Vascular Disease Flashcards
what causes peripheral vascular disease and where does it usually affect?
atherosclerosis
affecting aorta-iliac or infrainguinal arteries
what is the prevalence of peripheral vascular disease and what is the usual consequence of the condition?
7% middle aged men
4.5% middle aged women
these patients are more likely to die of MI or stroke rather than losing a leg
what classification system is used to assess chronic limb ischaemia
fontaine classification
what are the stages in the fontaine classification of chronic limb ischaemia?
I - asymptomatic
II - intermittent claudication
III - rest pain/nocturnal pain
IV - necrosis/ gangrene
what is intermittent claudication?
cramping muscular pain, which is brought on by exertion, relieved by rest and is reproducible by walking that distance again
what is aorto-iliac disease?
exertional discomfort mainly in the calf which is relieved by rest
what are the signs of peripheral vascular disease?
lower limbs are cold with dry skin and lack of hair
pulses may be diminished or absent
ulceration may occur in association with dark discolouration of toes or gangrene
examine abdomen for possible aneurysm
what is the definition of peripheral vascular disease?
More correctly known as peripheral arterial disease (PAD), this refers to disease of the peripheral arteries (i.e. not the coronary or brain arteries) which causes narrowing (stenosis) or occlusion and affects the blood supply to the limbs (generally speaking to the lower limbs)
what can peripheral vascular disease a major cause of?
acute and chronic limb ischaemia
what is chronic limb ischaemia classified as?
intermittent claudication or critical limb ischaemia
when does PAD become critical ischaemia and what action must be taken?
when it reaches the level when it threatens the loss of limb
patient generally requires intervention such as open surgery or endovascular revascularisation to salvage the limb
what is the pathogenesis of atherosclerosis?
- formation of fatty streak
- inflammation and accumulation of foam cell macrophages
- fibrosis and progressive luminal narrowing
- plaque rupture or ulceration
- thrombosis or thromboembolism
what are the non-modifiable risk factors for the development of peripheral vascular disease?
age
sex (men more than women)
family history (genetics)
race
what are the modifiable risk factors for the development of peripheral vascular disease?
smoking hyperlipidaemia hypertension diabetes sedentary lifestyle
what are the aspects of the examination of a patient with PAD?
- inspection-(both legs, pallor, mottling, skin change, loss of hair, ulcers, gangrene)
- palpation (temp, capillary refill time. pulses)
- auscultate (femoral bruit)
what is Buerger’s test?
before doing this check for back/hip pain.
reported as the angle at which the leg becomes pale when you elevate it against gravity (healthy limbs don’t do this)
swing the patient’s leg over the side and watch for a ‘sunset foot’ (arteriolar vasodilation with foot reperfusion)
what is ankle-brachial pressure index?
use hand held doppler and sphygmomanometer.
highest pedal pressure in each limb is divided by the highest brachial pressure
when may ankle bracchial pressure index not be reliable?
patients with diabetes or CKD often have calcified arteries making them hard to compress and give falsely high reading.
what are some of the differentials for peripheral vascular disease?
- spinal canal claudication (pulses present)
- osteoarthritis hip/knee (knee pain at rest)
- peripheral neuropathy (numbness and tingling)
- popliteal artery entrapment (young patients may have normal pulses)
- venous claudication (pain on walking with history of DVT)
- fibromuscular dysplasia
- Buerger’s disease (young males, heavy smokers)
What investigations should be performed in a patient with peripheral vascular disease?
- examine pulses
- ABPI-severity of disease
What does an ABPI of 0.5-0.9 suggest?
intermittent claudication
what does an ABPI of <0.5 suggest?
critical limb ischaemia
what are the types of diagnostic imaging used to detect and assess severity of peripheral vascular disease?
- digital subtraction angiography
- duplex ultrasound
- 3D contrast enhanced magnetic resonance angiography
- computed tomography and angiography
how is digital subtraction angiography used to investigate peripheral vascular disease?
arterial map but requires peripheral artery cannulation and exposes patient to iodinated contrast so used immediately before intervention
how is duplex ultrasound using B mode ultrasound and colour doppler used to investigate peripheral vascular disease?
accurate anatomical map of the lower limbs with high sensitivity and specificity compared to angiography. operator dependent
how is 3D contrast enhanced magnetic resonance angiography used to investigate peripheral vascular disease?
imaging of both legs with simple contrast injection without exposure to ionising radiation
high sensitivity and specificity
how is computed tomography and angiography used to investigate peripheral vascular diseas?
effective alternative to MRA but calcification can obscure stenosis
requires ionising contrast media
what is rest pain?
severe unremitting pain in the foot which stops a patient sleeping. it is partially relieved by dangling the foot over the end of the bed or standing on cold floor
what is the cause of intermittent claudication?
inadequate oxygen delivery to the muscles
angina is intermittent claudication of the cardiac muscle
what is critical limb ischaemia?
when chronic limb ischaemia threatens the loss of limb
ischaemic rest pain for more than 2 weeks despite analgesia or the presence of tissue loss (ulcers/gangrene)
what is leriche syndrome?
type of perpheral arterial disease
aortoiliac occlusive disease
what is the medical management of peripheral vascular disease?
