Intravesical Aminophylline for Urgent Ureteral Stenting in Acute Calculous Anuria

Acute calculous anuria is a urological emergency caused by ureteral stone obstruction in a solitary functioning kidney or bilateral ureteral obstruction. Urgent decompression of the upper urinary tract is required to restore urine drainage and prevent further renal impairment. This prospective randomized double-blind controlled trial will evaluate whether intravesical aminophylline can facilitate urgent retrograde ureteral stenting in adult patients with acute calculous anuria due to ureteral stones. Eligible patients will be randomly assigned to receive either intravesical aminophylline diluted in normal saline or placebo saline before attempted retrograde Double-J ureteral stent placement. The primary outcome is technical success, defined as successful placement of a Double-J ureteral stent across the obstructing stone without the need for percutaneous nephrostomy. Secondary outcomes