Most ureteral injuries happen not from accidents but during surgery, when a scalpel, stapler, or energy device inadvertently damages one of the two narrow tubes that carry urine from the kidneys to the bladder. These injuries are uncommon overall, but they carry outsized consequences because they are frequently missed at the time they occur, sometimes going undetected for days or weeks until symptoms force a second trip to the hospital. The stakes of that delay are high: complications roughly quadruple when the damage is caught late rather than in the operating room.
Why the Ureter Is So Vulnerable During Surgery
Each ureter is roughly 25 to 30 centimeters long and runs from the kidney down through the abdomen and into the pelvis before entering the bladder. Along that path, it passes close to several structures that surgeons routinely operate on: the colon, the uterus, the ovaries, and the major blood vessels of the pelvis. The ureter also has three natural narrow points where it is especially thin-walled and exposed: where it leaves the kidney, where it crosses over the iliac artery near the pelvic brim, and where it tunnels into the bladder wall.1Anaesthesia & Intensive Care Medicine. Anatomy of the kidney and ureter These anatomical relationships mean that any pelvic or abdominal surgery carries some degree of risk to the ureter, a reality well-recognized among surgeons.2PubMed Central. Iatrogenic ureteric injuries: approaches to etiology and management
Surgical Causes Are the Most Common
The single largest category of ureteral injury is iatrogenic, meaning caused by a medical procedure. Gynecological, colorectal, urological, and vascular operations all carry risk, though the specific danger zones differ by procedure.
Gynecological Surgery
Hysterectomy, in both its abdominal and vaginal forms, is one of the most frequently cited operations associated with ureteral damage. The ureter runs within a couple of centimeters of the uterine artery and the cervix, and during routine clamping, stapling, or cauterizing, it can be accidentally ligated, kinked, cut, or burned. During abdominal hysterectomy, the most common injury site is at the pelvic brim, beneath where the ovarian blood supply is tied off. During vaginal hysterectomy, the danger zone shifts closer to the cervix and the point where the ureter enters the bladder.3American Journal of Obstetrics and Gynecology. Ureteral injuries in gynecologic surgery Laparoscopic procedures for endometriosis add their own twist: the thickened uterosacral ligaments that result from endometriosis pull the ureter into the surgical field, making it especially vulnerable near the back of the pelvis.3American Journal of Obstetrics and Gynecology. Ureteral injuries in gynecologic surgery
Several patient factors raise the odds. Obesity, prior pelvic surgery, adhesions from previous procedures, large pelvic masses, and heavy bleeding during the operation all make the ureter harder to see and easier to injure.4PubMed Central. Ureteric Injury During Gynaecological Surgery – Lessons from 20 Cases in Canada
Colorectal Surgery
The colon and rectum sit directly alongside the ureters in the pelvis, so complex colorectal procedures carry a distinct risk. Among a large nationwide cohort of over half a million colorectal surgery patients, about one percent experienced a urinary tract injury, and the ureters were the most commonly damaged structure, followed by the bladder and urethra.5PubMed. Iatrogenic urinary injuries in colorectal surgery: outcomes and risk factors from a nationwide cohort Other estimates put the rate at roughly 0.3 to 1.5 percent depending on the complexity of the operation.6PubMed. Ureteral complications during colorectal surgery
An interesting finding from the nationwide data: laparoscopic colorectal surgery was associated with a lower overall rate of ureteral injury compared to open surgery, but it came with a higher rate of delayed detection. In other words, the smaller incisions may make it harder to spot the damage in real time.5PubMed. Iatrogenic urinary injuries in colorectal surgery: outcomes and risk factors from a nationwide cohort Risk factors specific to colorectal patients include advanced or spread cancer, diverticular disease, higher body mass index, prior radiation therapy, and inflammatory bowel disease.7PubMed Central. Urological Injuries during Colorectal Surgery
Traumatic Ureteral Injuries
Outside the operating room, ureteral injuries from external trauma are uncommon. The ureters sit deep in the body and are relatively well-protected by surrounding muscle and bone. When they are injured by trauma, it is overwhelmingly from penetrating mechanisms such as gunshot wounds or stabbings, which account for roughly three-quarters or more of traumatic ureteral damage.8PubMed. Trauma to the bladder and ureter: a review of diagnosis, management, and prognosis In a review of over 22,000 genitourinary injuries, only 582 involved the ureter. Among those, about 60 percent were from penetrating trauma and 40 percent from blunt force. Penetrating injuries tended to come with bowel and vascular damage, while blunt trauma patients had more bone and pelvic fractures.9PubMed. Ureteral trauma: patterns and mechanisms of injury of an uncommon condition Virtually all traumatic ureteral injuries involve damage to other organs as well, which can make the ureteral component easy to overlook during emergency care.10PubMed. Ureteral injury due to blunt and penetrating trauma
