The document discusses abdominal aortic aneurysm (AAA), covering its definition, anatomy, classification, incidence, etiology, risk factors, and management. AAA is a significant health concern, especially among males over 50 years old, and often presents asymptomatically until rupture, leading to severe complications. Effective management requires prompt diagnosis and consultation with vascular surgeons to reduce high operative mortality rates associated with ruptured aneurysms.

1. ABDOMINAL AORTIC
ANEURYSM(AAA)
DR MOHD SHAFIQ FIRDAUS BIN MOHD ZAKI
SUPERVISOR: DR ZAKI

2. OUTLINES
Introduction
Anatomy
Definition
Classification
Etiology/Risk factor
Pathophysiology
Approach AAA
Management

3. INTRODUCTION
• Aortic disease includes conditions such as:
Chronic aortic aneurysms
Acute aortic syndromes (aortic dissection, intramural hematoma,
penetrating atherosclerotic ulcer, periaotic hematoma, intimal tear
without tear, aortic trauma)
Congenital aortic abnormalities (Marfan’s syndrome and
coarctation of the aorta)
• The incidence of aortic diseases is expected to rise with the
increasing age of the population

4. ANATOMY OF AORTA
Divided into 4 section:
• Ascending aorta
• Aortic arch
• Descending aorta
• Abdominal aorta

5. THE ABDOMINAL AORTA
• Begins from aortic hiatus of the
diaphragm ,anterior to the lower border of
vertebra T7/T8.
• It desends to the level of vertebra L4.
• The terminal branches of the abdominal
aorta are two common iliac arteries .
• The abdominal aorta (average diameter
2.0 cm) is further branches into
Suprarenal and Infrarenal portion

6. HISTOLOGY
It is composed of three layers:
• The intima –
- is the innermost layer
- includes the single-layered endothelium.
• The media –
- the thickest layer of the aortic wall
- composed of sheets of elastic tissue, smooth muscle cells
and collagen
- provide the aorta with its tensile strength and distensibility.
• The adventitia –
- the outermost layer
- it is composed of loose connective tissue and contains
the vasa vasorum,

7. DEFINITION
• Aortic aneurysm, refers to
enlargement of the aorta beyond its
normal diameter.
• A segment of the aorta is called
aneurysmal if its maximal diameter is
greater than 1.5 times that of the
adjacent proximal normal segment.
• True aneurysm : containing three layers of
the arterial wall in the aneurysm sac
• False aneurysm : Leaking artery that leads to
a hematoma between the vessel and
surrounding tissue.

8. Incidence
AAA is the one of leading cause of death in western societies.
Higher in males (4-8%) compared to females (1-1.3%) in those older than 50 years old.
It is a silent killer because there are often no symptoms that an aneurysm is developing in the
abdominal aorta.
Incidence of AAA is common in elderly : chance of getting aneurysm in genitacally related first
degree relatives is 11 times more.

9. Classification
Based on shape of the aneurysm
1. Fusiform : uniform dilatation of
entire circumference of arterial wall
2. Saccular : dilatation of part of
circumference of the part of arterial
wall

11. Based on site
Small aneurysm : <4.0cm
Medium aneurysm : 4.0cm- 5.5cm
Large aneurysm : >5.5cm
Very large aneurysm :>6.0cm

12. Etiology
Atherosclerosis (as degenerative process) (95%)
First degree relatives : 11 fold increase in risk
Familial aortic aneurysm (25%)
-Enler Danlos syndrome ( Genetic defect in collagen synthesis)
-Marfan’s Syndromes : autosomal dominant
Others: Salmonella infection,syphilis,trauma,collagen diease,arteritis

13. RISK FACTORS
•Male
•Hypertension
•Smoking
•Hyperlipidaemia
•Increasing age
•Infection/inflammation
•Gene(marfan,Ehlers-Danlos syndrome)

14. Pathophysiology
1. Certain disease or Inflammatory process causes weakening of the aortic walls.
2.
-Causing breakdown of elastic elements
-Decrease in elastin and collagen in arterial wall
-Elastin becomes fragmented -- arterial elongation and dilatation
3. When blood is pumped through these weakend areas,it bulges out,which called aneurysms.
4.As the flow and thus the pressure through this area increases ,it causes the rupture of the
aneurysm of the aortic wall.

