Presentation Authors: Michael Chua*, Jack Zuckerman, Rob Strehlow, Ramon Virasoro, Jessica DeLong, Jeremy Tonkin, Kurt McCammon, Norfolk, VA
Introduction: A novel liposomal formulation of bupivacaine is available as a 96-hour delayed release formulation. Given that patient reported pain from the Buccal Mucosal Graft (BMG) harvest site is worst in the first 1-2 days following surgery, infiltration of this medication has the potential to dramatically reduce post-operative pain in these patients. We aim to assess the efficacy and safety of liposomal bupivacaine infiltration on the BMG harvest site in alleviating pain by evaluating the post-operative pain score, narcotic requirement and associated morbidities.
Methods: After IRB approval, a single-blinded randomized controlled trial was conducted among adult patients with urethral stricture, that were evaluated suitable for substitution urethroplasty using BMG. Patients were randomized using computer generated allocation scheme to group 1 (liposomal bupivacaine) and group 2 (control). Patient demographic and peri-operative data were collected. Outcome assessed were: post-operative day 1 -2 narcotic use, converted as cumulative morphine equivalents on a 24-hour basis. A validated survey with 10-point visual analogue scale for evaluation of patient reported oral pain score, associated oral morbidities, and oral conditions on post-procedural day 1-3 and 1-month follow-up. Fisher-exact test and independent T-test was used to analyze the data with statistical significance set at 0.05 level. (Clinicaltrials.gov registration NCT03720223)
Results: A total of 50 eligible patients were enrolled, 7 were excluded according to predefined exclusion criteria (Group 1: 21, Group 2: 22). No significant baseline characteristics difference was noted between the treatment groups. Compared to group 2, a significantly lesser narcotic requirement was noted among the patients in group 1 on post-op day 1 (IV Morphine equivalent mean difference 8.58; 95%CI 1.59, 15.56, p=0.017). No significant between group difference was noted for narcotic requirements on post-op day 2. Likewise, no between group difference was noted for post-procedural oral pain score, and oral morbidities on post-op day 1 to 3, and at 1-month follow-up. For post-procedural oral conditions, a significantly higher number of patients in group 1 have reported oral numbness at post-op day 2 (14 (87.5%) vs 8 (44.4%); p=0.013), which was not sustained and equivalent to group 2 at 1-month follow-up.
Conclusions: Our study showed that Liposomal bupivacaine infiltration to the BMG harvest site is safe and may adequately address the post-procedural oral pain, with noted significantly fewer narcotic requirements at post-op day 1. Although, higher incidence of oral numbness can be reported among these patients on post-op day 2, which was not long-lasting. Future studies may consider to evaluate the cost-effectiveness to determine suitability for routine use.