Radiation as a Cause of Ureteral Damage
Pelvic radiation therapy for cancers of the cervix, rectum, bladder, or prostate can also injure the ureters, though the damage usually develops gradually rather than all at once. Radiation causes scarring and reduced blood supply in the tissues surrounding the ureter, which over months or years can lead to narrowing, known as a stricture. These radiation-induced strictures present a particularly difficult surgical problem because the tissue around the ureter is dense, poorly vascularized, and stiff, limiting the options for reconstruction.11SpringerLink. Navigating the irradiated ureter: multi-institutional outcomes of robotic ureteral reconstruction for radiation-induced strictures
How Ureteral Injuries Present
One of the most dangerous features of ureteral injury is how silently it can develop. When the damage happens during surgery, the patient is under anesthesia and cannot report symptoms. If the surgical team does not notice the injury in the operating room, the first signs may not appear until days or weeks later. Between half and 70 percent of ureteral injuries during colorectal surgery are diagnosed after the operation rather than during it.6PubMed. Ureteral complications during colorectal surgery
When symptoms do emerge, they can be vague and easily attributed to normal postoperative recovery. Flank pain, low-grade fever, decreased urine output, and a general sense of feeling unwell are common early signs. More alarming presentations include complete loss of urine output (if both ureters are affected or the patient has only one functioning kidney), urine leaking from a surgical wound or drain, and signs of infection such as high fever and dropping blood pressure. Some patients develop a collection of leaked urine in the abdomen called a urinoma. After hysterectomy specifically, patients have presented with anything from complete inability to urinate to severe blood infection requiring emergency drainage of an infected, obstructed kidney.12PubMed Central. Posthysterectomy ureteric injuries: Presentation and outcome of management
Diagnosis
When ureteral injury is suspected, CT imaging is the primary diagnostic tool. CT urography, which captures images as contrast dye filters through the kidneys and down the ureters, can show where urine is leaking or where the ureter is blocked.13PubMed. Computed tomography in the evaluation of bladder and ureteral trauma: indications, technique, and diagnosis The key is that the scan needs to be timed correctly. Standard abdominal CT taken in the first few minutes after contrast injection may not show a ureteral leak, because the dye has not yet reached the ureters. Delayed images, taken 10 to 15 minutes later, are what reveal the problem. This detail matters: an emergency CT done for other injuries may miss a ureteral injury entirely if those delayed images are not obtained.
During surgery, some teams use techniques to make the ureter visible in real time. One approach gaining traction involves injecting a fluorescent dye called indocyanine green directly into the ureters. Under near-infrared light, the dye makes the ureters glow, allowing the surgeon to track their course and avoid them. A recent analysis found that this approach had a 100 percent success rate for visualization and was associated with a lower rate of ureteral injury compared to traditional ureteral stenting.14PubMed. Retrograde intraureteral injections of indocyanine green versus ureteral stents to reduce urinary tract complications during pelvic surgery: Systematic review and meta-analysis However, a retrospective study in colorectal surgery found that while indocyanine green fluorescence significantly improved intraoperative visualization of the ureters, the actual rate of ureteral injury was statistically similar between the fluorescence group and the non-fluorescence group.15PubMed Central. The role of ureteric indocyanine green fluorescence fluorescence in colorectal surgery: a retrospective cohort study The technology is promising but still being evaluated to determine whether better visualization consistently translates into fewer injuries.
Why Timing of Detection Matters So Much
The gap between catching a ureteral injury on the operating table and finding it days later makes an enormous difference in outcomes. When the damage is recognized immediately, the surgeon can repair it in the same operation, and complications are relatively manageable. When it goes unnoticed, the consequences escalate. Leaked urine can cause infection, abscess formation, and sepsis. An obstructed ureter can lead to kidney swelling and, if prolonged, permanent loss of kidney function.
