Arterial Disease of the Limbs Flashcards
What is intermittent claudication?
Cramp like pain in the muscles of the buttock, thigh and calf which occurs on exercise and is relieved by rest
What is critical limb ischaemia?
A more severe disease than intermittent claudication
Rest pain, ulceration and gangrene which starts peripherally and moves centrally
What are the potential causes of peripheral arterial disease?
Atherosclerosis
Diabetes mellitus
Less common vasculitis e.g. Beurger’s disease, hyperhomocysteinaemia, thromboangiitis obliterans
How is peripheral arterial disease diagnosed?
History
Examination
Ankle brachial pressure index (ABPI)
What investigations are needed if surgery or angioplasty is planned to treat peripheral arterial disease?
Duplex scan
MRA
Angiography
What is the prevalence of intermittent claudication in patients > 55 years?
4-7?
What percentage of people with intermittent claudication require intervention to prevent limb loss?
10%
What percentage of people with intermittent claudication require amputation?
1% per year
What are the important aspects to consider in amputation/treatment of perisperhal vascular disease?
Quality of life
Survival
What is the reduction in functional capacity in people with intermittent claudication compared to a healthy population?
50% reduced functional capacity
What are the risk factors of peripheral arterial disease?
Smoking Lack of exercise Diabetes Hypertension Hyperlipidaemia
What drugs can be prescribed for peripheral arterial disease prevention/secondary prevention?
Aspirin
Statins
ACEIs
What is the single most powerful risk factor associated with the aetiology and clinical progression of peripheral arterial disease?
Smoking
Within how long does the excess risk of cardiovascular disease diminish following smoking cessation?
4-6 years
What should be screened for in peripheral arterial disease? Why?
Diabetes
10% of those attending clinic will have undiagnosed diabetes
What effect does diabetes have on peripheral arterial disease?
Associated with more severe peripheral arterial disease
What will tight glycaemic control help the prevention of in peripheral arterial disease?
Microangiopathy
What will tight blood pressure control lead to in peripheral arterial disease?
Reduction in macrovascular complications and mortality rates
When is lipid lowering therapy with a statin recommended (according to SIGN)?
For patients with peripheral arterial disease and total cholesterol > 3.5 mmol/l
What do statins decrease the 5 year incidence of?
Major coronary events, coronary revascularisation and stroke by 1/5th per mmol/l reduction in LDL cholesterol
What are the kinds of statins?
Cholesterol lowering
Pleiotrophic
How do statins work?
Inhibit platelet activation, thrombosis, plaque rupture, inflammatory activation and endothelial activation
According to SIGN, what is the current BP target for hypertensive patients with peripheral arterial disease?
< 140/85mmHg
According to SIGN/TASC II, what patients with peripheral arterial disease should be prescribed anti-platelet therapy?
All patients
What measures can be taken in the secondary prevention of peripheral arterial disease?
Anti-platelet therapy with aspirin (or clopidogrel 2nd line)
Statins
Screen for diabetes
Diabetics achieve HbA1C < 7% and reassess at 3-6 months for exercise and PTA
Smoking cessation
BP control, to < 140/85 mmHg
What can be done for the symptom improvement of peripheral arterial disease?
Pharmacotherapy
Exercise therapy
Angioplasty
Surgery
After an acute MI, what is the reduction in mortality caused by cardiovascular rehabilitation?
25% reduction
What does exercise in peripheral arterial disease improve?
BP
Dyslipidaemia
Endothelial function
What is severe limb ischaemia?
Rest pain in more than 2 weeks per year
Tissue loss
ABPI < 0.5
What is critical limb ischaemia?
Absolute ankle pressure < 50mmHg
What measures can be taken in the modern management of critical limb ischaemia?
Antiplatelet therapy Statins Screen for diabetes Diabetics achieve HbA1C < 7% Smoking cessation BP < 140/85 mmHg ACEIs Surgery Angioplasty Amputation
What is the typical presentation of acute limb ischaemia?
Pain Pulseless Paraesthesia Pallor Paralysis Cold
What are the potential causes of acute limb ischaemia?
30% embolus
60% in-situ thrombosis
What suggest an in-situ thrombosis as the cause of acute limb ischaemia?
History of intermittent claudication
What suggests atrial fibrillation and embolus as the cause of acute limb ischaemia?
All pulses present in the contralateral limb
What are the most important parts of history and examination of a patient with acute limb ischaemia?
Intermittent claudication history MI history Co-morbidities Examination to determine severity of ischaemia Absent sensation or movement Duration Pulses present - above or below femoral Atrial fibrillation
What are the investigations necessary in acute limb ischaemia?
ECG CXR Routine bloods Cross match Angiography for suspected in-situ thrombosis Straight to theatre if suspected embolus
What are the treatment options for acute limb ischaemia caused by embolus?
Analgesia and heparin first line Embolectomy if immediate danger Thrombolysis if time available Amputation if leg is un-salvageable and patient is fit May require fasciotomy
What are the treatment options for acute limb ischaemia caused by thrombosis?
Angiography, thrombolysis and PTA and bypass
or
Angiography and bypass if leg is salvageable
Amputation if leg is unsalvageable
What are the contraindications for thrombolysis?
Recent stroke
GI bleed
Bleeding diathesis
Age > 80 years
What are other causes of acute limb ischaemia?
Transection/ stretched/ compressed/ percussion injury Limb fractures/dislocations Stabbings Blunt injury from RTA Iatrogenic injury Popliteal aneurysm Intra-arterial drug administration Thoracic dissection
In what percentage of patients is percutaneous transluminal angiography (PTA) considered?
49%
What is PTA recommended for?
Short occlusions
What is the improvement of quality of life achieved by PTA?
Improves quality of life until at least 24/12
What kind of disease is unsuitable for PTA?
Extensive
What are the patient requirements for PTA?
Well-managed risk factors
Poor quality of life
Acceptably co-morbidity
Clear understanding of mortality and morbidity
What are the advantages and disadvantages of angioplasty?
Less morbidity
Reduced latency rates
Less durable
What is the 5 year patency rate for aortobifemoral angioplasty?
90%
What is the 5 year patency rate for femoral above knee/popliteal angioplasty?
65-70% with vein graft
35% with PTFE graft
What is the 5 year patency rate for femoral posterior tibial angioplasty?
50% with vein graft
12% with PTFE graft
What is the mortality and morbidity of femoral-popliteal bypass?
2% mortality
5-12% morbidity
What is the amputation rate following femoral-popliteal bypass?
30 day 0.6%
future 0.2-3.3%
What is the re-intervention rate following femoral-popliteal bypass?
18.3-38.8%
What is the five year latency rate of a femoral-popliteal bypass?
45-73% - depends on conduit
What are the amputation options in critical limb ischaemia?
Digital
Transmetatarsal
Below knee
Above knee
What is the prosthetic mobility following amputation?
Unlimited household in;
80% below knee
40% above knee
Outdoor in;
65% below knee
43% above knee
What is the energy cost of walking following amputation?
63% increase below knee
117% increase above knee
