Peripheral Vascular Disease Flashcards
What is an aneurysm?
Dilatation of a vessel by more than 50% of its normal diameter - (around 3cm)
What is the normal aortic diameter?
1.2 – 2.0 cm
What is a false aneurysm?
There is a breach in vessel wall (surrounding structures act as vessel wall)
What is a true aneurysm?
The vessel wall is intact (i.e. all 3 layers)
What is the pathenogenesis of an aneurysm?
- Regulation of elastin/collagen in aortic wall
- Aneurysmal dilatation
- Increase in aortic wall stress
- Progressive dilatation
How do aneurysms present?
Asymptomatic (75% of AAA) –Identified on imaging for other pathology –Surveillance Symptomatic –Pain May mimic renal colic –“Trashing” –Rupture
How does an Abdominal Aortic Aneurysm rupture present?
- Sudden onset epigastric/central pain
- May radiate through to back
- May mimic renal colic
- Collapse
When would you intervene in a AAA?
if it grows over 0.5cm in 6 months or >1cm in a year
What is the only way to identify a ruptured AAA?
CT Scan
What are the two types of AAA imaging?
CT scan and Duplex Ultrasound
What are the two management options for an AAA?
Open Repair – open the body up
–Laparotomy
–Clamp aorta + iliacs
Endovascular Aneurysm Repair (EVAR) – requires a lot of follow up appointments
–Exclude AAA from ‘inside’ the vessel
–Inserted via peripheral artery
–X-ray guided
What has a lower mortality? EVAR or Open Repair?
EVAR
What can cause aneurysms?
Smoking Hypertension High Cholesterol CVD Diabetes
What is acute limb ischaemia?
Sudden loss of blood supply to a limb due to occlusion of native artery or bypass graft
What are the causes of Acute Limb Ischaemia?
Embolism Atheroembolism – atherosclerosis plaque can break off and travel down the limb Arterial dissection Trauma Extrinsic compression
What are the 6 Ps of acute limb ischaemia? (clinical features)
Pain Pallor Pulseless Perishingly cold Paraesthesia Paralysis
What does non blanching mottling mean?
Irrevesible ischaemia
Describe acute limb ischaemia pain?
Severe, sudden onset, resistant to analgesia
Calf/muscle tenderness with tight (‘woody’) compartment indicates muscle necrosis - Often irreversible ischaemia
Describe acute limb ischaemia pallor?
Limb initially white with empty veins
Later, capillaries fill with stagnated de-oxygenated blood giving a mottled appearance
What is salvageable acute limb ischaemia?
0-4hrs
- white foot
- painful
- sensorimotor deficit
What is partially reversible acute limb ischaemia?
4-12hrs
- mottled
- blanches on pressure
What is non salvageable acute limb ischaemia?
12+hrs
- fixed mottling
- non blanching
- paralysis
- compartments red
What is the management of acute limb ischaemia?
ABC – resuscitate and investigate FBC, U/Es, CK, Coag +/- Troponin ECG – MI, dysrhythmia CXR – underlying malignancy Anticoagulate –Stops propagation of thrombus Arterial Imaging Urgent CT angiogram/ Catheter angiogram
What do diabetic foot problems encompass?
Diabetic neuropathy
Peripheral vascular disease
Infection
Where could diabetic foot sepsis come from?
simple puncture wound
infection from the nail plate or inter-digital space
from a neuro-ischaemic ulcer
What is the biggest risk factor for loss of a leg?
Diabetes
How does diabetic infection spread?
Within the foot the intrinsic muscles of the digits are confined within rigid compartments
Infection tracks in the soft tissues into this rigid compartment.
If the build up of pus cannot escape – the pressure builds up in this rigid compartment rapidly leading to impairment of capillary blood flow and further ischaemia and further tissue damage.
–can rapidly progress to sepsis
What are the systemic clinical findings of diabetic foot sepsis?
Pyrexia Tachycardic Tachypnoeic Confused Kussmauls breathing
What are the local findings of diabetic foot sepsis?
Swollen affected digit (‘sausage’ like) Swollen forefoot (‘boggy’ feeling to swelling) Tenderness Ulcer with pus extruding Erythema, may track up the limb Patches of rapidly developing necrosis Crepitus in the soft tissues of the foot
What is the management of diabetic foot sepsis?
Vascular Surgical Emergency
Appropriate antibiotics -
Gram +ve cocci (S. aureus + Streptococcus sp.)
Gram –ve bacilli (E. coli, Klebsiella sp, Enterobacter, Proteus sp and Pseuodomonas sp.)
Anaerobes (Bacteroides)
How do you prevent diabetic foot sepsis?
adequate education
foot assessment (diabetic foot clinic, podiatrist)
pressure offloading footwear
What is intermittent claudication?
muscle ischaemia on exercise
What are the ranges for Ankle-Brachial Pressure?
Normal 0.9 - 1.2
Claudication0.4 - 0.85 (– 1.0)
Severe 0 - 4.5
What are the non invasive and invasive investigations of lower limb ischaemia?
Non invasive - Measurement of ABPI - Duplex ultrasound scanning Invasive - Magnetic resonance angiography (good cause no radiation, but need to lie for long) - CT angiography - quick - Catheter angiography
What is the treatment of lower limb ischaemia?
Slowing progression - Stop Smoking - Lipid Lowering - Antiplatelets - Hypertension Rx - Diabetes Rx - Life Style Issues Symptom improvement: - Angioplasty - Surgery - Exercise training
What is critical limb ischaemia?
Pain at rest = toe / foot ischaemia (nerve ending pain)
Ulcers/gangrene = severe ischaemia + damage
What are the amputation levels?
- transfemoral
- hip disarticulation
- through knee
- transtibial
