Carotid stenosis



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CAROTID STENOSIS
Clinical features:

  • TIAs – focal neurological deficit which resolves completely within 24 hours

  • CVAs (stroke) – sudden onset of irreversible neurological deficit

  • Amourosis fugax – transient monocular visual loss (retinal artery) – curtain

  • Internal capsule stroke – due to involvement of striate branches of middle cerebral artery. Get dense hemiplegia usually involving face.

Does not cause dizziness, weakness, blackouts, etc. These are too global.

These people should have a brain scan to r/o tumour
Most common location? Carotid bulb (at bifurcation). Get atheromatous plaques. Platelets and atheromatous material can embolise to brain via internal carotid.

However these emboli could also come from the heart, from the aortic arch, from diseased arteries in the brain itself.


Stroke risk in carotid surgery is 1-2%. Hence, only offer carotid surgery to people who’s stroke risk is higher than 1-2% without surgery.
Unstable carotid is when a patient has TIAs one after the other. This should be treated urgently. Can use ABCD scoring system to assess risk of stroke after a TIA (Age, Blood pressure, Clinical features, Duration). Risk of stroke shortly after a TIA is roughly 5% at 7 days and 10% at 3 months.
When to treat carotid stenosis?

  • When its >80% occluded

  • When stenosis is getting progressively worse

  • If its symptomatic and stenosis is >70%

If less stenosis than this – should scan regularly and monitor patient. Always – only treat if patient is fit.
Medical treatment – anti-platelet agents (aspirin, dypiridamole), stop smoking, optimize BP and DM control, statin to lower cholesterol.
Diagnosis and investigation:

  • Carotid duplex scan

  • MRA if duplex inconclusive


EMBOLUS
An embolus is an undissolved substanct (solid/liquid/gas) which moves from one part of the circulation to another (via arteries/veins/lymph).
So examples include an arterial embolus, a venous thromboembolus, or a lymphatic tumour embolus.
Most common site of occlusion…

  • by an embolus is the Common Femoral artery

  • by atherosclerosis is the Superficial Femoral artery.


ULCERS
Randomness:

  • 6 grades of varicose veins (CEAP classification)

  • Do MRA to assess arterial insufficiency

  • So Duplex scan to assess venous insufficiency

  • You technically don’t need to wait for a venous ulcer to heal to remove VV.

9 important features:



  1. Site – in relation to bony prominences. Medial aspect of distal third of leg. 5cm proximal to medial malleolus.

  2. Size & Depth – 8cm in diameter, 3mm in depth

  3. Shape – irregular round shape

  4. Surface

    1. strawberry red granulation tissue – healthy

    2. not strawberry red granulation tissue – unhealthy

    3. slough – dead tissue + bacteria + inflammatory cells – heading towards infection. Unlike pus, slough is adherent.

  5. Base

    1. What’s below the ulcer? Medial malleolus? Extensor tendons?

  6. Edge

    1. Flat sloping – think healing, shallow, venous

    2. Punched out vertical – think neuropathic, arterial, syphilitic

    3. Undermined – think infection, pressure sore, TB

    4. Rolled – think neoplastic – TB

    5. Everted healed – think cancer, rapid growth spill over normal skin

  7. Surrounding tissue

    1. Feel surrounding tissue (temperature? Tenderness?)

    2. Cap refill (is tissue well perfused)?

    3. Do surrounding tissues show signs of chronic venous disease/ischaemia/neuropathy?

  8. Peripheral pulses

So a typical venous ulcer would be:



  • There is an ulcer 3cm proximal to the medial malleolus. It is round, and 4cm in diameter and 2mm deep. The edge is irregular and sloping. The surface is granulation tissue with some sloughy areas. No pus. The base is not visible. The surrounding tissue is non-tender, of normal temperature, and cap refill is <2sec indicating good arterial perfusion. There are signs of chronic venous hypertension, including varicose veins, haemosiderin deposition, venous eczema, and venous flaring. The peripheral pulses are present.



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