Excision of the Nodule
When the uterosacral ligament is transected, this permits a closer inspection of the posterior vaginal wall and the ability to assess the need for further rectal dissection. The posterior fornix is then incised along the rectovaginal margin, allowing the space to be opened. The nodule is then excised by continuing along the original shape (triangular) of the pouch of Douglas (see photo at bottom of column).
One might find that the nodule extends into the pararectal fascia, the muscularis layer of the rectum, the posterior vagina, or the rectal wall. The rectal probe is used to help delineate the rectum from the remaining lesion. Such lesions can often be dissected with sharp scissors or may require excision with a Harmonic scalpel.
Reconstruction
The last step is the reconstruction of any structures that were compromised during the dissection. The patient is given IV indigo carmine to ensure the ureters are not compromised, and a cystoscopy is performed at the conclusion of the case to confirm function. The rectal wall integrity is confirmed with the injection of dilute indigo carmine through an 18 french foley catheter placed in the rectum or via an air leak test performed with the aide of a proctoscope.
Because the fibers of rectovaginal septum run vertically and blend with the muscular wall of the vagina, some deep-infiltrating lesions are part of the vaginal wall, and in these cases excision of the affected area of the vagina is necessary. Once these lesions are fully resected, the vagina is reattached to the cervix by means of an interrupted figure of eight suture, and the anterior rectal wall is also reinforced with sutures. The pneumoperitoneum can be maintained by using a blue suction bulb in the vagina.
Once the reconstruction is completed, the restoration of the pelvic anatomy should be apparent and additional attention should be paid to defects to ensure proper closure.
The surgical management of rectovaginal endometriosis nodules can be technically demanding as it can include the repair of the vagina, bowel, bladder, and ureters. A systematic approach and adequate endoscopic experience, however, can significantly decrease the risk of injury, Taking the time to perform the ureterolysis before the beginning of the case, moreover, is beneficial in providing landmarks and protecting the integrity of the ureters. Although long-term experience is forthcoming, the surgical intervention of DIE has proven to be beneficial in the short term by decreasing patients' pain and improving their quality of lifestyle.
The yellow-shaded region represents the ureter, the blue represents the infundibulopelvic ligament, and the red represents the bifurcation of the right common iliac artery.
The pararectal space is bordered by the pelvic sidewall, the cardinal ligament, and the rectal pillars.
The rectovaginal space is bordered by the uterosacral ligaments, the vaginal fascia, and the rectal fascia.
The space between the ureter and uterosacral ligament is utilized to transect the uterosacral ligament.
Source Images provided by Dr. Resad Pasic
Use of a rectal probe and vaginal tenaculum allows for proper plane appreciation when dissecting lesions in the rectovaginal space.
The right ureter is seen here on the medial aspect of the peritoneum. Ureterolysis can be done bluntly with the graspers and scissors, or with the Harmonic scalpel as shown here.
Bilateral ureterolysis is done before dissection of the rectovaginal septum.
To transect the rectovaginal septum, place the uterus on stretch in the anteverted position. The rectal probe is placed in the rectum and the uterosacral septum is identified and transected with the harmonic scalpel.
Transection of the uterosacral ligament is done after ureterolysis is completed. (Ureter is visible in the left upper portion; rectum is in lower right corner.)
The rectal nodule is grasped and placed on tension. The rectal probe is used to help delineate the rectal borders.
Source Images provided by Dr. Resad Pasic
Keys to the Obliterated Cul-de-Sac
Although the best approach to treatment of the obliterated cul-de-sac and excision of rectovaginal endometriosis is surgical, this laparoscopic procedure can be a daunting task for even the most experienced minimally invasive gynecologic surgeon. The potential risk to the rectum and ureter must be immediately recognized. It is for this reason that Dr. Harry Reich, one of the legendary pioneers in minimally invasive gynecologic surgery, stated over 20 years ago that dissection of the obliterated cul-de-sac and excision of deep rectovaginal endometriosis was the most difficult procedure in the gynecologist's armamentarium.