Can Loco-regional Anesthesia With Liposomal Bupivacaine Reduce Intra- and Post-operative Narcotic Use in Patients Undergoing Lower Extremity Revascularization? A Prospective, Triple Blinded, Randomized Trial.

This will be a single site, triple blinded, controlled randomized trial assessing potential reduction in narcotic use in patients undergoing lower extremity revascularization, when loco-regional anesthesia with Exparel solution is performed, compared to normal saline injection. Loco-regional anesthesia for lower extremity revascularization will include an ultrasound guided ilio-inguinal block with Exparel solution and local injection in the wound(s) edges of more Exparel solution. The control group will receive injection of normal saline instead. Lower extremity revascularizations will include femoral endarterectomy with patching ± antegrade or retrograde endovascular intervention (one or more combination of stenting, atherectomy, balloon angioplasty) or bypass (femoral popliteal or femoral tibial bypasses with vein or prosthetic graft).

The study will be conducted at Mayo Clinic Health System in Eau Claire only (single site).

The enrolled patients will be medicated in pre- and intra-operative phases by the anesthesia team in a standardized fashion, based on the protocol in attachment 4.

Patient, surgeon, and the team assessing the patient postoperatively will be blinded (triple blinded). Normal saline will be opacified by the pharmacy to keep the surgeon unaware of what he/she is injecting. As per Mayo policy, all patients will receive the surgical bill at least 30 days after surgery. This time frame will allow the patient to remain blinded if he/she received Exparel injection for the entire length of the study (which is 28 days after surgery).

The rounding team will evaluate the patient for signs of complications (based on the Clavien-Dindo grading system; figure 1) and ask the patients their minimum and maximum pain score (reported as 0-10 verbal numerical rating scale with 10 being worst pain) in the first 72 hours. The nurse will also assess patient's pain with the Visual Analogue Score (VAS; Figure 1). If VAS is >3 after the non-narcotic medications have been given, oral or intravenous narcotic medication will be administered. If patient is discharged before 72 hours, the team will call the patient at 48 and 72 hours to assess pain score. The maximal pain score value for the time period 0-72 hours will be chosen as the maximal pain during that time period.