A 62-year-old, obese woman is brought to the hospital due to acute-onset chest pain and shortness of breath. Medical history includes hyperlipidemia, diet-controlled type 2 diabetes mellitus, and peripheral artery disease. Two years ago, she had an ischemic stroke but had no residual neurologic deficits. The patient is a current smoker with a 30-pack-year history. After initial evaluation, she is taken to the cardiac catheterization laboratory where she has a cardiac arrest due to ventricular arrhythmia and cannot be resuscitated. Autopsy reveals thrombotic occlusion of the left anterior descending artery. In addition, it shows 95% atherosclerotic narrowing of the proximal right renal artery but no significant stenosis of the left renal artery. Compared with the right kidney, this patient's left kidney is more likely to demonstrate which of the following findings?

Question

A 62-year-old, obese woman is brought to the hospital due to acute-onset chest pain and shortness of breath.  Medical history includes hyperlipidemia, diet-controlled type 2 diabetes mellitus, and peripheral artery disease.  Two years ago, she had an ischemic stroke but had no residual neurologic deficits.  The patient is a current smoker with a 30-pack-year history.  After initial evaluation, she is taken to the cardiac catheterization laboratory where she has a cardiac arrest due to ventricular arrhythmia and cannot be resuscitated.  Autopsy reveals thrombotic occlusion of the left anterior descending artery.  In addition, it shows 95% atherosclerotic narrowing of the proximal right renal artery but no significant stenosis of the left renal artery.  Compared with the right kidney, this patient's left kidney is more likely to demonstrate which of the following findings?

Quizplus · Accepted Answer

11ec160b_38e7_813a_9249_5b5e4e99421f_MD0001_00 This patient's autopsy findings are consistent with severe, unilateral renal artery stenosis (RAS), a condition that occurs most commonly in older individuals due to atherosclerosis. Hypoperfusion of the stenotic (right) kidney stimulates renin release by juxtaglomerular apparatus cells. Renin converts angiotensinogen to angiotensin I, which is then converted by angiotensin-converting enzyme to angiotensin II, a potent vasoconstrictor that causes systemic hypertension. Unilateral RAS causes morphologic changes that markedly differ in the stenotic (right) kidney and the nonstenotic (left) kidney. Narrowing of the renal artery in the stenotic (right) kidney leads to hypoperfusion and renal parenchymal ischemia, which manifests as diffuse cortical thinning, tubular atrophy, interstitial fibrosis, and small crowded glomeruli. Juxtaglomerular apparatus enlargement can also occur due to chronic stimulation and increased renin release. In contrast, the contralateral, nonstenotic (left) kidney is exposed to high blood pressure and therefore demonstrates typical signs of hypertensive nephrosclerosis, which is characterized by arteriolar wall thickening due to hyaline arteriolosclerosis (hyalinization of the arterioles due to extravasation of plasma proteins) and hyperplastic arteriolosclerosis (concentric smooth muscle cell proliferation in response to pressure ["onion-skinning"]). (Choices B, C, D, and E) With unilateral RAS, the nonstenotic (left) kidney develops significant arteriolosclerosis due to exposure to high blood pressure. This can lead to narrowing of the arteriolar lumen with subsequent ischemic changes. However, these ischemic findings would be much more prominent in the stenotic (right) kidney. Educational objective: In unilateral renal artery stenosis, the narrowed renal artery causes hypoperfusion of the affected kidney with subsequent ischemic damage (eg, tubular atrophy, interstitial ischemia, glomerular crowding). In contrast, the contralateral kidney is exposed to high blood pressure and typically shows changes of hypertensive nephrosclerosis (eg, arteriolar wall thickening due to hyaline or hyperplastic arteriolosclerosis).

A 62-Year-Old, Obese Woman Is Brought to the Hospital Due