1-Abdominal Aortic Aneurysm Flashcards

1
Q

what is the abdominal aortic aneurysm (AAA)?

A

A focal dilatation of the abdominal aorta to more than 1.5 times its normal diameter. Most commonly infrarenal. Frequently asymptomatic and detected incidentally.

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2
Q

what is the definition of AAA?

A

Abdominal Aortic Aneurysm is a dilation of the abdominal aorta (> 3cm) formed by widening of the lumen secondary to weakness of the aortic wall, that may extend proximally or distally along the artery

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3
Q

what is the epidemiology of AAA?

A
  • -Peak incidence: 60–70 years (rare in patients < 50 years)
  • -Sex: ♂ > ♀: ∼ 2:1
  • -More common in white populations
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4
Q

AAA is more common in females. True/False

A

False

–Sex: ♂ > ♀: ∼ 2:1

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5
Q

AAA is commonly combined with other aneurysms. True False

A

True

 25% of patients with AAA have coexisting femoral or popliteal aneurysms

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6
Q

what are the risk factors of AAA?

A
  • -Advanced age
  • -Smoking (most important risk factor)
  • -Atherosclerosis
  • -Hypercholesterolemia and arterial hypertension
  • -Positive family history
  • -Trauma
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7
Q

what is the most important risk factor of AAA?

A

smoking

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8
Q

classify the aneurysm

A
  1. True / False
  2. Anatomical
  3. Aetiology
    –Degenerative
    –Inflammatory
    –Infective
    –Traumatic
    –Post dissection
    4)Below the renal arteries
    Most common location
    5)Above the renal arteries
    6)anatomical location
    - aortoiliac
    - suprarenal
    - thoracic/TAA
    - femoral
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9
Q

AAA most commonly is below or above renal arteries?

A

below

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10
Q

what is the pathophysiology of AAA?

A
  • -Inflammation and proteolytic degeneration of connective tissue proteins (e.g., collagen and elastin and/or smooth muscle cells) in high-risk patients → loss of structural integrity of the aortic wall → widening of the vessel → mechanical stress (e.g., high blood pressure) acts on weakened wall tissue → dilation and rupture may occur.
  • -The aneurysmatic dilatation of the vessel wall may cause disruption of the laminar blood flow and turbulence.
  • -Possible formation of thrombi in the aneurysm → peripheral thromboembolism
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11
Q

what is the difference between true and false aneurysm?

A

1) Involves all three layers of the vessel wall (i.e., tunica intima, tunica media, tunica adventitia).
2) A collection of blood that forms due to a vessel wall defect. Can result in the accumulation of blood between the tunica media and the tunica adventitia or between the blood vessel and surrounding tissue.

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12
Q

AAA is commonly asymptomatic or symptomatic?

A

Asymptomatic - 75%

  • Routine examination
  • Ultrasound Sound scanning/Plain
  • Film Abdomen for other reason
  • Patient notices pulsatile mass
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13
Q

how AAA is usually detected?

A

on routine examination by USG

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14
Q

what are the complications of AAA?

A

• Distal Embolisation(blue toe syndrome)

• Leak
(abdominal/back /flank pain)

• Rupture
(hypovolaemic shock, sudden epigastric/back pain)

• Fistulation – “Rare”
(aorto-caval/aorto-enteric)

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15
Q

what are the signs and symptoms of AAA?

A
  • -Aortic aneurysms are mostly asymptomatic or have nonspecific symptoms. Therefore, they are often incidental findings on ultrasound or CT scan. Rupture or dissection of the aneurysm is a life-threatening condition
  • -Lower back pain
  • -Pulsatile abdominal mass at or above the level of the umbilicus
  • -Bruit on auscultation
  • -Peripheral thrombosis and distal atheroembolic phenomena (e.g., blue toe syndrome and livedo reticularis)
  • -Decreased ankle brachial index
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16
Q

how AAA is assessed?

A

Clinical Examination
• Inspect for abdominal pulsations at eye level
• Feel for pulsatile/expansile mass in 2 planes
• Listen for bruits
• Examine femoral and popliteal arteries

Assessment: Ultrasound – Diagnose & Size

17
Q

what technique is used to monitor AAA progression?

A

USG
An abdominal ultrasound for AAA diagnosis has a sensitivity and specificity of nearly 100%, but may be limited by bowel gas or patient obesity. It also lacks sensitivity for the detection of aneurysmal leaks, branch artery involvement, and suprarenal involvement.

18
Q

what is the role of CT with contrast in AAA?

A

determines AAA rupture, suprarenal involvement, and visceral artery involvement.
• Tortuosity
» Involvement of renal arteries
» Evidence of leak

19
Q

what is the risk of AAA rupture based on size?

A
  • <4—0%
  • 4-5–0.5-5%
  • 5-6—3-15%
  • 6-7—10-20%
  • 7-8—20-40%
  • > 8—30-50%
20
Q

what are the indications of AAA surgery?

A
  • Rupture
  • Symptomatic - back/flank/abdominal pain, embolisation
  • Rapid increase in size >1.0 cm/year
  • Asymptomatic ≥ 5.5 cm – exact lower limit controversial
  • Aorto-caval/Aorto-enteric fistula
21
Q

how frequently USG should be done of done based on AAA size?

A

< 3 cm–No further follow-up
3–4 cm–Ultrasound every year
4–4.5 cm–Ultrasound every 6 months
4.5–5.5 cm–Ultrasound every 3 months

22
Q

what is the EVAR (endovascular aneurysm repair)?

A

A minimally invasive technique used to repair aortic aneurysms (e.g., AAA). An expandable stent graft is placed intraluminally under fluoroscopic guidance via the femoral or iliac arteries at the site of the aneurysm, thus excluding the dilated aortic segment from circulation. Known as TEVAR (thoracic EVAR) when performed for a thoracic aortic aneurysm.

23
Q

which one is preferred EVAR or open surgical repair?

A

EVARp referred over open surgery; esp. in patients with high operative risk

24
Q

what is the advantage of EVAR against surgery?

A
  • Suitable for older age groups
  • Suitable in significant co-morbid illnesses
  • Avoids the major 3 insults of surgery:
    1. Laparotomy
    2. Aortic Cross-Clamping
    3. Ischaemia-Reperfusion
25
Q

what are the EVAR complications?

A
  • Operative Mortality <1 %
  • Access
  • Endoleaks/ Graft Migration / Erosion - Reintervention
  • Limb Occlusion
  • Pelvic Ischaemia
26
Q

what are the routes of incision in AAA open surgical repair?

A
  • Midline
  • TV
  • Retroperitoneal
27
Q

what are the complications of AAA open surgical repair?

A

–Operative Mortality 5-10%
–Early
Cardiac / RespBleeding
Colonic / Limb Ischaemia
–Late
Hernia
Sexual ysfunction
PAS / Aorto-Enteric Fistula

28
Q

how AAA is screened?

A
  • -Screening for abdominal aneurysm with abdominal ultrasound
  • -One-time screening in men aged 65 to 75 years with a history of smoking
  • -Individuals ≥ 50 years with positive family history