PMI ABD 1 Abdominal Vascular System

What is the function of the vascular system?

- Transport gases, nutrients materials, and other essentials substances to the tissues

- Transport waste products from the cells to the appropriate sites for excretion

________ carry blood away from the heart

Arteries

______ carry blood to the heart and back from the tissues

Veins

What are arteries

- Divide into progressively smaller branches

- The smallest of which are called arterioles

What do arterioles lead to

Lead into the capillaries

What are capillaries

- Are tiny vessels that branch and form a network

- Materials are exchanged between blood and tissue fluid in the vessels.

- After blood passes through, it is collected in the small veins (venules)

What do venules form

Unite to form larger vessels (veins)

What do veins do

Return the deoxygenated blood to the heart for recirculation

What is the Tunica Intima

Inner Layer

What is the Tunica Media

- Middle Layer

- Muscle layer

- thicker in arteries

What is the Tunica Adventitia

- outer layer

- loose connective tissue

What is the largest principal artery in the body

Aorta

What are the 5 sections of the aorta

1. root

2. ascending aortic arch

3. decending aortic arch

4. abdominal aorta/branches

5. bifurcation into iliac arteries

What is the function of the aorta

Supply blood to abdominal organs, pelvis, and lower extremities

Where is the abdominal aorta

- Begins once the descending aorta passes through the aorta hiatus in the diaphragm

- Retroperitoneal, positioned anterior to the spine and left of midline

What is the celiac trunk

- The first main visceral branch of the abdominal aorta

- Arises from the anterior aspect of the abdominal aorta, between the crus of the diagram

What are the three branches of the celiac trunk

1. Splenic Artery (SA)

2. Common Hepatic Artery (CHA)

3. Left Gastric Artery

What has a "seagull" or 'T" shape appearance

CHA and SA combined with the celiac trunk

What is not typically seen in an ultrasound due to its small size

Left gastric artery

Explain where the splenic artery is in the body

- Travels in the direction of the left side of the patient, toward the spleen

- Can be seen along the posterosuperior margin of the pancreas

- Enters the splenic hilum and branches to smaller arteries

- Has low resistance flow

Explain where the common hepatic artery is in the body

- Travels in the direction right side of the patient, toward the liver

- Branches into the gastroduodenal artery and proper hepatic artery

- At the level of the pancreatic head

- Proper hepatic artery enters the liver at porta hepatis

- Branches into right and left hepatic artery

- Cystic artery comes off the RHA and supplies the gallbladder

Should be low resistance and have hepatopedal flow

What is the second main branch of the abdominal aorta

Superior mesenteric artery (SMA)

Explain where the SMA is in the body

Originates along the anterior aspect of aorta just distal to the celiac trunk and travels parallel to the aorta

What is the function of the SMA

Supplies parts of the small intestines, colon and pancreas

What should be seen posterior to the SMA and anterior to the aorta

Left renal vein (LRV)

What are the third main visceral branches of the abdominal aorta that

arise just below the level of the SMA

Renal arteries

Explain the right renal artery position (RRA)

- Originates from the right anterolateral aspect of aorta

- Travels posterior to the IVC

Explain the left renal artery position (LRA)

- Originates from the left anterolateral aspect of the aorta

- Travels posterior to the LRV as it progresses to the left kidney

Why is the RRA longer than the LRA

the aorta being on the left side of the abdomen

What is the fourth branch of the abdominal aorta

Gonadal arteries

explain where the gonadal arteries are in the body

Arise from the anterior surface of the aorta just below the renal arteries

What are the gonadal arteries referred to as (hint: this changes with sex of person)

- Ovarian arteries

- testicular arteries

(these aren't usually seen in abdominal ultrasound)

What supplies blood to the transverse colon, descending colon and rectum

Inferior Mesenteric Artery (IMA)

Explain where the IMA is in the body

- Arises from the anterior surface of the abdominal aorta

- May be difficult to see with ultrasound due to size and bowel

What artery feeds blood to the pelvis and lower extremities

Iliac Arteries

Explain how the Iliac arteries come off the aorta

-Aorta bifurcates to the common iliac arteries at about level of umbilicus

- The right and left common iliac arteries

In what way(s) would Sonographic assessment may be limited

- body habitus

- gas

How can we as a sonographer to work around any limitations that may arise

- Tell patients to fast. Fasting can aid with evaluating the abdominal aorta with the issue of gas

- Applying transducer pressure while scanning can help move the gas

- Scanning from the left side may also help

Normal size of abdominal aorta upper limits near diaphragm

2.5 cm

Normal size of abdominal aorta Mid-abdomen

2.0 cm or less

Normal size abdominal aorta Distally

1.8 cm or less

Normal size of abdominal aorta CIAs

not exceed 2cm

How should we measure aorta walls?

outer to outer

What is an aneurysm?

