Aneurysmal Disease Flashcards
An artery with a dilatation > ___% of its original diameter has an aneurysm.
An artery with a dilatation > 50% of its original diameter has an aneurysm.
what is a true aneurysm?
abnormal dilatations that involve all layers of the arterial wall
what is a false aneurysm?
involve a collection of blood in the outer layer only (adventitia) which communicates with the lumen (eg after trauma). These can be very worrying if they rupture.
what is a fusiform aneurysm?
spindle shaped - most AAAa are fusiform
what are the three categories of aneurysm shape?
- fusiform
- sacular (eg berry aneurysms)
- myototic- rare
how do myctotic aneurysms arise?
they arise secondary to an infectious process, involving all three layers of the artery. The artery expands rapidly because of the infection damage e.g in endocarditis or tertiary syphilis
where do most aneurysms occur? 4
aorta (infra-renal mot common)
iliac
femoral
popliteal
AAA:
- They occur _ times more frequently in men and in one in _ male children of an affected individual.
- Aneurysms may occur secondary to_____, _____
- They occur 5 times more frequently in men and in one in 4 male children of an affected individual.
- Aneurysms may occur secondary to atherosclerosis (bit iffy now though) , infection
what are the causes of AAA?
medial degeneration
- there is an imbalance in the proteins of the vessel wall.
- aneurysmal dilatation
- increase in aortic wall stress
- marfans syndrome
imbalance of proteins in the vessels wall - AAA
The problem is most likely due to impairment in the regulation of ____/_____ in the aortic wall and other enzymes
- _________ imbalance
Treatment of aneurysm could involve something that switches off this __________
The problem is most likely due to impairment in the regulation of elastin/collagen in the aortic wall and other enzymes
- metalloproteinase 9 imbalance
- Treatment of aneurysm could involve something that switches off this metalloproteinase
what are he risk factors for AAA?
age, smoking, male, hypertension
what are some complications of AAA
Rupture, thrombosis, embolism, fistulae, pressure on other structures
Elective aneurysm repair is a ______ operation to reduce the risk of____ balanced against the risk of the ______
Elective aneurysm repair is a prophylactic operation to reduce the risk of rupture balanced against the risk of the procedure
what are the two options for surgery of AAA?
1- EVAR - endovascular aneurysm repair)
2. open repair
what is EVAR?
- exclude AAA from ‘inside the vessel
- inserted via the peripheral arteries
- It is X-ray guided
how is open repair done for AAA?
- laparotomy
- clamp aorta and iliacs and insert dacron graft. Can use a tube or bifurcated graft
EVAR is not possible in __% of patients
25%
what are the benefits of EVAR vs open repair?
EVAR : Less mortality risk (2-4%)
(Far safer in complex aneurysms)
Much faster recovery (7-10 /7)
open repair:
- Once recovered can forget
- Rare further interventions
- Known to be effective for life
what are the symptoms of unruptured AAA?
Most are asymptomatic: they are identified on imaging for other pathologies
Roughly a quarter are symptomatic
may cause abdominal/back pain,
what are the signs of unruptured AAA?
An aneurysm is suspected if a pulsatile, expansile abdominal mass is felt
Patients may present with ‘trash feet’ which is dusky discolouration of the digits secondary to emboli from the aortic thrombus
how is an AAA first investigated?
by ultrasound
what does ultrasound for AAA allow you to assess?
this allows you to assess diameter and involvement of the iliac arteries
which imaging technique used for AAA is more accurate and relates the anatomical relationship to the renal and visceral vessels ?
CT
with contrast. Allows you to assess aneurysm morphology eg shape, size and iliac involvement
what is the only method of imaging to identify ruptured AAA?
CT
what size must an AAA be before it is operated on?
size: over 5.5 AP diameter
if it is not fixed at this point the aneurysm tends to expand quicker past this diameter
what expansion must an AAA present with before it is operated on?
over 0.5 in 6 months or over 1cm in 1 year
what is the other thing that means AAA should be operated on?
symptomatic
what things are needed for fitness of intervention
- cardiac assessment - Echo/Ejection fraction
- Respiratory assessment - PFT
- Cardiopulmonary eercise test - CPX testing
- Renal assessmet - U and E
- Vascular assessment - peripheral pulses / ABPI
- Anaesthetic assessment
- EBT- ‘End of bed or eyeball test’
what is important to modify at time of diagnosis of AAA?
risk factors - to prevent rupture
what are the symptoms of ruptured AAA?
severe pain - epigastric pain radiating to the back, iliac fossae or groins - this should not be dismissed as renal colic
what are the signs of ruptured AAA?
