AAA

Question 1

What are the Hx features of AAA?

Answer 1

-Patients invariably smoker (ex or current)
-FHx atherosclerotic disease
-Previous Hx IHD, PVD, CVA, CT disorders.
Symptoms: pain begins in centre of abdomen, radiates to back +/- groin along course of genitofemoral nerve.

Question 2

Examination features of AAA on inspection?

Answer 2

Abdomen often distended; if pt thin ==> large central pulsating mass in epigastrium or umbilical region.
Long standing rupture: Cullen’s or Grey Turner’s sign.

Question 3

What is Cullen’s sign?

Answer 3

bruising around the umbilicus indicative of long standing rupture.

Question 4

What is Grey Turner’s sign?

Answer 4

Bruising in the flank indicative of long standing rupture.

Question 5

Examination features of AAA on palpation?

Answer 5

Expansile pulsatile mass; usually tender.

Consists of aneurysm and surrounding haematoma. Define upper and lower limits of aneurysm.

Question 6

What is the first test to order in suspected AAA?

Answer 6

Ultrasound: aortic dilation >1.5 x that expected.

Question 7

What is an AAA?

Answer 7

Permanent pathological dilation of the aorta with a diameter >1.5 times the expected AP diameter of that segment (based on gender and size of pt).

Question 8

In whom are AAAs most common?

Answer 8

Men 4-6x more likely than women.

Risk increases with age.

Question 9

What is the aetiology of AAAs?

Answer 9

Historically thought to be atherosclerosis alone –> does usually accompany AAA.
Altered tissue metalloproteinases may diminish integrity of arterial wall.

Question 10

What is the pathophysiology of AAA formation?

Answer 10

• Obliteration of collagen and elastin in media and adventitia,
• smooth muscle cell loss with resulting tapering of the medial wall,
• infiltration of lymphocytes and macrophages, inflammation with matrix proteins and metal-proteinases
• neovascularisation.

Question 11

How can AAAs be classified?

Answer 11

• Congenital: medial degeneration occurs with age but is accelerated in pts with bicuspid aortic valves and Marfan’s syndrome.
• Infectious: infection of aortic wall rare aetiology (Staph, Salmonella).
• Inflammatory: controversial. Accumulation of M0 and cytokines.

Question 12

How should AAAs be screened for?

Answer 12

Recommended U/S for males >65 years. Rescreen if >3.5cm.

Question 13

What tests (other than U/S) could be considered in AAA workup?

Answer 13

ESR/CRP: elevated.
FBE: leukocytosis, anemia.
Once confirmed on U/S: CT/MRI for anatomical mapping.

Question 14

What are the standard resuscitation measures for AAA rupture?

Answer 14

+: urgent surgical repair
+: perioperative antibiotic therapy
ABC and straight to theatre; crossmatch 10u PRBCs.
-Airway: O2 and endotracheal intubation
-CVC insertion
-Insertion of arterial catheter and urinary catheter
-Target systolic BP of 50-70mmHg
-Withold fluids preoperatively (dilutional coagulopathy, clot displacement etc)

Question 15

What is the surgical method of AAA repair?

Answer 15

EVAR (endovascualr AAA repair). or traditional open repair (mortality 48%).

Question 16

Ruptured AAA triad?

Answer 16

1) Pain (sudden abdo/back)
2) Hypotension / fx of hypovolemia
3) Pulsatile Abdominal Mass

Question 17

True vs false aneurysm?

Answer 17

• True: involves all layers (intima, media, adventitia)
• False: disruption of aortic wall or anastomotic site between vessel and graft with containment of blood by fibrous capsule of surrounding tissue

Question 18

Conservative Mx AAA?

Answer 18

• CV RFx reduction (HTN / DM / smoking cessation)
• Regular exercise
• Watchful waiting (rpt US 6/12)

Question 19

When should surgical Mx AAA be pursued?

Answer 19

• Indications: rupture, mycotic, symptomatic, Type A dissection / complicated Type B dissection
• Rupture risk > surgical risk (>5.5cm)
• Rupture risk depends on size, rate of enlargement, symptoms, comorbidities

Question 20

Contraindications to surgical Mx of AAA?

Answer 20

-Life expectancy

Question 21

Surgical options for AAA repair

Answer 21

• Open (laparotomy) with graft replacement

- EVAR with graft replacement

Question 22

Possible complications of open AAA repair?

Answer 22

• EARLY: AKI, spinal cord injury, impotence, arterial thrombosis, anastomotic rupture/bleeding, peripheral emboli.
• LATE: infection/thrombosis, aortoenteric fistula, anastomotic aneurysm

Question 23

Complications of EVAR?

Answer 23

• EARLY: conversion to open, groin haematoma, arterial thrombosis, iliac artery rupture, thromboemboli
• LATE: endoleak, severe graft kinking, migration, thrombosis, rupture of aneurysm.

Question 24

What is an aneurysm

Answer 24

Focal arterial dilation

1.25-1.5x greater diameter than adjacent normal artery

Question 25

Natural Hx aneurysm?

Answer 25

Continued expansion and eventual rupture

Question 26

Common sites of arterial aneurysm?

Answer 26

• AAA
• Common iliac arteries
• Popliteal arteries
• Femoral arteries
• Thoracic aorta

Question 27

How is risk of aneurysm rupture determined?

Answer 27

Risk of aneurysm rupture related to diameter:

-8cm 25% annual risk of rupture

Question 28

Aneurysm primary prevention?

Answer 28

• Cease Smoking!

- Control HTN

Question 29

Aneurysm secondary prevention?

Answer 29

Screen and treat aneurysms >5-5.5cm

Question 30

Factors when consideration non-intervention in ruptured AAA?

Answer 30

• Already unconscious / intubated on arrival (esp >80y)
• Demented / nursing home
• Already rejected elective due to comorbidities