Preperitoneal or Subcutaneous Wound Catheters as Alternative for Epidural Analgesia in Abdominal Surgery: A Systematic Review and Meta-analysis

OBJECTIVE: To assess whether the location of wound catheters (ie, preperitoneal vs. subcutaneous) impacts outcomes, when compared with alternatives such as epidural analgesia. BACKGROUND: Continuous wound infiltration is an alternative for epidural analgesia in abdominal surgery but studies have shown conflicting results. This difference could be explained by different efficacy of preperitoneal versus subcutaneous placement of the infiltrative catheters. METHODS: A systematic review and meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines until April 3, 2017. Primary endpoints were pain scores in rest and when moving at 24 hours postoperatively. Secondary endpoints included postoperative pain scores at 12 and 48 hours, functional recovery, pain treatment-related complications, and patient satisfaction. RESULTS: After screening 2283 studies, 29 randomized controlled trials (RCTs) with 2059 patients were included. Methodological quality of these RCTs ranged from moderate to high. In the one direct comparison (60 patients), preperitoneal catheters led to better pain control than subcutaneous catheters. Superiority of preperitoneal compared with subcutaneous placement was confirmed indirectly in placebo-controlled RCTs. Preperitoneal wound catheters provided comparable pain control compared with active controls, such as epidural analgesia. Recovery parameters, opioid consumption, incidence of hypotension, and patient satisfaction seemed to be in favor of preperitoneal wound catheters compared with active alternatives, as well as placebo. CONCLUSION: Continuous wound infiltration with preperitoneal wound catheters is an effective pain modality in abdominal surgery. Pain control is as effective as epidural analgesia, but could be favored based upon recovery parameters and patient satisfaction.