• Tibials• Gastrocs, soleals, etc.

• Superficial• Great Saphenous Vein (GSV)• Small Saphenous Vein (SSV)• tributaries

Venous Insufficiency

• Evaluation of reflux (deep and superficial)• Supine•Manual hand augments

• Standing• Rapid inflation/deflation cuff system• “stresses” vein – hydrostatic pressure

• Valsalva• Patient unable to stand

Venous Insufficiency

• Patient standing• Cuff around calf• Rapidly inflates•Measure reflux on

cuff deflation• Ergonomic

challenges• Patient

limitations

Venous Insufficiency• Normal values• < 0.5 seconds

• Abnormal• > 0.5 seconds

• Indication of valvular incompetency (reflux)

Perforator Assessment• Connection between

deep and superficial systems• Drains superficial into

deep system• Contain valves• Associated with ulcer

formation

Perforator Assessment

• Dodd’s• Boyd’s• Cockett’s• Name given by

1st physician who described them

Venous Duplex• Other considerations• Size of veins• May help determine

intervention method• Too large may not

respond well to local sclerotherapy or some types of venous ablation

• “map” of veins• Anatomical blueprint

sometimes required• Help guide intervening

physician

Venous Ulcers• Role of Duplex

essential to understanding presence, location, and severity of disease• Guides intervention

and management

Conclusion

• Patients presenting with ulcerations to the vascular lab is a common occurrence• Technologist and physician education important• Use all available skills and tools to assess your

patients• Wound management is complex and your role is

critical in providing the necessary vascular information

Thank you!