A Randomized Controlled Trial of Wound Infiltration With Extended-release Versus Short-acting Bupivacaine Before Laparoscopic or Robotic Hysterectomy

Lidocaine and bupivacaine hydrochloride (HCl) are the most commonly used drugs for wound infiltration during laparoscopic surgery for post-operative pain control. There is some evidence that wound infiltration decreases immediate post-operative pain. While bupivacaine has a slightly slower onset of action (5-10 minutes), it has become the preferred injectable anesthetic for surgical use because of its longer duration of effect (4-8 hours versus 1-2 hours for lidocaine).

DepoFoam bupivacaine (EXPAREL, Pacira Pharmaceuticals, Inc., Parsippany, NJ, USA) is a newer extended-release formulation of bupivacaine HCl approved by the U.S. Federal Drug Administration in October 2011. In this suspension, bupivacaine is encapsulated in microscopic spherical lipid-based particles of varying size to allow dispersion of the drug over an extended period of time. Analgesia is prolonged up to 96 hours. Given the extended duration of action, this liposomal bupivacaine may be better at providing post-operative pain relief in laparoscopic surgery.

Phase three trials have shown better pain control in the first 24 hours and less opioid use overall in bunionectomies, hemorrhoidectomies, and total knee replacement surgery when compared to placebo. No studies, however, have been published evaluating extended-release liposomal bupivacaine for laparoscopic surgery, or gynecologic surgery in general. Currently, we are using liposomal bupivacaine for pain relief after laparoscopic hysterectomies, but as stated, it has never been formally evaluated.

We hypothesize that liposomal bupivacaine ("extended-release") provides extended pain relief and decreases the need for supplemental opioid use after major laparoscopic surgery. We will be evaluating whether pre-incision infiltration of extended-release bupivacaine decreases post-operative pain from laparoscopic and robotic-assisted hysterectomy compared to bupivacaine HCl ("short-acting"). To achieve this evaluation we designed a double-blinded randomized controlled trial.

Patients who are scheduled to undergo a laparoscopic or robotic-assisted hysterectomy will be invited to participate. Group A will receive pre-incision infiltration of each trocar site with 4 ml of 0.25% Bupivacaine HCl. Group B will receive pre-incision infiltration of each trocar site with 4 ml of extended-release bupivacaine (EXPAREL) (13.3mg/ml). Subjects and outcome assessors will be blinded to group allocation.