Aneurysms 1- aneurysm disease Flashcards
Define aneurysms
weakened blood vessel wall, which is pushed outwards due to blood pressure causing excessive localised swelling in the wall of an artery
Dilatation of all layers of the aorta, leading to an increase in diameter of >50%
What is the four sections of the aorta, where are they located and what do they supply
- The ascending aorta - rises up from the heart and is about 2 inches long. The coronary arteries branch off the ascending aorta to supply the heart with blood.
- The aortic arch - curves over the heart, giving rise to branches that bring blood to the head, neck, and arms.
- The descending thoracic aorta - travels down through the chest. Its small branches supply blood to the ribs and some chest structures.
- The abdominal aorta - begins at the diaphragm, splitting to become the paired iliac arteries in the lower abdomen. Most of the major organs receive blood from branches of the abdominal aorta.
What is the three layers of the aorta and their functions
- The intima, the innermost layer, provides a smooth surface for blood to flow across.
- The media, the middle layer with muscle and elastic fibers, allows the aorta to expand and contract with each heartbeat.
- The adventitia, the outer layer, provides additional support and structure to the aorta.
What layer of the aorta is at most risk of damage and why
The intima - thinest layer
Where do aneurysms usually occur in aneurysm disease
abdominal aorta
What does the aorta bifurcate to
Iliac vessels
What is the aetiologies of aneurysm disease
Degenerative disease
Connective tissue disease (e.g. Marfan’s disease)
Infection (mycotic aneurysm)
What is the risk factors for abdominal aortic aneurysm
Male sex Age Smoking Hypertension Family history
What can be found of clinical examination of an abdominal aortic aneurysm
aneurysm can be palpated at abdomen above umbilicus.
What is the purpose of aortic abdominal aneurism screening and what patients is it critical for
To detect a dangerous swelling of the aorta
Men over aged 65 with a heart problem
What is the 4 outcomes of a screening that can be found (size dependant)
A) Normal aorta, discharged
B) Small AAA (3.0-4.4cm) will be invited for annual USS scans
C) Medium AAA (4.5-5.5cm) will be invited for 3 monthly USS scans
D) Large AAA (>5.5cm)
What is the typical presentation of a AAA
asymptomatic
When AAA becomes symptomatic what does this indicate
Means there is an impending rupture or has been a rupture
What is the symptoms of an AAA impending a rupture
Increasing back pain
Tender AAA
Inflammation
What is the symptoms of a ruptured AAA
abdominal, back, side pain; painful pulsatile mass; haemodynamic instability (unstable blood flow/pressure); hypoperfusion (shock)
What is the unusual presentations of AAA
Distal embolisation Aortocaval fistula Aortoenteric fistula (connection between the aorta and the intestines, stomach, or esophageus) Ureteric occlusion (blockage in the ureters) Duodenal obstruction (failure of food to pass out of the stomach)
How does AAA lead to distal embolisation
Aneurysm sack has flow channel and around it there’s a lot of thrombus and disease. Pieces of thrombus can flick off, travel and get lodged elsewhere leading to distal embolisation
What three factors need to be investigated in the management of an asymptomatic AAA
Is the aneurysm a size to consider repair?
Is the patient a candidate for repair?
Is the aneurysm suitable for endovascular or open repair?
Risk of rupture increases with size so what size in an aneurysm is surgical treatment offered
> 5.5cm
surgery does not serve any benefit is less that 5.5cm
How do you asses that patients fitness of AAA surgery
Full history and examination to find out co morbidities, fitness, lung function, ECG, bloods, end of bed test etc
How do you assess is an AAA is suitable for repair
Imaging: ultrasound, CTA, MRA
What is the advantages and disadvantages of Ultrasound in AAA
ADV:
No radiation
No contrast
Cheap
DIS:
Operator dependent
Inadequate for surgical planning
What is the advantages and disadvantages of CT/MRA in AAA
ADV:
Quick
Not operator dependent
Necessary for surgical planning – detailed anatomy due to contrast
DIS:
Contrast - retail failure
Radiation
What is the two surgical treatments available for aortic aneurysm repair
〈 Endovascular repair (key hole approach)
〈 Open repair (more traditional operation).
What does the procedure if an open repair of aortic aneurysm involve
A surgical incision into the abdominal cavity (Laparotomy) from the xiphisternum to pubic symphysis
Then occlude aorta proximally
What is the general complication of an open repair of an AAA
Wound infection / dehiscence
Bleeding
Pain
Scar
What is the technical complications of an open repair AAA
Damage to bowel, ureters, veins, nerves Incisional hernia Graft infection Distal emboli Renal failure Colonic ischaemia
What patients factors of complications in open and endovascular repair of AAA
DVT/PE
MI
Stroke
Death
What happens in the procedure of endovascular repair
Key hole approach with a puncture at groin.
Operation takes 1 to 2 hours done under anaesthetic
What is the technical complications of endovascular repair
5 different types of Endoleak
Femoral artery dissection / pseudoaneurysm
Rupture
Distal emboli / ischaemia / colonic ischaemia
Damage to femoral vein / nerve
What is the general complications of endovascular repair
Wound infection Bleeding / haematoma Pain Scar Contrast – reaction / kidney injury Radiation
What is the less complicated method in rupture repair of an AAA
Endovascualr - damage to groin area but far less complications
What is the management of the complication of endoleaks
Ongoing surveillance with scans needed to check for leaks.
What is the treatment option if patient is unstable with an AAA rupture
Straight to theatre pre or post CT for an Emergency open repair
What kind of operation is an emergency open repair
a massive transfusion protocol
Why must abdomen be prepped rapidly before anaesthetising
As abdominal muscles as are more stable when you are awake, as work as a tamponade preventing further bleeding in the abdomen - therefore is wise to anaesthetise last minute, so maintain this tamponade for as long as possible before surgery
What is the risk of emergency open repair rupture AAA
30-50% mortality,
significant morbidity
Risk of abdominal compartment syndrome.
What is the management of an AAA before it reaches 5.5cm
Surveillance
