Lecture 16 Flashcards
What are the different classifications of the veins?
Deep veins: underneath deep fascia/through muscles
Superficial veins: in subcutaneous tissue
Connected by perforating veins, from superficial in subcutaneous tissues into deep veins, and sent back to heart
What is the divisions of the deep vein?
- inferior vena cava
- common iliac
- external/internal iliac
- external iliac branches to femoral (which branches into deep femoral and superficial femoral)
- superficial femoral turns into the popliteal vein behind knee
- popliteal branches into anterior and posterior tibial veins and the peroneal vein
What are the classifications of the superficial veins?
Long saphenous vein- runs medially down inside of leg from the femoral vein via perforators
Short saphenous vein- connects through perforators at popliteal vein, at the back of the calf
Where is the long saphenous vein?
Runs medially along leg, and along front of medial malleolus
Used to be the site where IV’s were cannulated
What is the calf muscle pump?
‘Peripheral heart’
- soleus and gastrocnemius push blood against gravity back towards heart (push blood from superficial veins, through perforating veins, into deep veins)
- valves open:blood pushed through, valves closed: prevent retrograde movement
What happens to the venous pressure in the foot during exercise?
Venous pressure is reduced
-as blood is no longer pooling in the feet, it is being pumped back towards right side of heart
What is peripheral venous disease?
Varicose veins
- more common in older ages/females
- valves ineffective, blood movement is slow/reversed
- saphenous veins common site (superficial)
- walls of veins weaken (valve cusps separate and varicosities form), causing the veins to become incompetent, can get pooling
What are some symptoms associated with varicose veins?
- heavy/ache/muscle cramps/throbbing
- thin, itchy skin along affected veins
- haemorrhage: in shower, venous pooling and heat causing vasodilation=bleeding out of legs
- varicose eczema
- superficial vein thrombophlebitis (inflammatory process resulting in a clot in the vein= these put you at a greater risk of a DVT)
- chronic venous insufficiency
What is an example of haemosiderin staining?
-venous eczema/ulceration
Why does the calf muscle pump fail?
Need to be using the calf muscles-plantarflexion of ankle joint during walking
-if not using muscles, leads to retrograde flow
Who is at risk of venous hypertension/calf muscle pump not working?
- elderly, obese, injured (immobile)
- Parkinson’s: shuffling- not plantarflexing properly
What does calf muscle pump failure cause?
- deep vein incompetence (retrograde flow)
- superficial vein incompetence (retrograde flow back down through perforators into superficial veins)
What is the most common cause of arterial thrombosis?
Atheroma
-platelet rich aggregate, plug damaged vessel
What is Virchow’s triad?
- vessel wall damage
- stasis (flow)
- hypercoagulability
What is a venous thrombosis like?
Little platelet component, fibrin rich
Often due to slow flow:stasis-trauma, dehydration, chemo, pregnancy
What factors can cause venous thrombosis?
- trauma
- chemo
- pregnancy
- inflammatory conditions
What is a DVT?
Clotting of blood in a deep vein (common in calf)
- impaired venous return
- inflammatory component: redness/swelling following thrombosis
Who is risk at a DVT?
- ambulatory patients
- long flight
- post surgery patients
What are some symptoms of DVT?
- calf tenderness
- warm
- distended/visible superficial veins
- oedema
- pyrexia with no other cause (if a patient post-op have pyrexia with no other cause it could be a DVT)
- asymmetry
Why do DVT’s occur?
Stasis-no calf muscle pump
-prothrombotic/hypercoagulability state following malignancy/pregnancy/before or after surgery
=promote mobility soon after surgery
What is a fatal consequence of a DVT?
Pulmonary embolism
How do you treat a DVT?
Prophylaxis
Anticoagulant agents
How do you limit incidence of acute ischaemia/stenosis of major vessel?
Collateral circulation (Knee/shoulder/hip/stenosed arteries- around joints, as vessels could be occluded while flexing or around stenosis)
What is acute limb ischameia?
