1. Arterial Physiologic Testing- Lower Extremities
Chapter 11
Arterial Physiologic Testing- Lower Extremities

2. Arterial physiologic testing Purpose:
Evidence for arterial occlusive disease?
Responsible for the patient’s symptoms?
Arterial disease and neurospinal compression, which condition is causing the symptoms?
If disease is present, how severe? 14

3. Indications for Extremity Arterial Testing
Claudication
Ischemic Rest Pain
Ulceration
Gangrene
F/Up for limb vascularization or intervention
F/up Disease Progression (PVD)
Suspected Aneurysm
ASOD
Asymptomatic Bruit
Acute Arterial Occlusion
Pre-Op radial harvest or hemodialysis access creation
Raynaud’s
TOS

4. Indications for Extremity Arterial Testing
Claudication-primary symptom
Muscle cramping, aching, or tiredness brought on by exercise and relieved quickly by rest
Symptoms are reproducible
Distance
Severity
Location

5. Indications for Extremity Arterial Testing
Claudication
The location of pain often correlates with a more proximal flow limiting stenosis
Site of Pain Level of Disease
Calf SFA and/or Pop
Thigh Distal EIA; CFA
Thigh or Buttock A/I; IIA
Most common site of disease is the SFA

6. Indications for Extremity Arterial Testing
Rest Pain
End Stage Disease- sx of advances arterial insufficiency
Decreased perfusion to the tissue causes constant burning or throbbing pain in the forefoot, heel, toes
Relieved by dependency

7. Indications for Extremity Arterial Testing
Chronic Critical Limb Ischemia
Criteria
>2 weeks of foot pain at rest
Non-Healing wounds or gangrene of the foot or toes

8. Indications for Extremity Arterial Testing
Necrosis; Tissue Loss
End stage disease- death of the tissue
Effects the tips of the toes and extends upward
Severe pain – pre-gangreous state
Intervention is necessary to prevent further destruction of the tissue and infection

9. Indications for Extremity Arterial Testing
Gangrene- local death of body tissue
Dry Gangrene- most common destruction of blood supply to tissue in pts with DM, ASOD, thrombosis, or trauma
Moist- (odor) results from invasion of toxin- producing bacteria that destroys the tissue

10. Indications for Extremity Arterial Testing
Gas Gangrene- results from invasion of wounds by anaerobic bacteria
Gas forms under the skin and a watery exudates is produced
Emergency treatment is needed with penicillin and anti toxins otherwise fatal

11. ?? Symptoms
Begin when the endothelial cells are damaged by RISK FACTORS and plaque begins to form in the arteries
There is inadequate blood flow and oxygen to the tissue and muscle Arterial lumen is 50% diameter reduction or a 75% area reduction

12. Cross section view, plaque development Artery wall
Atherosclerosis plaque
Ultrasound color Doppler
Ultrasound image
plaque
Normal artery
residual lumen

13. Arterial occlusive disease
Mild arterial disease
Pt. Asymptomatic
May have decreased pedal pulses
With exercise a mild decrease in ankle pressure
Moderate disease
Asymptomatic at rest
Intermittent claudication
Significant decease in ankle pressure during and following exercise.

14. Arterial occlusive disease
Severe disease
Ischemic rest pain in feet and toes
Non-healing wounds on feet/toes
Ulceration
Tissue necrosis, gangrene

15. Patient History Obtain a thorough History
Important to understand that the majority of patients have co-existent Cardiac Disease and/or PVD
The entire cardio-vascular system, including past surgeries and invasive procedures, reconstructive surgeries, amputations, as well as renal or transplant operations should be recorded

16. Patient History Document Pain (Location, Distance, Rest Time)
Risk Factors (patient and family history)
DM (insulin dependent?)
Smoking (how long/how much)
HTN- (controlled?)
Hyperlipidemia
Cardiac History (CAD,MI, A-Fib, Angina)
TIA/CVA
List Medications

17. Physical Exam What to look for & palpate.
Cold foot (Polar)
Pallor
Dependent rubor
Ulceration, gangrene, necrosis
Trophic Changes
Blue Toe
Reduced pulses
CFA, POP, PTA, DPA
Rating 0-3

18. Arterial Pathology
Thrombo-emboli
Blue Toe Syndrome

19. Arterial Pathology
Aneurysm
AAA
Popliteal

20. Arterial Extremity Testing
Indirect Testing Methods:
Pressure Assessment
Plethysmography
Continous Wave Doppler
Exercise Stress Testing

21. 1. Pressure Assessment: ABI and/or Segmental Pressures

22. Segmental Pressure Principle
In a normal individual in a supine position, ankle systolic pressure is ≥ brachial pressure.
Pt. should be in a basal state prior to pressure acquisition

23. Blood pressure cuff size:
Bladder should be 20% wider than limb diameter
Thigh = 12 x 54 cm
Arms, Calf, Ankle = 10* or 12* x 40 cm
Metatarsal (child-size) = 9 x 20 cm
Digit = 2cm or 2.5 x 5 cm
Non-uniform limb sizes = variations in pressures.

