Transcript Vascular Ultrasound and Wound Care

Lower Extremity
Wounds: The role of
the vascular
technologist
Jesse Thomas, RVT
UNC 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 = v2/v1
V2= highest peak systolic velocity
V1= proximal normal vessel
Velocity Ratio (VR) = 6.1
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!