Flashcards in Aortic aneurysms and Carotid artery disease Deck (53):
What is Aneurysm disease?
Dilatation of all layers of the aorta, leading to an increase in diameter of >50% (abdominal aorta >3.5cm)
What are causes of aneurysm disease?
- Degenerative disease
- Connective tissue disease (e.g. Marfans's disease)
- Infection (mycotic aneurysm)
What are risk factors for abdominal aortic aneurysm (AAA) disease?
- Being Male
- Family history (prevalence of 30% in 1st degree male relatives)
Can aneurysms be asymptomatic?
Yes, if they have not ruptured
- These aneurysms are typically small in size.
What is abdominal aortic aneurysm (AAA) screening?
-It aims to detect dangerous swelling of the aorta.
- It is a simple ultrasound scan.
Who is the AAA screening programme targeted at?
- Aged > 65
- The scan detects swelling of the aorta
What is the criteria for AAA screening?
- Definable disease
- Severity of disease
- Natural history
- Reliable detection
- Early detection confers advantage
- Treatment options available
What does sensitivity mean in screening?
The sensitivity of a clinical test refers to the ability of the test to correctly identify those patients with the disease.
What does specificity mean in screening?
The specificity of a clinical test refers to the ability of the test to correctly identify those patients without the disease.
What are the four different outcomes of AAA screening?
1. Normal aorta - discharged
2. Small AAA (3.0-4.4cm) will be invited for annual USS scans
3. Medium AAA (4.5-5.5cm) will be invited for monthly USS scans
4. Large AAA (>5.5cm) - fast treatment
What are symptoms of an impending rupture?
- Increasing back pain
- Tender AAA
What are symptoms of a rupture?
- Abdo/back/flank pain
- Painful pulsatile mass
- Haemodynamic instability (single episode or progressive)
What are unusual presentations of an aneurysm?
- Distal embolisation
- Aortocaval fistula
- Aortoenteric fistula
- Ureteric occlusion
- Duodenal obstruction
Questions to ask for asymptomatic management of an aneurysm?
Is the aneurysm a size to consider repair? > Is the patient a candidate for repair? > Is the aneurysm suitable for endovascular or open repair?
What questions and tests would you check to determine patient fitness?
- Full history and examination
- End of the bed test
- Patient preference
Advantages of Ultrasound in AAA imaging
- No radiation
- No contrast
Disadvantages of Ultrasound in AAA imaging
- Operator dependent
- Inadequate for surgical planning
Advantages of CTA/MRA (angiography) in AAA imaging
- Not operator dependent
- Necessary for surgical planning: detailed anatomy
Disadvantages of CTA/MRA (angiography) in AAA imaging
Treatments for AAA
- Conservative: patient/aneurysm not fit for repair, consider event of rupture
- Endovascular repair
- Open repair
General complications of open repair
- Wound infection/ dehiscence
Technical complications of open repair
- Damage to bowel, ureters, veins, nerves
- Incisional hernia
- Graft infection
- Distal emboli
- Renal failure
- Colonic ischaemia
Patient factor complications with open repair?
- DVT/PE (deep vein thrombosis/ pulmonary embolism)
General complications with endovascular repair
- Would infection
- Contrast: reaction/kidney injury
Technical complications with endovascular repair
- Femoral artery dissection / pseudoaneurysm
- Distal emboli / ischaemia / colonic ischaemia
- Damage to femoral vein / nerve
Patient factor complications with endovascular repair
What is an Endoleak?
Endoleak is defined as a persistent blood flow outside the lumen of an endoluminal graft but within the aneurysm sac or adjacent vascular segment being treated by the device used for endovascular aneurysm repair (EVAR).
What is a type I endoleak?
Occurs when an ineffective seal at the top or bottom edgeof the stent allows blood to flow directly into the aneurism sac directly from the aorta.
What is a type II endoleak?
- These are the most common
- These are due to reversed direction blood flow entering the aneurism sac from small lumbar arteries and/or the inferior mesenteric artery.
What is a type III endoleak?
They occur when there is a gap between the main body of the stent and the smaller leg component.
- These are not as common
What is a type IV endoleak?
- Transgraft Hyperfiltration
- This is when blood slowly filters through the walls of the stent into the aneurism sac.
What is a type V endoleak?
Characterised by continued pressure and growth of the aneurism sac without any definable endoleak.
Features/findings of EVAR 1
- 3-fold reduction in operative mortality for EVAR vs OR
- Improved QOL initially with EVAR
- QOL improvements lost with increased reintervention and surveillance for EVAR
- No difference in overall mortality
Features/findings of EVAR 2
- No difference in AAA related mortality, all cause mortality or QOL.
- 9% operative mortality vs 9% person year rupture rate if no repair
Features of emergency open repair
- Straight to theatre (pre/post CT)
- Massive transfusion protocol
- Prep abdomen, rapid anaesthetic
- Laparotomy xiphisternum to pubic symphysis
- Occlude aorta proximally
- 30-50% mortality, significant morbidity
Features of emergency EVAR
- Anatomic suitability
- Local anaesthetic
- Abdominal compartment syndrome
-Women may benefit more than men from EVAR
What is atherosclerosis of the carotid arteries associated with?
It is associated with transient ischaemic attacks and ischaemic stroke
What is a transient ischaemic attack (TIA)?
Focal CNS disturbance caused by vascular events such as microemboli and occlusion, leading to cerebral ischaemia.
Features of transient ischaemic attack (TIA)
- Symptoms last less that 24 hours
- There are no permanent neurological sequelae.
What is a Stroke?
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.
Causes of stroke (/TIA)
- Cerebral infarction (84%): AF, carotid atherosclerotic plaque rupture/thrombus. endocarditis, MI, carotid artery trauma/dissection/ drug abuse/ haematological disorder
- Primary intracerebral haemorrhage
- Subarachnoid haemorrhage
Pathophysiology: Virchow's triad
- Vessel wall
What are risk factors for carotid artery atherosclerosis?
- Family history
Diagnosis for carotid artery atherosclerosis
Neurological: remember contralaeral symptoms of paralysis/paresis/visuospatial neglect, dysphasia; ipsilateral amaurosis fugax symptoms
- Carotid USS
What is Poisuille's law in radius, resistance to flow and velocity
As radius of a vessel decreases, velocity increases
- e.g. like in stenosis
Velocity compared with stenosis
- Velocity <125cm/s = <50% stenosis
- Velocity >125cm/s = 50-69% stenosis
- Velocity >270cm/s = 70-79% stenosis
- End diastolic velocity >140cm/s = 80-99% stenosis
Best medical therapies for carotid artery atherosclerosis
- Smoking cessation
- Control of hypertension
- Diabetic control
What is a Carotid Endarterectomy?
- An incision is made to open the carotid artery.
- Plaque is removed.
- Then the repaired artery is closed.
Carotid endarterectomy may prevent a stroke if you have a severely narrowed carotid artery.
What are the branches of the external carotid?
Superior to inferior
- Posterior auricular
- Ascending pharyngeal
- Superior thyroid
Complications for the branches of the external carotid
- General: wound infection, bleeding, scar, anaesthetic risks
- Nerve damage
What can cause a perioperative stroke?
- Plaque rupture
- Virchow's triad: raw intimal surface and thrombosis
When would you offer carotid surgery for symptomatic patients?
If they have >70% stenosis (except occluded)
Consider surgery in asymptomatic stenosis >70%.