Renal emboli, infarcts and sickle cell nephropathy
- Lesion
The kidney gets a fifth of the cardiac output, so emboli, sickled cells and clots in its veins leave characteristic lesions.
What it is
Several vascular disorders injure the kidney without being glomerular diseases. Cholesterol crystals released from aortic plaques after catheterization or surgery lodge in small arteries. Emboli from the heart cause wedge-shaped pale infarcts because the renal arteries are end arteries. Sickling in the hypoxic, hyperosmolar medulla damages the vasa recta and papillae. Renal vein thrombosis complicates nephrotic syndrome, especially membranous nephropathy, and dehydration in infants.
Structure
- Atheroemboli: empty cholesterol clefts in arteries with giant cells and intimal fibrosis; downstream ischemic atrophy.
- Infarct: coagulative necrosis with a hyperemic rim, later a depressed V-shaped scar.
- Sickle cell: congested vasa recta packed with sickled cells, medullary fibrosis, papillary necrosis; enlarged glomeruli.
- Renal vein thrombosis: swollen, congested kidney; hemorrhagic infarction if collaterals are poor.
Vascular lesions outside the glomerulus
| Disorder | Mechanism | Typical finding |
|---|---|---|
| Atheroembolic renal disease | Cholesterol crystals from aortic plaque | Needle clefts in small arteries, eosinophilia, livedo |
| Renal infarct | Embolus in an end artery | Pale wedge with base at the capsule |
| Sickle cell nephropathy | Sickling in a hypoxic, hypertonic medulla | Hyposthenuria, hematuria, papillary necrosis |
| Renal vein thrombosis | Hypercoagulable nephrotic state, dehydration, tumour invasion | Enlarged congested kidney, flank pain, hematuria |
Clinical notes
- Kidney failure days to weeks after a vascular procedure, with blue toes and eosinophilia, suggests atheroemboli.
- Atrial fibrillation and endocarditis are the commonest sources of renal emboli.
Test yourself
Think of the answer, then tap the question to see it.
What finding in a biopsy proves atheroembolic disease?
Biconvex, needle-shaped empty clefts left by dissolved cholesterol crystals in small arteries.
Why are renal infarcts wedge-shaped?
Renal arteries are end arteries: occlusion kills the cone of tissue they supply, with the base at the capsule.
Why does the renal medulla favour sickling?
It is hypoxic, hypertonic and acidic, all of which promote polymerization of hemoglobin S.
Elsewhere in DurgiPedia
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Renal vein thrombosis: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2025); Renal papillary necrosis: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2025).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.