Acute Aortic Syndromes

KEY LEARNING POINTS

All Clinicians

• Acute aortic syndromes encompass intramural haematoma, penetrating aortic ulcer, and aortic dissection – each with distinct but overlapping management implications.

• Aortic dissection can present as abdominal pain, limb ischaemia, stroke, or chest pain mimicking ACS. High vigilance is essential.

• Type A dissection: mortality rises rapidly in the first 48 hours without surgery. Current ANZ 30-day surgical mortality is 10–25%.

• Malperfusion involving a single organ carries approximately 30% mortality; each additional organ bed worsens outcomes significantly.

• Non-haemorrhagic stroke is NOT a contraindication to surgery – prompt repair may reduce infarct size.

• CPR in the setting of tamponade (reversible cause): proceed. Prolonged CPR >10–15 minutes outside the OR: surgical outcomes are very poor.

Surgeons

• Open distal anastomosis is standard of care – clamping the aorta in Type A dissection risks arch aneurysm formation and re-entry tears.

• Primary intimal tear is in the arch or descending aorta in ~40% of cases; multiple tears are common. Ascending repair alone does not address these.

• Root decision: resuspension is adequate if root ≤35–40mm with no circumferential dissection or coronary involvement. Replace (Bentall) if root ≥45–50mm or extensive dissection.

• Zone 2 arch replacement with antegrade cerebral perfusion (ACP) avoids deep hypothermic arrest and its coagulopathic complications.

• Frozen elephant trunk: use selectively for circumferential arch dissection, large arch fenestration, retrograde Type B, or to create a TEVAR landing zone.

• Up to 90% of patients have persistent false lumen flow after ascending-only repair. Plan for completion TEVAR and long-term imaging surveillance.

• Approximately one in four patients will require re-intervention by 10 years.

Anaesthetists

• Haemodynamic goals at induction: target SBP 100–120 mmHg, avoid tachycardia and hypertension. Use beta-blockers and/or opiates.

• Bilateral radial arterial lines if antegrade cerebral perfusion planned; femoral arterial line when cerebral and systemic circuits are separated.

• TOE at induction: confirm dissection, assess AR mechanism and severity, identify LV function and regional wall motion abnormalities.

• True lumen on TOE: more circular, expands in systole, no spontaneous echo contrast. False lumen: thrombus/smoke, does not expand in systole.

• Circumferential STJ intimal flap prolapse: can cause unrecognised coronary malperfusion when pulsatile flow is lost on bypass. Watch the TOE. ECG changes or declining cardiac output – check TOE and consider briefly restoring pulsatile flow.

• Cerebral oximetry: useful for unilateral drops (cannula position, incomplete circle of Willis). Bilateral desaturation – evidence for intervention is limited; optimise haemoglobin, oxygenation, and pressure.

• Coagulopathy is predictable and severe. Get all products into the room early. Guide treatment with TEG/ROTEM.

ICU

• Anticipate bleeding, multi-organ failure, and neurological complications.

• Early post-operative CT (day 3–7), then 3 months, 6 months, and annually. False lumen surveillance is lifelong.

• Endo-first approach for mesenteric malperfusion: endovascular fenestration and stenting followed by delayed central repair (~24–48 hours). Allows reperfusion before the insult of open surgery.

• Frank gut ischaemia at presentation carries close to 100% mortality regardless of approach – the endo-first strategy avoids futile central repair in this group.

• Spinal cord malperfusion: lumbar drains and spinal perfusion pressure optimisation. Neurological recovery is possible with time.

Cardiologists and Echocardiographers

• Genetic testing yield is higher with syndromic features (Marfan, Loeys-Dietz), age <50 at presentation, family history of aortic disease, and ascending aorta involvement.

• Most patients should receive a gene panel rather than single-gene FBN1 testing – unless there is a clear Marfan phenotype meeting revised Ghent criteria.

• Variant interpretation: population-specific databases matter. NZ Māori population-specific variant frequencies must be considered when classifying variants.

• Patent false lumen on follow-up CT is associated with reduced survival and increased re-intervention. True lumen remodelling and false lumen regression are favourable.

• Refer patients to genetics: syndromic features, aortic disease <50 years of age, or strong family history. HealthPathways is the standard NZ referral route.