What are the anesthetic considerations for abdominal aortic aneurysm (AAA) repair?

From the Guidelines

Anesthetic management for abdominal aortic aneurysm (AAA) repair should prioritize general anesthesia with careful consideration of postoperative pain control, with thoracic epidural anesthesia/analgesia considered for postoperative analgesia, as recommended by the guidelines 1.

Key Considerations

• Preoperative assessment should include thorough cardiac evaluation, including echocardiography and stress testing, as many AAA patients have concurrent coronary artery disease.
• Premedication typically includes anxiolytics like midazolam (1-2 mg IV) and continuation of cardiac medications, including beta-blockers and statins.
• General anesthesia is the standard approach, using etomidate (0.2-0.3 mg/kg) or propofol (1-2 mg/kg) for induction, along with fentanyl (2-5 mcg/kg) or remifentanil infusion, and rocuronium (0.6-1.2 mg/kg) for muscle relaxation.
• Intraoperative monitoring is essential, including arterial line placement before induction, central venous catheter, and possibly pulmonary artery catheter for patients with significant cardiac disease.
• Intraoperatively, the anesthesiologist must prepare for significant hemodynamic changes, particularly during aortic cross-clamping and unclamping.
• Postoperative care should include intensive care monitoring with attention to hemodynamic stability, renal function, and pain management.

Anesthetic Techniques

• General anesthesia is the preferred technique for AAA repair, with consideration of neuraxial anesthesia (epidural or spinal anesthesia) as a supplement or primary anesthetic in select cases.
• Thoracic epidural anesthesia/analgesia may be considered for postoperative analgesia, as it has been shown to provide excellent pain control in patients undergoing abdominal aortic surgery 1.
• The use of volatile anesthetics, such as sevoflurane, may provide cardioprotective effects, but the evidence is not strong enough to recommend their use as a primary anesthetic technique for AAA repair 1.

Postoperative Care

• Postoperative pain management is crucial, with epidural analgesia (typically bupivacaine 0.125% with fentanyl 2 mcg/ml at 6-12 ml/hr) providing excellent pain control in patients undergoing open AAA repair.
• Intensive care monitoring should include attention to hemodynamic stability, renal function, and pain management, with careful balance of fluid management and temperature control to prevent coagulopathy.
• The guidelines recommend considering thoracic epidural anesthesia/analgesia for postoperative analgesia in patients undergoing abdominal aortic aneurysm surgery, with a level of evidence of +1B 1.

From the Research

Anesthetic Considerations for Abdominal Aorta Aneurysm Repair

• The choice of anesthesia for abdominal aorta aneurysm repair depends on various factors, including the type of surgery, patient's health status, and surgeon's preference 2, 3, 4, 5, 6.
• Combined epidural-general anesthesia has been shown to be associated with improved survival and reduced postoperative complications compared to general anesthesia alone for elective abdominal aortic aneurysm repair 2, 5.
• Loco-regional anesthesia, such as spinal or epidural anesthesia, may be a suitable alternative to general anesthesia for endovascular aortic aneurysm repair, with potential benefits including reduced postoperative complications and shorter hospital stay 4, 6.
• However, the evidence is limited, and more studies are needed to determine the optimal anesthetic technique for abdominal aorta aneurysm repair 3.
• The decision on the anesthetic technique should be made on a case-by-case basis, taking into account the individual patient's needs and preferences, as well as the surgeon's and anesthesiologist's expertise 2, 4, 5, 6.

Types of Anesthesia

• General anesthesia: commonly used for abdominal aortic aneurysm repair, but may be associated with increased postoperative complications 2, 3, 5, 6.
• Epidural anesthesia: may be used as an adjunct to general anesthesia to improve postoperative pain control and reduce complications 2, 5.
• Spinal anesthesia: may be used for endovascular aortic aneurysm repair, but may have limited duration of anesthesia 4.
• Loco-regional anesthesia: may be a suitable alternative to general anesthesia for endovascular aortic aneurysm repair, with potential benefits including reduced postoperative complications and shorter hospital stay 4, 6.

Outcomes

• Combined epidural-general anesthesia has been shown to be associated with improved survival and reduced postoperative complications compared to general anesthesia alone for elective abdominal aortic aneurysm repair 2, 5.
• Loco-regional anesthesia may be associated with reduced postoperative complications and shorter hospital stay compared to general anesthesia for endovascular aortic aneurysm repair 4, 6.
• However, the evidence is limited, and more studies are needed to determine the optimal anesthetic technique for abdominal aorta aneurysm repair 3.