Introduction to Abdominal Aortic Aneurysm, Signs and Symptoms of AAA, possible treatment, Diagnosis of Abdominal Aortic Aneurysm. Diagnosing Abdominal Aortic Aneurysm with Ultrasonography. Appearance of AAA on a sonogram and limitation of ultrasound in diagnosing Abdominal Aortic Aneurysm.

1. Ultrasonography in “Abdominal Aortic Aneurysm” Diagnosis Literature Review
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The abdominal aorta is the artery that runs
through the middle of the abdomen,
supplying blood to the lower half of the
body. Various factors including age, sex,
ethnicity, smoking, atherosclerosis,
hypertension etc. [1, 2, 3] can cause
alterations of the connective tissues in the
aortic wall leading to disruption of its elastic
fibers. These alterations most often result in
the formation of an aneurysm in the aorta.
An abdominal aortic aneurysm (AAA) is
defined as the dilation of the abdominal
aorta of at least one and one-half times the
normal diameter of 2.0 cm at the level of the
renal arteries [2, 4, 7]. This vascular disease
is prevalent in men but it can occur almost
exclusively in both gender, with the mean
age between 65 and 75 years [3, 4, 6].
Most AAA is considered silent, owing to the
fact that most patients are asymptomatic
until the AAA expands or ruptures [3, 4, 7].
Symptoms due to pressure on adjacent
structures or changes in the aneurysm wall
include: severe abdominal, back, flank, or
groin pain. Patients may have an abrupt
onset of fatigue or even syncope. Rupture of
the AAA presents more serious
complications including, hypotension, lactic
acidosis, coma, hemorrhage and shock etc
[2, 3]. Currently, surgical interventions
including open surgical and endovascular
repair are the only treatment options for
AAA patients [6].
The diagnosis of an AAA should ideally be
made before the development of clinical
symptoms to prevent rupture as only
approximately 50% of patients with ruptured
AAAs reach the hospital alive; of those who
reach the hospital, up to 50% do not survive
repair [7]. AAAs may be detected on
physical examination by abdominal
palpation ( revealed as a pulsatile, expansile
mass at or above the umbilicus) and by
ultrasonography (US) or computed
tomography as well as other imaging tests
including radiography, magnetic resonance
imaging (MRI), and angiography [1, 2, 3, 6,
8]. Compared with other imaging
techniques, ultrasonography is noninvasive,
quick, inexpensive, free of radiation, less
Abdominal Aortic Aneurysm
(Ramzee Small)

2. Ultrasonography in “Abdominal Aortic Aneurysm” Diagnosis Literature Review
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technically demanding, and yet quite
accurate, all of which are ideal features for
screening and diagnosing AAAs [4, 5, 6, 8].
In the hands of a skilled clinician, US has a
sensitivity of about 100% and specificity of
about 96% for AAA, making it one of the
most valuable and practical tools for
confirming or ruling out AAA; a diagnosis
can be confirmed in less than 60 seconds
[3].
Abdominal aortic US examinations should
be performed with real-time scanners with
transducers that allow for appropriate
penetration and resolution, depending on the
patient’s body habitus [9]. Prior to the
examination patient is require to fast for 8
hrs -12 hrs to prevent food /liquids in the
stomach and urine in the bladder from
obscuring the image. High-frequency sound
waves are then emitted from the US
transducer placed against the abdomen, to
obtain the ultrasound images based on the
sound wave reflected back from the internal
organs to rule out AAA [6]. Measurements
of the proximal, mid, and distal aorta should
be obtained using predominantly the long
axis view to measure the AP dimension.
Transverse or coronal views should also be
obtained to measure the width [8, 9]. The
maximum diameter is key in defining AAA;
an infrarenal abdominal aorta greater than or
equal to 3 cm in diameter or greater than or
equal to 1.5 times the diameter of the more
proximal infrarenal aorta, confirms the
presence of an AAA [1, 2, 3, 9]. For the area
above the celiac artery, an aneurysm may be
reported if the diameter is greater than 3.9
cm for males or 3.1 cm for females [9].
3D US is emerging as an even more accurate
technique as it allows for measurement of
the maximum diameter perpendicular to the
AAA centerline as well as the AAA volume
[5, 6]. Another technique, pulse-wave
imaging (PWI), was reported to be capable
of mapping the pulse-wave propagation
along the abdominal aorta. Since AAA leads
to changes in the mechanical properties of
the aortic wall, the pulse-wave velocity
(PWV) may indicate a regional change due
to the non-uniformity along the normal and
pathological arteries, using PWI [6].
US technology is highly operator dependent.
It is also limited by its ability to accurately
visualize the aortic aneurysm or a stent in
patients who are very obese, have extensive
wall calcification, subcutaneous
emphysema, significant bowel gas, ascites,

3. Ultrasonography in “Abdominal Aortic Aneurysm” Diagnosis Literature Review
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or a large ventral hernia [2, 3, 5, 6].
Moreover, finding the correct cross-
sectional scan plane with the maximum
aortic diameter remains the most difficult
part in AAA diagnosis [1].
References
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Verhagen H, Bosch G. J, Bom N,
Bax J. J, Poldermans D. Screening
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system: early results. European
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doi:10.1093/ejechocard/jep 081
2. Silverstein D. M, Pitts R. S, Chaikof L.
C, Ballard J. D. Abdominal aortic
aneurysm (AAA): cost-effectiveness
of screening, surveillance of
intermediate-sized AAA, and
management of symptomatic AAA.
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3. Howell M C, Rabener J. M.
Abdominal aortic aneurysm: A
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5. Brekken R, Dahl T, Hernes, A. N. T.
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6. Honga H, Yanga Y, Liub B, Caia W.
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Curr Vasc Pharmacol. 2010 Nov 1;
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Sharma A. Abdominal aortic
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exp Clin Cardiol 2011;16(1): 11-15.
8. Long A , Rouet L, Lindholt J. S,
Allaire E. Measuring the maximum

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diameter of native Abdominal Aortic
Aneurysms: review and critical
analysis. European Journal of
vascular and endovascular
surgery.2012 Jan 12;43:515-524.
doi:10.1016/j.ejvs.2012.01.018