Aortic aneurysm: indications for repair and treatment
THE CONTEXT
Management of an abdominal aortic aneurysm (AAA) depends on diameter, symptoms, embolisation and rupture. The passage also describes repair techniques and treatment in Marfan syndrome.
When to repair
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For an asymptomatic AAA, surgical risks generally outweigh rupture risks until the maximum diameter reaches 5.5 cm.
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All symptomatic AAAs should be considered for repair because symptoms warrant relief and pain often precedes rupture.
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Distal embolisation strongly indicates repair regardless of aneurysm size because limb loss is otherwise common.
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Most patients with ruptured AAA do not reach hospital alive. For those who arrive and are considered suitable for surgery, transfer to theatre for aortic clamping must not be delayed.
Open repair and outcomes
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Open repair replaces the aneurysmal segment with a prosthetic graft, usually Dacron, and has been the treatment of choice in elective and emergency settings.
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Approximate 30-day mortality is 5%–8% for elective asymptomatic AAA, 10%–20% for emergency symptomatic AAA and 50% for ruptured AAA.
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Patients who survive the operation and leave hospital have long-term survival approaching that of the normal population.
Endovascular repair
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Endovascular aneurysm repair (EVAR) uses a stent graft introduced through the femoral arteries in the groin.
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The source describes EVAR as increasingly replacing open surgery, being cost-effective and likely to become the treatment of choice for infrarenal AAA.
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Many suprarenal and thoraco-abdominal aneurysms can also be treated by EVAR.
Marfan-associated aneurysm
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β-blockers reduce the rate of aortic dilatation and the risk of rupture when the aneurysm is secondary to Marfan syndrome.
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Elective ascending aortic replacement may be considered for progressive aortic dilatation; the stated mortality is 5%–10%.