A case of acute kidney injury due to complex, partial, multifocal ureteral strictures.

BACKGROUND: An 89-year-old man with a history of prostate cancer who had undergone radical prostatectomy 15 years ago presented with hyperkalemia (serum potassium level 6.9 mmol/l) and kidney failure (serum creatinine level 937 micromol/l [10.6 mg/dl]). Ultrasound scan of his kidneys showed mild bilateral hydronephrosis. Although placement of a bladder catheter led to an initial increase in glomerular filtration rate, the improvement was delayed and incomplete. Subsequently, the patient's glomerular filtration rate decreased acutely. This unusual biphasic course of kidney injury begged explanation. INVESTIGATIONS: Physical examination, measurements of serum creatinine level and electrolytes, imaging of the urinary tract (ultrasound and CT scans), and nephrostograms. DIAGNOSIS: Acute kidney injury due to upper (multiple ureteral strictures bilaterally) and lower (urethral) urinary tract obstruction. MANAGEMENT: Placement of bladder catheter and percutaneous nephrostomy tubes followed by bilateral internal ureteral stents.