Major occlusion of an arterial in lower limb
(Occurs in mins/days= acute)
-no collateral circulation can develop in this time
What are the 6 P’s in leg ischameia?
Pain Pallor (can become cyanotic and necrotic, can become hyperkalaemic) Perishing with cold Pulseless Paraesthesia Paralysis/reduced power
What is chronic peripheral arterial disease?
Intermittent claudication in limb-occurs over a period of time
- caused by atherosclerosis: oxygen supply/demand ratio is not balanced
- cramping in leg: exercise induced (pain goes away when resting)
How do you manage chronic peripheral arterial disease?
- exercise: increase collateral circulation
- smoking cessation
- antiplatelet drugs
- angioplasty
- bypass graft
What is critical ischaemia?
Rest pain: poor blood supply so pain at rest
(Get pain when sleeping, and relieve it when they stick their leg out of the bed- last attempt to try and get blood to lower limbs)
-at rest oxygen supply/demand ratio is not sufficient
(Like unstable angina- chest pain at rest)
What can untreated critical ischameia lead to?
-ulceration
-gangrene (dry)
(Viability of limb is compromised)
-requires referral to vascular surgical unit immediately
What are the different classifications of claudication?
-mild
-moderate
-severe
-rest pain
Where stenosis is, dictates what pulses you will be able to feel
What are the difference pulses of lower limbs?
- femoral pulse: mid-inguinal point, midway between anterior superior iliac spine and pubic symphysis ) (if can’t palpate= urgent as this pulse is high up)
- popliteal pulse: deep in popliteal fossa
- dorsalis pedis pulse: lateral to extensor hallucis longus tendon
- posterior tibial pulse: behind medial malleolus
What is ultrasonography and its uses?
Sonogram using ultrasound and Doppler effector measure flow/velocity
- used to record flow/velocity of blood: disrupted in occlusion
- used in echocardiogram
- used in distal vessels
- echoes produced from moving blood are detected and computed into flow direction and velocity
What is the ankle-brachial pressure index?
ABPI
- measure pressure in brachial artery
- measurement of BP in dorsalis pedis, posterior tibial arteries
- if the BP in the ankle is less than in the brachial = peripheral artery disease
DIVIDE ANKLE SYSTOLIC BY BRACHIAL SYSTOLIC
ABPI <0.9 indicated peripheral artery disease
What do varicose veins look like?
Tortuous/twisted
What is haemosiderin staining?
Venule pressure is high, RBC’s leak out, macrophages oxidise RBC’s and haem converted to ferrous > ferric
-staining in tissues
What is lipodermatosclerosis?
Inflammation and thickening of fat layer under skin
=chronic venous insufficiency
What can eczema lead to?
Chronic/itchy/red skin can lead to lipodermatosclerosis (hard to the touch)
Where does venous eczema and ulceration usually present?
Hard modular areas e.g. medial malleolus
What is chronic venous insufficiency and what can it cause?
Venous wall/valves in leg aren’t working properly making it difficult for blood to return back to the heart
=stasis
Causes:
- venous hypertension
- oedema
- haemosiderin staining
- lipodermatosclerosis
- venous ulceration
In what patients is the development of chronic venous deficiency common?
50% of DVT patients
How do you treat venous ulceration?
Ligation/vein stripping perforating vein (stop retrograde blood flow back into superficial veins)
What is Virchow’s triad?
- vessel wall damage
- stasis
- hypercoagulability
What are some diagnosis you should consider when diagnosing a DVT?
- soft tissue trauma
- cellulitis
- lymphatic obstruction
What is the Well’s score?
Pre-test probability
-give different numbers to different risk factors, overall number dictates whether you should be considering a DVT as prognosis
What are the most common causes for acute limb ischaemia?
- trauma
- leg embolism
What is the most common presentation of claudication?
Atheroma
-atherosclerosis of superficial femoral artery
What is an atheroma?
Degeneration of walls of arteries caused by accumulation of fatty deposits
