Aortic size in acute type A dissection: implications for preventive ascending aortic replacement §

Objective: Electiveascending aortic replacement is recommended to prevent acute type A aortic dissection when any segment of the proximal aorta is greater than 5.5 cm. However, little data exist that meticulously describe the size of the ascending aorta at multiple levels in patients who suffer acute type A dissections. We sought to definitively characterize the size distribution of the proximal aorta in this patient population. Methods: Preoperative transesophageal echocardiography was used to measure the diameter of the proximal aorta at the aortic annulus, in the sinussegment,at thesinotubularjunctionandinthe ascendingaortain177non-Marfanpatientswith tricuspid aorticvalveswhopresentedtoone institutionovera10-yearperiodwithanacutetypeAdissection.Predictedaorticdiametersforeachpatientbasedontheindividual’sage,gender and body size were also calculated at all four aortic positions using previously published regression equations derived from a large cohort of normal patients. Results: Sixty patients were female (33.9%; aged 67 12 years) and 117 were male (66.1%; aged 60 17 years). Sixty-two percent of all patients had maximum aortic diameters less than 5.5 cm at time of dissection and 42% of patients had maximum aortic diameters less than 5.0 cm. Over 20% of all patients had maximal aortic dimensions of less than 4.5 cm. In women,12% of the dissected aortas had a maximal dimension less than 4.0 cm. Conclusions:The majority of patients with acute type A aortic dissection present with aortic diameters <5.5 cm and thus do not fall within current guidelines for elective ascending aortic replacement. Methods other than size measurement of the ascending aorta are needed to identify patients at risk for dissection. Aggressive medical management of patients with ascending aortic diameters over 4 cm is warranted. Preventative replacement of the ascending aorta at 4.5 cm should be considered especially at high volume aortic surgery centers and patients having cardiac surgery for other indications. # 2009 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.