A systematic review of bladder and ureteric injury during caesarean section and hysterectomy; incidence, risk factors and prevention

Introduction & Objectives: Iatrogenic injury of the bladder or ureter is a known complication of abdominal, pelvic or vaginal surgery. The majority of such injuries occur secondary to caesarean section and hysterectomy. However, there remains great variation in the estimation of the frequency of urological injury during these major obstetric and gynaecological procedures which limits the mandate for quality improvement exercises.

We aimed to systematically review iatrogenic bladder and ureteric injuries sustained during caesarean section and hysterectomy as well as risk factors and advocated preventative strategies.

Methods: A search of Cochrane, Embase, Medline and grey literature for the period 01/01/2000–20/10/2019 was performed using methods pre-published on PROSPERO. Eligible studies described the incidence of iatrogenic injury to the bladder or ureter during caesarean section or hysterectomy. Meta-analyses were performed by procedure sub-type. The largest fifteen studies were included for each procedure sub-type. The primary outcome was injury incidence. Secondary outcomes were risk factors and preventative measures.

Results: In total, 96 eligible studies were identified, representing 1,741,894 women. Amongst women undergoing caesarean section, weighted pooled mean risk of bladder or ureteric injury were 0.3% or 0.02% respectively. Injury rates during hysterectomy varied by approach and pathology. Weighted pooled mean rates for bladder injury were 0.4–1.0% for all approaches (open, vaginal, laparoscopic, and laparoscopically assisted vaginal) and all pathologies (benign, malignant, any), with the two exceptions of open peripartum hysterectomy (6.0%) and laparoscopic hysterectomy for malignancy (1.8%). Similarly, weighted pooled mean rates for ureteric injury were 0.1–0.6% for all hysterectomy approaches (open, vaginal, laparoscopic, and laparoscopically assisted vaginal) and all pathologies (benign, malignant, any), with the same two exceptions of open peripartum hysterectomy (0.8%) and laparoscopic hysterectomy for malignancy (0.9%). There was insufficient data for meta-analyses of urological injury rates during robot-assisted hysterectomy. Surgeon inexperience was the leading risk factor for iatrogenic injury, and improved anatomical knowledge the most commonly suggested preventative strategy.

Conclusions: Caesarean section and most types of hysterectomy carry low rates of bladder and ureteric injury. Obstetricians and gynaecologists should counsel the patient for her individual risk of injury, prospectively establish risk factors and implement preventative strategies to minimise risk.