Abdominal aortic aneurysm

Question 1

aneurysm

Answer 1

permanent localised dilation of the artery to twice the normal diameter

Question 2

true aneurysm

Answer 2

vessel walls are still intact just heavily dilated

Question 3

aetiology

Answer 3

• present in 5% in population over 60% of age
• more frequent in men
• occur secondary to atherosclerosis
• genetic links
• hypertension

Question 4

pathophysiology 1

Answer 4

• usually results from the degeneration of the media of the arterial wall
• abnormal regulation of elastin and collagen proteins in the aortic wall by enzymatic agents
• occur below renal arteries

Question 5

pathophysiology 2

Answer 5

• in a ruptured AAA the wall of aorta completely fails and blood escapes freely into a body cavity
• continuous expansion of AAA until rupture
• decision to fix AAA is a balance between risk of rupture vs risks of surgery

Question 6

asymptomatic

Answer 6

75% asymptomatic - incidental finding - until rupture occurs

Question 7

symptomatic

Answer 7

can have epigastric/central pain with no rupture or dissection
a ruptured AAA will present as sudden onset abdominal pain radiating to back with an expansile abdominal mass

Question 8

other signs

Answer 8

• dusky discolouration of digits
• collapse
• tachycardia

Question 9

monitoring - USS

Answer 9

• check if asymptomatic patient has aneurysm
• shows if there is an AAA
• when a small aneurysm is detected patients enter a surveillance programme with regular ultrasound scans

Question 10

ruptured AAA

Answer 10

• diagnosis must be made quickly an surgeon contacted
• are briefly contained by retroperitoneum
• CT is the only scan that can identify a ruptured AAA

Question 11

medical managemetn

Answer 11

control of risk factors - antihypertensives, smoking cessation, lipid lowering medication

Question 12

surgical medication

Answer 12

no intervention vs EVAR vs Open repair

Question 13

EVAR

Answer 13

• EVAR not possible in 25% of patients
  
  • Less mortality risk
  • Faster recovery
  • Needs life long follow-up appointments to check the stent graft
  • The iliacs need to be disease free to insert the stent to the aorta

Question 14

open repair

Answer 14

• possible in everyone
  
  • Greater mortality risk
  • Slower recovery
  • Further appointments are rare

Question 15

surgery on asymptomatic

Answer 15

• Elective surgery only performed if the AAA is > 5.5 cm in diameter - before this risk of surgery outweighs the risk of rupture
• Prophylactic operation
  
  • Balances risk of rupture vs risk of procedure

Question 16

surgery for symptomatic

Answer 16

• Graft - EVAR or open lap
• Therapeutic operation
  
  • Balances expectation of death vs risk of procedure

Question 17

outcome of repair for ruptured AAA

Answer 17

50-75% of patients will not make it to hospital

Question 18

outcome of repair for asymptomatic AAA

Answer 18

3% of patients will die

Question 19

fitness for intervention tests

Answer 19

• Cardiac assessment → Echo/ejection fraction
• Respiratory assessment → PFT
• Cardiopulmonary exercise test → CPX testing
• Renal assessment → U&Es
• Vascular assessment → Peripheral pulses/ABPI
• Anaesthetic assesment
• EBT → End of bed test

Question 20

method of open repair

Answer 20

• General anaesthetic
• Laparotomy
• Clamp the aorta above and below the aneurysm
• Dacron graft

Question 21

methods of EVAR

Answer 21

• Needs imaging+contrast
• Local/regional anaesthetic
• Majority are performed via percutaneous access in groin with he stent inserted up through the femoral artery