Long-term outcome of the false lumen after surgery of acute type A dissection of the aorta.

The long-term outcome (64.3 +/- 45 months) of 44 patients operated for acute dissection of at least the ascending aorta was assessed by regular clinical examination and annual CT scan. The diameter of the aorta at different levels was measured at each CT scan for all patients. initially 7 patients (16 %) had acute dissection limited to the ascending aorta; none had a false lumen after surgery. No signs of aneurysmal dilatation were observed during follow-up of these patients. In the 37 other cases (84 %) dissection of the aorta extended beyond the innominate artery; the false lumen remained patent distal to the prosthetic tube replacing the ascending aorta in 34 patients (92 %). The false lumen was partially thrombosed in 8 % of patients, leading to distal emboli in 1 patient. Moderate increases (less than 15 mm) in diameter of the false lumen were observed in 32 % of patients; more severe dilatation (over 20 mm) was observed in 12 % of patients. The management of dilatation of the false lumen is not standard; it depends mainly on the rate of progression and the clinical consequences. It is hoped that extension of the initial repair to the aortic arch, when the intimal tear is situated in this zone, will reduce the short and longterm progression of the false lumen.