Spinal Arterial Circulation

Question 1

75% of spinal cord perfusion comes from which artery?

Answer 1

Anterior Spinal artery

Question 2

Spinal arteries have this similar function of cerebral arteries that allows them to maintain consistent blood flow despite changing systemic blood pressure.

Answer 2

Autoregulation

Question 3

What is the name of the radicular artery that provides 2/3 perfusion to the lower portion of the cord.

Answer 3

Great Radicular Artery (GRA)/ “Artery of Adamkiewicz”

Question 4

Which side of the body is the GRA most likely to branch

Answer 4

Likely from the left side because that’s where the aorta is located

Question 4

The posterior spinal arteries combine contribute ____% of cord tissue perfusion

Answer 4

25%

Question 4

Loss of blood flow to which spinal artery would be the worst

Answer 4

Anterior spinal artery- 75% of perfusion

Question 5

Where does the anterior spinal artery lie

Answer 5

Lies in the anterior median fissure

Question 5

Which vertebrae is the GRA branching most common

Answer 5

T10

T9-12 (75% of population), can be as high as T5 or low as L5

Question 5

How many posterior spinal arteries do we have

Answer 5

2

Question 5

Which arteries can feed into the posterior spinal arteries?

Answer 5

Vertebral arteries, Cerebellar (anteriorinferior or posteriorinferior), Radicular/Posterior segmental medullary artery via intercostal arteries

Question 6

What is another name for radicular artery

Answer 6

“medullary” or “segmental”

Question 6

What is the downside to clamping the aorta during procedures

Answer 6

inhibiting blood flow to the spinal cord - higher radicular artery = safer

Question 6

Where do radicular arteries feed from?

Answer 6

intercostal artery

Question 6

What could occur if a clamped aorta is unclamped too fast?

Answer 6

Ischemia reperfusion injury- sudden restoration of blood flow to tissue. Vessels wide open causing massive increase of blood flow that tissues can’t handle. Too much oxygen can cause damage to cells.

Question 6

Spinal arteries lie within which spinal meninges?

Answer 6

subarachnoid space

Question 7

Where do coronal arteries lie?

Answer 7

Smallest branches that lie on outer surface of the spinal cord

Question 7

How much does clamping the aorta typically change CSF pressure?

Answer 7

clamping increases CSF pressure by ~10mmHg

may place lumbar drain to drain CSF to control pressure

Question 8

What is the pathway of blood flow from the aorta to spinal cord

Answer 8

aorta -> intercostal -> dorsal branch -> spinal branch -> radicular (posterior or anterior) -> anterior or posterior spinal artery

Question 8

What are ways to reduce cord ischemia if clamped for long period of time?

Answer 8

anything to reduce inflammation, reduce metabolic rate

Question 9

What is different about the spinal arterial circulation from the brain?

Answer 9

The spinal circulation doesn’t have a circle of willis; there isn’t a connection between the anterior and posterior spinal arteries

Question 10

What is the main difference between the arterial and venous circulation of the spine?

Answer 10

There is an extra posterior vein midline in addition to the two lateral posterior spinal veins

Question 11

What are the arteries coming off the abdominal aorta on each side?

Answer 11

renal arteries and mesenteric arteries

Question 12

In the neck, there are usually __ feed arteries that feed into the anterior spinal artery

Answer 12

2

Question 13

In the thorax, there are usually __ feed arteries that feed into the anterior spinal artery

Answer 13

2-3

Question 14

In the lumbar, there are usually __ feed arteries that feed into the anterior spinal artery

Answer 14

1-2

Question 15

Cerebral perfusion pressure =

Answer 15

MAP - ICP

Question 16

Normal cerebral perfusion pressure

Answer 16

50-150 mmHg

Question 17

normal ICP

Answer 17

10 mmHg