A 66-year-old Caucasian woman with the past medical histoty of diabetes mellitus, hypertension, ischemic heart disease with s/p myocardial infarction, and cerebrovascular accident (s/p TIA), was admitted to the hospital and transferred to the intensive care unit after she developed anuric acute renal failure. Percutaneous transluminal coronary angioplasty (PTCA) had been performed seven days prior to admission without any notable complication. On admission, she complained of abdominal and joint pain. Her vital signs were BP: 110/60 mm Hg, HR: 85/min., RR: 14/min., and temp 98° F. She was obese (BMI: 32 kg/m2). On physical exam she had skin rash (see photos).
She was diagnosed as having oliguric acute-on-chronic renal failure based on a rise in serum creatinine to 7.6 mg/dL (up from 1.8 mg/dL prior to PTCA) and a urine output of 5 mL/hour. Urinalysis and urine sediment were reported negative. Her other laboratory results included serum sodium 130 mmol/L, serum potassium 6.8 mmol/L, hemoglobin 9.8 g/dL, WBC 11 × 103/µL with an notable eosinophilia of 11%, amylase 540 U/L, AST 76 U/L, and ALT 88 U/L.
Chest X-ray was negative. Renal ultrasound showed normal echogenicity in renal cortices with right kidney at 11.0 cm and left kidney at 12.0 cm in length, and no stone or hydronephrosis.
Submit your diagnosis to see full explanation.
Answer: Cholesterol emboli (renal atheroemboli)
The clinical history (acute on chronic renal failure) and laboratory results (negative urinary sediment and eosinophilia), the livedo reticularis on her skin confirmed the diagnosis of cholesterol emboli (see image of the histology of cholesterol emboli). The kidney is one of the principal end organs that may be affected by atheroembolic events. There are five main findings that suggest that atheroemboli is responsible for the development of acute renal failure after cardiac catheterization:
- persistent acute renal failure
- sign of embolization such as livedo reticularis, blue toe, and Hollenhorst plaques in the retina (see photo)
- abdominal pain.
The incidence of ARF after catheterization is 1%, but more than half of these cases are due to renal embolization. Treatment of an episode of cholesterol emboli generally focuses on symptoms and complications. The phenomenon cannot be reversed.
The case was prepared by Miklos Z Molnar, MD, PhD, Research Associate, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California.