Carotid artery surgery

Question 1

“Atherosclerosis of the carotid arteries is associated with ______”

Answer 1

Transient ischaemic attacks & ischaemic stroke

Question 2

What is a transient ischaemic attack?

Answer 2

Focal CNS disturbance

Caused by vascular events such as microemboli & occlusion leading to cerebral ischaemia

Symptoms last less than 24 hours & there are no permanent neurological effects

Question 3

What is a stroke?

Answer 3

Clinical syndrome consisting of rapidly developing clinical sings of focal or global disturbance of cerebral function

Lasting more than 24 hours or until death

With no apparent cause other than vascular origin

Question 4

What is the main simple difference between a stroke and a TIA?

Answer 4

TIA lasts < 24 hours and isn’t life changing

Stroke lasts > 24 hours and aint good

Question 5

Summarise the causes of strokes

Answer 5

Cerebral infarction - 85%

Haemorrhage - 15%

Question 6

List the types of cerebral infarction

Answer 6

Atrial fibrillation

Carotid atherosclerosis plaque rupture/thrombus

Endocarditis

MI

Carotid artery trauma/dissection

Drug abuse

Haematological disorder - eg sickle cell disease

Question 7

There are two types of haemorrhage that cause strokes

What are they?

Answer 7

Primary intracerebral haemorrhage (more common):
- Vessel within the brain bursts

Subarachnoid haemorrhage:
- Bleeding into space around the brain

Question 8

What causes TIA’s?

Answer 8

Cerebral infarctions

Question 9

List the risk factors for carotid artery atherosclerosis

Answer 9

Smoking 
Diabetes 
Male 
Old 
Family history 
Hypertension 
Hyperlipidaemia & hypercholesterolaemia 
Obese

Question 10

Describe the diagnosis route for TIA

Answer 10

History

Examination

CT scan

Carotid USS

Question 11

What is important to examine in diagnosing TIA?

Answer 11

Neurological:

• Paralysis/paresis/visuospatial neglect
• Dyshpasia: ipsilateral amaurosis fugax symptoms

Cardiac

Auscultation of carotids

Question 12

What are typical statements you would hear from a patient with a TIA?

Answer 12

Numb, tingling sensation shooting down a leg

Drooping around eye

Loss of control of limbs / motor skills

Slurring words (sound drunk)

Question 13

What is the effect of stenosis on the velocity of blood flow through a vessel?

Answer 13

Stenosis causes an increase in velocity

Velocity is used to measure how badly stenosed a vessel is:

• < 125 cm/s = < 50% stenosis
• > 125 cm/s = 50-69% stenosis
• > 270 cm/s = 70-79% stenosis
• EDV of > 140 cm/s = 80-99% stenosis

Question 14

Management of carotid atherosclerosis includes ‘Best medical therapy’

What does this include?

Answer 14

Smoking cessation 
Control hypertension 
Antiplatelet medication 
Statin 
Diabetic control

Question 15

A patient has TIA with left sided symptoms

Which carotid artery is likely to be occluded?

Answer 15

Right internal carotid

Question 16

Even if an internal carotid artery is occluded by a thrombus or some shite, the brain is still largely perfused

What allows this?

Answer 16

Circle of willis

circuit of arteries in the brain allows blood to take another route basically

Question 17

After a patient presents with TIA/stroke, it is a risk that they will have another stroke

What causes this?

Answer 17

Despite the circle of willis allowing alternative flow routes for blood in the brain…

Risk of emboli being ripped up from the diseased carotid artery by high flow velocity (high velocity due to stenosis) and causing distal ischaemia

Risk of further event is highest within the first 2 weeks

Question 18

What is a carotid endarterectomy?

Answer 18

Procedure to remove a plaque from a highly stenosed carotid artery

For example, if someone had a TIA and a doppler showed 90% stenosis of the internal carotid, then this would be done

This aims to prevent a stroke from happening

Question 19

List the branches of the external carotid artery

Answer 19

Posterior auricular 
Occipital 
Facial 
Lingual 
Ascending pharyngeal 
Superior thyroid

Question 20

What unusual risks do carotid endarterectomies pose?

Answer 20

Risk damaging nerves

Perioperative stroke

Question 21

What nerves are at risk during a carotid endarterectomy?

Answer 21

Hypoglossal nerve (XII) - passes over the external & internal carotid arteries

Vagus nerve (X) - Runs inferior alongside the common & internal carotid arteries

Glossopharyngeal nerve (IX) - less at risk but is still cutting about

Question 22

What can happen during a carotid endarterectomy that would cause a stroke?

Answer 22

Plaque rupture

Hypoperfusion

Operation causes raw intimal surface & may cause thrombosis

Question 23

Summarise the management of carotid atherosclerosis to reduce the risk of stroke

Answer 23

Best medical therapy

Carotid endarterectomy

Stenting

Question 24

According to NASCET, NEJM 1998

How large does carotid artery stenosis need to be, before surgery becomes beneficial?

Answer 24

No benefit to surgery if <50% stenosis

Question 25

Summarise the difference in stroke management in women compared to men

Answer 25

Surgery only becomes beneficial for women if stenosis is 70-99%

For men, stenosis only needs to be 50% or above for surgery to become beneficial

Question 26

So what are the 2 basic treatment routes for someone with a stroke or TIA?

Answer 26

1) If patient has carotid stenosis of <50% (NASCET criteria) or <70% (ECST criteria):
- Best medical treatment

2) If patient has stenosis of >50% (NASCET) or >70% (ECST):
- Best medical treatment
- Carotid endarerectomy
- Carotid stenting

Question 27

Describe the management options for asymptomatic carotid stenosis

Answer 27

CEA (endarterectomy) should only be considered for asymptomatic patients with high grade stenosis >70%

Only should be done with patients <70 years old
(ACAS trial shows no benefit to patients >75 y.o)

Only should be done by surgeons with low perioperative stroke or death rate