Most Common Site of Ureteric Injury During Total Laparoscopic Hysterectomy
The most common site of ureteric injury during total laparoscopic hysterectomy (TLH) is at the level of the cardinal ligament, where the ureter passes near the uterine artery at the internal cervical os. 1, 2
Anatomical Basis for Injury Location
The ureter is most vulnerable during dissection and division of the cardinal ligament below the uterine vessels, which corresponds to the distal/lower ureter region 1. This occurs because:
- The ureter crosses under the uterine artery approximately 2 cm lateral to the cervix at the level of the internal cervical os 3
- In 3.2% of women with normal pelvic anatomy, this distance is only 0.5 cm, placing the ureter at extreme risk 3
- The segment between the uterine artery intersection and the bladder is not visible without retroperitoneal dissection 3
Evidence from Clinical Studies
Research specifically examining ureteric injuries during laparoscopic hysterectomy demonstrates:
- In a 6-year series of 790 laparoscopic procedures, all three ureteral complications occurred during laparoscopically assisted vaginal hysterectomies, with both delayed injuries occurring in the lower segment of the ureter after laparoscopic bipolar coagulation and division of the cardinal ligament 1
- A larger Chinese study of 12,868 gynecological laparoscopic surgeries found that injury sites were either at the pelvic brim (2 cases) or the lower part of ureter (10 cases), with the vast majority occurring during laparoscopic hysterectomy 2
- The incidence of ureteral injury during laparoscopic hysterectomy ranges from 0.2-6.0%, which is 2.6-35 times higher than abdominal hysterectomy 4
Answer to Multiple Choice Question
Based on the evidence, Option A (Cardinal ligament) is the correct answer, as this is where the ureter passes in close proximity to the uterine artery and is most vulnerable during the critical step of dividing the cardinal ligament during TLH 1, 2.
Risk Factors That Increase Injury Risk
- Enlarged uterus from myomas 2, 4
- Pelvic adhesions 2
- Endometriosis 2, 3
- Adnexal masses 3
- Anatomic variants with closer ureter-cervix proximity 3
Prevention Strategies
Ureterolysis (retroperitoneal dissection to visualize the entire pelvic course of the ureter) should be considered in high-risk cases, as visualization at the pelvic brim alone is inadequate to prevent injury at the cardinal ligament level 3. Prophylactic ureteral catheter placement has been shown to reduce injury rates, with one study demonstrating zero injuries in 60 catheterized patients versus 1/34 in non-catheterized patients 4. The ureter can be safely dissected up to 15 cm without compromising viability 3.