A population-level analysis of ureteral injuries during hysterectomy found that when the injury was caught during surgery, about 2 percent of patients needed a nephrostomy tube to drain the kidney. When the injury was missed, that number jumped to over 23 percent. Unrecognized injuries were independently linked to a dramatically higher risk of sepsis, urinary fistula formation, kidney failure, and death.16PubMed. Complications of Recognized and Unrecognized Iatrogenic Ureteral Injury at Time of Hysterectomy: A Population Based Analysis Other data suggest that patients whose ureteral injuries are caught late develop complications in roughly 40 percent of cases, compared to about 10 percent when the injury is found right away. Those delayed complications include infected urine collections, fistulas connecting the ureter to other organs, chronic strictures, and in some cases, the need for removal of a nonfunctioning kidney.17PubMed Central. Delayed Diagnosis of Ureteral Injury Following Penetrating Abdominal Trauma: A Case Report and Review of the Literature
Treatment Depends on Location and Severity
The approach to repairing a ureteral injury depends on where along the ureter the damage occurred, how much tissue was lost, and whether the injury was caught early or late. Broadly, injuries are classified by their location: upper (near the kidney), mid (in the abdomen), or lower (in the pelvis near the bladder).
Minor or Partial Injuries
If the ureter is only partially damaged or kinked, and the injury is caught early, the simplest intervention may be placing a ureteral stent, a thin flexible tube threaded through the ureter to hold it open while it heals. Patients who presented early after hysterectomy, within about two weeks, had higher success rates with these less-invasive endoscopic approaches, sometimes avoiding open surgery entirely.12PubMed Central. Posthysterectomy ureteric injuries: Presentation and outcome of management
Upper and Mid-Ureter Injuries
When the upper or middle portion of the ureter is transected or severely damaged, the standard repair is a ureteroureterostomy, in which the two healthy ends of the ureter are trimmed back to good tissue and sewn together over a stent.2PubMed Central. Iatrogenic ureteric injuries: approaches to etiology and management This is the most commonly performed procedure for upper and mid-ureteral defects.18PubMed Central. Etiology, characteristics and management of ureteric injury: experience from a nationwide study It works well when the gap between the two ends is short enough that they can be brought together without tension.
Lower Ureter Injuries
Injuries to the lower ureter, closer to the bladder, are typically repaired by reimplanting the ureter directly into the bladder, a procedure called ureteroneocystostomy. This is the go-to approach for distal ureteral damage and is the most common reconstruction for lower strictures.19PubMed Central. Management of iatrogenic ureteral injury When the gap is too large for a straightforward reimplantation, surgeons can mobilize the bladder upward by hitching it to the psoas muscle (a psoas hitch), which effectively shortens the distance the ureter needs to bridge. For even longer defects, typically 8 to 12 centimeters, a Boari flap technique creates a tube from a portion of the bladder wall to reach the ureter.20PubMed Central. Laparoscopic ureteral reimplantation with Boari flap for the management of long-segment ureteral defect: A case series with review of the literature A review of 100 ureteral reimplantations spanning over 25 years, using combinations of simple reimplantation, psoas hitch, and Boari flap, reported excellent functional outcomes without major complications.21PubMed. Outcomes of distal ureteral reconstruction through reimplantation with psoas hitch, Boari flap, or ureteroneocystostomy for benign or malignant ureteral obstruction or injury
Complex or Extensive Damage
When a long segment of ureter is destroyed or when the surrounding tissue is too scarred or irradiated for standard repairs, surgeons turn to more creative solutions. One option is transureteroureterostomy, in which the injured ureter is connected to the healthy ureter on the opposite side. Another is replacing the missing segment with a piece of small intestine, known as an ileal interposition. Long-term follow-up of this technique has shown it to be a durable solution for properly selected patients, maintaining kidney function over periods of more than four years.22PubMed. Long-term Follow Up of Ileal Ureteral Replacement for Complex Ureteral Strictures: Single Institution Study In the most extreme cases, where no reconstruction is feasible, the kidney itself may be moved to a new location in the pelvis and connected to the bladder directly, a procedure called renal autotransplantation.
