Fate of the dissected aortic arch after ascending replacement in type A aortic dissection†

To evaluate the fate of a dissected aortic arch after limited surgical repair of type A aortic dissection.

Of the 271 patients operated for acute type A dissection between 2001 and 2015, 86 (age 57 ± 13 years, 74% men) with predischarge computed tomographic (CT) scans had a residual dissection in the arch. Aortic diameters, lengths, ellipticity and communications between lumina were assessed using predischarge and follow-up CT scans. The median CT scan follow-up was 31 months (first quartile 15, third quartile 52).

The largest increase in the total aortic diameter at follow-up was 20 mm distal to the left subclavian artery (median +4.0 mm; first quartile +1.5, third quartile +9.2 mm; P  = 0.004), with an average growth rate of 1.5 mm/year (first quartile 0.6, third quartile 3.9 mm). The true lumen diameter was unchanged at follow-up. At least 1 communication between the true and the false lumina was observed in 80% of patients on the predischarge CT scan, and 70% had communications at the distal aorta-graft anastomosis. Accelerated increase in the diameter of the dissected aorta was associated with the number of communications between the lumina, communication at the distal anastomosis and false lumen perfusion (all, P  < 0.001).

Dissection of the residual aortic arch leads to aortic growth that may result in an aneurysm requiring treatment. The number of communications between the lumina, communication at the distal anastomosis and false lumen perfusion are associated with the accelerated aortic growth. Endovascular repair may be difficult due to the small true lumen and the presence of many communications between the lumina.