Liposomal bupivacaine efficacy for postoperative pain following posterior vaginal surgery: a randomized, double-blind, placebo-controlled trial.

BACKGROUND

Effective postoperative pain management is a crucial component of recovery following surgery. Narcotics are a cornerstone of postoperative analgesia, but can require a redosing requirement, encompass a lengthy list of side effects and adverse reaction risks, as well as carry a dependency potential. The national focus on decreasing opioid use has directly impacted postoperative pain management. Previous studies have reported the beneficial use of a single intraoperative injection of extended-release liposomal bupivacaine in postoperative pain management, however the same results have not been extensively studied in the urogynecology literature.

OBJECTIVE

We sought to evaluate cumulative postoperative vaginal pain on days 1 and 3 after posterior vaginal wall surgery comparing study medication (extended-release liposomal bupivacaine) to placebo (saline). Secondary aims were to evaluate vaginal pain on postoperative day 7 and total morphine-equivalent narcotic usage on days 1, 3, and 7.

STUDY

DESIGN

This is a randomized, double-blinded, placebo-controlled trial with 100 subjects recruited from Walter Reed National Military Medical Center urogynecology clinic. All subjects were age >18 years and scheduled for surgery involving the posterior vaginal wall or muscularis (including posterior colporrhaphy, colpocleisis, sphincteroplasty, perineorrhaphy), excluding those with regular narcotic usage or concurrent pain management requiring the use of epidural anesthesia. A sample size of 96 patients was calculated. Subjects were randomized to receive either 20 mL of extended-release liposomal bupivacaine (Exparel) (Pacira Pharmaceuticals Inc, Parsippany, NJ) or 20 mL of placebo (saline) at the end of surgery. Concealed syringes were used and injected immediately postoperative into the lateral vaginal wall/levator muscle area and perineal body. In-house morphine-equivalent narcotic usage was recorded along with the postoperative day 1 pain scores. Patients were contacted by telephone on postoperative days 3 and 7. Vaginal pain scores were evaluated using the Defense and Veterans Pain Rating Scale, cumulatively and on days 1, 3, and 7. Overall morphine-equivalent narcotics were compared between the 2 groups.

RESULTS

From October 2014 through August 2017, 100 patients were enrolled and completed the study; 49 (49%) of the patients were randomized to the study group and 51 (51%) were in the placebo group. There was no significant difference between vaginal pain scores between the study group and the placebo group (postoperative day 1: study medication median score 1 [interquartile range 0-3], placebo median score 1 [interquartile range 0-3] [P = .59]; postoperative day 3: study medication median score 2 [interquartile range 0-3], placebo median score 1 [interquartile range 0-3] [P = .20]; postoperative day 7: study medication median score 3 [interquartile range 1-4], placebo median score 1.5 [interquartile range 0-3] [P = .06]). Cumulative pain scores postoperative day 1-7 were also not significant (study medication median score 6 [interquartile range 1-10], placebo median score 4 [interquartile range 1-8] [P = .14]). Multivariate model for the presence of vaginal pain was calculated and after controlling for body mass index, age, and combined laparoscopy surgery, there was no significant difference between the study and the placebo groups (P = .62). There was no statistically significant difference in morphine equivalents for the 2 groups: study medication 112.5 (interquartile range 45-207) and placebo 101.5 (interquartile range 37.5-195), P = .81.

CONCLUSION

The use of extended-release liposomal bupivacaine in posterior vaginal wall surgeries, injected into the lateral posterior vaginal wall and perineal body, does not provide a significant decrease in postoperative pain or decrease narcotic medication usage when compared to saline.