Managing dissections of the thoracic aorta

Abstract

Thoracic aortic dissection is associated with substantial morbidity and mortality, and it requires timely and accurate diagnosis and treatment. Long-term antihypertensive therapy remains critical for the treatment of this disease. Surgical intervention, although still a formidable undertaking, has evolved to better address both acute and chronic dissection, and the results have improved. Basic and clinical research, as well as technological advances, have increased our understanding of this challenging disease state.

Fig. 1

Classification of aortic dissections according to three systems: anatomic, DeBakey, and Stanford.

Fig. 2

Axial computed tomdgraphic images of acute (left) and chronic (right) aortic dissections. The membrane (arrow) separating the compressed true lumen from the larger false lumen (*) is typically thin and wavy in acute dissections, with an acute angle (black arrowhead) subtended between it and the outer wall on the side of the false lumen. In chronic dissections, the membrane often appears thick and straight. The true lumen is often marked by mural and eccentric membrane calcification (white arrowheads). Thrombus (†) within the false lumen may also be visible.

Fig. 3

Drawing illustrating the repair of an acute ascending aortic dissection with glue. The arrows indicate the direction of arterial inflow from the cardiopulmonary bypass pump. In this case, a beveled repair of the aortic arch is performed during hypothermic circulatory arrest while antegrade cerebral perfusion is delivered via a right axillary artery cannula. (A) Glue is applied inside the false lumen of the aortic arch. Note the inflated balloon catheter in the proximal descending thoracic aorta and the protective moist sponge inside the true lumen; these are placed as precautions against distal migration of glue into the descending aorta. (B) The distal anastomosis is performed between the beveled graft and the reapproximated layers of the aortic arch. A thin layer of glue is applied to the suture line after this anastomosis is completed. (C) Glue is also used to obliterate the false lumen during repair of the dissected aortic root. Note the protective moist sponge covering the aortic valve and coronary ostia.

Fig. 4

Drawings illustrating an extent II repair of a thoracoabdominal aortic aneurysm caused by chronic aortic dissection. (A) The proximal anastomosis has been completed, and the dissecting membrane is excised to enable exposure of all branch arteries. A left heart bypass system is used to provide continuous normothermic perfusion of the celiac and superior mesenteric branches. Cold crystalloid solution is intermittently delivered to the kidneys to maintain renal hypothermia. (B) The completed repair includes reattachment patches for two pairs of intercostal arteries and for the celiac, superior mesenteric, and renal arteries.

Fig. 5

Classification of landing zones for endovascular stent-graft deployment, according to the Criado and Ishimaru systems. Zone 4 begins 2 cm distal to the subclavian artery in the Criado system and at the caudal end of the T4 vertebral body in the Ishimaru system. The other divisions are at the distal ends of the arch vessel origins.