Carotid Artery Surgery - Presentation, Investigation & Therapy

Question 1

What is often the cause of —transient ischaemic attacks and ischaemic stroke.?

Answer 1

Atherosclerosis of the carotid arteries

Question 2

What is the definition of a TIA?

Answer 2

Focal CNS disturbance caused by vascular events such as microemboli and occlusion, leading to cerebral ischaemia. Symptoms last less than 24hours and there are no permanent neurological sequelae.

Question 3

What is the definition of stroke?

Answer 3

Clinical syndrome consisting of rapidly developing clinical signs of focal or global disturbance of cerebral function, lasting more than 24hours or leading to death, with no apparent cause other than that of vascular origin.

Question 4

What are the causes of stroke (TIA)

Answer 4

Cerebral infarction (84%)

Primary intracerebral haemorrhage (10%)

—Subarachnoid haemorrhage (6%)

Question 5

What are the causes of cerebral infarction?

Answer 5

—AF

—Carotid atherosclerotic plaque rupture/thrombus (15%)

—Endocarditis

—MI (clot arises from here)

—Carotid artery trauma/dissection

—Drug abuse

—Haematological disorder e.g. sickle cell disease

Question 6

What are the risk factors for carotid atherosclerosis?

Answer 6

Smoking

Diabetes

Family history

Male sex

Hypertension

Hyperlipidaemia/hypercholesterolaemia

Obesity

Age

NOT: DVT 2° to flight – venous disease is different from arterial disease

Question 7

How is diagnosis of carotid artery atherosclerosis achieved?

Answer 7

History

Examination

CT

Carotid USS

Question 8

How can you examine for athersclerotic carotid artery?

Answer 8

Cardiac

Auscultate carotids

—Neurological: remember contralateral symptoms of paralysis, paresis (partial paralysis) /visuospatial neglect, dysphasia (deficiency in the generation of speech, and sometimes also in its comprehension, due to brain disease or damage.); ipsilateral amaurosis fugax symptoms (this is when the embolus is in the retinal artery – only circumstance it is ipsilateral)

Question 9

How does the velocity of blood change as it passes through an occluded coaritf artery?

Answer 9

Velocity increases - diagnosis via carotid imaging is achieved this way

Question 10

What is the best management for Stroke and TIA?

Answer 10

—Smoking cessation

—Control of hypertension

—Antiplatelet (aspirin or clopidogrel)

—Statin

—Diabetic control

Question 11

What are the names of these arteries?

Answer 11

Question 12

What is carotid endarterectomy?

Answer 12

Artery is clamped above and below the plaque

An incision is made to open the carotid artery

Plaque is removed

Repaired artery is closed

Can prevent stroke in the case of a severely narrowed carotid artery

Question 13

What does the external carotid give supply to?

Answer 13

External gives supply to the thyroid, tongue and the facial artery.

Internal carries onto the next territory

Question 14

What are the complications of an endarterectomy?

Answer 14

Wound infection

Bleeding

Scar

Anaesthetic risks

Nerve damage

Perioperative stroke:

• Plaque rupture
• Hypoperfusion (caused by clamping of the carotid)

—Virchow’s triad – raw intimal surface and thrombosis – any change to the vessel wall can cause thrombus formation

Question 15

What are the possible nerves that you may damage during a carotid endarterectomy?

Answer 15

Hypoglossal nerve which controls the tongue

Glossopharyngeal nerve

Question 16

What is another means of reducing restriction of blood flow through the carotids?

Answer 16

Stenting

Question 17

What is the difference in treatment between non-significant carotid stenosis and significant stenosis?

Answer 17

Non-significant - Best medical treatment

Significant - BMT - imaging - carotid endarterectomy and carotid stenting

Question 18

What is the surgery described as?

Answer 18

PROPHYLACTIC

Question 19

When should we offer carotid surgery to women?

Answer 19

At a higher stenosis value -

—The NNT (number needed to treat) to prevent one stroke at five years is 9 for men and 36 for women.

—There is clear benefit in women with 70-99% stenosis but not in those with 50-69% stenosis

Women have higher operative risk and respond better to BMT

Question 20

What are the rules for when you should start suregry?

Answer 20

—Offer carotid surgery for all symptomatic patients with >70% stenosis (except occluded)

—Consider surgery in men with 50-69% stenosis

—Consider surgery in asymptomatic stenosis >70%