vascular Flashcards
Peripheral Vascular/Artery Disease definition
• Obstruction or narrowing of arteries distal to the aorta and not within the coronary or brain circulation.
• Different classifications FONTAINE’S STAGES:
- I – asymptomatic
- II – intermitten claudication
- IIa – pain with walking more than 200m
- IIb – pain with walking less than 200m
- III – rest/nocturnal pain
- IV – necrosis, gangrene and/or ulceration
how common is Peripheral Vascular/Artery Disease
- Affects 4-12% of people aged 55-70 and 15-20% of people aged >70
- Acute limb ischaemia has an incidence of around 1 in 12,000 people per year
- Chronic limb ischaemia is much more common than this
who does Peripheral Vascular/Artery Disease affect
- 7% of middle-aged men and 4.5% of middle-aged women
* Strongly age-related
biological causes of Peripheral Vascular/Artery Disease
- PVD can result from atherosclerosis, inflammatory processes leading to stenosis, an embolism, or thrombus formation
- It causes either acute or chronic ischaemia.
symptoms of Peripheral Vascular/Artery Disease
ACUTE LIMB ISCHAEMIA:
- Onset of leg pain over minutes, hours or days
- Pulseless, pallor, painful, paraesthesia, paralysis and perishingly cold
CHRONIC LIMB ISCHAEMIA:
- Progressive development of cramp like pain in the calf, thigh or buttock after walking a given distance (claudication distance) – buttock pain suggests iliac disease, calf pain suggests femoral disease; buttock pain + male impotence suggests Leriche syndrome
BOTH:
- Pain resolves with rest
- Pain at night resolved by hanging leg out of bed
- Male impotence – suggests Leriche syndrome if with buttock pain
- Painful ulcer
signs for Peripheral Vascular/Artery Disease
6 Ps of Acute Limb Ischaemia (Acute Occlusion Causing Ischaemia):
• Pallor – redness returns on lowering leg
• Pulselessness – absent femoral, popliteal or foot pulses
• Pain
• Paralysis
• Parasthaesia
• Perishing with cold
General Signs: • Hair loss • Delayed capillary refill (>15s) • Small, painful, ‘punched-out’ ulcers over bony prominences • Thickened, brittle toenails • Smooth, shiny, dry skin • Hang legs over the bed • +ve Buerger’s test – angle to which the leg has to be raised for it to turn pale; normal = no pallor even at 90 degrees; <20 degrees is positive sign
DDx for Peripheral Vascular/Artery Disease
- Sciatica/spinal cord claudication - all pulses present; shooting pain
- DVT/venous claudication – hot, swollen leg; no hair loss; painless ulcer with ragged edges; haemosiderin
- Knee or hip osteoarthritis – joint pain and stiffness; worse in evening; pulses present; no pallor or hair loss
- Peripheral neuropathy – numbness or tingling; pulses present; weakness; gait abnormalities; not cold or pale
- Popliteal artery entrapment – young patients; congenital; myotomy of gastrocnemius; diminished pulses on forced plantar/dorsiflexion
- Buerger’s disease – young to middle aged presentation; affects mainly males; two or more limbs affected; Raynaud’s phenomenon
Investigations for Peripheral Vascular/Artery Disease
ABPI (ANKLE BRACHIAL PRESSURE INDEX):
• Measure 4 ankle and 2 arm pressures
• Right ABPI = highest of right ankle pressures/highest arm pressure
• Left ABPI = highest of left ankle pressures/highest arm pressure
• <1 = circulatory problems
• >0.9 = borderline – higher prognosis
• 0.5-0.9 = PAD
• <0.5 = critical limb ischaemia – low prognosis
• If resting ABPI is normal then an exercise one can be done – measure before and after exercise, if there is a drop of 15-20% then this is diagnostic of PAD
• >1.4 = incompressible arteries – seen in DM or renal disease, falsely high results
COLOUR DUPLEX USS:
• If ABPI abnormal
• To assess extent of atherosclerosis
MR/CT ANGIOGRAPHY:
• If considering intervention
• Largely replaced digital subtraction angiography
Management for Peripheral Vascular/Artery Disease
RISK FACTOR MODIFICATION: • Quit smoking • Treat HTN and high cholesterol • Weight reduction if overweight • DM control • Exercise to point of maximal pain • Supervised exercise programmes – reduce symptoms by improving collateral blood flow
MEDICAL:
• Clopidogrel to reduce MI/stroke risk 1st line
• Vasoactive drugs e.g. naftidrofuryl oxidate offer modest benefit and recommended only in those who do not wish to undergo revascularisation and if exercise fails to improve symptoms
SURGICAL – if conservative measures fail; PAD severely affecting patient’s life-style or becoming limb threatening
PERCUTANEOUS TRANSLUMINAL ANGIOPLASTY:
• For disease limited ot a single arterial segment
• Balloon inflated in narrowed segment
SURGICAL RECONSTRUCTION:
• If atheramotous disease is extensive but distal run-off is good
• Arterial reconstruction with bypass graft
• Femoral-popliteal bypass, femoral-femoral crossover, aorto-bifemoral bypass grafts
• Autolgous vein grafts are superior to prosthetic grafts
AMPUTATION:
• In sever ischaemia with unreconstructable arterial disease
• <3% patients with intermittent claudication require major amputation within 5 years
• Knee should be preserved wherever possible as it improves mobility and rehabilitation potential
Prognosis for Peripheral Vascular/Artery Disease
Outcome for patients presenting with intermittent claudication over five years:
• 50% will improve, 25% will stabilise and 25% will worsen. Of those who worsen, 20% (5% of total) will need intervention and 8% (2% of total) will need a major limb amputation.
