Vasopressin Administration During Laparoscopic Myomectomy: a Randomized Controlled Trial

• Estimating blood loss at the end of myomectomy [ Time Frame: 5 minutes post-operatively ] [ Designated as safety issue: Yes ]
  To evaluate whether volume of dilute Vasopressin administered during minimally-invasive myomectomy affects blood loss. Three parameters will be collected to assess this outcome: Hematocrit change (%) pre and post-operatively; subjective surgeon's estimate of blood loss; objective calculation of blood loss: Suction canister fluid will be measured. The calculation for estimated blood loss will be as follows: EBL = [total suction canister volume] - [volume of irrigation used] - [volume of vasopressin solution injected /2].
  
  

• Peri-operative complications [ Time Frame: 8 weeks postoperatively ] [ Designated as safety issue: Yes ]
  Intra or post-operative complications (including but not limited to need for blood transfusion or adverse effect related to Vasopressin).
  
  
• Total operation time [ Time Frame: 5 minutes postoperatively ] [ Designated as safety issue: No ]
  Time from incision to end of surgery
  
  

All surgeons who enroll patients into our study are experienced laparoscopic surgeons who have performed at least 100 advanced laparoscopic procedures including hysterectomies and myomectomies. Briefly, our laparoscopic myomectomy technique is as follows: After gaining peritoneal access and placing visual and operative trocars, the surgical site is inspected carefully and fibroid locations identified. After informing the anesthesia team that vasopressin (from pharmaceutical company American Regent 20 units/ml) is about to be injected, the uterus is infiltrated with vasopressin.

Patients will be randomized one of two treatment groups pre-operatively on the day of surgery:

1. One arm will receive injection of 200 ml total of the 0.05 units/ml dilute vasopressin solution (total 10 units Vasopressin used, dilution of 20 units vasopressin in 400 ml of normal saline).
2. The second arm will receive injection of 30 ml total of the 0.3 units/ml dilute vasopressin solution (total 10 units Vasopressin used, dilution of 20 units Vasopressin in 60 mL of Normal Saline).

The procedure is done according to surgeon preference using various energy modalities such as monopolar or Harmonic Scalpel® (Ethicon Endo-Surgery, Cincinnati OH), for making the incision in the uterus. The fibroid is then removed from the uterus and examined. The incision is then closed in several layers with laparoscopic standard suturing technique, and hysterotomy site is generally covered with an adhesion barrier (Gynecare Interceed® (Ethicon Women's Health and Urology, Somerville NJ) or Seprafilm® slurry (Genzyme Biosurgery, Framingham MA)).

Blood Samples:

As per routine, preoperative blood samples to assess hematocrit levels will be taken no greater than 2 weeks prior to surgical date; if no preoperative laboratory studies have been obtained a sample will be drawn on the day of surgery. Postoperative blood samples to assess hematocrit will be taken no sooner than 4 hours after surgery for patients who are discharged the same day; for patients who are monitored overnight in hospital, the lab will be drawn on postoperative day #1.

Follow-up:

Patients will be followed for 8 weeks after surgery to assess for occurrence of any postoperative complication. A member of the team (health care worker such as research assistant who has been trained in HIPPA procedures) will be in charge of abstracting data from the medical records and entering this information into a study database.