Bupivacaine vs. RopivacaineLiposomal Bupivacaine/Bupivacaine in Rectus Sheath Blocks Versus Ropivacaine in Rectus Sheath Blocks And Catheters

Inclusion Criteria:

1. Patients aged 18-80 years
2. Patients scheduled for elective vascular surgery with an open mid-abdominal laparotomy incision, including abdominal aortic aneurysm repair surgery (AAA), mesenteric artery bypass surgery, and aortobifemoral bypass surgery for aortic occlusive disease.
3. Patients who are able to speak and read English
4. Patients with American Society of Anesthesiology (ASA) physical status score I-IV
5. Patients who are admitted to the hospital and are incidentally discovered to require any of the aforementioned surgeries, being asymptomatic for vascular issues, and having their surgery scheduled no sooner than three days after admission, are also considered eligible.

Exclusion Criteria:

1. Emergency vascular reconstruction surgery., patients admitted to the hospital due to symptoms directly associated with their vascular condition, such as severe abdominal pain or a ruptured aneurysm causing bleeding, will be excluded.
2. Patients with contraindications to RSB, including but not limited to anatomical abnormality, previous surgical intervention that limits or prevents receiving bilateral RSBs, or infection at the injection site.
3. History of allergy to local anesthetics.
4. Weight < 40 kg, as a combination of 20 mL of Bupivacaine 0.25% with 30 mL of LB is greater than the maximal dose allowed, given concern for local anesthetic toxicity.
5. Patients who take long-acting opioid medication, or on continuous opioid use > 50 MME per day for at least 30 days within 90 days prior to surgery.
6. Patients who have chronic pain syndrome with a recent preoperative consultation with the chronic pain service. Also, patients with distant metastatic cancers (e.g. bone, lung, brain) confirmed by CT scan.
7. Patients with current substance abuse, or history of substance abuse within 3 months, this includes any illicit drugs (not including marijuana) or excessive alcohol consumption as defined as 4 or more drinks per day or 8 or more drinks per week for women and 5 or more drinks per day or 15 or more drinks per week for men.
8. Lack or refusal to sign the study consent.
9. Patients who are unable to receive postoperative ropivacaine intermittent boluses within the first 5 days after surgery due to issues with their catheter (such as dislodgement, migration, or kinking) will be excluded from the final analysis.
10. Patients with a plan to undergo abdominal wall surgery, in addition to the vascular surgery that involves a mid-abdomen incision, such as abdominal wall reconstruction surgery. The additional abdominal wall incisions or interventions might have an impact on the study's pain, opioid, and LOS outcomes.