A New Clinically Driven Classification for Acute Aortic Dissection

Figure 1. Graphical representation of the proposed aortic dissection classification (type A, B, or C) and malperfusion syndrome (MPS) subtypes (grade 0, 1, 2, or 3). MPS grade 1 is represented as a compression of the true lumen in the abdominal aorta, grade 2 as an extension of the dissection into the left renal artery, and grade 3 as a combination of both.

Figure 2. A 63-year-old male patient with type A2 AAD. Patent false lumen (a), without compromise of the superior mesenteric artery (b); post-ostial dissection of the right renal artery (white arrow) (c); post-ostial stenosis of the right renal artery resulting in a static MPS. Note the accessory renal artery supplying the superior pole of the right kidney (white arrowheads) (d). Extension into the left common iliac artery with compression of the true lumen (arrow) resulting in a static MPS of the left lower limb (e); transcatheter angiography shows a significant stenosis of the true lumen in the left common iliac artery (f); follow-up CTA shows that the iliac artery stenosis disappeared following endovascular fenestration procedure (g); 5-year follow-up CTA shows right renal atrophy due to untreated static MPS. Cortical thinning spares the upper pole (star) because of the patent accessory renal artery.

Figure 3. A 55-year-old woman with type C2 AAD. Dissecting membrane arising in the aortic arch with hematic infiltration causing eccentric thickening of the left common carotid artery wall (white arrowheads) (a); extension to the left common carotid artery (white star) and intimomedial flap arising at the level of the left subclavian artery (black arrowhead) (b); absence of vascular compromise in the superior mesenteric artery (white arrow) (c); transcatheter angiography following subsequent endovascular stent-graft placement with lack of opacification of the left common carotid artery.

Figure 4. A 49-year-old male patient with type C0 AAD. Soft tissue density surrounding the origin of the supra-aortic vessels (white arrowheads) consistent with non-communicating dissection (a); patent false lumen (black star) distal to the left subclavian artery (b); superior mesenteric artery (c), and right renal artery (d) arising from the false lumen with no evidence of vascular compromise; infrarenal abdominal aorta with complete collapse of the true lumen (black arrowheads) (e); vascular compromise of the right common iliac artery due to the collapsed true lumen causing dynamic MPS of the right lower limb (f); transcatheter angiography immediately after endovascular fenestration shows restored blood flow in the right common iliac artery (g); follow-up CTA shows axial image of the infrarenal abdominal aorta with patent false lumen (h).

Figure 5. A 64-year-old male patient with type B1 AAD. Intimomedial flap arising distally to the left subclavian artery with patent false lumen (black star) (a); flap prolapsing over the ostium of the superior mesenteric artery, causing dynamic MPS (black arrowhead) (b); complete collapse of the true lumen due to hemodynamic forces draping the dissecting membrane against the anterior wall of the aorta and prolapsing the flap over the ostia of the celiac and superior mesenteric artery. Atherosclerotic calcifications are in line with the aortic wall (black arrow) (c); follow-up CTA shows patent true lumen following urgent endovascular fenestration, restoration of celiac and superior mesenteric artery blood flow, and atherosclerotic calcifications now displaced into the lumen (d).

Figure 6. A pregnant 31-year-old female patient with a history of Marfan syndrome, having type B3 AAD. Intimomedial flap in the descending aorta (a); collapse of the true lumen (white arrowheads) causing dynamic MPS of the celiac artery and extension into the superior mesenteric artery causing static MPS (b); compromised blood flow in the superior mesenteric artery (white arrow) (c); transcatheter angiography following angioplasty and stent placement shows patent superior mesenteric artery with blood pressures raised to systemic levels (d).