Peripheral arterial and venous disease Flashcards
What are the lower limb veins divided into?
Superficial and deep
Where are superficial veins located?
Subcutaneous tissue
What do the superficial veins drain into?
Deep veins
Where are the deep veins located?
Within muscles
e.g. calf
What are the veins that go between superficial and deep veins called and why?
Perforating veins - because they perforate the deep fascia
What is the function of valves?
To prevent backflow of blood
What are the deep veins of the lower limb?
External iliac vein
Femoral vein
Popliteal vein
What are the superficial veins of the lower limb?
Long saphenous vein
Short saphenous vein
What does the long saphenous vein drain into?
Femoral vein
Describe the course of the long saphenous vein
Descends medially down though
posterior to knee
medially down leg
anterior to medial malleolus
What does the short saphenous vein drain into?
Popliteal vein
Describe the course of the short saphenous vein
Midline of posterior leg
What happens to blood flow when the muscles relax?
Deep veins expand
blood is sucked into the deep veins
from the superficial veins
What happens to blood flow when the muscles contract?
Muscles contract within their compartments
increases pressure within compartments
compresses deep veins
pushes blood along
What happens to velocity of blood after a stenosis? Why?
Increases
Because cross-sectional area of blood vessel decreases, same amount of blood moving through smaller area, has to move faster
What happens to blood flow after a stenosis?
Decreases
less blood passing through narrowed area of blood vessel
If flow increases, what happens to velocity?
Increases
more blood moving through same blood vessel means it has to move faster
If area of blood vessel decreases, what happens to velocity?
Increases
because same amount of blood moving through smaller vessel, so has to move faster
If area of blood vessel increases, what happens to velocity?
Decreases
because same amount of blood moving through larger vessel
can move slower
What is a varciose vein?
Tortuous, twisted or lengthened veins
Are varicose veins more common in men or women?
Men
What is the pathophysiology of varicose veins?
Wall of vein becomes weak
vein dilates
valves separate
become incompetent
What are the symptoms of varicose veins?
Heaviness
Tension
Aching
Itching
Where are the symptoms of varicose veins felt?
Only along the actual vein
What are the causes of complications of varicose veins?
Problems with the vein itself
Venous hypertension
Problems with the vein itself causes which complications?
Haemorrhage
Thrombophlebitis
Venous hypertension causes which complications?
Oedema Skin pigmentation Varicose eczema Lipodermatosclerosis Venous ulceration
How is haemorrhage from varicose veins treated?
Lie patient down
Lift leg up
What is thrombophlebitis?
Venous thrombosis
producing inflammatory response - pain
How does arterial thrombosis differ from venous thrombosis?
Arterial thrombosis doesn’t itself cause pain
the consequences e.g. ischaemia, infarction cause pain
Whereas venous thrombosis itself causes pain
What does thrombophlebitis look like?
Dark brown staining over skin
Why is there dark brown staining over the skin with thrombophlebitis?
Red blood cells leak out of vein
macrophages phagocytose red blood cells
oxidise Fe2+ in Hb to ferric oxide
What is lipodermatosclerosis?
Hardening of fat in subcutaneous tissue over vein
What causes venous hypertension?
Calf muscle pump failure
What causes calf muscle pump failure?
Immobility
Obesity
Reduced hip, knee, ankle movement
Deep vein incompetence
Volume overload - superficial vein incompetence
How does deep vein incompetence cause calf muscle pump failure?
Valve in deep vein allows some backflow of blood
blood falls back into down deep vein
How does superficial vein incompetence cause calf muscle pump failure?
Valve between superficial and deep vein is incompetent
allows some backflow of blood
blood keeps falling back into superficial vein
enters deep veins
What is the pathophysiology of thrombosis? - Virchow’s triad
Change in lining of vessel wall
Change in flow of blood
Change in constituents of blood
What is the pathophysiology of arterial thrombosis?
Change in lining of wall of artery
What is the most common cause of changes in lining of arterial walls?
Atheroma
What is the pathophysiology of venous thrombosis?
Changes in flow of blood
What change in blood flow causes venous thrombosis?
Stasis of blood
Does stasis alone cause venous thrombosis?
Not usually
other factors involved
What are some of the other factors involved in venous thrombosis - alongside stasis of blood?
Trauma e.g. surgery
Oral contraceptive pill
Cancer
How does arterial thrombosis occur?
Platelets
Clotting factors - intrinsic and extrinsic pathway
How are arterial thrombi described in terms of their constituents?
Platelet-rich
How does venous thrombosis occur?
Firstly the intrinsic pathway
then the extrinsic pathway aswell
How are venous thrombi described in terms of their constituents?
Fibrin rich
What occurs in both arteries and veins when they bleed?
Constriction of blood vessel
arteries - vasoconstriction
veins - venoconstriction
Where is deep vein thrombosis most common?
Deep calf veins
What are the symptoms of deep vein thrombosis?
