A Randomized Control Trial of Combined Vaginal Misoprostol and Perivascular Vasopressin During Robotic Myomectomy

Uterine fibroids are common benign tumors affecting women, and produce symptoms severe enough to warrant treatment in 20-50% of reproductive age women, including abnormal uterine bleeding, pelvic pain, and infertility. While hysterectomy with removal of the uterus is standard of care for symptomatic uterine fibroids, women desiring future child bearing require removal of the fibroids alone via uterine myomectomy, with re-construction of the uterus after removal. A well established risk to such a procedure is the operative blood loss, which can be quite significant due to the increased blood supply fibroids accumulate. Several interventions have been looked at as potential methods to help decrease operative blood loss. Injection of Vasopressin into the uterine tissue surrounding fibroids constricts blood vessels, and has been found to be beneficial by decreasing blood flow to fibroids, and thereby resulting in less bleeding with removal. A known potential side effect of vasopressin is cardiovascular compromise, which can be catastrophic if vasopressin is inadvertently injected into the large vessels of the uterus. This limits the amount that can be safely used in surgery. Additionally, Misoprostol has been looked at as an additional method to decrease operative blood loss given its ability to increase uterine muscle tone, which therefore constricts the amount of blood flow to the uterus. While Vasopressin is more commonly used during surgery, the associated potential risks limit the amount that can be safely administered. However, the addition Misoprostol, with a relatively safe side effect profile, can further improve control of the blood supply and decrease operative blood loss. Misoprostol can be administered orally, sublingually, or as vaginal or rectal suppositories. While the systemic absorption of vaginal Misoprostol is slower in onset than the oral or sublingual routes, the effect is maintained for a longer period of time, and is more conducive to use during laparoscopic or robotic assisted myomectomies given the prolonged operative time associated with minimally invasive techniques when compared to traditional open approaches. This study aims to determine whether using vaginal Misoprostol in combination with Vasopressin is more effective at decreasing operative blood loss during robotic assisted laparoscopic myomectomy than Vasopressin alone.