Advance in re-do pyeloplasty for the management of recurrent ureteropelvic junction obstruction after surgery

Ureteropelvic junction obstruction (UPJO) is characterized by decreased flow of urine down the ureter and increased fluid pressure inside the kidney. Open pyeloplasty had been regarded as the standard management of UPJO for a long time. Laparoscopic pyeloplasty reports high success rates, for both retroperitoneal and transperitoneal approaches, which are comparable to those of open pyeloplasty. However, open and laparoscopic pyeloplasty have yielded disappointing failure rates of 2.5%-10%. The main causes for recurrent UPJO are severe peripelvic and periureteric fibrosis due to urinary extravasation, ureteral ischemia, and inadequate hemostasis. In addition, failing to diagnose lower pole crossing vessels before or during the primary procedure is also responsible for recurrent UPJO. In addition, poor preoperative split renal function, hydronephrosis, presence of renal stones, patient age, diabetes, prior endopyelotomy history, and retrograde pyelography history were considered as predictors of pyeloplasty fai