Disposable Energy Sources and Operating Room Time for Laparoscopic Hysterectomy

This will be a randomized, prospective study. The investigators study design would have each patient serve as their own control. One side of the uterine attachments would be transected using the disposable device, Ligasure (Covidien), and the other using the two reusable devices (Robi bipolar and Storz laparoscopic shears). It is the investigators standard practice that the attending surgeon is on the patient's left side while the resident physician is on the patients right. To eliminate the bias of surgical experience, the investigators will randomize the energy source used on each side for every case. Therefore, the number of cases performed by the attending surgeon with the disposable or reusable energy sources, will equal that of the less experienced resident surgeon.

The primary endpoint of this study would be the time difference between cauterizing one side of the uterine attachments, from the round ligament to the uterine artery on one side, to the time detaching the same tissues on the other side. The vesico-uterine peritoneum or "bladder flap", will always be transected from the left for consistency. Sealed, opaque envelopes will be randomized to determine which side of the uterus will get the single disposable instrument, and which will get the 2 reusable instruments.

A time savings of 6.7 minutes for the total case can also be explained by a 3.35 minute time savings PER SIDE of the uterine attachments, given each uterus has two "sides". There is no pre-existing data on time needed for coagulation and cutting of the vascular tissues. Based on experience, the investigators estimate that it takes on average about 20 min total time for vessel sealing, with an estimated variability that approximately 70% of the time, vessel sealing is done within 35 minutes. Given these estimates, and using a power of 0.8, the sample size needed is 45.

The primary endpoint of surgical time will be initially assessed for each individual patient by determining the difference between the half of the laparoscopic hysterectomy procedure performed with the disposable device, specifically the Ligasure (Covidien) and the half of the laparoscopic hysterectomy procedure performed with the two reusable devices (Robi Bipolar and Storz laparoscopic shears) and determining if the mean difference score summed across all patients differs significantly from zero. Subsequent analyses will examine surgical times for attending physicians and residents separately where those using the disposable device are compared to those using the two reusable devices with independent students t test or the Kolmogorov-Smirnov test depending on the normality of the distributions. Parallel analyses will be performed for the secondary endpoint of estimated blood loss. Secondary endpoints of organ damage and other categorical intraoperative complications will be compared between the disposable and reusable device groups using chi-square and Fisher's Exact test.