Peripheral Vascular Disease

Question 1

Define/describe peripheral vascular disease.

Answer 1

AKA peripheral arterial (occlusive) disease

Chronic PVD is due to atherosclerosis of peripheral arteries. Usually affecting legs but may affect arms.

Acute limb ischaemia results from total occlusion of an artery, due to progression of longstanding disease or an acute embolus (e.g. from AF). Tissue necrosis results within 6 hours if not treated.
-PVD is often synonymous with arterial occlusive disease. However, other types of peripheral vascular disease include- venous disease, aneurysmal disease and carotid artery disease.

Question 2

What are the signs and symptoms of chronic peripheral vascular disease?

Answer 2

Locations of pain and affected arteries-

• COMMONEST SITE Upper 2/3 of calf (superficial femoral artery)
• SECOND COMMONEST SITE Buttock and hip (aortic and iliac artery)
• Thigh (iliac or common femoral artery)
• Lower 1/3 of calf (popliteal artery)
• Foot (tibial or peroneal artery)

CLAUDICATION

• Claudication is a predictable, reproducible pain on exertion caused by ischaemia of the muscle, which is relieved by rest.
• 30% have classic intermittent claudication but most have a more atypical pattern, with some being asymptomatic. There may be a limp.
• Quantify severity by asking about how many yards they can walk before they have to stop because of the pain, on the flat, at a regular pace, on their best day.

CRITICAL LIMB ISCHAEMIA-

• Rest pain, unrelieved by medication for more than 2 weeks and/or evidence of tissue loss (ulcer or gangrene)
• In the context of neuropathy pain may be absent.
• Pain is in the feet and toes rather than calves. Worse at night due to reduced gravitational pull, so patient may sleep in a dependent position in an attempt to maintain perfusion. This can result in a swollen leg, which may also be red from metabolite-triggered capillary dilation.

Question 3

What is the Fontaine classification?

Answer 3

1. Asymptomatic
2. Intermittent claudication 2a) if stop >200m 2b) if <200m
3. Nocturnal pain or pain on rest
4. Necrosis / gangrene

Question 4

How does acute limb ischaemia present?

Answer 4

THE 6 Ps

Pain at rest
Pulselessness
Pale
Parasthesia
Perishingly cold
Paralysis- LATE FEATURE SUGGESTING IRREVERSIBLE DAMAGE.

Question 5

What are the differentials for leg pain?

Answer 5

• Musculoskeletal eg. osteoarthritis
• Vascular- PVD, DVT
• Neurospinal- disc degeneration, spinal stenosis
• Neuropathic- diabetes, alcoholic neuropathy

Question 6

How is PVD investigated?

Answer 6

Initial investigations-
Diagnose with ABPI-
-The ratio of systolic blood pressure at the ankle and arm, measured using doppler US.
-Procedure- take after 10 minutes at rest, and use the sides with the highest measurements.
-Results- Roughly <0.9 is claudication, <0.6 is rest pain and <0.3 is impending gangrene.

Cardiovascular investigations-
ECG, lipids, glucose and BP.

Imaging-

• Duplex ultrasound- combines usual grayscale US image with colour-doppler US to visualise flow.
• Helps determine site of disease
• Angiography if surgery considered-
• MR angio is a good choice when available
• CT angio is better for showing wall abnormalities (aneurysm) and more available than MRA. Risks include contrast nephropathy and radiation exposure.
• Intra-arterial digital subtraction angiogram (invasive)- gold standard that also allows treatment. Risks- thrombus embolisation and/or vessel puncture, with 1% leading to limb loss.

Question 7

How is PVD managed?

Answer 7

Conservative medical management-

• Advise patients to keep active. Can refer to exercise rehab programme.
• Cardiovascular disease prevention- clopidogrel first line in PVD.
• Foot care
• The vasodilator naftidrofuryl can mildly increase walking distance.

Revascularisation-
-Indications- treatment resistant disease, critical limb ischaemia, acute limb ischaemia.
-Options- surgical bypass, surgical endarterectomy, radiological angioplasty and stunting (easier with larger vessels eg. iliac)
Bypass may involve grafting native vessel.
-Acute limb ischaemia- heparin IV then embolectomy with Fogarty catheter. Thrombolysis with alteplase if not surgically fit.
-Reperfusion injury may result from revascularisation, due to the systemic release of substances in the damaged tissue eg. potassium, myoglobin. Other complications include graft failure and limb loss.

Amputation-
As a last resort, considered in patients with ulceration and gangrene.

Question 8

What are the complications of PVD?

Answer 8

• Arterial ulcers
• Gangrene
• Amputation