Peripheral Vascular Disease Flashcards
Modifiable risks for atherosclerosis
Smoking
DM/Glycemic control
HT
HL
Renal disease
High homocysteine levels
Hypercoagulability
Non-modifiable risks for atherosclerosis
Age
Gender
Ethnicity
Definition of Peripheral arterial disease (PAD)
atherosclerosis leads to arterial stenosis and occlusion of major vessels supplying the lower extremities
Definition of Intermittent claudication (TASC II)
Reproducible ischemic muscle discomfort in lower limb by exercise, and relieved by rest within 10 minutes
Classifications for chronic lower limb ischemia
- Anatomical
- GLASS
- TASC
- Bolinger score
- Graziani
- Symptom
- Rutherford
- Fontaine
- WIfI
Rutherford classification
- Stage 0 – Asymptomatic
- Stage 1 – Mild claudication
- Stage 2 – Moderate claudication
- Stage 3 – Severe claudication
- Stage 4 – Rest pain
- Stage 5 – Minor tissue loss with ischemic nonhealing ulcer or focal gangrene with diffuse pedal ischemia
- Stage 6 – Major tissue loss – Extending above transmetatarsal level, functional foot no longer salvageable
Fontaine classification
- Stage 1 – No symptoms
- Stage 2 – Intermittent claudication subdivided into:
- Stage 2a – Without pain on resting, but with claudication at a distance of greater than 200 meters
- Stage 2b – Without pain on resting, but with a claudication distance of less than 200 meters
- Stage 3 – Nocturnal and/or resting pain
- Stage 4 – Necrosis (death of tissue) and/or gangrene in the limb
WIfI
- Wound (Grade 0-3)
- Severity of ischemia (Grade 0-3)
- Foot infection (Grade 0-3)
Stratifies risk of amputation
Difference between intermittent and spinal claudication
Spinal claudication associated wtih nerological symptoms and relieved by spinal flexion
DDX for Intermittent claudication
Osteoarthrosis
Spinal stenosis
Nerve root compression
Venous claudication
Symptomatic baker cyst
Chronic limb threatening ischemia (CLTI) (TASC II)
Clinical syndrome defined by:
- the presence of PAD in combination with
- rest pain, gangrene, or a lower limb ulceration >2 weeks duration
Leriche syndrome
Buttock claudication
Gluteus muscle atrophy
Impotence
*internal iliac arterial occlusion
Ankle brachial index
Highest systolic ankle pressure in DP/PT
Highest systolic pressure over brancila artery
ABI
1) Normal
2) PAD
3) Intermittent claudication
4) Critical limb ischemia
1) >0.9
2) <0.9
3) 0.5-0.8
4) < 0.5
Duplex USG
1) Doppler: evaluates velocity and direction of flow
2) B mode: obtains image of vessel
IMEX
- Cuffs of appropriate size are placed at above ankle, mid calf and mid thigh
- Doppler placed at pedal artery
- Sequential inflation and deflation of each cuff
- pressure drop >20mmHg acorss segments = significant stenosis
Describe normal Doppler waveform
Management of PAD
Aims:
- Decrease overall cardiovascular morbidity
- Improve QOL
- Avoid limb loss
- Risk factor modification
- ABCDE
- Antiplatelet
- BP control
- Cholesterol reduction
- DM control
- Exercise /Smoking
- Pharmacological treatment
- Localize lesion
- Revascularization
Cilostazol (Pletaal)
Phosphodiesterase III inhibitor
increases intracellcular cyclic AMP -> vasodilation and antiplatelet activity
CI in HF
Aspirin
irreversible COX inhibitor
Blocks prostaglandin synthesis from arachidonic acid
Naftidrofuryl (Praxilene)
Peripheral vaso-dilator
Selective 5HT antagonist
Reduces RBC and plt aggregation
Used for intermittent claudication
Management for suprainguinal
1) Type A
2) Type B
3) Type C
4) Type D
1) Endovascular
2) Endovascular
3) Surgery
4) Open surgical treatment
Endovascular vs Surgical for infrainguinal disease
Open surgery if:
- anatomy suitable,
- good vein,
- relatively young,
- no other comorbidities likely survive > 2 years
Otherwise endovascular
Vein vs Prosthetic graft
Vein has higher 5 year primary patency rate
Miller cuff
Venous cuff interposing between synthetic graft and artery at distal anastomosis
- reduces intimal hyperplasia at the toe and heel of anastomosis
- higher patency rate
Name some distal anastomosis-adjunctive procedures.
Special signs for PVD
- Buerger’s angle
- Dependent rubor
- Venous gutting
- Sluggish vein refilling
Explain the pathophysiology behind dependent rubor
Pre-capillary arteriole sphincter dilatation secondary to lactic acid production after anaerobic metabolism in ischemic state while elevating the leg
What is supervised regular exercise?
Exercise for 30 minutes 3 times a week for 5 months
Meta-analysis (JAMA 1995) shows improves in walking distance
Non-operative treatment of intermittent claudication
- Risk factor modification
- Smoking cessation
- Treat DM/HT
- Statin
- Supervised regular exercise
- Proper foot-care
- Pharmacological treatment
- Anti-platelet agent (reduces risk of MI, stroke)
- Vasoactive agents
Factors involved in deciding between endovascular and open surgery
- Surgical risk
- Life expectancy
- Severity of ischemia
- Anatomical pattern
- Vein availability
How to perform intra-arterial thrombolysis
- Puncture of femoral artery (ipsilateral if palpable, contralateral if not palpable
- Pass guidewire through clot
- Introduce thrombolysis catheter
*
What is the antidote for intra-arterial thrombolysis?
Aprotinin (plasma inhibitor)
Whole blood, FFP
How to perform upper limb embolectomy?
- Drape whole upper arm
- Lazy S incision (medial to distal bicep)
- Control brachial artery, ulnar artery and radial artery
- Transverse arteriotomy 1cm proximal to bifurcation
- Fogarty ballon first pass through proximal limb (for clot retrieval and confirm flow)
- Pass through distal limb (clot retrieval and confirm backflow)
- Closure of arteriotomy with fine non-absorbable monofilament sutures
