Ureteroneocystostomy (UNC) refers to reimplantation of the ureter into the bladder. In the adult population, ureteroneocystostomy is primarily used for disease or trauma involving the lower third portion of the ureter that results in obstruction or fistula. In children, ureteroneocystostomy it is commonly used for surgical treatment of vesicoureteral reflux (VUR).
Generally, treatment for ureteral injury, stricture, and obstruction depends on the length of the defect, location, etiology, and time of diagnosis. Ureteroneocystostomy is the procedure of choice to correct distal ureteral injuries in close proximity to the bladder that measure 3-5 cm. These injuries differ from more proximal injuries in that they are frequently associated with disruption of the blood supply from the iliac vessels and are thus best repaired with a ureteroneocystostomy. Modifications, such as a psoas hitch (tacking the posterior bladder wall to the psoas muscle) and a Boari flap (tubularization of a flap of bladder to extend from the bladder to the ureteral orifice), allow for correction of ureteral defects that are longer than 5 cm.
Principles for obtaining successful ureteroneocystostomy outcomes include lack of tension, debridement, and spatulation of the ureter, and postoperative drainage. Open and minimally invasive laparoscopic approaches to ureteroneocystostomy have been described.
Injury, stricture, or obstruction of the distal 3-4 cm of the ureter is an indication for ureteroneocystostomy. More extensive loss of the ureter can be bridged with a vesico-psoas hitch or Boari bladder flap. Approximately one third of traumatic injuries and most iatrogenic injuries during pelvic procedures occur in the distal ureter. Other indications for ureteroneocystostomy include distal ureteral cancers that cannot be removed endoscopically, pelvic malignancies involving the ureter, and renal transplantation and complications arising from transplanted kidneys.