Is Postrenal Acute Renal Failure Possible in the Absence of Hydronephrosis?

Acute renal failure (ARF) is a clinical situation that renal functions deteriorate suddenly within hours to days. Postrenal causes are responsible for a small part of ARF. In this article, we presented a case gone to left nephrectomy priorly, with a right ureter stone led to complete obstruction, ARF, and treated by ureterorenoscopy (URS). A seventy year old male patient was sent to Emergency Department because of anuria for 48 hours. In ultrasonographic exam; there wasn’t hydronephrosis of right kidney. A right lower ureter stone was seen in the non-contrast spiral abdominal computed tomography. The lower ureter stone was removed by URS and JJ catheter was replaced. He was discharged with normal renal function tests. In conclusion, postrenal ARF must be ruled out in patients with acute anuria, especially zero urine, even if hydronephrosis delinea. If postrenal ARF is diagnosed and treated quickly, the outcomes will be excellent.