A ureteral injury involves damage to the tubes that transport urine from the kidneys to the bladder. These injuries often occur because of the ureters’ retroperitoneal location and close proximity to numerous organs and blood vessels within the abdomen and pelvis. If not recognized and managed immediately, an injury to the ureter can lead to significant issues, including infection, loss of kidney function, and other severe complications.
Defining the Ureter and the Injury
The ureters are paired, narrow, muscular tubes that connect each kidney to the urinary bladder, forming part of the upper urinary tract. They transport urine from the renal pelvis down to the bladder using rhythmic, wave-like contractions called peristalsis.
A ureteral injury occurs when this tube is damaged, disrupting the normal flow of urine. Injuries can manifest as a complete cut (transection), a partial tear (laceration), or a crushing injury that damages the ureter’s wall and blood supply. The tube can also be accidentally tied off (ligated), causing an obstruction. Any damage can cause urine to leak into the surrounding abdominal or pelvic cavity, creating a high risk for infection and abscess formation.
Mechanisms of Injury
The vast majority of ureteral injuries are classified as iatrogenic, meaning they occur unintentionally as a complication during a medical procedure. The ureter is highly susceptible to damage during complex pelvic or abdominal operations because of its course through the pelvis.
Gynecologic surgery is the most common context for iatrogenic injury, accounting for over half of all cases. Procedures like hysterectomy place the ureter at risk because it crosses near the uterine artery in the lower pelvis. Risk is also present during colorectal surgery and complex vascular procedures, such as the repair of an abdominal aortic aneurysm. Injuries in these settings result from clamping, suturing, or using thermal energy like cauterization, which can damage the ureter’s blood supply.
Non-iatrogenic causes are less common and typically result from external trauma. Penetrating injuries, such as stab or gunshot wounds to the abdomen, are the most frequent cause of traumatic damage. Blunt force trauma, like that sustained in a motor vehicle accident, can also cause injury, particularly where the ureter connects to the kidney.
Recognition and Diagnostic Procedures
Identifying a ureteral injury is often challenging because initial symptoms can be subtle or masked by pain from the original surgery or trauma. If not recognized immediately, signs may develop days or weeks later. Common symptoms include persistent, unexplained flank or abdominal pain, indicating urine blockage or leakage.
Other signs suggesting infection include a prolonged fever, a general feeling of illness, or an elevated white blood cell count. Urine leakage may manifest as a fluid collection, known as a urinoma, or as urine draining from the surgical wound or into the vagina (ureterovaginal fistula). Although blood in the urine (hematuria) may be present, its absence does not rule out a significant injury.
When an injury is suspected, imaging studies are necessary to confirm the diagnosis and determine the location and extent of the damage. A computed tomography (CT) scan with intravenous contrast is a common initial test, showing if the dye leaks out or if the ureter is obstructed. A retrograde pyelogram is often the most accurate diagnostic tool, involving the injection of contrast directly up the ureter to visualize the injury site and guide management decisions.
Surgical Repair and Management
The management strategy depends on the time of diagnosis, the location, and the extent of the damage. If the injury is minor, such as a contusion or small laceration, or if the patient is medically unstable, a temporary, non-operative approach may be used first. This involves placing a ureteral stent, a thin tube inserted inside the ureter to promote healing, or a percutaneous nephrostomy tube, which drains urine directly from the kidney.
For more significant damage or immediate recognition, surgical repair is the definitive treatment. Injuries to the upper or middle portions of the ureter are often treated with a ureteroureterostomy, which involves trimming the damaged section and reconnecting the two healthy ends. This end-to-end connection is performed over an internal stent to ensure a watertight and tension-free repair.
When the injury is located in the lower, pelvic part of the ureter, the preferred method is a ureteroneocystostomy, where the healthy upper portion is re-implanted directly into the bladder. If the ureter is too short to reach the bladder without tension, specialized techniques are employed, such as a psoas hitch, which anchors the bladder to a nearby muscle to gain length. For extensive defects, a segment of the bladder may be fashioned into a tube (Boari flap), or, in rare cases, a segment of the small intestine may be used to bridge a long gap.