• 5-10% will have a non-fatal cardiovascular event.
• 30% will die: cardiac 16%, cerebral 4%, other vascular 3%, non-vascular 7%.
• 55-60% will survive with no cardiovascular event.
Abdominal Aortic Aneurysm (AAA) definition
- A permament and irreversible localised dilatation of the abdominal aorta by more than 50% of its normal diameter
- The abdominal aorta is normally 2cm so an AAA is classed as >3cm
- Majority of aortic aneurysms are abdominal but some can be thoracic and can also extend to affect the iliac, femoral and popliteal arteries
- 90% of AAAs oocur infrarenally, below the level of the renal arteries.
- TRUE ANEURYSM - involves all layers of the arterial wall. False aneurysms (pseudoaneurysms) involve a collection of blood in the outer layer only (adventitia) which communicates with the lumen
- Aneurysms can be fusiform (most AAAs) or sac-like (e.g. Berry Aneurysms)
how common is Abdominal Aortic Aneurysm (AAA)
- Incidence increases with age.
* Present in 3% of population >50y.
who does Abdominal Aortic Aneurysm (AAA) affect
- M 3x>F and in ¼ of male children of an affected individual.
- 8:1 in smokers.
- Rarely affects African/Hispanic, low prevalence in Asians, mainly affects Caucasians.
- Less common in diabetics.
biological causes of Abdominal Aortic Aneurysm (AAA)
Most will have no clear identifiable cause in these cases there may be:
- Atherosclerosis - new evidence suggests this is not the only factor and that there is also a distinct arterial pathology
- Trauma
- Infection e.g. mycotic aneurysm in endocarditis, tertiary syphilis
- Connective tissue disorders (e.g. Marfan’s, Ehlers-Danlos)
- Inflammatory e.g. Takayasu’s aortitis
pathophysiology of Abdominal Aortic Aneurysm (AAA)
- AAA results from a failure of the major structural proteins of the aorta – elastin and collagen
- The mechanism is not fully understood but it is to do with proteolysis or degradation of the proteins
- The elimination of elastin from the tunica media means the aortic wall is more susceptible to the influence of blood pressure
- The diameter of the aorta gradually decreases distally and infrarenally it contains less elastin which means the mechanical tension is higher
- This is why abdominal aneurysms are more common than thoracic
risk factors of Abdominal Aortic Aneurysm (AAA)
- Smoking – 8x more likely
- Male
- Fx– 15% of first degree releatives will also develop an AAA; probably strong genetic links
- Age
- HTN
- Hyperlipidaemia
- COPD
- DM seems to decrease the risk
symptoms of Abdominal Aortic Aneurysm (AAA)
- Most are asymptomatic and found on routine abdo exam
- As it expands it may cause:
- Epigastric pain radiating to back
- Pulsating sensations in abdomen
- Pain in chest, lower back or scrotum – due to pressure on nearby structures; back pain may be due to erosion of vertebral bodies
signs of Abdominal Aortic Aneurysm (AAA)
- Pulsatile abdominal swelling
- Aortic bruits
RUPTURED AAA MAY PRESENT WITH: • Pain in abdomen, back or loin – may be sudden and severe • Hypotension • Pulsatile and expansile abdominal mass • Syncope, shock or collapse • Sudden death
DDx of Abdominal Aortic Aneurysm (AAA)
- Acute abdomen e.g. cholecystitis, appendicitis, bowel obstruction, pancreatitis, pyelonephritis
- If TAA then other causes of chest pain e.g. MI, PE
Investigations of Abdominal Aortic Aneurysm (AAA)
• If suspected rupture, then investigations need to be swift and pertinent.
INVESTIGATIONS:
• BLOODS – FBC, clotting, renal function, liver function, cross-match if surgery planned, ESR/CRP if inflammatory cause suspected
• ECG
• IMAGING – do not waste time on if rupture, CT can be useful in more stable patient with uncertain diagnosis
• USS – used for intial assessment and follow-up, can assess to accuracy of 3mm
• MRI Angiography – put in two cannulas, call a vascular surgeon and anaesthetist, treat with ORh –ve, keep systolic bP <100mmHg, take blood for amylase, Hb, cross match
