At initial presentation, her hematocolpos was noted to be 4-5 cm from the perineum by rectal examination. She underwent drainage of her hema- tocolpos and vaginal pull through, 3 months after her initial presentation due to increasing pain, and at that time her hematocolpos was noted to be 1 cm from the perineum. Her procedure was uncomplicated, entailed use of only native tissue without graft or stent placement, nor requirement for post op dilation therapy. She was discharged the same day and was seen at 2 and 6 weeks post op without issues. She is currently one year following procedure, she is doing well and not requiring any vaginal dilation therapy or experiencing stenosis. Comments: At our institution, we also present 6 other similar cases similarly surgically managed. Currently, we have 7 patients at 1-10 years follow up without vaginal stenosis or need for dilator therapy (see figure 2). We demonstrate long term data following vaginal pull through repair for distal vaginal agenesis and feel that when appropriate it is the most bene- ficial to patients for long term outcomes. A larger multi-center study would be needed to further confirm this finding given the rarity of this condition. 125. Single Incision Laparoscopic Surgery for Complex Uterine Pathology in the Pediatric and Adolescent Population Yuan Yuan Gong, Verghese George, Xiaoming Guan, Jewel Appleton, Oluyemisi Adeyemi-Fowode Baylor College of Medicine Background: Single-incision laparoscopic surgery (SILS) is an exciting new modality in the field of minimal access surgery that provides the advantage of further reducing the number of scars of standard laparoscopy. While there are case reports of single incision laparoscopic surgery for adnexal pathology in this population, there are none in regards to treat- ment of uterine pathology such as leiomyoma. This case illustrates the feasibility of single incision laparoscopic surgery for uterine pathology in the pediatric and adolescent population. Case: 18 year old presented to the Pediatric and Adolescent Gynecology clinic with complaint of pelvic pain. She reported menarche at age 11 with regular menses. Medical history significant for chromosomal abnormality (absence of heterozygosity), developmental delay, acquired generalized lipodystrophy and related complications; hypertriglyceridemia, recurrent pancreatitis and insulin dependent diabetes. She had never been on hor- monal medication due to abnormal lipids. She denied history of sexual activity and urine pregnancy test was negative. Transabdominal pelvic ultrasound revealed periuterine soft tissue masses of uncertain etiology. Further investigation with magnetic resonance imaging (MRI) revealed multiple fibroids with the largest measuring 2.8 cm. Patient was lost to follow up and represented 1 year later with worsening pelvic pain. Repeat MRI was concerning for rapid interval enlargement of the previously seen fibroids with the largest now measuring 9 cm with solid and vascular components (Fig. 1 and 2). Tumor markers (CA125, HCG, AFP and LDH) were normal with the exception of slightly elevated CA125 at 50 U/mL. Given worsening pelvic pain, she was counseled on medical and surgical options and opted for definitive treatment with surgery. In collaboration with the Minimally Invasive Gynecologic Surgery team, single incision laparoscopic myomectomy was performed. A 9 cm right broad ligament fibroid, 6 cm posterior subserosal degenerating fibroid, and a 2 cm sub- serosal fibroid were excised with no complications. She recovered well and pathology revealed leiomyoma with varying degrees of degeneration and ischemic necrosis. Comments: Complex uterine pathology in the pediatric and adolescent population can be managed with minimally invasive surgery with excel- lent clinical outcomes. The major advantages of SILS over standard lapa- roscopic surgery are in cosmesis and decreased post operative pain. SILS is a rapidly developing field that may represent the future of laparoscopic surgery and can be utilized to treat reproductive pathology in the pediatric and adolescent population. 126. Hysterectomy on Conjoined Twins: an Example of the Use of Virtual Preoperative Planning Pedro Mercado 1 , Maria Ormaechea 1 , Virginia Tuchbaum 1 , Roberto Vagni 1 , Lucas Ritacco 2 , Miguel Puigdevall 3 , Francisco de Badiola 1 , Juan Moldes 1 1 Department of Pediatric Surgery and Urology, Hospital Italiano de Buenos Aires 2 Department of Virtual Surgical Planning and Navigation, Hospital Italiano de Buenos Aires 3 Department of Orthopaedics and Traumatology, Hospital Italiano de Buenos Aires Background: Preoperative planning is essential to secure the best sur- gical outcome when the anatomy of the patient is altered or unknown. Conjoined twins are the perfect example of this paradigm. The develop- ment of image processing technology and virtual navigation can help overcome several anatomical barriers and prevent surgical complications, specially in this infrequent patients. Case: We present the case of a hysterectomy on parapagus conjoined twins with a double uterovaginal system. They presented with abdominal pain secondary to hematocolpos. Virtual Preoperative Planning showed the obstructed hemi-uterus trapped between both spines and a posterior iliac bone (Fig 1). Additionally, an aberrant vessel coming out from the right spinal canal was identified. Based on those findings, the best surgical approach was determined. Under general anesthesia, the anatomy of the patient was matched intraoperatively with the preoperative image data, Poster Presentation Abstracts 2 / J Pediatr Adolesc Gynecol 33 (2020) 212e237 236