Vascular Flashcards
(118 cards)
Incidence of chronic limb ischaemia?
5% of males >50 yrs have intermittent claudication
Definition of chronic limb ischaemia?
- Ankle artery pressure <50mmHg (toe <30mmHg)
- And either:
Persistent rest pain requiring analgesia for >2 weeks
Ulceration or gangrene.
Causes of chronic limb ischaemia?
Atherosclerosis
- Typically asymptomatic until 50% stenosis
- Vasculitis and fibromuscular dysplasia are very rare causes.
Atherosclerosis summary - pathophysiology?
- Endothelial injury: haemodynamic, HTN, icnreased lipids.
- Chronic inflammation
- Lipid-laden foam cells produce GFs, cytokines, ROS and MMPs.
- lymphocyte and SMC recruitment.
- SM proliferation: conversion of fatty streak to atherosclerotic plaque.
Difference between Arteriosclerosis and atherosclerosis?
Arteriosclerosis = general arterial hardening Atherosclerosis = Arterial hardening specifically due to atheroma
Atheroma pathology?
Fibrous cap: SM cells, lymphocytes, collagen
Necrotic centre: Cell debris, cholesterol, Ca, foam cells.
Risk factors for chronic limb ischaemia?
Modifiable: Smoking, BP, DM control, hyperlipidaemia, decreased exercise.
Non-modifiable: FH and PMH, Male, increased age, genetic.
Associates vascular diseases with chronic limb ischaemia?
IHD: 90% Carotid stenosis: 15% AAA. Renovascular disease. DM microvascular disease.
Presentation of chronic limb ischaemia?
Intermittent claudication
- Cramping pain after walking a fixed distance
- Pain rapidly relieved by rest
- Calf pain = superficial femoral disease (commonest)
- Buttock Pain = Iliac disease
What is the presentation of critical limb ischaemia?
Fontaine 3-4
1 or more of: Rest pain - Especially @ night - >2 weeks - Usually felt in the foot - Not helped by analgesia - Pt hangs foot out of bed - Due to decreased CO and loss of gravity help.
Ulceration
Gangrene
What is Leriche’ syndrome?
Leriche’s syndrome: aortoiliac occlusive disease
- Atherosclerotic occlusion of abdominal aorta and iliacs
Presents with triad
- Buttock claudication and wasting
- Erectile dysfunction
- Absent femoral pulses
What is Buerger’s Disease?
Thomboangiitis Obliterans
- Young, male heavy smoker
- Acute inflammation and thrombosis of arteries and veins in the hand and feet.
- Leads to ulceration + gangrene.
Signs of chronic limb ischaemia?
Pulses: Pulse and increased CRT (normall <2sec)
- Ulcers: painful, punched out, on pressure points.
- Nail dystrophy/onycholysis.
- Skin:cold, white, atrophy, absent hair.
- Venous guttering (veins collapse)
- Muscle atrophy
Decreased Buerger’s Angle
- >90: normal
- 20-30: ischaemia
- <20: Severe ischaemia.
+ve Buerger’s Sign - Reactive hyperaemia due to accumulation of deoxygenated blood in dilated capillaries.
What is Buerger’s test?
Patient is positioned supine.
Standing at bottom of bed, raise both of the patient’s feet to 45 degrees for 2-3mins.
- Look for pallor - Note at what angle this occurs. If less than 20 degrees indicates severe limb ischaemia.
Then drop leg over side.
- Look for reactive hyperaemia.
Clinical classification? - Fontaine?
- Asymptomatic
- Intermitted claudication
a. >200m
b. <200m - Ischaemic rest pain
- Ulceration/gangrene
What is the rutherford classification?
Mild claudication Moderate claudication Severe claudication Ischaemic rest pain Minor tissue loss Major tissue loss.
What are the investigations for chronic limb ischaemia?
Doppler Waveforms
- Normal: triphasic
- Mild stenosis: biphasic
- Severe stenosis: monophasic
What if ABPI is high? >1.4
Calcification: CRF, DM
>1.4 . Diabetes leading to high ABPI. Neuropathic and duplex shows its normal.
Can use toe pressure <30mmHg.
What is normal ABPI?
> or equal to 1.
What is asymptomatic ABPI?
Fontaine 1: 0.8-0.9
What is claudication ABPI?
Fontaine 2: 0.6-0.8
What is rest pain ABPI?
Fontaine 3: 0.3-0.6
What is ulceration and gangrene ABPI?
Fontaine 4 <0.3.
Walk Test
Walk on treadmill @ certain speed and incline to establish max claudication distance.
ABPI measured before and after: 20% decreased is significant