Unreported clinical trial of the week: Liposomal Bupivacaine (Exparel) for postoperative pain control for open and laparoscopic abdominal hernia repair (NCT02128646)

Georgia Richards, Nick Devito, and Ben Goldacre describe another unreported trial that could be used to improve patient care

The US FDA Amendments Act (FDAAA 2007) requires certain clinical trials to report their results onto ClinicalTrials.gov within one year of completion. Our FDAAA TrialsTracker shows all individual trials that breach this legal requirement. In each episode from this series we write about one unreported clinical trial: you can read more background here and read past entries here.

Trial NCT02128646

This week’s unreported trial is “Liposomal Bupivacaine (Exparel) for postoperative pain control for open and laparoscopic abdominal hernia repair” (NCT02128646). Forty adults were enrolled in the study, who were scheduled to undergo an open or laparoscopic abdominal hernia repair. The trial included four study groups: Treatment Group 1 had open surgery and Treatment Group 2 had laparoscopic surgery, and both received 266 mg of EXPAREL followed by a 30 mg dose of IV ketorolac at the end of surgery. Control Group 1 had open surgery, Control Group 2 had laparoscopic surgery, and both received “traditional treatment” (which is not defined any further in the registry entry). The primary outcome was patient satisfaction with pain management after surgery, as measured using a composite score, which included a Likert scale and “opioid consumption/satisfaction log.” The secondary outcomes were the total length of stay in the post-anesthesia care unit, and the change in post-surgical opioid consumption during the 72 hours after surgery.

Discussion

Abdominal hernia is a common presentation. In the United States, an estimated 2.3 million abdominal hernia repairs were performed between 2001 and 2010; of which nearly 570 000 were performed as emergencies. Pain relief is important after major surgery. Given the growing concern of opioid dependence, it is important to determine patient satisfaction with a non-opioid alternative such as liposomal bupivacaine. A Cochrane systematic review on the analgesic efficacy and adverse effects of liposomal bupivacaine for postoperative pain was published in 2017. They found liposomal bupivacaine reduced postoperative pain when compared to placebo and no serious adverse events associated with its use. However, they concluded that “. . . due to the low quality and volume of evidence our confidence in the effect estimate is limited and the true effect may be substantially different from our estimate.” The 2017 Cochrane review specifically mentions the unreported trial under discussion today as a useful source of future evidence. This unreported trial could therefore have an impact on clinical practice and post-operative pain relief for patients who require an abdominal hernia repair.

Conclusion

This unreported trial was sponsored by the study’s PI, Dr Michael Moncure from the University of Kansas Medical Center, where the study was conducted, and was completed in collaboration with Pacira Pharmaceuticals Inc. The trial’s registry record was last updated by the researchers on 19 January 2017. The trial is listed as completing on 31 January 2017; it is currently 183 days late for reporting results onto ClinicalTrials.gov. We hope the investigators will share the complete results of this trial soon.

Georgia C Richards is a doctoral researcher at the Centre for Evidence Based Medicine at the University of Oxford.

Competing interests: GCR is a joint NHS National Institute of Health Research (NIHR) School for Primary Care Research (SPCR), Naji Foundation, and Rotary Foundation Scholar, studying for a doctor of Philosophy (DPhil/PhD) at the University of Oxford.

Ben Goldacre is a doctor, author, and director of the EBM DataLab at the University of Oxford. He co-founded the AllTrials campaign for trials transparency.

Competing interests: BG has received research funding from the Laura and John Arnold Foundation, the Wellcome Trust, the Oxford Biomedical Research Centre, the NHS National Institute for Health Research School of Primary Care Research, the Health Foundation, and the World Health Organization; he also receives personal income from speaking and writing for lay audiences on the misuse of science.

Nicholas J DeVito is a researcher at the EBM Datalab at the University of Oxford.

Competing interests: ND is employed on BG’s LJAF grant and is a Naji Foundation scholar at the University of Oxford.