Aortic Aneurysms and Carotid Artery Disease- Presentation, Investigation and Therapy Flashcards
What is an aneurysm
Dilatation of all layers of the aorta, leading to an increase in diameter of >50% (abdominal aorta >3.5cm)
Branches of descending aorta (6)
- Left gastric artery
- Hepatic artery
- Splenic artery
- Right and Left renal artery
- Superior and Inferior mesenteric artery
- Bifurcation and iliac vessels
Causes of aneurysm disease (3)
Degenerative disease
Connective tissue disease- Marfan’s
Infection (mycotic aneurysm)
Risk factors
Smoking Age Male Hypertension Family history
How prevalent is the disease in 1st degree male relatives
30%
Why is a screening programme used
To detect dangerous swelling of the aorta, the largest blood vessel in the body
Who is the screening programme aimed towards (2)
Men
65+
What is the criteria for screening (10)
- Definable disease
- Prevalence
- Severity of disease
- Natural history
- Reliable detection
- Early detection confers advantage
- Treatment options available
- Cost
- Feasibility
- Acceptability
Outcomes for screening (4)
Normal
Small AAA
Medium AAA
Large AAA
Small AAA
3.4-4cm invited for annual USS
Medium AAA
4.5-5.5 invited for 3 monthly USS scans
Large AAA
> 5.5cm
Impending rupture symptoms (2)
- Increasing back pain
* Tender AAA
Rupture Symptoms (4)
- Abdo/back/flank pain
- Painful pulsatile mass
- Haemodynamic instability (single episode or progressive)- perfusion failure leading to shock and advanced heart failure
- Hypoperfusion- decreased blood flow through an organ
Presentation (5)
Distal embolism- Trash foot Aorticaval fistula Aortoenteric fistula Ureteric occlusion Duodenal obstruction
UK Small Aneurysm Trial (Lancet 1998)
- Surgery did not confer any benefit (e.g. survival) for aneurysms <5.5cm
- 30 day mortality 5.8% vs risk of rupture 1% (per year)
How is patient fitness assessed for surgery (9)
Full history and examination Bloods ECG ECHO PFTs MPS CPEX End of bed test Patience preference
USS (5)
No radiation No contrast Cheap Operator dependent Inadequate for surgical planning
CT/MRA (5)
Quick Not operator dependent Necessary for surgical planning Contrast Radiation
General complications of open repair (4)
Wound infection / dehiscence
Bleeding
Pain
Scar
Technical complications (6)
Damage to bowel, ureters, veins, nerves Incisional hernia Graft infection Distal emboli Renal failure Colonic ischaemia
Complication of open repair involving patient factors (4)
DVT/PE
MI
Stroke
Death
Management (symptomatic) (4)
- ABCDE
- History, check records
- Examination
- Computed Tomography Angiography (CTA)
Emergency open repair procedure
Laparotomy (xiphisternum to pubic symphysis)
Emergency EVAR (3)
Local anaesthetic
Percutaneous
Abdominal compartment syndrome
EVAR1 Lancet 2005
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
EVAR2 Lancet 2005
No difference in AAA related mortality, all cause mortality of QOL. 9% operative mortality vs 9% person year rupture if no repair
IMPROVE trial BMJ 2014 (3)
- EVAR vs open repair for rAAA
- No difference in 30 day mortality between the 2 interventions
- Women may benefit more than men from EVAR
Atherosclerosis of carotid arteries results in
Ischaemic attacks and strokes
transient Ischaemic Attack
Focal CNS disturbance caused by vascular events such as micro emboli and occlusion, leading to cerebral ischaemia. Symptoms last less than 24 hours and there are no permanent neurological sequelae
Stroke
clinical syndrome consisting of rapidly developing clinical signs of focal or global disturbance of cerebral function, lasting more than 24 hours or leading to death, with no apparent cause other than that of vascular origin
Causes of stroke
Cerebral infarction
• Primary intracerebral haemorrhage
• Subarachnoid haemorrhage
What can cause cerebral infarction (7)
AF
Carotid atherosclerotic plaque rupture/thrombus (15%)
Endocarditis
MI
Carotid artery trauma/dissection
Drug abuse
Haematological disorder e.g. sickle cell disease
Risk Factors for Carotid Artery Atherosclerosis
- Smoking
- Diabetes
- Family history
- Male sex
- Previous DVT secondary to slight
- Hypertension
- Hyperlipidaemia
- Obesity
- Age
Diagnosis of Carotid artery disease
History
Examination (neurological, Cardiac and auscultate carotids)
CT
USS of Carotids
Poiseuille’s Law
• As radius of a vessel decreases, resistance increases and velocity increases
Best Medical Treatment
- Smoking cessation
- Control of hypertension
- Antiplatelet
- Statin
- Diabetic control
- Carotid doppler
Circle of Willis
• Provides collateral circulation: If one part of the circle becomes blocked or narrowed (stenosed) or one of the arteries supplying the circle is blocked or narrowed, blood flow from the other blood vessels can often preserve the cerebral perfusion well enough to avoid the symptoms of ischemia
What is the Circle of Willis Composed of
Anterior cerebral artery (left and right)
Anterior communicating artery
Internal carotid artery (left and right)
Posterior cerebral artery (left and right)
Posterior communicating artery (left and right)
What is an endarterectomy
incision is made in carotid artery and plaque is removed. It may prevent a stroke if the carotid artery has been narrowed severely
Complications of endarterectomy (6)
wound infection, bleeding, scar, anaesthetic risks, nerve damage (Vagus nerve and Hypoglossal nerve) Complications (perioperative): Plaque rupture, hypoperfusion,
Branches of the External carotid (5)
- Posterior auricular
- Occipital
- Facial
- Lingual Ascending pharyngeal
- Superior thyroid
NASCET, NEJM 1998
No benefit of surgery is stenosis is less than 50%. Dramatic benefit to CEA with stenosis greater than 70%. Risk of reduction of 17% for stroke in 2 years following CEAT compared
ECST, Lancet 1998
Risk of major stroke or death in 70-79% stenosis is similar between CEA and BMT (best medical treatment). With 90-99% stenosis BMT was more effective
CREST, NEJM 2010
No difference in composite endpoint. Risk of periprocedural stroke high in CAS (coronary artery stenting). Risk of perioperative MI higher in CEA
ACAS trial, Lancet 2004
CEA vs BMT in asymptomatic stenosis >60%. 26% of BMT patients went on to develop symptoms and have CEA in the next 10 years
NNT
: number of patients needed to treat to prevent 1 bad outcome
Management in Women
- The NNT to prevent one stroke at 5 years is 9 for men and 36 for women
- Clear benefit in women with 70-99% stenosis but not in those with 50-69% stenosis
- This is driven by a high operative risk in women and more rapid reductions in risk of stroke recurrence on medical therapy in women
When should CEA be considered (2)
asymptomatic patients with high grade carotid stenosis
more beneficial for male patients less than 70 or those with bilateral disease
When should asymptomatic CEA be performed
low perioperative stroke or death rate
What kind of surgery is CEA
Prophylactic