From the Research
The posterior vaginal fornix is the safest entry point to the peritoneum during a hysterectomy. When performing this surgical procedure, accessing the peritoneal cavity through the posterior fornix offers several advantages. The posterior fornix provides the most direct anatomical route to the peritoneal cavity, as the peritoneum reflects over this area (the pouch of Douglas or rectouterine pouch) and is typically in close proximity to the vaginal wall. This location is relatively avascular compared to other fornices, reducing the risk of significant bleeding during entry. Additionally, the posterior fornix is further away from critical structures such as the bladder, ureters, and major blood vessels that could be injured during peritoneal entry. The anterior fornix, by contrast, is in close proximity to the bladder and ureters, while the lateral fornices contain the uterine vessels and ureters, making them more hazardous entry points.
Key Considerations
- The posterior vaginal fornix is the most direct route to the peritoneal cavity, with the peritoneum reflecting over this area and being in close proximity to the vaginal wall 1.
- This location is relatively avascular, reducing the risk of significant bleeding during entry 1.
- The posterior fornix is further away from critical structures such as the bladder, ureters, and major blood vessels that could be injured during peritoneal entry 2.
- Surgeons should ensure adequate exposure of the posterior fornix and careful identification of anatomical landmarks before incision to maximize safety during this critical step of the hysterectomy procedure 3.
Anatomical Landmarks
- The posterior vaginal fornix is equivalent to the Level I section of the vagina, measured posteriorly from the top of the posterior vaginal wall (apex or highest part of the vagina) to 2.5 cm below this point 2.
- The posterior aspects of the cervix and upper vagina are supported by the uterosacral (USL) and cardinal ligaments (CL), the distal segments of which fuse together to form a cardinal-uterosacral ligament complex (cardinal utero-sacral complex), around 2-3 cm long 2.
Clinical Implications
- The use of a multichannel abdominal port and vaginal support ring can make laparoscopic instruments easier to fix and operate, reducing the leakage of carbon dioxide pneumoperitoneum and resulting in cosmetic benefits and rapid postoperative recovery 4.
- The posterior vaginal fornix is a safe and effective entry point for transvaginal natural orifice transluminal endoscopic surgery (NOTES) procedures, including hysterectomy and bilateral adnexectomy 4.