Anaesthesia for Aortic Surgery

Quick Answer

Aortic surgery ranges from open repair (high risk, physiological insult) to endovascular stent grafting (EVAR/TEVAR, less invasive but still significant). Anatomy: Ascending aorta (coronary arteries, aortic valve), arch (brachiocephalic, left carotid, left subclavian arteries), descending thoracic, thoracoabdominal, abdominal (infrarenal most common). Open repair: Requires aortic cross-clamping causing proximal hypertension (LV afterload increase, myocardial strain) and distal ischaemia (spinal cord, kidneys, viscera, lower limbs). Haemodynamic management during cross-clamp: Sodium nitroprusside or GTN infusion to reduce proximal hypertension (target SBP 100-140 mmHg), inotropic support if LV failure (dobutamine, milrinone), distal perfusion techniques (passive shunt, active bypass, femoro-femoral bypass) for prolonged clamping or high risk. Spinal cord protection: Highest risk with thoracoabdominal aortic aneurysm (TAAA) repair; motor evoked potential (MEP) and somatosensory evoked potential (SSEP) monitoring; cerebrospinal fluid (CSF) drainage (target pressure 10-14 cm H₂O); distal aortic perfusion; intercostal artery reimplantation; mild hypothermia (32-34°C); methylprednisolone (30 mg/kg pre-clamp, 30 mg/kg at 8 hours post-op); permissive mild hypotension post-op to prevent spinal cord hyperaemia. Renal protection: Avoid suprarenal clamping if possible; mannitol 0.5 g/kg pre-clamp (free radical scavenger); furosemide not protective; fenoldopam (dopamine-1 agonist) may reduce AKI; minimize clamp time; retrograde renal perfusion if prolonged clamp. Coagulopathy: Dilutional and consumptive; massive transfusion protocol; ROTEM/TEG-guided therapy; maintain fibrinogen >2 g/L, platelets >100 × 10⁹/L, INR <1.5. TEVAR/EVAR: Endovascular stent graft deployment under fluoroscopy; local/regional anaesthesia or GA depending on complexity and patient factors; lower physiological insult than open repair; complications include endoleak, graft migration, spinal cord ischaemia (lower risk than open), access site complications (iliac artery injury), contrast-induced nephropathy. Postoperative care: ICU admission, invasive monitoring (arterial, CVP, cardiac output), urine output monitoring, lower extremity perfusion checks, spinal cord function assessment (motor/sensory), respiratory support, analgesia (epidural vs. systemic). Indigenous patients: Higher rates of smoking, hypertension, peripheral vascular disease; may present with advanced disease; ensure social support for long recovery and rehabilitation needs. [1-10]