Abdominal aortic aneurysm

Question 1

What is an abdominal aortic aneurysm also known as?

Answer 1

AAA.

Question 2

Define an AAA.

Answer 2

A permanent pathological dilation of the aorta.

Question 3

Where do more than 90% of AAA’s originate from?

Answer 3

Below the renal arteries.

Question 4

Who is most affected?

Answer 4

· More common in males.
· Higher prevalence in men.
· High risk of rupture in women.

Question 5

What is the pathophysiology of an AAA?

Answer 5

· Obliteration of collagen and elastin in the media and adventitia.
· Smooth muscle cell loss with tapering of medial wall.
· Infiltration of lymphocytes and macrophages.
· Neovascularisation.

Question 6

What is the likely prognosis for a patient with an AAA?

Answer 6

· Most patients with rupture don’t survive to reach the operating theatre.
· Good prognosis for elective repair.

Question 7

What is the aetiology of an AAA?

Answer 7

· Intimal atherosclerosis.
· Altered tissue metalloproteinases that diminish the integrity of the arterial wall.
· Smoking.
· Diabetes protects against the growth and enlargement of AAA.

Question 8

Typical risk factors associated with an AAA?

Answer 8

· Cigarette smoking.
· FHx. 
· Increased age. 
· Male for prevalence.
· Female for rupture. 
· Congenital/Connective tissue disorders. 
· Atherosclerosis.

Question 9

Typical signs and symptoms associated with an AAA?

Answer 9

· Palpable, pulsatile abdominal mass. 
· Abdominal, back or groin pain. 
· Rupture:
 - Hypotension. 
 - Pain. 
 - Pulsatile mass.

Question 10

What investigations would you request if you suspected a patient had an AAA?

Answer 10

· Abdominal USS.

· CTA.

Question 11

Differentials?

Answer 11

· Diverticulitis.
· Ureteric colic.
· IBS. 
· IBD.
· Appendicitis.
· Ovarian torsion. 
· GI haemorrhage.

Question 12

Treatment of a ruptured AAA?

Answer 12

· Resuscitation.
· Urgent surgical repair.
· Perioperative abx

Question 13

Treatment of a symptomatic patient who does not have a ruptured AAA?

Answer 13

· Urgent surgical repair.
· Preoperative cardiovascular risk reduction.
· Perioperative abx.

Question 14

Treatment of an incidental AAA finding on screening?

Answer 14

· Surveillance.
· Aggressive cardiovascular risk management.
· Elective surgical repair.
· Risk reductions as above.

Question 15

Complications?

Answer 15

· Abdominal compartment syndrome. 
· Ileus, intestinal obstruction and ischaemic colitis. 
· AKI. 
· Anastomotic pseudoaneurysm. 
· Aortic neck dilation. 
· Post-implantation syndrome - fever, malaise and back pain due to cytokine release.
· Amputation due to limb ischaemia. 
· Spinal cord ischaemia.
· Impaired sexual function. 
· Graft infection. 
· Gastric outlet obstruction.
· Endoleak.