- an expansile abdominal mass
- may cause Hypotension, tachycardia, tachypnoea, profound anaemia and sudden death
Treatment for ruptured AAA
- Summon a vascular surgeon and an experienced anaesthetist
- Do an __, and take blood for amylase, Hb, crossmatch. Catheterise the bladder
- Gain IV access. Treat shock with ORh- ve blood (if desperate) but keep systolic BP less that __ to avoid ___ a contained leak ( NB: __ BP is common early on)
- take the patient straight to theatre.
- Give prophylactic __
- Surgery involves clamping the __ above the leak and inserting a __ __ (eg tube graft) or, if significant iliac aneurysm also a trouser graft with each ‘leg’ attached to an iliac artery
- Summon a vascular surgeon and an experienced anaesthetist
- Do an ECG, and take blood for amylase, Hb, crossmatch. Catheterise the bladder
- Gain IV access. Treat shock with ORh- ve blood (if desperate) but keep systolic BP less that 100mmHg to avoid rupturing a contained leak ( NB: raised BP is common early on)
- take the patient straight to theatre. Don’t waste time on X-rays.
- Give prophylactic antibiotics
- Surgery involves clamping the aorta above the leak and inserting a dacron graft (eg tube graft or, if significant iliac aneurysm also a trouser graft with each ‘leg’ attached to an iliac artery
The ascending, arch or descending aorta may become aneurysmal. Ascending TAAs occur most commonly in ______ or_____.
The ascending, arch or descending aorta may become aneurysmal. Ascending TAAs occur most commonly in marfan’s syndrome or hypertension.
Descending or arch TAAs occur secondary to ____ and are now rarely due to ____.
Descending or arch TAAs occur secondary to atherosclerosis and are now rarely due to syphilis.
what are the symptoms of TAA?
- Most are assymptomatic and are found on routine CXR or cardiologic investigation.
- rapid expansion may cause severe chest pain (chest pain radiating to the upper back)
what are the signs of TAA?
- rupture is often associated with hypotension, tachycardia and death
- chest symptoms from expansion may include stridor (compressed bronchial tree), haemoptysis (aortobronchial fistula) and hoarseness (compression of the recurrent laryngeal nerve)
what investigations should be done for TAA?
CT scan
aortography
transoesophageal echocardiography
why would an aortography be useful for TAA?
may be used to assess the position of the key bracnches in relation to the aneurysm
If TA aneurysm is >___ then operative ___ or _____ may be appropriate, but these can technically be difficult and carry high mortality risk
If aneurysm is >6cm then operative repair or stenting may be appropriate, but these can technically be difficult and carry high mortality risk
____ is te 1st line procedure in isolated descending thoracic aneurysms
EVAR
what is aortic dissection?
where the blood splits the aortic media
what is a type A dissection?
involving the aortic arch and the ascending aorta irrespective of the site of tear
what is a type B dissection?
if the ascending aorta is not involved
what are the symptoms of dissection?
- severe and central chest pain (± radiation to the back and down arms ) mimicking MI
- may have neurological symptoms secondary to loss of blood supply to the spinal cord
- they may develop renal failure, acute lower limb ischaemia
what are the signs of dissection?
As the dissection extends, branches of the aorta occlude sequentially leading to hemiplegia (carotid artery), unequal arm pulses and BP or acute limb ischaemia, paraplegia (anterior spinal artery) and anuria (renal arteries)
peripheral pulses may be absent
what investigations should be done?
CXR, DO CT or transoesophageal echocardiography
All patients with type __ dissection should be considered for surgery
All patients with type A should be considered for surgery
definitive treatment for type _ is less clear and may be managed medically, with surgery reserved for distal dissections that are _____, _____ or compromising ____ _____
definitive treatment for type B is less clear and may be managed medically, with surgery reserved for distal dissections that are leaking, ruptured or compromising vital organs
management of dissection:
- crossmatch 10ublood
- ECG and CXR
- CT/MRI or transoesophageal echocardiography (TOE)
- take to ITU
- hypotensives: keep systolic at ___ - ___mmHg : labetalol
management of dissection:
- crossmatch 10ublood
- ECG and CXR
- CT/MRI or transoesophageal echocardiography (TOE)
- take to ITU
- hypotensives: keep systolic at 100- 110mmHg : labetalol
what are the complications of dissection?
- aortic valve incompetence
- inferior MI
- Cardiac arrest
- these may develop if the dissection moves proximally