- Any dilation of a blood vessel, focal or diffuse

- A result of the weakening of the vessel walls

- Can be described by the wall layers of the vessel that are affected

What is a true aneurysm?

involves all 3 layers

What is an abdominal aortic aneurysm (AAA)?

exceeds 3cm

Name and describe the two different types of aneurysms

- Fusiform:

- One that has a gradual enlargement

- Most common shape

- Saccular:

- Sudden dilation of a vessel

- Often spherical and large

- Can be also bulbous, eccentric or dumbbell shaped

Whats the most common location for abdominal aortic aneurysms (AAA)?

infrarenal

What are the causes of AAA

- Many AAA causes is unknown

- Most common is arteriosclerosis

- Have been associated with Marfan Syndrome, syphilis, familial inheritance, and infection

- Mycotic Aneurysms- Aneurysm caused by infections

Clinical AAA (signs and symptoms)

- Pulsatile abdomen mass

- Abdominal bruit

- Back pain

- Abdomen pain

- Lower extremity pain

How does AAA show up on ultrasound

- Aorta measuring greater than 3 cm in diameter

- Lumen may contain mural thrombus

- True lumen can be evaluated in contrast to false lumen

What is a true lumen

Is the actual lumen of the aorta, including the thrombus

What is a false lumen

Opening available after the narrowing from the thrombus has occurred

What are complications that come with abdominal aortic aneurysms (AAA)?

- Distal Embolism

- Infection

- Dissection

- Rupture

What is aortic dissection?

- Occurs when there is a separation of the layers of the arterial wall

- Predominately disturbing the intima

Clinical aortic dissection (signs and symptoms)

- Chest pain

- Hypertension

- Abdominal Pain

- Lower back pain

- Some neurological symptoms can occur

How does aortic dissection show up on ultrasound?

Linear echo flap called intimal flap

When does an abdominal aortic rupture

this occurs when AAA surpasses 7cm in diameter. This has a high mortality and morbidity rate

Clinical abdominal aortic rupture (signs and symptoms)

- Same symptoms of AAA

- Decreased hematocrit

- Hypotension

How does abdominal aortic rupture show up in ultrasound?

AAA with an adjacent hematoma (looks like color is "bleeding out" of the AAA)

What is a pseudoanurysm

- AKA- false aneurysm

- Contained rupture of a blood vessel

- Most likely secondary to the disruption of one or more layers of the vessel wall

- Typically results from injury to an artery

- IV, surgery or trauma

Where is the pseudoaneurysm usually located

- Common site is groin at level of femoral artery post heart catheterization

Clinical pseudoanurysm (signs and symptoms)

- Pulsatile mass in area of puncture

- Tenderness in area

What does a pseudoanurysm look like in an ultrasound

- Perivascular hematoma with swirling blood and a neck contain to the vessel

- Color Doppler shows turbulent flow (swirling)

What is the Inferior Vena Cava (IVC)?

- Largest vein in the body

- Created by the union of the common iliac veins

What is the function of the Inferior Vena Cava (IVC)?

- Bring de-oxygenated blood from lower extremities, pelvis and abdominal organs back to the heart

Name the four sections the Inferior Vena Cava (IVC) is separated into superior to inferior

1. Hepatic

2. prerenal

3. renal

4. post renal

What are the hepatic veins?

- Most superior portion of the IVC

- Segment just below the diaphragm

- Courses posterior to the caudate lobe of the liver and through the bare area

- Largest visceral tributaries of the IVC

What are the three hepatic veins within the liver

- Left:

Drains the left lobe of the liver

- Middle:

Drains the caudate lobe

- Right:

Drains the right lobe

What is Budd-Chiari syndrome?

- The occlusion of the hepatic veins

- Possible occlusion of IVC also

enlargement of the hepatic veins and IVC is often seen with _________ _________ ______ ________?

Right sided heart failure

What veins travel to the lateral aspect of the IVC

Renal veins

Why is the left renal vein longer?

- It's longer since IVC is on right side of spine

- It also travels anterior to LRA and Aorta and posterior to SMA

The right gonadal vein connects to the ___________ ?

the anterior aspect of IVC

The left gonadal vein drains into the _______ ________ ________ ?

left renal vein

What veins combine to form the IVC?

The right and left common iliac veins combine to form IVC near the umbilicus typically just right of the midline

How does the IVC appear in an ultrasound?

- Appears as an anechoic tube in sagittal plane and oval in transverse plane

- Postrenal section may be difficult to see, should be right of aorta

- Marks the posterior border of the caudate lobe

- Size is variable with respiration although should not exceed 2.5cm

- Deep inspiration or Valsalva maneuver can cause it to collapse

- Sustained inspiration will eventually lead to enlargement of IVC

- Has a pulsatile waveform near the heart and more phasic near the common iliac veins

What does the portal venous system do?

Collects blood from splenic and superior mesenteric vein and supplies the liver with nutrient rich blood

Where is the splenic vein located?

- Located posterior to the pancreatic body and tail

- Should flow toward the midline

The arterial supply to the gallbladder is via the:

cystic artery

The IVC courses anteriorly to enter the:

right atrium

Where does the left renal artery (LRA) travel as it progresses to the left kidney?

Posterior to the LRV

The most common cause of abdominal aneurysms is:

arteriosclerosis

What is the primary use of Doppler ultrasound in medical imaging?

To assess blood flow in arteries and veins

(ture or false) The inferior mesenteric artery branches directly from the celiac trunk.

False

Which one of the following vascular structures courses between the aorta and SMA?

Left renal vein