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Flashcards in AAA Deck (30):
1

What are the Hx features of AAA?

-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.

2

Examination features of AAA on inspection?

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.

3

What is Cullen's sign?

bruising around the umbilicus indicative of long standing rupture.

4

What is Grey Turner's sign?

Bruising in the flank indicative of long standing rupture.

5

Examination features of AAA on palpation?

Expansile pulsatile mass; usually tender.
Consists of aneurysm and surrounding haematoma. Define upper and lower limits of aneurysm.

6

What is the first test to order in suspected AAA?

Ultrasound: aortic dilation >1.5 x that expected.

7

What is an AAA?

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).

8

In whom are AAAs most common?

Men 4-6x more likely than women.
Risk increases with age.

9

What is the aetiology of AAAs?

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

10

What is the pathophysiology of AAA formation?

-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.

11

How can AAAs be classified?

-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.

12

How should AAAs be screened for?

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

13

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

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

14

What are the standard resuscitation measures for AAA rupture?

+: 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)

15

What is the surgical method of AAA repair?

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

16

Ruptured AAA triad?

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

17

True vs false aneurysm?

-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

18

Conservative Mx AAA?

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

19

When should surgical Mx AAA be pursued?

-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

20

Contraindications to surgical Mx of AAA?

-Life expectancy

21

Surgical options for AAA repair

-Open (laparotomy) with graft replacement
-EVAR with graft replacement

22

Possible complications of open AAA repair?

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

23

Complications of EVAR?

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

24

What is an aneurysm

Focal arterial dilation
1.25-1.5x greater diameter than adjacent normal artery

25

Natural Hx aneurysm?

Continued expansion and eventual rupture

26

Common sites of arterial aneurysm?

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

27

How is risk of aneurysm rupture determined?

Risk of aneurysm rupture related to diameter:
-8cm 25% annual risk of rupture

28

Aneurysm primary prevention?

-Cease Smoking!
-Control HTN

29

Aneurysm secondary prevention?

Screen and treat aneurysms >5-5.5cm

30

Factors when consideration non-intervention in ruptured AAA?

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