Surgical injury to the ureter is an uncommon but potentially serious complication of pelvic and abdominal operations, and a new retrospective single-center analysis suggests that the timing of diagnosis may shape how the injury is managed. The study, published in BMC Urology, reviewed 23 patients with confirmed iatrogenic ureteral injury treated between January 2000 and December 2025, and found that injuries spotted on the operating table were almost always repaired immediately, while injuries discovered after surgery typically required urinary diversion first and definitive reconstruction later.
The researchers, led by Takanori Mochizuki and colleagues, began with 35 potentially eligible patients but excluded 12 because the injury could not be adequately verified or clinically characterized. That left 23 cases for analysis, a small sample the authors themselves describe as descriptive and exploratory.
The split was uneven. Sixteen patients had their injuries recognized during the index surgery, while seven learned of the damage only afterward. Among those diagnosed postoperatively, the median interval between the original operation and the urological diagnosis was seven days, with an interquartile range of three to 28 days and a full range stretching from one to 53 days. That spread illustrates how long the diagnosis can be delayed: in this group, the time from index surgery to diagnosis ranged from one to 53 days.
The management pathways diverged sharply between the groups. Nephrostomy, in which a tube drains the kidney directly through the skin, was used in one of 16 patients (6.3 percent) in the intraoperative group but in four of seven patients (57.1 percent) in the postoperative group. Ureteral stenting, which keeps a channel open inside the ureter, showed the reverse pattern, appearing in 15 of 16 intraoperative cases (93.8 percent) and four of seven postoperative cases (57.1 percent). Most strikingly, definitive repair performed during the index surgery itself was carried out in 15 of 16 patients (93.8 percent) diagnosed intraoperatively, and in none of the patients diagnosed after surgery.
For the postoperative group, definitive reconstruction came later, if it came at all. Three of the seven patients eventually underwent definitive repair: one received a ureteroureterostomy, in which the severed ends of the ureter are rejoined, and two underwent ureteroneocystostomy with a Boari flap, a reconstructive technique that uses a strip of bladder wall to bridge a gap between the bladder and the injured ureter. The remaining patients in that group were managed without such reconstruction during the recorded follow-up, a detail that underscores how heterogeneous the delayed-diagnosis pathway can be.
Follow-up durations differed considerably between the two groups, which complicates any direct comparison of outcomes. Median follow-up was 7.7 months (interquartile range, 3.1 to 22.2 months) in the intraoperative group and 26.5 months (interquartile range, 7.1 to 41.8 months) in the postoperative group. The postoperative patients were therefore observed for substantially longer on average in this cohort.
When the authors assessed final urological outcomes, they found unfavorable results in four of 14 evaluable patients (28.6 percent) in the intraoperative group and three of six evaluable patients (50.0 percent) in the postoperative group. The authors concluded that no clear difference in urological outcomes was detected between the groups during the available follow-up. With only 14 and six evaluable patients respectively, and with the postoperative group followed longer, the numerical gap cannot be read as evidence that one pathway protects the kidney better than the other.
The study’s own framing is deliberately cautious. The authors note that between-group comparisons were considered exploratory because of the small sample size, and they emphasize that the findings should be interpreted as descriptive and exploratory given the small cohort, the heterogeneous clinical context, and the long 25-year study period. The study spanned January 2000 to December 2025, and the authors note that the findings should be interpreted as descriptive and exploratory given the small cohort, the heterogeneous clinical context, and the long study period.
What the study does offer is a clear descriptive picture of how practice diverges with timing. Injuries recognized intraoperatively were overwhelmingly managed with immediate definitive repair and internal stenting, while injuries recognized postoperatively were managed first with urinary diversion, either nephrostomy or stenting, and only sometimes with later reconstruction. The authors state that the management of iatrogenic ureteral injury differed according to the timing of diagnosis in this small retrospective cohort. Whether earlier recognition would improve outcomes remains untested by this design, since the study did not randomize management and cannot establish causal effects.
In this cohort, the two diagnostic scenarios were associated with different management pathways. Injuries diagnosed intraoperatively were usually repaired during the index surgery, whereas injuries diagnosed postoperatively were managed first with urinary diversion, and some later underwent definitive reconstruction. The authors' data also highlight the diagnostic gap itself: of 35 potentially eligible patients, seven were diagnosed postoperatively, and the median time from index surgery to diagnosis in that group was seven days. The study is open access and, as the journal notes, was shared early to provide faster access to peer-reviewed, accepted research, with a final version of record to follow.
Subject of Research: Management and outcomes of iatrogenic ureteral injury according to timing of diagnosis
Article Title: Management strategies and outcomes of iatrogenic ureteral injury according to the timing of diagnosis: a retrospective single-center study
Article References: Mochizuki, T., Sawada, N., Sugimura, K., Tsuchida, T., Furuya, R., Suda, R., Shimura, H., Kira, S., & Mitsui, T. (2026). Management strategies and outcomes of iatrogenic ureteral injury according to the timing of diagnosis: a retrospective single-center study. BMC Urology. https://doi.org/10.1186/s12894-026-02432-7
Image Credits: AI Generated
DOI: 10.1186/s12894-026-02432-7
Keywords: iatrogenic ureteral injury, ureteral stenting, nephrostomy, ureteroureterostomy, Boari flap, intraoperative diagnosis, postoperative diagnosis, urinary diversion, retrospective cohort, BMC Urology, surgical complications, Management
News Source: Ophelia Keating. (October 30, 2026). Immediate repair or delayed diversion: timing shapes care of surgical ureteral injuries. Scienmag.
