Most ureteral injuries occur during surgery. Procedures that most often injure the ureter include ureteroscopy, hysterectomy, low anterior colon resection, and open abdominal aneurysm repair. Mechanisms include ligation, transection, avulsion, crush, devascularization, kinking, and electrocoagulation.
Noniatrogenic ureteral injuries account for only about 1 to 3% of all genitourinary trauma. They usually result from gunshot wounds and rarely from stab wounds. In children, avulsion injuries are more common and occur at the ureteropelvic junction. Complications include peritoneal or retroperitoneal urinary leakage; perinephric abscess; fistula formation (eg, ureterovaginal, ureterocutaneous); and ureteral stricture, obstruction, or both.
Diagnosis of ureteral injuries is suspected on the basis of history and requires a high index of suspicion, because symptoms are nonspecific and hematuria is absent in > 30% of patients. Diagnosis is confirmed by imaging (eg, CT with contrast that includes delayed images, retrograde pyelography), exploratory surgery, or both. Fever, flank tenderness, prolonged ileus, urinary leakage, obstruction, and sepsis are the most common delayed signs of otherwise occult injuries. Intraoperative findings suggestive of a ureteral injury include urinary leakage, ureteral bruising, or decreased peristalsis. The diagnosis can be further aided by injecting dye (eg, indigo carmine, methylene blue) intravenously or intraureterally.
All ureteral injuries require intervention. A diverting percutaneous nephrostomy tube or placement of a ureteral stent (retrograde or antegrade) is often sufficient for minor injuries (eg, contusions or partial transections). Complete transection or avulsion injuries typically require reconstructive techniques, either open or laparoscopic. These techniques include ureteral reimplantation, primary ureteral anastomosis, anterior (Boari) bladder flap, transureteroureterostomy, ileal interposition, and, as a last resort, autotransplantation. In unstable patients a damage control approach is used whereby the ureter is temporarily drained with definitive management done later.