Pre-sacral nerve block for Postoperative Pain

Hysterectomy (removal of the uterus) is the most common major gynecologic surgery performed in Canada. With a focus on minimally invasive techniques and optimization of peri-operative pain control, gynaecologists have made great strides towards reducing hospital stay and accelerating post-operative recovery. These are essential achievements, both for patients and their families and for our resource-limited public healthcare system. Optimization of peri-operative pain control is multifactorial and includes, for example, administration of pre-operative analgesics, infiltration of incision sites with local anesthetic and provision of post-operative pain medications. As the understanding of pain mechanisms evolves, the incorporation of intra-operative nerve blocks has become yet another effective strategy to reduce post-operative pain. The presacral nerve plexus, which carries nerve fibers from the uterus to the brain, is an important pathway that transmits midline pelvic pain in women. Destruction of the pre-sacral nerves has been shown to provide excellent pain control in a variety of clinical settings. While transection of the presacral nerve at the time of surgery is technically challenging, instilling a presacral nerve block is surprisingly straightforward making this technique safe to perform in the hands of many gynecologists. In this technique, local anesthetic is instilled into the presacral space using a needle inserted through the abdomen. Given that the presacral nerve plexus is an integral pain pathway for the uterus, the investigators hypothesize that the addition of a presacral nerve block during laparoscopic (camera surgery) hysterectomy would confer an additional reduction in immediate post-operative pain. The proposed study therefore aims to look at the impact of presacral nerve block versus a sham (blank) block on immediate post-operative pain in a group of women scheduled to undergo laparoscopic hysterectomy.