- risk factor management
- smoking cessation
- chiropodist care for those with diabetes mellitus
- treat hypercholesterolaemia (if over 3.5mmol/L treat with statin)
- low dose aspirin
- exercise and avoid obesity
when is surgical vascular intervention usually indicated in claudication?
when is percutaneous transluinal angioplasty used for claudication?
first option and carried out via catheter inserted into femoral artery
when can arterial stents be used for claudication?
used in recurrent iliac disease and drug elating stentsallowing long term latency are being used
how can bypass procedures be performed in treatment of claudication?
using dacron, polytetrafluroethlene (PTFE) or autologous veins
bypasses to dital vessels have poorer long term potencies
what surgial treatment needs to be given in a patient with severe ischaemia with unreconstructable arterial disease
amputation (70% below knee)
what is the pharmacological management of claudication?
- cilostazol
- naftidrofury
- oxpentifylline, inositol nicotinate and cinnarizine
what is the mechanism of action of cilostazol,what is it used to treat and what is a typical dose?
phosphodiesterase III inhibitor increases level of cyclic AMP and cause vasodilation and reversible inhibits platelet aggregation
claudication
100mg daily can increase walking distance in patients with short distance claudication
what is the mechanism of action of Naftidrofuryl, what is it used to treat and what dose is typically given?
vasodilator agent inhibiting vascular and platelet 5-HT2 receptors reducing lactic acid levels
claudication
1-200mg 3 times a day increase walking distance and improve quality of life
what drugs are not currently recommended for treatment of claudication
Oxpentifylline, inositol nicotinate and cinnarizine
what is the risk of amputation in a patient with intermittent claudication?
1-3%
what percentage of patients with intermittent claudication will progress to chronic limb ischaemia?
20-25%
what treatment should be given to patients with peripheral arterial disease?
- antiplatelet
- statin (atorvastatin 80mg OD)
- BP management
- diabetic control
- smoking cessation
- exercise programmes
- naftidrofuryl
what is the management of critical limb ischaemia?
- refer to vascular surgeon
- limb revascularisation
- vascular MDT
what are the options for limb revascularisation?
- open surgical procedure (bypass, endartectomy)
- andovascular procedure (angioplasty, stenting)
- hybrid procedure
describe open surgical procedures used to treat critical limb ischaemia?
bypass, endarterectomy autologous vein (eg great saphenous vein) is preferred to prosthetic (dacron/PTFE) graft wherever possible, particularly for below the knee disease
describe endovascular procedure?
angioplasty, stenting
technology is moving very quickly, various drug coated balloons, drug eluting stents etc
what is a hybrid approach in management of critical limb ischaemia?
combination of both open and endovascular surgical techniques
what is critical limb ischaemia?
end of the spectrum of chronic limb ischaemia
usually occurs after history of intermittent claudication but can happen in patients who are immobile without prior intermittent claudication
the limb is at risk
what is the core clinical feature of critical limb ischaemia?
- rest pain
- pain felt in toes/forefoot as this is the most distal site
- pain often wakes patient up at night due to loss of gravity in helping foot perfusion
- patients typically hang their legs over the side of the bed of sleep in chairs
what is percutaneous transluminal angiography/angioplasty?
- an arterial puncture seldinger technique places a sheat and catheter within the arterial tree. injection of contrast gives a ‘roadmap’ of the vessels
- digital subtraction angiography (removes all backgrounf structures, such as bone)
what are the risks and benefits of using percutaneous transluminal angioplasty?
- gold standard
- radiation dose must be considered
- uses iodinated contrast-renal impairment (CO2 as alternative)
- risk of damage to vessels, bleeding, emboli, dissection, pseudoaneurysm
- endovascular procedures such as balloon angioplasty or stenting can be performed at the same time
what are the indications for percutaneous transluminal angioplasty and arterial reconstruciton surgery?
- Angina patients
- Acute myocardial infarction
- Intermittent claudication that interferes with lifestyle and/or ability to work
- Non-healing wounds
- Chronic limb ischaemia
- Infection/ gangrene
- These all depend on the extent of disease, how salvageable the limb is (in the case of peripheral arterial disease), how significant the procedure would be to the patient’s quality of life and how fit the patient is to undergo surgery
describe the proces of percutaneous transluminal angioplasty?
- PTA describes the process of fixing the vessel wall; it involved passing a small plastic tube (with a balloon in a stent at the end of it) through an artery in the leg. It takes about an hour and a half.
- Once the wire reaches the blockage, the balloon is inflated to expand the vessel. This then expands the stent (which is ultimately like chicken wire) which stays in the vessel to keep it so that blood can flow through it.
