[Surgery for type A aortic dissection: long-term results and risk factor analysis]

Identification of risk factors may help prevent mortality and recurrence after surgical treatment of type A aortic dissection.

From January 1995 to March 2006, 100 consecutive patients (82 men, 18 women, mean age 58 +/- 12 years) with type A acute aortic dissection were submitted to replacement of ascending aorta (n = 62), arch (n = 27), or the aortic root (n = 11, 9 with the Bentall operation and 2 with the David aortic valve reimplantation). Patients were followed up for 48 +/- 33 months (range 1-120 months).

Operative mortality was 18% for aortic root replacement, 24% for ascending aorta replacement, 26% for arch replacement, respectively (p = NS). Independent risk factors for operative mortality were: acute (p = 0.001) and chronic renal dysfunction (p = 0.02), advanced patient age (61 +/- 13 vs 56 +/- 13 years, p = 0.02), prolonged bypass time (p = 0.01). Antegrade cerebral perfusion and moderate hypothermia during arch replacement was associated with better results than deep hypothermia (mortality 0/12 vs 7/15 patients, p = 0.008). Eight-year survival and freedom from cardiovascular events were 74 +/- 7.5% and 70 +/- 7.4%, respectively. Independent risk factor for late death was left ventricular ejection fraction < 0.50 (p = 0.02). Five out of 67 patients (7.5%) submitted to replacement of the ascending aorta with a tubular graft, who presented a dilated aortic root diameter (47 +/- 3.4 vs 40.4 +/- 4.9 mm, p = 0.004), were reoperated for proximal progression of the disease into the native aortic root (dilation n = 3, dissection n = 2) after 33 +/- 20 months (range 2-58 months). Proximal aorta reoperation was associated with markedly reduced 8-year survival (52 +/- 23 vs 82 +/- 7%, p = 0.017).

Surgery for acute aortic dissection represents an emergency treatment with satisfactory long-term results. Survival is affected by renal dysfunction at presentation, which should be aggressively treated, and by progression of the disease requiring reoperation; a dilated diameter of the aortic root should therefore indicate root replacement at the time of first operation.