Renal Artery Stenosis

Question 1

What is the etiology of most RAS?

Answer 1

Most cases of RAS result from atherosclerotic ischemic renal disease

Question 2

What age group is ras most prevalent in?

Answer 2

Most common in adults > 45 yrs with atherosclerotic disease

Question 3

What is a rare cause of ras?

Answer 3

Fibromuscular dysplasia , most commonly seen in young women

Question 4

What are risk factors of ras?

Answer 4

1. Atherosclerotic vessel disease
2. Kidney disease
3. Diabetes mellitus
4. Tobacco use
5. HTN

Question 5

What are the sxs of ras?

Answer 5

1. HTN: Unexplained HTN in young woman < 40 yrs should be investigated for RAS
2. Moderate to severe retinopathy
3. Abdominal bruit on affected side

Question 6

Bun/Cr test results in ras

Answer 6

Increased

Question 7

What does a kidney US look like in ras?

Answer 7

May revel asymmetry of kidneys

Question 8

What other imaging studies are used to screen for ras?

Answer 8

Doppler ultrasonography
CT angiography
Magnetic resonance angiography (MRA)

Question 9

What is the sensitivity and specificity of doppler us?

Answer 9

> 90% (if experienced sonographer)

Question 10

What type of pts should not get a doppler us?

Answer 10

Poor choice for obese pts or pts who are unable to lie supine

Question 11

How does doppler us work?

Answer 11

Measurements of blood flow are made at the aorta and along each third of renal artery in order to assess the disease

Question 12

What is a misc. advantage of doppler us?

Answer 12

relatively inexpensive

Question 13

What is the sensitivity of CT angiography?

Answer 13

77-98%

Question 14

How does a ct angiography work?

Answer 14

Noninvasive procedure

Spiral CT scan with contrast

Question 15

What is a disadventage of MRA?

Answer 15

expensive

Question 16

What is the sensitivity of MRA?

Answer 16

77-100%

Question 17

What is the imaging agent in MRA?

Answer 17

gadolium

Has been asst with nephrogenic fibrosis

Question 18

What is the gold standard for diagnosing ras?

Answer 18

Renal angiography

Question 19

Where are lesions most commonly located?

Answer 19

proximal third or ostial region of renal artery

Question 20

How does fibromuscular dysplasia appear on a renal angiography?

Answer 20

Fibromuscular dysplasia has characteristic “beads on a string” appearance on angiography

Question 21

What are the medical treatments for ras?

Answer 21

Medical management: 
BP control
DM control
Smoking cessation
Manage dyslipidemia

Question 22

What are the surgical options for ras?

Answer 22

Surgical bypass

Question 23

What are the procedural option for ras?

Answer 23

1. Angioplasty with or without stenting
   - May reduce number of antihypertensive meds
   - Does not significantly change progression of kidney dysfunction compared to pts medically managed

Question 24

True/false: Angioplasty is less safe than surgery

Answer 24

False.

Angioplasty is equally as effective and safer than surgical revision