55: A pre-sacral cyst: Dissection in the retro-rectal space

Abstract

The objectives of this video are to present an unusual case of a pre-sacral cyst and to demonstrate techniques for dissection in the retro-rectal space. A 27-year-old presented with acute pelvic pain, nausea, vomiting, and headache. She had normal vital signs and lab values. On pelvic exam, a large mobile mass was palpated inferior to the cervix. Imaging showed a cystic lesion in the rectovaginal space measuring 6.4 by 6.6 by 5.9 centimeters. There was anterior compression of the cervix and vagina and lateral displacement of the rectum. She proceeded with surgical removal via robotic-assisted excision. The mass was visualized posterior and inferior to the uterus. The retro-rectal space was developed by opening the peritoneum lateral to the mass and medial to the uterosacral ligament. This incision was carried toward the sacral promontory. When the promontory was visualized, the sigmoid colon was displaced towards the right pelvic sidewall. The pre-sacral space was developed to the level of the levator muscles bilaterally. The mass was freed circumferentially and excised entirely. It was placed in a specimen retrieval bag. A surgical hemostatic agent was placed in the dissection plane to decrease the risk of bleeding, and the peritoneum was re-approximated using a running 2-0 barbed suture. Flexible sigmoidoscopy was performed noting intact bowel lumen and no evidence of injury. Pathology showed a dermoid cyst with associated histiocytic response. The patient was discharged home in a stable condition. Gynecologic surgeons rarely enter the retro-rectal space, but knowledge of anatomy is essential during this dissection. Tumors in the retro-rectal space are rare, but the differential diagnosis is broad.