Open Abdominal Aortic Aneurysm Repair
Patient phenotype
Typically male 65–85, multi-vessel CAD, COPD, smoker. Symptomatic = back/flank pain or pulsatile mass. Ruptured = hypotensive + altered mental status (true emergency, separate plan).
Procedure
Midline or transabdominal incision, expose aorta + iliacs, heparinize, cross-clamp aorta below renals (preferred) or supra-renal, replace with Dacron graft, unclamp, close. ~3–5 hours, major fluid + blood shifts.
Anesthetic plan
GETA with thoracic epidural for postop pain. A-line pre-induction. CVC + PA cath or TEE. Massive transfusion preparation. Consider beta-blocker + statin pretreatment if not already on.
Setup
- ·Two A-lines or one + femoral backup
- ·CVC + PA cath OR TEE (institutional)
- ·2-3× large-bore PIVs + rapid infuser primed
- ·Type & cross 6 units PRBC, FFP + platelets available, MTP activated mentally
- ·Cell saver
- ·Foley + temp + Foley with continuous CVP/PCWP-equivalent monitoring
- ·Forced air warmer + fluid warmer + ambient temp up
- ·Heparin + protamine + ACT machine
Biggest concerns by phase
Cardiac risk — 30% have significant CAD, 10% have CHF
Pre-op MI rate is the leading mortality cause for open AAA. Optimize: continue beta-blocker (esmolol or metoprolol intraop if needed), continue statin. Stress test if not done recently. ECHO if any concern about EF.
Smooth induction + tight BP control
Hypertension can rupture an unprotected aneurysm, hypotension can cause coronary ischemia. Goal MAP ≥ 65 + SBP < 140. Pre-induction A-line. Etomidate or fentanyl-heavy induction. Have phenylephrine + esmolol pre-drawn.
Aortic cross-clamp — massive afterload + visceral ischemia
Cross-clamp causes immediate ↑SVR, ↑LV wall stress, ↓preload distally. Bowel + kidneys + spinal cord ischemic. Treat with: vasodilator (nitroglycerin or sodium nitroprusside) anticipated before clamp + restart afterward, deepen anesthesia. Consider mannitol 25 g for renal protection.
Cross-clamp release — sudden hypotension + acidosis + hyperkalemia
Releasing clamp dumps acidotic hyperkalemic distal blood centrally. Sudden ↓BP + arrhythmia possible. Pre-release: ensure euvolemia, lighten vasodilator, restart vasopressor titration, calcium ready. Surgeon releases slowly with ABG check + bicarb + calcium ready.
Spinal cord ischemia — esp. supra-renal clamp
Spinal cord ischemia incidence ~1% infrarenal, ~10% supra-renal. CSF drainage (lumbar drain placed pre-op) reduces risk by maintaining cord perfusion pressure (CPP = MAP - CSF pressure). Maintain MAP > 80 throughout clamp + post-clamp, drain CSF to keep ICP < 10.
Postop: bleeding, MI, renal failure, ileus, bowel ischemia
Highest mortality first 24 h is from bleeding + MI. Watch a-line trends, urine output > 0.5 mL/kg/hr, lactate trend (rising = bowel ischemia). ICU intubated overnight. Resume β-blocker + statin POD 1.
Mock-defense scenarios
Practice answering these out loud. The probes show what an examiner is listening for.
Surgeon is about to release the supra-renal aortic clamp after 90 minutes. CVP is 8, MAP 78 on phenylephrine 0.5 mcg/kg/min, K is 5.3, lactate 3.2. What's your plan?
What an examiner probes for
- ▹Pre-release: optimize volume, ensure calcium + bicarb + epi available
- ▹Communicate with surgeon: slow release, partial first
- ▹Anticipate hypotension + arrhythmia from acidotic hyperkalemic blood
- ▹Ready vasopressor up-titration, fluid bolus, calcium 1 g
Same patient, 24 hours postop in ICU. UOP has been 5 mL/hr × 2 hr, creatinine up from 1.0 → 1.6, lactate 4.5, distended abdomen. What's your differential and what do you do?
What an examiner probes for
- ▹Top differential: bowel ischemia (post-aortic surgery), renal failure (clamp + contrast), ongoing surgical bleeding
- ▹Workup: STAT labs, CT angio if stable, surgical reassessment
- ▹Recognize: rising lactate + UOP drop + abdominal pain = surgical emergency
Sources
- Miller's Ch 65 (vascular)
- ESVS AAA Guidelines
- ASA Practice Advisory
Anatomy reference
Sourced reference images. 4 matches for "aorta abdominal arterial".
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