24. 4 cuff technique

25. 3 cuff technique
A three cuff method may be used with a 19 x 40 cm or 17 cm cuff. Placement of a single thigh cuff replaces the two thigh cuffs in a four cuff method.

26. 3 cuff versus 4 cuff 3 cuff method (17cm thigh cuff)
if abnormal, cannot differentiate AI from SFA disease
4 cuff method (12 cm thigh cuffs)
upper thigh cuff pressure artifact (≥ 20 mmHg)
suppose to differentiate AI from SFA

27. Doppler Pressure Sites
Dorsalis Pedis
easily compressed
harder to locate
Posterior Tibial
harder to compress
easier to locate
Essential not to drift off vessel !

28. Segmental Limb Pressures Sites
Useful in identifying region(s) of disease
Metatarsal and toe pressures often useful
This study indicates probable inflow disease and femoro- popliteal disease in the left leg
Note: the numerical value within the box is the actual pressure of the corresponding segment; the number outside of the box is an index that is automatically calculated by the machine

29. Segmental Limb Pressure
compare to contralateral limb segment
compare to adjacent ipsilateral segments
compare to brachial pressure
A 20 mmHg or greater pressure gradient (drop) is significant in the presence of an abnormal ABI

30. If thigh pressure (3 & 4 cuff) is normal = no significant inflow disease
If upper thigh Pressure (4 cuff) or large thigh cuff Pressure (3 cuff) is abnormal, other methods are needed to differentiate AI from Femoral disease

31. Cuff pressures vary from intra-arterial pressures due to variations in limb girth
Expect a “fudge factor” up to 20 mmHg.

32. The Ankle/Brachial Index (ABI)
Highest ankle pressure divided by the higher brachial pressure
Highest ankle pressure value is used for reported ABI 7

33. Resting (ABI) values >1.0 = Normal .9 – 1.0 = Usually normal
Perform Exercise Stress Test if borderline and patient is symptomatic
= mild
= moderate
= severe
= rest pain; critical, impending tissue loss 20

34. Pressure limitation: calcified arteries
diabetics
chronic steroid therapy
renal dialysis patients
segmental pressures unobtainable or excessively high (ABI > 1.4)
PTA

35. PPG pressure assessment

36. PPG Segmental Pressures
+ digital arteries rarely calcify
+ convenient
+ requires less skill
- ambient light interference
- no audible pulse
- not good for severe disease
- ulceration

37. Toe Pressures with PPG method

38. Toe Brachial Index (TBI)
Digit vessels are not affected by calcific medial sclerosis
Normal > 0.75
Abnormal < 0.66

39. Pressure advantages Quantitative information on limb perfusion
Easy to perform
Substantial clinical validation

40. 2. Arterial Plethysmography
Pneumoplethsmography
Strain-gauge
Impedance
Photo electric

41. Arterial Plethysmography: The measurement of a volume change in a limb or organ
Air (pneumo) plethysmography
Pulse volume recording (PVRs)
Photo-plethysmography (PPG)
Infrared light transmitted into tissue
Reflected light processed for cutaneous blood flow

42. Pulse Volume Recording (PVR)
Limb volume changes w /systole
Air is displaced within a cuff
Instantaneous pressure change is recorded.
PVR wave
air
cuff
trans
Limb
air

43. Normal PVR
Peak systole
Reflected wave

44. PVR Waveforms Waveform morphology changes with disease severity
MILD MODERATE

45. Pt. -- Jeff F. Rt ABI = 0 Lt ABI = 1.2 Rt Rt Thigh Lt Thigh
Rt Above Knee
Rt Below Knee
Rt Ankle
Rt Metatarsal
Lt Thigh
Lt Above Knee
Lt Below Knee
Lt Ankle
Lt Metatarsal

46. Patrick, 59 year old male High thigh Above knee Below Knee Ankle
Lt Thigh
Rt Thigh
RT ABI LT ABI 0.0
Above knee
Lt Above Knee
Rt Above Knee
Below Knee
Ankle
Lt Below Knee
Rt Below Knee
Rt Ankle
Lt Ankle

47. Rt ABI 0.49 Lt ABI 0.53 Pt April. 46 yr old female
R Brachial pressure
L Brachial Pressure
Pt April. 46 yr old female
Hx of bilateral hip and buttock claudication

48. PVR Limitations Tremor - motion Dist. disease with prox. occlusion
Subjective
Atrial Fib.

49. PVR advantages easy to learn and to perform
assessment of global limb perfusion
metatarsal and toe evaluation
not affected by calcified arteries

50. PPG waveforms for digit assessment
index fingers
Right
Left