Abstract
INTRODUCTION: Ureteropelvic junction obstruction is a common congenital anomaly that causes hydronephrosis but rarely accompanies ipsilateral retrocaval ureter. CASE PRESENTATION: A 39-year-old woman, who visited to our hospital complaining of worsened right low back pain and fever, was diagnosed with right hydronephrosis due to ureteropelvic junction obstruction by contrast-enhanced computed tomography. Intraoperatively before the planned robot-assisted laparoscopic pyeloplasty, retrograde pyelography was performed to reveal concomitant ipsilateral retrocaval ureter. Laparoscopically, ureteropelvic junction obstruction due to aberrant blood vessel and coexisting retrocaval ureter was confirmed. Transposition of the ureter from posterior to anterior of the inferior vena cava and following dismembered pyeloplasty was performed. Two years after surgery, her right hydronephrosis improved and she had no complain of any symptom. CONCLUSION: Retrocaval ureter is a rare abnormality; however, combination of preoperative retrograde pyelography and laparoscopic evaluation was important for management of this concomitant abnormality.