Peripheral Vascular Disease Flashcards
What is peripheral vascular disease
A range of arterial syndromes caused by atherosclerotic obstruction of the lower-extremity arteries
How do you classify peripheral vascular disease
Rutherford classification
What are the different stages of the Rutherford classification
0 - Asymptomatic
1 - Mild claudication
2 - Moderate claudication
3 - Severe claudication
4 - Rest pain
5 - Ischaemic ulceration not exceeding ulcer of the digits of the foot
6 - Severe ischaemic ulcers or frank gangrene
What are some other (rarer) causes of claudication
Aortic coarctation
Arterial tumour
Arterial dissection
Even rarer causes:-
Takayasu’s arteritis
Thoracic outlet obstruction
Buerger’s disease
What is the definition of claudication
Inadequate blood flow during exercise, causing fatigue, discomfort or pain
What is the defintion of critical limb ischaemia
Patients with all of:
- Rest pain (constant, distal worse, worse at night or on raising feet) or tissue loss (ulceration or gangrene)
- ABPI less than 40mmHg
- At least 2 weeks of symptoms
Due to compromised blood flow to extremity
What is the definition of acute limb ischaemia
Sudden decrease in limb perfusion that threatens limb viability
Associated with the 6 Ps:- Pain Pulselessness Pallor Perishingly cold Paralysis Paraesthesis (last two- require immediate revascularisation)
Which artery causes calf claudication
Superficial femoral artery stenosis
Which artery causes thigh claudication
External iliac artery stenosis
Which artery causes buttock claudication
Stenosis of the lower aorta and common iliac artery
*May be associated with impotence
What are some differentials of claudication
Musculoskeletal - osteoarthritis
Neurological - spinal stenosis
Vascular - intermittent claudication, DVT
Why might a limb be red in peripheral vascular disease
Vasodilatation of the microcirculation due to tissue ischaemia
What is ankle brachial pressure index
Ankle pressure divided by brachial pressure
Normal index is 1
As the perfusion of the leg begins to decrease in a patient with peripheral vascular disease, the ratio begins to fall
What is the ABPI of a patient with intermittent claudication
0.5-0.8
What is the ABPI of a patient with rest pain
Less than 0.5
What are the features of rest pain
Felt in the least well perfused areas of the leg - over the toes and forefoot
Very severe, aching pain
Wakes the patient from sleep
Relieved by walking/hanging the foot over the edge of the bed
*Calf pain at night in the absence of foot pain is unlikely ischaemic
What are the features of critical limb ischaemia used to define it
Presence of arterial ulcers or gangrene OR
Rest pain that lasts for 2 or more weeks and is only relieve by opiate analgesia AND
An absolute ankle pressure of less than 50mmHg
Why do patients with rest pain get more severe pain at night
Decreased perfusion of the limb due to:-
Decreased cardiac output at night
Reduced effect of gravity (which normally increases blood supply to the legs)
Dilatation of the skin vessels due to the warmth of the bedclothes
What is the non-surgical management of peripheral vascular disease
Management of CV risk factors
Exercise programmes- “walk through pain”
Analgesia
*Naftidrofuryl oxalate (vasodilator therapy) available for patients who do not want revascularization surgery
What is the surgical management of peripheral vascular disease
Duplex ultrasound must be performed when revascularization is considered
Endovascular approach: Angioplasty, stunting or balloon
Surgical:
Endarterectomy- for localised lesions only
Anatomical bypass surgery- around lesion e.g. ileo-femoral bypass
Extra-anatomical bypass e.g. fem-fem cross over, ax-fem bypass
Amputation
What is the pathophysiology of reactive hyperaemia
Due to the vasodilation of microcirculation, secondary to the build up of toxic metabolites due to a period of oxygen deprivation.
What would patients with critical limb ischaemia die of without amputation?
Gangrene or sepsis
What would be the symptoms of a patient with critical limb ischaemia without treatment?
Unremitting pain at rest requiring opiates
Ulceration without pain (especially in DM)
Limb loss if untreated
What is acute-on-chronic limb ischaemia?
Acute ischaemia that occurs on a background of claudication
What is the usual cause for acute-on-chronic limb ischaemia?
Thrombotic occlusion of atherosclerotic vessels
What symptoms would you see with acute-on-chronic limb ischaemia?
Legs may be pale, cold and pulseless but no parasthesia or paralysis present
Why are the symptoms of acute-on-chronic limb ischaemia not as severe as those of acute limb ischaemia?
As collaterals have developed due to the chronic nature of the disease so the degree of ischaemia is not as severe.
What are the causes of acute limb ischaemia?
- Embolic (solid/liquid/gas travelling from one point of circulation to a point in the distal circulation where it causes obstruction). Look proximal for source: heart valves (IE), AF (thrombus), ventricle (post MI)
- Thrombotic
How do you treat acute limb ischaemia due to embolic occlussion?
Embolectomy- cut in artery, place uninflated balloon down past embolus, inflate and pull up to take embolus with it.
Must be done within 6 hours to avoid irreversible tissue loss
How to you manage acute-on-chronic ischaemia?
Longer time interval than acute:
- Thrombolysis
- Thrombolysis + angioplasty
- Bypass graft
Why do you need to feel for pulses in a patient with varicose veins?
Certain percentage will also have arterial disease
What is Aortoiliac Occlusive Disease (AKA Leriche syndrome)?
Atherosclerotic occlusion of abdominal aorta and iliacs
What are the classic triad of symptoms of Aortoiliac Occlusive Disease (AKA Leriche syndrome)?
Buttock claudication and wasting
Erectile dysfunction
Absent femoral pulses
What is a Duplex scan?
2 parts:
- B-mode USS
- Multidirectional Doppler: gives idea re flow. Monophasic wave form suggests significant stenosis in arterial system above.
What differentiates intermittent claudication from spinal claudication?
Spinal- positional: better upstairs and on leaning forward. Ill defined pain
Arterial- set difference, reproducible, worse upstairs, eased by rest
What is Buerger’s test?
Lift leg to 45 degrees and observe for pallor and venous guttering
Normal- raise leg to 90 degrees with no pallor
What would a Buerger’s angle of 20 degrees be suggestive of?
Severe ischaemia