15. COMPLICATION
Rupture
Thrombosis & embolism
Distal ischemia & gangrene
Aorta-caval fistula
Aorta-enteric fistula
Spinal cord ischaemia when thrombosis develops

16. Diameter for AAA vs Risk of Rupture
AAA DIAMETER (CM) RUPTURE RISK
4-4.5 5%
6-7 33%
>7 95%

17. Approach to Abdominal
Aortic Aneurysm

18. History
Clinical Presentation
Often asymptomatic at time of presentation. Physical findings may also be absent.
May present with
1. Abdominal mass,often pulsatile,but ocassionally not
2. Syncope with postural hypotension
3. Acute limb ischamic or mottling of toe (Embolization)
4. Malena/vomit fresh blood (Aortoenteric fistula)
5. Dysphagia,nausea,vomiting (Compression of the bowel,stomach or oesophagus)
6. Symptom of Myocardial ischemia/infaction (Enlargement of the aortic sinuses can lead to narrowing
of the coronary artery ostia)
7. Rupture Triad : Abdominal or back pain + palpable/pulsatile abdominal mass + hypotension

19. Clinical examination
Ruptured Aneurysm
1. A patient with a ruptured aneurysm at any level is likely to look pale and unwell
2. The pulse will be rapid,weak and thready.
3. Hypotension is common.
4. Per Abdominal Examination
-Pulsatile abdominal mass
-Grey Turner sign,Cullen sign,Fox’s sign and Bryant’s sign
-Distension/Tenderness

21. Investigation
Blood : FBC,Renal Profile,Coagulation profile,GXM
Imaging
1.Xray :
-Abdominal xray: show calcium deposit in the aneurysm wall ,Eggshell pattern
2.Ultrasound :
-Give a clear picture of the size of aneurysm.
-Not ideal method for detacting rupture of aneurysm as it is unable to image all portion of aortic
wall.

23. 3.Computed Tomography (CT)
-provides excellent imaging of AAA compared to ultrasound
-CTA provides :
 Anatomic information
 Detect vessel calcification thrombus
 Concurrent arterial occlusive disease
 Determined if there is leaking of the aneurysm
4. Electrocardiogram (ECG)
-may be performed to rule out evidence of myocardial infarction (MI)
5. Echocardiography
-assists in the diagnosis of aortic valve insufficiency related to ascending aortic
dilation

25. Management
1. Triage : Ruptured aortic aneurysm should be manage in critical care area (RED ZONE)
2. ABC primary survey,ensure patent airway and perform resuscitative measures as needed.
3. Target a goal systolic blood pressure of 80-90 mm Hg, and transfuse packed red blood cells if needed.
4. Esmolol or Labetalol is recommended in the event of suspected expanding aneurysm and severe
hypertension.
5. Provide pain control while avoiding hypotension.
6. Consult emergently with a vascular surgeon when a rupturing AAA or aortoenteric fistula is
suspected.
7. When a small asymptomatic AAA (3.0 to 5.0 cm) is identified as an incidental finding, refer the
patient to see a vascular surgeon.
8. Large AAAs (>5.0 cm) are at higher risk for spontaneous rupture and may warrant close follow-up

26. References
Shirley ooi seconda edition
Tintinalli’s Emergency Medicine Manual 8th Edition

27. Case scenario 1
74 years old ,malay male .Active smoker,with underlying hypertension.
Presented with abdominal pain over epigastric area radiated to the back.
Assiociated with pulsatile mass at epigastric area and had brief syncopal attack about 3 minutes
at home.

28. TRIAGE
DIFFERENTIAL DIAGNOSIS

29. •On examination:
Alert conscious
Not tachypneic
Warm peripheries
Good pulse volume
CRT<2sec
Bp 173/98
Hr 110
Spo2 98 under ra
T 36.8
Per abdomen: pulsatile mass over epigastric area,soft non tender

30. Investigation

31. FBC : wbc 7/hb 14/plt 234
Bedside scan :
abdominal aorta size 5cm
Liver homogenous
Gallbladder not distended ,no stone seen
bilateral kidney normal,no hydronephrosis,no stone seen

32. Management

33. Scenario 2
53 years old malay man,active smoker,with underlying IHD,COPD,HPT.
Done formal US KUB with report : Long segment of abdominal aortic aneurysm with intramural
thrombus causing 69% stenosis.Size 5-6cm diameter.
The main complaint are genaralised abdominal pain more over left iliac fossa.
Assiociated with lethargic.

34. Triage
Differential Diagnosis

35. •On examination
Alert concious,not tachypneic,warm peripheries,good pulse volume,crt<2sec
BP 159/106
HR 113
SPO2 99 under ra
Per Abdomen:
Inspection :Pulsatile central abdominal mass seen.
Palpation: soft,mild tender epigastric and left iliac fossa.

36. Investigation

37. Abdominal xray: no dilated bowel seen
Ultrasound abdomen: Abdominal aneurysm diameter size about 5x7cm,no free fluid seen.
Ecg : SR
FBC : wbc 8/hb 15.5/plt 256

38. Management

39. Take Home Message!
1.Early diagnosis of AAA so important because the operative mortality of treating a ruptured
aneurysm is 80%.
2.Only 1/3 of all ruptured AAA reaches hospital alive (33%).
3.All patient that we suspected for rupture aneurysm should be consult emergently to surgical
team (vascular surgeon ).

40. THANK YOU