Lesson 20

Lesson 20: Aortic Aneurysm Repair: Open & EVAR

  • Aortic Cross-Clamping Effects:

    • Application: Creates central hypervolemia, increasing MAP, SVR, SVO2.

    • Removal: Causes central hypovolemia, decreasing CO, MAP, SVR, SVO2.

  • EVAR:

    • Minimally invasive procedure for abdominal aortic aneurysms.

    • Benefits: Shorter operative times, lower transfusion rates, shorter length of stay, and reduced morbidity compared to open surgery.

  • Endoleaks:

    • Occur when graft fails to prevent blood entry into aortic sac.

    • May resolve spontaneously or require further intervention.

  • Physiological Responses to AoX:

    • Factors: Location of AoX, intravascular volume, and cardiac reserve.

    • Starvation of distal tissues: Leads to anaerobic metabolism and increased lactic acid production, contributing to metabolic acidosis.

    • Impact on Organs: Increased risks of renal injury even with infrarenal clamps.

  • Monitoring During EVAR:

    • Blood pressure monitored via arterial line.

    • IV contrast may pose risks (e.g., allergic reactions, renal injury).

    • Vital to maintain urine output throughout procedure.

  • Risks in EVAR:

    • Potential complications: baroreceptor reflex activation, hemorrhage, aortic rupture, cerebral embolism.

    • Comparative Technique: Better outcomes with regional/local anesthesia over general anesthesia due to reduced respiratory risks.