Renal artery stenosis resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Karol Gema Hernandez, M.D. [2]

Definition

This section provides a short and straight to the point definition of the disease or symptom in one sentence.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• Life threatening cause 1
• Life threatening cause 2
• Life threatening cause 3

Common Causes

• Common cause 1
• Common cause 2
• Common cause 3
• Common cause 4
• Common cause 5

Clinical Clues to the Diagnosis of RAS

❑ Determine if one or more of the above is present

Scenario Level of evidence 1.Onset of hypertension before the age of 30 years or severe hypertension after the age of 55 Class I; LOE B 2. Accelerated, resistant, or malignant hypertension Class I; LOE C 3. Development of new azotemia or worsening renal function after administration of an ACE inhibitor or ARB agent Class I; LOE B 4. Unexplained atrophic kidney or size discrepancy between kidneys of greater than 1.5 cm Class I; LOE B 5. Sudden, unexplained pulmonary edema Class I; LOE B 6. Unexplained renal dysfunction, including individuals starting renal replacement therapy Class IIa; LOE B 7. Multi-vessel CAD Class IIb; LOE B 8. Unexplained CHF Class IIb; LOE C 9. Refractory angina Class IIb; LOE C

❑If one or more of the above are present, proceed to further diagnostic testing

Noninvasive Imaging

Invasive Imaging

❑ Duplex ultrasound ❑ Gadolinium enhanced MRA ❑ CT angiography

❑ Abdominal aortography to assess the renal arteries during coronary and peripheral angiography

Negative noninvasive test but with high clinical suspicion

Evidence of RAS

Evidence of RAS

Renal angiography

Evidence of RAS

Confirmed RAS, proceed to treatment

Algorithm based on the 2013 AHA Guidelines Recommendations for Management of Patients with PAD.

Indications for Renal Revascularization

Indication	Level of evidence
1.Hemodynamically significant RAS with recurrent, unexplained CHF or sudden, unexplained pulmonary edema	Class I; LOE B
2. RAS with: Accelerated, resistant, or malignant hypertension Hypertension with unilateral small kidney Hypertension with medication intolerance	Class IIa; LOE B
3.RAS and CRI with bilateral RAS or RAS to solitary functioning kidney	Class IIa; LOE B
4. RAS and unstable angina	Class IIa; LOE B
5. Asymptomatic bilateral or solitary viableʰ kidney with a hemodynamically significant RAS	Class IIb; LOE C
6. Asymptomatic unilateral hemodynamically significant RAS in a viable* kidney	Class IIb; LOE C
7. RAS and CRI with unilateral RAS (2 kidneys present)	Class IIb; LOE C

ʰViable means kidney linear length greater than 7 cm.

Shown below is a table of the definition of hemodynamically significant RAS.

Hemodynamically significant RAS

≥70% by visual estimation

≥70% by intravascular ultrasound measurement≥70%

50-70% RAS with a systolic gradient of ≥20 mm Hg or a mean gradient of ≥10 mm Hg.

Shown below there is an algorithm of therapeutic options after any of the indications for revascularization are met.

❑ Presence of one or more indications for revascularization:

❑Renal Angioplasty/Stent

❑ Renal artery surgery

Atherosclerotic RAS

Fibromuscular dysplasia RAS

Renal stent placement is indicated for ostial atherosclerotic RAS lesions that meet the clinical criteria for intervention

Balloon angioplasty with bailout stent placement if necessary is recommended for fibromuscular dysplasia lesions

Algorithm based on the 2013 AHA Guidelines Recommendations for Management of Patients with PAD.

Recent studies reveal that athough there are high technical success rates with angioplasty/stenting, the clinical end points are inconsistently and modestly modified.

References

Template:WikiDoc Sources