Preventing Ureteral Injuries During Surgery
The best prevention is detailed knowledge of pelvic anatomy and a deliberate effort to identify the ureters before operating near them. Surgeons performing complex pelvic cases are taught to locate the ureter at the pelvic brim early in the procedure and keep track of it throughout.2PubMed Central. Iatrogenic ureteric injuries: approaches to etiology and management
One debated prevention strategy is placing ureteral catheters or stents before the operation begins, so the surgeon can feel the stent inside the ureter and know exactly where it runs. A national database analysis of colectomy patients found that prophylactic catheter placement was associated with a lower rate of ureteral injury.23PubMed. Prophylactic Ureteral Catheters for Colectomy: A National Surgical Quality Improvement Program-Based Analysis The European Association of Urology recommends deciding on a case-by-case basis whether to place preventive catheters, weighing the patient’s individual risk factors against the surgeon’s experience with the planned procedure.24PubMed Central. Prophylactic Ureteral Catheterization for Preventing Ureteral Injury in Colorectal Cancer Surgery The stents themselves are not entirely benign, as discussed below, so the decision involves a genuine tradeoff.
Living with a Ureteral Stent
Whether placed to prevent injury, to treat one, or to keep a repaired ureter open while it heals, ureteral stents cause significant discomfort for many patients. These are thin plastic tubes that sit inside the ureter with one coiled end in the kidney and the other in the bladder. They prevent obstruction and promote healing, but they can also cause pain, frequent urination, urgency, blood in the urine, and a persistent feeling of bladder pressure.
Stent-related symptoms tend to be worst in the first couple of days, but they remain elevated the entire time the stent is in place and vary widely from person to person.25PubMed Central. Quality of life impact and recovery after ureteroscopy and stent insertion: insights from daily surveys in STENTS One study found that stent-related urinary symptoms and pain reduced quality of life in up to 80 percent of patients, interfering with daily activities, work, and sleep.26PubMed. Indwelling ureteral stents: evaluation of symptoms, quality of life and utility The good news is that quality of life scores tend to recover within about two weeks of stent removal, returning close to baseline.27PubMed Central. Morbidity and impact on quality of life in patients with indwelling ureteral stents: A 10-year clinical experience For patients who need a stent for weeks or months during recovery from a ureteral repair, this represents a real and sometimes underappreciated source of suffering that is worth discussing with the surgical team upfront.
Medicolegal Considerations
Ureteral injuries are one of the more common triggers for malpractice claims in gynecological and colorectal surgery. A review of legal databases found that the majority of ureteral injury lawsuits actually ruled in favor of the surgeon. However, when plaintiffs did win, the financial awards were substantial. The factors most strongly linked to higher payouts were how long the patient required temporary drainage, whether the repair was delayed, whether the initial workup was deemed inadequate, and whether a supervising surgeon failed to properly oversee a trainee.28Urology. Malpractice Litigation in Iatrogenic Ureteral Injury: a Legal Database Review The takeaway for patients is not that they should assume malpractice if they experience a ureteral injury. Surgeons injure ureters even with meticulous technique, and courts recognize that. The legal landscape instead reflects how much worse outcomes become when the injury is not recognized, not investigated, or not repaired promptly.
Tissue Engineering and the Future of Ureteral Repair
For patients with extensive ureteral loss, where traditional reconstructive options are insufficient, researchers are exploring whether the ureter can be rebuilt using engineered tissues. The concept involves seeding a biological scaffold with the patient’s own cells and allowing them to grow into functional ureteral tissue. In animal experiments, researchers have successfully used scaffolds derived from blood vessel tissue, seeded with stem cells isolated from the patient’s own urine, to reconstruct ureteral segments. After two months, the grafts showed properly layered tissue with a lining on the inside and muscle on the outside.29PubMed. Ureter tissue engineering with vessel extracellular matrix and differentiated urine-derived stem cells However, reviews of the field acknowledge that while regenerating ureteral tissue is possible in principle, producing well-developed tissue remains extremely complex and time-consuming.30PubMed. Reconstruction Strategies of the Ureter and Urinary Diversion Using Tissue Engineering Approaches This is not yet a clinical option for patients, but it represents a direction that could eventually benefit people who today face kidney removal as their only option when too much ureter has been lost.