Vascular Surgery Flashcards
What is critical limb ischaemia?
A presentation of peripheral arterial disease
An ankle-brachial pressure index (ABPI) of < 0.5 is suggestive of critical limb ischaemia
What are the causes of critical limb ischaemia?
Atherosclerosis is the main cause
Vasculitis and fibromuscular dysplasia is very rare
What is the process of atherosclerosis?
- Endothelial injury: haemodynamic, HTN, lipids
- Chronic inflammation: Lipid-laden foam cells produce GFs, cytokines leading to lymphocyte and SMC recruitment
- Smooth muscle proliferation: conversion of fatty streak to
atherosclerotic plaque
What is the pathology of an atheroma plaque?
Fibrous cap: Smooth muscle cells, lymphocytes, collagen
Necrotic centre: cell debris, cholesterol, Calcium, foam cells
What are the modifiable risk factors for peripheral arterial disease?
Smoking
Blood pressure
DM control
Hyperlipidaemia
Exercise
What are the non-modifiable risk factors for peripheral arterial disease?
Past medical history
Family history (genetics)
Gender -male
Age
What are the three main patterns of peripheral arterial disease?
- Intermittent claudication
- Critical limb ischaemia
- Acute limb-threatening ischaemia
What are the features of intermittent claudication?
Cramping pain after walking a fixed distance
Pain rapidly relieved by rest
Vessel affected:
Calf pain = superficial femoral disease (commonest)
Buttock pain = iliac disease (internal or common)
What are the features of critical limb ischaemia?
Include one or more of:
1. rest pain in foot for more than 2 weeks
2. ulceration
3. gangrene
What is Leriche’s Syndrome?
Also known as Aortoiliac Occlusive Disease
Atherosclerotic occlusion of abdominal aorta and iliacs
Triad of:
1. Buttock claudication and wasting
2. Erectile dysfunction
3. Absent femoral pulses
What is Buerger’s Disease?
Also known as Thromboangiitis Obliterans
Seen in young, male, heavy smokers
Acute inflammation and thrombosis of arteries and veins in the hands and feet
Leads to ulceration and gangrene
What are the classifications of peripheral arterial disease based on the ankle-brachial pressure index (ABPI)?
1 = normal
0.6 - 0.9 = claudication
0.3 - 0.6 = rest pain (critical)
< 0.3 = impending (acute)
What is the most important modifiable risk factor in peripheral arterial disease?
Smoking
What are some appropriate investigations for peripheral arterial disease?
ABPI
Doppler wave forms:
1. Normal = triphasic
2. Mild stenosis = biphasic
3. Severe stenosis = monophonic
Walk test? Useful to determine maximum claudication distance
Bloods including glucose and lipids
Colour doppler US
What are the management options for peripheral arterial disease in general?
Conservative:
1. Treat co-morbidities (HTN, DM and obesity)
2. Exercise training
Medical:
1. For established cardiovascular disease = secondary prevention, atorvastatin 80mg and clopidogrel
Surgical (reserved for severe PAD):
1. Endovascular revascularisation
2. Surgical revascularisation
What is involved in end-vascular revascularisation?
Percutaenous transluminal angioplasty +/- stent placement
Endovascular techniques are typically used for short segment stenosis (e.g. < 10 cm), aortic iliac disease and high-risk patients
What is involved in surgical revascularisation?
Surgical bypass with an autologous vein or prosthetic material
endarterectomy
Open surgical techniques are typically used for long segment lesions (> 10 cm), multifocal lesions, lesions of the common femoral artery and purely infrapopliteal disease
When would amputation be considered in peripheral arterial disease?
Reserved for patients with critical limb ischaemia who are not suitable for other interventions such as angioplasty of bypass surgery
What drug could be used for peripheral arterial disease?
Naftidrofuryl oxalate: vasodilator, sometimes used for patients with a poor quality of life
What is acute limb-threatening ischaemia?
Surgical emergency
Severe presentation of peripheral arterial disease
What is acute limb-threatening ischaemia characterised by?
One or more of the 6 P’s:
1. Pale
2. Pulseless
3. Painful
4. Paralysed
5. Paraesthetic
6. ‘Perishing with cold’
What are the two main causes of acute limb-threatening ischaemia?
- Thrombus = due to rupture of atherosclerotic plaque
- Embolus = e.g. secondary to atrial fibrillation
What are the factors suggestive of a thrombus in acute limb-threatening ischaemia?
- Pre-existing claudication with sudden deterioration
- No obvious source for emboli
- Reduced or absent pulses in contralateral limb (bilateral)
- Evidence of widespread vascular disease (e.g. MI, stroke, TIA, previous vascular surgery)