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Figure 10. Classification of Thoracoabdominal Aortic
Aneurysms
e classification of thoracoabdominal aortic aneurysms according to extent of aortic
involvement as originally proposed by Crawford is as follows:
• Extent I, below the left subclavian to above the celiac axis or opposite the superior
mesenteric and above the renal arteries
• Extent II, below the left subclavian and including the infrarenal abdominal aorta to
the level of the aortic bifurcation
• Extent III, below T6 intercostal space, tapering to just above the infrarenal
abdominal aorta to the iliac bifurcation
• Extent IV, below T12, tapering to above the iliac bifurcation.
• Extent V, below T6 tapering just above the renal arteries.
