Timing of diagnosis of complex lower urinary tract injury in the 30-day postoperative period following benign hysterectomy

Background: Complex lower urinary tract injury resulting from hysterectomy is a rare but highly morbid complication. Although intraoperative recognition reduces the risk of serious sequelae, observational studies have shown that most complex lower urinary tract injuries are recognized in the postoperative period. To date, limited research exists describing the timing of diagnosis of complex lower urinary tract injury or risk factors associated with complex lower urinary tract injury diagnosed in the postoperative period. Objective: This analysis aimed to describe the time to diagnosis of complex lower urinary tract injury among women undergoing benign hysterectomy. We also aimed to identify the intraoperative risk factors for differences in type and timing of complex lower urinary tract injury in the 30-day postoperative period using a large prospective national surgical database. Study Design: This was a retrospective analysis using the National Surgical Quality Improvement Program hysterectomy data set from 2014 to 2018. All benign hysterectomies were included. Sociodemographic factors, health status, surgeon type, and other operative characteristics were extracted. A complex lower urinary tract injury was defined as at least 1 ureteral obstruction, ureteral fistula, or bladder fistula diagnosed within the first 30 days following surgery. Bivariate and multivariate logistic regression and cox proportional hazards assessed differences in odds of and time until diagnosis of complex lower urinary tract injury. Proportional hazard assumptions were evaluated with martingale residuals and supremum tests. Significance thresholds were 0.05 for all analyses. Results: In this study, 100,823 women met the inclusion criteria. Median time to diagnosis of complex lower urinary tract injury was 10 days (interquartile range, 3–19) and varied significantly based on type of injury (P<.01) with ureteral obstruction (6; interquartile range, 2–16) recognized earlier than ureteral fistula (12; interquartile range, 7–21) and bladder fistula (14; interquartile range, 4–23). In addition, 8.65% of complex lower urinary tract injury were diagnosed on the day of surgery. Total laparoscopic hysterectomy had the lowest rate of complex lower urinary tract injury in unadjusted and adjusted analysis, with abdominal hysterectomy (adjusted odds ratio, 2.02; 95% confidence interval, 1.21–3.36) and vaginal hysterectomy (adjusted odds ratio, 2.05; 95% confidence interval, 1.16–3.62) having greater odds of ureteral obstruction, whereas laparoscopic assisted vaginal hysterectomy had the greatest odds of fistula (adjusted odds ratio, 2.10; 95% confidence interval, 1.26–3.48). Concomitant apical suspension was associated with a 6-day reduction in median time to diagnosis (P=.01), and surgery with a gynecologic oncologist was associated with a 9.5-day increase in median time to diagnosis (P=.01). Cox proportional hazards analysis confirmed these findings when controlling for confounders. Conclusion: Greater than 91% of complex lower urinary tract injury diagnoses in the National Surgical Quality Improvement Program hysterectomy database were diagnosed after the day of surgery. Route of hysterectomy, concomitant apical suspension, and primary surgeon specialty are associated with differences in both type of injury and time until diagnosis. These intraoperative risk factors should be considered when assessing for complex lower urinary tract injury in the 30-day postoperative period.