Ureter and Bladder Anatomy During Hysterectomy
Critical Anatomical Relationships
The ureters are at highest risk of injury at the level of the uterine artery crossover and the distal segment near the bladder, requiring meticulous identification and protection throughout hysterectomy. 1
Key Anatomical Measurements
The pelvic ureter follows a predictable course that must be understood:
- From pelvic brim to uterine artery crossover: 8.2-8.5 cm 1
- From uterine artery crossover to bladder wall: 3.2-3.3 cm 1
- Intramural ureter length within bladder: 1.5-1.7 cm 1
- Distance from ureter to uterine isthmus: median 1.7 cm (range 1.0-3.0 cm) 1
- Distance from ureter to lateral vaginal apex: 1.2-1.3 cm 1
- Average distance between ureter and cervix: 2 cm, but only 0.5 cm in 3.2% of women with normal anatomy 2
High-Risk Zones for Ureteral Injury
The following anatomical areas require heightened vigilance during hysterectomy 3:
- At the pelvic brim entrance - during ligation of the infundibulopelvic ligament 3
- Incision of the posterior leaf of broad ligament 3
- Dissection of the pararectal space 3
- Ligation of the uterine artery - the most common site of injury, occurring at the level of the internal cervical os 2, 3
- Dissection of the vesicouterine ligament and fourth space 3
- Transection of the sacrouterine ligaments 3
- Incision of the anterior vaginal wall 3
Vesicouterine Ligament Anatomy
Understanding the vesicouterine ligament (VUL) is essential for safe bladder mobilization 4:
- Anterior leaf of VUL: Contains the cervicovesical vessels that cross over the ureter from bladder to cervix; after vessel isolation and division, only avascular connective tissue remains 4
- Posterior leaf of VUL: Tissue under the ureter connecting the posterior bladder wall to the lateral cervix/upper vagina, containing middle and inferior vesical veins connecting with the deep uterine vein 4
- Division of these veins allows complete separation of the bladder with ureters from the lateral cervix and upper vagina 4
Parametrial Tissue Characteristics
The distal ureter is surrounded by complex parametrial tissue with specific characteristics 1:
- Denser fibrovascularity posteromedial to the ureter 1
- Greater nerve density posterior to the distal ureter 1
- This anatomy mandates avoiding extensive ureterolysis in the distal region to preserve blood supply and nerve function 1
Surgical Protection Strategies
Ureterolysis Technique
When complex pathology is present (endometriosis, large myomas, adnexal masses), ureterolysis may be necessary 2:
- The ureter can be safely dissected up to 15 cm without compromising viability 2
- Visualization at pelvic brim and sidewall alone is inadequate - the segment between the uterine artery intersection and bladder is not visible without retroperitoneal dissection 2
- Complete separation of the uterine artery and superficial uterine vein from the ureter must be achieved before dividing the VUL 4
Blood Supply Preservation
The blood supply to the pelvic ureter must be respected 5:
- Avoid extensive dissection of the distal ureter where blood supply is most vulnerable 1
- Maintain awareness of the vesico-ureteral unit anatomy as complications, especially following pelvic irradiation, are related to kidney and ureter function 5
Common Pitfalls
- Assuming adequate distance exists: In 3.2% of women, the ureter is only 0.5 cm from the cervix despite normal anatomy 2
- Relying solely on superficial visualization: The critical segment between uterine artery and bladder requires retroperitoneal dissection for safe identification 2
- Excessive distal ureterolysis: The increased nerve density and complex vascularity posterior to the distal ureter make aggressive dissection in this region particularly hazardous 1
- Inadequate identification before vessel ligation: Most injuries occur during uterine artery division; the ureter must be clearly identified before any vessel is ligated 2, 3