Aorta Flashcards
What vessel layer is made of endothelial cells?
Tunica intima
What vessel layer is made of epithelial cells?
Tunica adventitia / external
What is the thickest vessel wall?
Tunica media
When does the aorta coarse more anteriorly than the IVC?
At the level of the umbilicus
What are the paired branches of the aorta?
- Suprarenal arts. - adrenal glands
- Renal arts -kidneys
- Gonadal arts.
- Lumbar arts.
- Common iliac arts.
What are the unpaired branches of the aorta?
- Celiac axis
- SMA
- IMA
- Median sacral art.
Name the aorta branches from superior to inferior
- Celiac axis (left gastric, splenic, CHA)
- SMA
- Renal
- Gonadal
- IMA
- CIA
At what level does the aorta bifurcate?
L3-4 vertebra / the umbilicus level
What are the common iliac arteries waveform ?
High resistant waveform - triphasic
Above the umbilicus, abdominal arteries are ________ to veins.
While below the umbilicus they are______ to veins
- Posterior
- Anterior
Indications to scan the aorta
- Abdominal pain
- pulsatile mass
- aneurysm seen on X-ray
- f/u aneurysm
- trauma
What can low hematocrit indicate?
An active bleed in the body
What probes should you use for scanning aorta?
(Adult and peds)
Adult- 2.5MHz to 6.5 MHz
Peds- 4 MHz to 8MHz
Normal measurements of aorta?
Prox- 2.0 - 2.6 cm
Mid- 1.6 - 2.4 cm
Distal- 1.1 - 2.0cm
Iliac - 0.6 - 1.4cm
What is the wave form above the renal arteries?
And below?
Above - biphasic due to low resistance branches to organs.
Below-triphasic; supplies lower ext. Which causes an increased resistance
What measurement corresponds to a triple A?
> 3 cm or an increase in diameter >50% between 2 adjacent segments
What is the most common cause of triple A?
Atherosclerotic disease
What are the risk factors for triple A?
- male gender
-Family history - smoking
- chronic HTN
What are the types of AAA?
- Saccular -localized round outputting may have stalk
- Fusiform - vessel wall stretches focally MOST COMMON
- Berry- tiny out pouching, usually found in the cerebrum and splanchic arteries
- Mycotic- infected aneurysm; seen with syphillis
Where is the most common location of fusiform aneurysms?
Infrarenal
When do AAA need surgical intervention?
Above the rentals - immediate intervention
Below- diameter >5.5cm
If you find a AAA where else should you check?
CIA, CFA, and pop
A AAA can cause what complications?
- Rupture
-Blue toe syndrome - affects renal circulation and systemic blood pressure if suprarenal or juxtarenal location
- large AAA can compress IVC causing reduced flow toward the heart and pedal edema
A saccular AAA has an increased risk of?
Rupture due to increased pressure in the neck
What sign is associated wl a AAA?
Yin yang
Where is the most common splanchnic artery aneurysm located?
Splenic artery
( splanchnic = splenic)
Who are more at risk for splenic artery aneurysms?
Women due to multigravida
What is the 2nd most common splanchnic artery aneurysm?
Hepatic artery
What is a hepatic artery aneurysm associated with?
Associated with systemic infection and trauma
Most are extrahepatic location
What is the least common splanchnic artery aneurysm
SMA
What is blue toe syndrome?
Emboli material lodges in the digital arteries of the toes leading to cyanosis of the distal tissues
What is a dissection?
Initial layer tears and allows flow between the intimate and media layers into a blind pocket (false lumen)
Where do dissections most commonly occur?
In the aortic arch due to the shearing forces of the blood as it rounds the curve of the arch
What syndromes are associated with a dissection?
- Marfan
- Ehlers-danlos syndrome
Debakey classifications?
(Dissection)
Type l - involves ascending and depending aorta
Type Il - involves ascending aorta ;associated with marfan; least common
Type lll- involves the descending aorta (below the organ of the left subclavian artery); lowest mortality rate
What is marfans syndrome?
- A genetic disorder that affects connective tissue of the heart, vessels and bones
-Patients are usually very tall with a thin frame, long extremities and fingers - The aortic root and arch are the most commonly affected blood vessel (debakey type Il)
- Aorta dissection, aneurysm and value insufficiency are common in this syndrome.
Significant risk of rupture in aneurysm measurement?
> 7cm in diameter
What causes pseudo aneurysms?
Caused by trauma or invasive procedures
What is leriche syndrome?
- Aka aortoiliac occlusive disease
- due to occlusion of the abd aorta just above the site of its bifurcation
- causes bilateral symptoms and flow changes of the lower extremities
- can be related to erectile dysfunction as the internal iliac arteries supply the penis with blood.
What is retroperitoneal fibrosis?
- Aka ormond disease
- idiopathic (usually) overgrowth of fibrous tissue around an atherosclerotic aorta
- most commonly occurs at the level of the aortic bifurcation and inferiorly in the pelvis
- can be related to drugs, infection, malignancy or cancer therapy
- may lead to hydronephrosis (because of ureteral obstruction)
- may compress IVC causing bilateral pedal edema
- may compress the gonadal veins causing scrotal swelling.
Retroperitoneal sonographic appearance
- Soft tissue mass surrounding great vessels
-Hypoechoic - smooth borders
