Repeat or Single Quadratus Lumborum Block for the Reduction of Opioid Prescriptions After Surgery in Retroperitoneal Sarcoma Patients ("RESQU-SARC" Trial)

This phase II trial studies how well a repeat or single liposomal bupivacaine injection (quadratus lumborum block) works in reducing opioid prescriptions after surgery in patients with retroperitoneal sarcoma. Liposomal bupivacaine is a numbing medication. Giving a second injection block may decrease dependency on opioid medications for pain relief after surgery and prevent long-term use and addiction.

Inclusion Criteria: * Patients undergoing elective open sarcoma resection for potentially curative intent who would otherwise be treated with quadratus lumborum (QL) block + intravenous-patient controlled analgesia (IV-PCA) converted to oral pain medications (meds) (non-narcotic bundle + opioid pain pill) Exclusion Criteria: * Patients with current or past substance (drug or alcohol) abuse disorder * Laparoscopic or minimally invasive surgery * Cases in which anticipated discharge is on or before postoperative day 4