title: Aortic size in acute type A dissection: implications for preventive ascending aortic replacement.
abstract: OBJECTIVE
  Elective ascending 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 sinus segment, at the sinotubular junction and in the ascending aorta in 177 non-Marfan patients with tricuspid aortic valves who presented to one institution over a 10-year period with an acute type A dissection. Predicted aortic diameters for each patient based on the individual's age, 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.
authors.affiliation: Department of Surgery, Gorman Cardiovascular Research Group, University of Pennsylvania, Philadelphia, PA 19036, USA.
authors.forename: Landi M
authors.initials: LM
authors.lastname: Parish
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Gorman
authors.forename: Sophia
authors.initials: S
authors.lastname: Kahn
authors.forename: Theodore
authors.initials: T
authors.lastname: Plappert
authors.forename: Martin G
authors.initials: MG
authors.lastname: St John-Sutton
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Bavaria
authors.forename: Robert C
authors.initials: RC
authors.lastname: Gorman
mesh_terms: D000208:Acute Disease; D000368:Aged; D000784:Aortic Dissection / Q000000981:diagnostic imaging / Q000473:pathology / Q000517:prevention & control*; D001011:Aorta / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D001014:Aortic Aneurysm / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation; D017548:Echocardiography, Transesophageal; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D018579:Patient Selection; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors