Chronic limb ischaemia Flashcards
What is critical limb ischaemia?
decrease in limb perfusion that poses a threat to limb viability(leading to rest pain, ulcers and gangrene) that occurs for more than 2 weeks
What are the clinical features of critical limb ischaemia?
- rest pain that is only allevaited by opioids(codeine) for more than 2 weeks
- gangrene or ulcers over toes or feet
How should we interpret the ABI?
0,4 to 0,9 claudication
0,2 to 0,4 rest pain
0,0 to 0,2 ulcers/tissue loss(gangrene)
What are the features of the rest pain?
- rest pain worse distally
- the pain is worse when lifted(because it is against gravity). It gets better when laying on the side of the bed
- the only that helps is analgesia(opiods)
What are the features of the ischaemic ulcers?
- often painul
- usually from mild trauma and non healing wounds
- usually dry,deep and punctate
- can become infected that leads to a cellulitis/abscess that can cause bone osteomyelitis
Where do the ulcers usually occur?
-bunions, lateral malleolus, tips of the toes, heel of the foot
What are the features of the gangrene?
- can be wet or dry
- wet: moist, swollen and often blistered-emergenency amputation neede here
dry: hard, dry texture-you can see the demarcation between normal and gangrenous foot-safe surgery
What is non-critical limb ischaemia?
- intermittent claudication of a defined muscle group upon walking or exertion and relieved by rest
Which arteries are the problem in calf claudication?
-superficial femoral near adductor hiatus or the popliteal artery
Which arteries are the problem in foot claudication?
-peroneal artery disease and tibial
Which arteries are the problem in thigh claudication?
- femoral artery
- aortoiliac artery
What are the main causes of vascular disease?
- artherosclerosis
- takayasus disease, vasospasm, buergers disease
What is LeRiches syndrome?
- occlusion of the aorta and external and internal iliacs
- classical tetrad of buttock claudication,absent femoral pulses and impotence in men
What is neurogenic claudication?
- when the pt. has to sit down frequently and flex their spine
- this is because the cord is compressed in spinal stenosis
- paraesthesia is a common feature
Where do venous ulcers usually occur?
-medial malleolus
What is beurgers test?
- you will lift both of the patients legs together to compare
- lift the leg until the toes become pale
- in a normal patient the leg can be 90 degrees and there will be no changes
- in ischaemia the leg can be less than 30-40
- put the leg over the side of the bed and then there will be reactive hyperaemia that shows increased acidity and autonomic response
How do we take the ankle brachial index?
- compare brachial and ankle pressures
- put BP cuff around arm and have doppler at the brachial artery and inflate until you cannot hear the artery. deflate the cuff again and measure the pressure you can hear the artery at
- measure the ankle by putting the cuff around the calf and measure the dorsalis pedis and the posterior tibialis
- take the highest ankle reading
- divide the ankle pressure by the brachial pressure
What is an arterial duplex ultrasound?
- It is less invasive than a DSA/angiogram
- it has 2 modalities (2D duplex ultrasound)
- can define anatomy of the occlusion and look for good arteries that will be a good landing zone for bypasses
What is a DSA? Or angiogram
- invasive procedure that is done when angioplasty and stenting has been planned for
- digital subtraction means that the bone is removed so that we can visualize the arteries better
What are the risks of an angiogram?
- Bleeding from the arterial puncture
- Dissection
- Damage to artery with worsening ischaemia
What are the 3 L’S?
- Life-does they disease threaten life
- Limb-will the patient lose their limb
- Lifestyle -will their lifestyle be severely impacted
What is the treatment for non-critical limb ischaemia?
- Conservative
- stop smoking
- assess cardiovascular risks with cardiologist
- antiplatelets(aspirin) and statins
- exercise daily 30-1 hour
- podiatrist for foot care
- Monitor regularly ankle brachial index
What is the interventional treatment for non-critical ischaemia?
- Endovascular or surgery
- at least 6 months of conservative treatment first
- monitor claudication with ABPI and if the patient experiences claudication at<50m
- angioplasty or bypass will be the option
What is the stages of the Fontaine system?
- Asymptomatic
2a. Mild claudication
2b. Moderate to severe claudication - Ischaemic rest pain
- Ulceration or gangrene
What are the 2 ways to revascularise?
- angioplasty
- bypass surgery
When do we do a bypass?
- when we cannot do an angioplasty
- when there is complete occlusion and the lesion extends for a long distance
What is an angioplasty?
- used for focal stenotic lesions and large vessels
- the problem is that it can restenose
What are the 3d’s required for an amputation?
- dead tissue
- dangerous(sepsis that is ascernding) gangrene
- damn nuisance-non viable limb, smelly
What are the causes of chronic peripheral vascular disease?
- atherosclerosis
- HIV
- vasculitis
- hypercoaguability
- Buergers disease
What are the risk factors associated with peripheral vascular disease?
- smoking
- hypertension
- hyperlipidaemia
- diabbetes
- poor socio-economic background
- gender
- chronic renal disease
- old age
What are the 3 symptoms of chronic peripheral vascular disease?
- rest pain
- intermittent claudication
- impotence
What is the differential diagnosis for claudication?
- osteoarthritis of the knee or hip
- venous claudication
- atheletes chronic compartment syndrome
- neurospinal compartment syndrome
What is intermittent claudication?
This is muscle pain caused by ischemia(exercise), and is relieved by rest
How does rest pain usually present?
It presents with burning pain in the toes/foot caussed by decreased cardiac output and is worse at night
-it is relieved by hanging the foot off of the bed or walking
What is the differential diagnosis of rest pain?
- diabetes or other neuropathy
2. local pathology like gout
Which blood vessels are involved in impotence?
- bilateral aorto-iliac disease
also known as le riche syndrome
What are the clinical signs of chronic peripheral disease?
- pallor upon elevation
- cold extremity
- rubor
- bruit
- atrophy of the limb
- trophic changes to the nails, hair and skin
- ulcertion
- gangrene
What are the different pulses we feel for and what levels do they indicate?
- absent femoral pulse- aorto iliac
- absent popliteal pulse- femeo-politeal
- absent foot pulse-trifurcation
4
What is the gold standard special investiation?
DSA
What is the management of claudication?
- Stop smoking
- Manage risk factors for hypertension, DM, cholesterol
- Start on aspirin
- Start statins
- Start patient on supervised exercise program
Managment of critical limb ischaemia?
- Refer to vascular surgeon
- Imaging and revascularisation will be attempted
- Thereafter amputation of the toes
What are the 3 treatment options for critical limb ischaemia?
- Amputation
- surgical-bypass, endarterectomy(femoral artery), sympatectomy
- endovascular
What are the 2 types of bypass material we can use?
- synthetic like Dacron in aortoiliac bypasses
2. Autogenous coming from the great saphenous vein, cephalic , basilic veins etc. which cause less infection
What are the 4 types of bypasses we can do at the aorta?
- FEM-fem bypass
- aortofemoral bypass
- axillobifemoral bypass
- thoracobifemoral bypass
What is the treatment options for septic diabetic foot?
- Resuscitate patient
- treat ketoacidosis
- give IV fluids
- start on antibiotics
- insulin
- correct electrolytes - debridement of the septic foot and possible amputation/revascularise
What is the carotid endarecterecomy and when do we do it?
- > 70% stenosis in symptomatic patients
- 50-70% with symptomatic patients mostly
- if >70% stenosis and asymptomatic but with high risk profile
This must be done within 2 weeks
