The Incorrect Statement is E: Renal Artery Stenosis DOES Cause Chronic Renal Failure
Statement E is FALSE – renal artery stenosis (RAS) is a well-established cause of chronic renal failure, particularly in the context of bilateral disease or stenosis to a solitary functioning kidney. 1
Let me systematically evaluate each statement:
Statement Analysis
A) Hypertension is a Common Clinical Finding - TRUE
Hypertension is both a cause and complication of chronic kidney disease 2. More than 80% of patients beginning dialysis have hypertension 3. The pathophysiology involves renin-angiotensin system hyperactivity and decreased sodium excretion capacity accompanying the decline in GFR 3, 4.
B) Defined as Decreased GFR Over Months or Years - TRUE
Chronic kidney disease is explicitly defined as kidney damage or decreased GFR for 3 or more months 2, 5. This distinguishes it from acute kidney injury and reflects the progressive, long-term nature of the condition 6.
C) Ultrasound Typically Reveals Shrunken Kidneys - TRUE
Chronic kidney disease characteristically shows atrophic kidneys (7-8 cm or smaller) on imaging 1. This finding is so consistent that unexplained kidney atrophy or size discrepancy raises clinical suspicion for renovascular disease and warrants further diagnostic evaluation 1.
D) Most Common Causes are Diabetes and Hypertension - TRUE
Diabetic kidney disease is the largest single cause of kidney failure in the United States 2. Hypertension is the other leading cause, with these two conditions together accounting for the vast majority of chronic renal failure cases 7, 4, 8.
E) Renal Artery Stenosis Does NOT Cause Chronic Renal Failure - FALSE
This statement is definitively incorrect. The ACC/AHA guidelines explicitly describe how RAS causes chronic renal dysfunction through multiple mechanisms 1:
- Bilateral RAS or stenosis to a solitary kidney causes progressive chronic kidney disease through volume expansion and reduced renal perfusion 1
- Longstanding unilateral RAS with contralateral renal dysfunction mimics bilateral disease and causes renal failure 1
- Approximately 90% of renovascular stenotic lesions are atherosclerotic, representing systemic disease 1
The guidelines specifically recommend percutaneous revascularization for patients with RAS and progressive chronic kidney disease with bilateral stenosis or stenosis to a solitary functioning kidney 1. Studies document that revascularization can stabilize or improve renal function in symptomatic atherosclerotic RAS 1.
Clinical Pitfall to Avoid
Don't dismiss RAS as a cause of chronic renal failure simply because it's less common than diabetes or hypertension. RAS should be suspected in patients with:
- Unexplained renal failure 1
- Flash pulmonary edema with preserved systolic function 1
- Acute kidney injury after ACE inhibitor or ARB initiation 1
- Known atherosclerotic disease elsewhere 1, 9
The answer is E.