An extended paIn relief trial utilizing the infiltration of a long-acting Multivesicular liPosome foRmulation Of bupiVacaine, EXPAREL (IMPROVE): a Phase IV health economic trial in adult patients undergoing ileostomy reversal

Jorge E Marcet,¹ Valentine N Nfonsam,² Sergio Larach<sup>3

1</sup>Department of Surgery, Morsani College of Medicine, University of South Florida, Tampa, FL, USA; ²Department of Surgery, University of Arizona Cancer Center, Tucson, AZ, USA; ³The Center for Colon and Rectal Surgery, Florida Hospital Cancer Institute, Orlando, FL, USA

Background: Opioid analgesics are effective for postsurgical pain but are associated with opioid-related adverse events, creating a significant clinical and economic burden. Gastrointestinal surgery patients are at high risk for opioid-related adverse events. We conducted a study to assess the impact of an opioid-sparing multimodal analgesia regimen with liposome bupivacaine, compared with the standard of care (intravenous [IV] opioid-based, patient-controlled analgesia [PCA]) on postsurgical opioid use and health economic outcomes in patients undergoing ileostomy reversal.
Methods: In this open-label, multicenter study, sequential cohorts of patients undergoing ileostomy reversal received IV opioid PCA (first cohort); or multimodal analgesia including a single intraoperative administration of liposome bupivacaine (second cohort). Rescue analgesia was available to all patients. Primary outcome measures were postsurgical opioid use, hospital length of stay, and hospitalization costs. Incidence of opioid-related adverse events was also assessed.
Results: Twenty-seven patients were enrolled, underwent the planned surgery, and did not meet any intraoperative exclusion criteria; 16 received liposome bupivacaine-based multimodal analgesia and eleven received the standard IV opioid PCA regimen. The multimodal regimen was associated with significant reductions in opioid use compared with the IV opioid PCA regimen (mean, 20 mg versus 112 mg; median, 6 mg versus 48 mg, respectively; P < 0.01), postsurgical length of stay (median, 3.0 days versus 5.1 days, respectively; P < 0.001), and hospitalization costs (geometric mean, $6482 versus $9282, respectively; P = 0.01).
Conclusion: A liposome bupivacaine-based multimodal analgesic regimen resulted in statistically significant and clinically meaningful reductions in opioid consumption, shorter length of stay, and lower inpatient costs than an IV opioid-based analgesic regimen.

Keywords: surgery, ileostomy, multimodal analgesia, opioid-related adverse events, hospitalization cost, length of stay