Acute renal failure due to severe bilateral ureteropelvic junction obstruction treated by urinary drainage in a 2‐year‐old infant

INTRODUCTION: Conscientious follow‐up is essential for bilateral grade 4 hydronephrosis with ureteropelvic junction obstruction to ensure optimal surgical timing. We have reported a case of a male infant who required emergent urinary drainage due to severe bilateral ureteropelvic junction obstruction‐derived acute renal failure. CASE PRESENTATION: Bilateral grade 4 hydronephrosis was diagnosed in a male neonate. Vesicoureteral reflux was ruled out. Two years after the initial diagnosis, he developed acute renal failure and underwent bilateral emergent urinary drainage, followed by multiple urinary tract reconstructions against left ureterovesical junction stenosis and bilateral ureteropelvic junction obstruction. The postoperative renogram demonstrated a bilateral nonobstructive pattern. CONCLUSION: Bilateral emergency drainage for acute renal failure was successful without hemodialysis. Unilateral drainage or pyeloplasty should be planned early for bilateral grade 4 hydronephrosis with ureteropelvic junction obstruction to avoid lethal events if the obstruction pattern with decreased split renal function is <40% or if it is symptomatic.