Influence of patent false lumen on long-term outcome after surgery for acute type A aortic dissection

Objective: The fate of the dissected distal aorta after surgery for acute type A aortic dissection has not been fully understood. We assessed the influence of a residual patent false lumen on long-term outcomes. Methods: Two hundred eighteen patients underwent emergency surgery for DeBakey type I or IIIb retrograde acute type A aortic dissection (1997-2006). Aortic arch replacement was performed in selected patients whose entry site was in or extended into the aortic arch. In-hospital mortality was 7.3% (16/218), and 193 survivors (mean age 62 years) underwent enhanced computed tomography within 1 month after the operation. These patients were divided into two groups according to the status of the false lumen, whether patent (n = 124) or thrombosed (n 69). In each group, segment-specific aortic growth rate, distal reoperation, and late survival were examined. Results: Growth rate was determined in 139 (72.0%) patients who underwent serial computed tomography. Average growth rate in the patent group was greater than that in the thrombosed group (aortic arch [1.1 vs -0.41 mm per year; P.005], proximal descending aorta [1.9 vs-0.71 mm per year; P<. 001], and distal descending aorta [1.3 vs-0.70 mm per year; P = .002]). However, growth was slow (< 1 mmper year) in about 50% of patients in the patent group. There was no significant difference in distal reoperation or late survival between the two groups. Conclusions: The patent false lumen influences postoperative aortic enlargement. However, with careful followup, a favorable prognosis is expected even for patients with a residual patent false lumen.