Pain
Can’t walk
Swelling
Blue-red skin discolouration
What are the signs of deep vein thrombosis?
Calf tenderness - pain
Muscle induration - muscles harden
Skin warmth
Skin discolouration
Distended, warm superficial veins
Oedema
Pyrexia - fever
Why is surgery associated with deep vein thrombosis?
Immobility prior to, during, and after surgery
don’t use calf muscle pump
Surgery induces a prothrombotic state
What is the complication of deep vein thrombosis? Why is it important?
Pulmonary embolism
Can lead to death
How is peripheral arterial disease categorised?
Acute
Chronic
Where are collateral arteries common? Why?
Around joints e.g. elbow and knee
Because flexing the joint occludes the main arteries
but the collateral arteries ensure there is still sufficient blood supply
When do new collateral arteries form? Why?
Gradual narrowing of blood vessel
Collateral arteries develop to bypass the stenosis
maintain blood supply
What is acute limb ischaemia?
Limb suddenly has largely impaired blood supply
over a few minutes
What causes acute limb ischaemia?
Embolism from heart
or from abdominal aortic aneurysm
Trauma
Within what timeframe must acute limb ischaemia be reversed?
Within 6 hours
What are the consequences of acute limb ischaemia after 6 hours?
Muscle necrosis
Dead cells release lots of K+, hyperkalaemia
Causes cardiac asystole, cardiac arrest
What must be done to the limb after 6 hours?
It must be amputated
What are the signs and symptoms of acute ischaemia? 6 P’s
Pain
Paraesthesia
Paralysis
Pallor
Perishing cold
Pulseless
What is the apperance of an acute ischaemic limb with different times from onset?
Onset - white
1 hour - moveable mottling
6 hours - fixed mottling
What does moveable mottling look like?
Patchy cyanosis - blue/purple discolouration
What causes moveable mottling?
Deoxygenated Hb in blood
Deoxygenated blood in limb
What is a feature of moveable mottling?
It blanches
still some blood flow in capillaries
What does fixed mottling like?
Widespread constant cyanosis
What causes fixed mottling?
Deoxygenated Hb, blood
as with moveable mottling
What is a feature of fixed mottling?
Non-blanching
because absolutely no blood flow
How is chronic peripheral arterial disease categorised?
Intermittent claudication
Critical ischaemia
What does claudication mean?
Limping
What are the features of chronic peripheral arterial disease?
Rest pain
Ulceration, gangrene
What does intermittent claudication mean?
Pain in muscles of lower limb
brought on by walking, exercise
Which muscles are most frequently affected by intermittent claudcation?
Calf muscles
What relieves the pain of intermittent claudication?
Stopping exercising, standing up
sitting down
What are the arteries of the lower limb?
Common iliac artery
Internal iliac artery - gives off gluteal arteries
External iliac artery
Femoral artery
Profunda femoris artery
Popliteal artery
Anterior tibial artery - continues as dorsalis pedis into foot
Posterior tibial artery - continues into foot
Common fibular artery
Where is the common femoral artery palpated?
Mid-inguinal point
What is the mid-inguinal point?
Midway between ASIS and pubic symphysis
Is the popliteal artery easy or difficult to palpate?
Difficult
What does an easily palpable popliteal artery possibly mean?
Popliteal aneurysm
Where is the dorsalis pedis palpated?
Lateral to tendon of extensor hallucis longus
Where is posterior tibial artery palpated?
Posterior to medial malleolus
What are the features of chronic aorti-iliac occlusion?
Bilateral buttock, thigh, calf claudication
Absent lower limb pulses
What are the features of chronic right common iliac occlusion?
Right-sided buttock, thigh, calf claudcation
Absent right lower limb pulses
What are the features chronic right common femoral artery occlusion?
Right-sided thigh and calf claudcation
Absent right lower limb pulses
What are the features of right superficial femoral artery occlusion?
Right-sided calf claudication
Absent right-sided popliteal artery, posterior tibial artery and dorsalis pedis artery
Which artery is most commonly occluded?
Superficial femoral artery occlusion
What is rest pain?
Pain in the foot at rest
What causes rest pain?
Skin, muscles, bone are ischaemic at rest
Not enough oxygen for basal metabolic requirements of cells
What is the typical history of rest pain?
Comes on when going to bed
Relieved by hanging foot out of bed
Explain the typical history of rest pain - why does it come on when going to bed?
Reduced effect of gravity drawing blood down arteries of foot
Increased temperature of foot
metabolic rate goes up
increased demand for oxygen
Cardiac output decreases at night
increased parasympathetic activity
If rest pain is untreated, what are the consequences?
Ulceration
Gangrene
Where is ulceration due to ischaemia most common?
Anterior tibia (shin)
because poor blood supply to this region
more prone to worsening ischaemia, ulceration
What is intermittent claudication equivalent to when compared to heart disease?
Stable angina
What is rest pain equivalent to when compared to heart disease?
Unstable angina