- X-rays will also be taken at the same time to make sure that the blockage is opened; once it is, the plastic tube can be removed
what are the possible risks of percutaneous transluminal angioplasty and arterial reconstruction surgery?
- Haemorrhage
- Wound infection
- Nerve injury
- Thrombosis
- MI
- Arrhythmias
- Leg oedema
- Pulmonary oedema
- Bleeding/ clot at the catheter insertion site
- Restenosis = blockage in blood vessels after procedure
- There is also risk of rupturing the vessel, though this will be considered and reflected in the type of stent used. Burr stent has little holes in whereas a covered stent has no holes, allowing it to patch up ruptured vessels.
- Most patients go home the next day.
what are the characteristics of venous ulcers?
- painful-relieved by elevation
- commonly affect gaiter (perimalleolar) area
- ulcer is large, shallow, and irregular with exudative and granulating base
what are the associated features of venous ulcers?
- warm skin
- normal peripheral pulses
- varicose veins
- leg oedema
- haemosiderin pigmentation (leaching of iron from blood into soft tissues)
- venous eczema
- lipodermatosclerosis and atrophie blanche
what are the risk factors for developing venous ulcers?
- superficial venous incompetence (varicose veins)
- previous DVT
- phlebitis
- previous fracture, trauma or surgery to leg
- family history
- symptoms of venous incompetence including leg pain, itching, swelling, pigmentation, eczema and ulceration
Describe the characteristics of arterial ulcers?
- painful and worse when legs are elevated
- most commonly affect pressure and trauma sites (pretibial and supra-malleolar) and distal points such as toes
- lesion is typically small, deep, sharply defined (punched out appearance with time) often with necrotic base
- represent advanced PAD critical ischaemia
what are the associated features with arterial ulcers?
- cold skin
- weak or absent peripheral pulses
- shiny pale skin
- loss of hair
what are the risk factors associated with developing arterial leg ulcers?
- peripheral arterial disease
- coronary heart disease
- history of stroke or transient ischaemic attack
- diabetes mellitus
- obesity and immobility
what are mixed ulcers?
arterial and venous
shallow, irregular exudative gaiter area ulcers (venous) with smaller punched out deep ulcers on dorsum of the feet (arterial)
what are the characteristics of diabetic ulcers?
- usually foot ulcer rather than leg
- most commonly affects pressure sites: soles, heels, toes, metatarsal heads
- painless with absent sensation
- peripheral neuropathy secondary to diabetes
- lesion usually punched out, variable size and depth and granulating base
- many diabetics have coexisting PAD so may be neuroischaemic ulcer
what are the associated features seen in a patent with diabetic ulcers?
warm skin
peripheral neuropathy
normal peripheral pulses
what are the causes of venous ulcers?
- Most due to from chronic venous insufficiency (valves incompetent -> reflux -> pooling of blood in lower limb -> sustained venous hypertension)
- Others due to capillary fibrin cuff or leucocyte sequestration
what are the causes of arterial ulcers?
-Due to reduced arterial blood supply to the lower limb -> hypoxia & tissue damage.
Most common cause = atherosclerosis
-Other causes include diabetes (which involves poor quality endothelium & microvascular damage, worsening wound healing), vasculitis, thalassaemia & SCD
generally speaking what are leg ulcers?
a breach in epithelial integrity of the skin
- occur between the knee and malleoli
- chronic when it has been present for more than 6 weeks
- > 90% of chronic leg ulcers are vascular
- chronic venous hypertension is the primary cause of 70% of leg ulcers
what is the prevalence of chronic venous ulceration?
0.5%-1%
in patients over 80 it rises to 3%
what is the difference in prevalence in different socioeconomic groups?
no difference in prevelance between socioeconomic classes but people in lower social class take longer to heal
how much of NHS budget does leg ulcers make up?
2%
what are the investigations involved in recurrent leg ulcers?
- based on underlying aetiology
- ABPI to exclude arterial disease
- venous-venous duplex ultrasound to look for venous incompetence
- arterial-arterial imaging-usually multilevel disesae
- diabetic-assess sensation-monofilament test. check HBA1C. foot X-rays for osteomyelitis. arterial imaging as for PAD if neuroischaemia
how do you interpret the ABPI score?
- > 1.3: generally indicates calcified, stiff arteries. May be seen with advanced age, diabetes, or chronic kidney disease
- 0.9 – 1.29: normal
- 0.8 – 0.9: borderline-often requires additional tests such as exercise ABPI (treadmill)
- <0.8: PAD likely
- <0.5: indicates severe PAD and should be referred urgently
what is the management for diabetic face ulcers?
- Need an MDT approach
- Podiatry and orthotists – debridement, offloading/pressure relieving footwear
- Diabetology – management of diabetes
- Vascular surgeon – improving perfusion, controlling infection soft tissue, osteomyelitis
