Aortic Root Dilation After the Ross Procedure M. Victoria T. Tantengco, MD, Richard A. Humes, MD, Sandra K. Clapp, MD, Kevin W. Lobdell, MD, Henry L. Walters III, MD, Mehdi Hakimi, MD, and Michael L. Epstein, MD This study evaluated changes in neoaortic root geometry in patients who underwent the Ross procedure. Serial postoperative echocardiographic measurements of the neoaortic root indexed to the square root of body sur- face area (centimeters divided by meters) were obtained from 30 patients (age range 3.1 to 31.4 years) and compared with paired preoperative and immediate postoperative values. Normal aortic root diameter Z scores were derived from root dimensions obtained from 217 healthy controls. Compared with preoperative val- ues, an immediate stretch of the neoaortic versus pul- monary root (annulus and sinuses of valsalva) was ob- served at a mean follow-up period of 1 week. Additional aortic annular dilation from baseline prehos- pital discharge values was observed at 2 to 12 months (baseline vs follow-up annulus Z score: 1.4 vs 2.6, p <0.01, n  16) and at 16 to 33 months follow-up (0.8 vs 2.0, p <0.05, n  12). In a similar fashion, there was additional enlargement of the aortic sinus from its stretched state at hospital discharge at 2 to 12 months (baseline vs follow-up sinus Z score: 2.0 vs 3.3, p <0.01, n  17) and at 16 to 33 months (1.7 vs 3.0, p <0.01, n  13). There were no differences in root size between 2 to 12 and 16 to 33 months after surgery. There was a decrease in left ventricular size with no alteration in blood pressure or degree of aortic valve regurgitation. Thus, aortic root dilation occurs up to the first year after the Ross procedure but does not appear to progress beyond this time. 1999 by Excerpta Medica, Inc. (Am J Cardiol 1999;83:915–920) L ong-term success with the use of pulmonary au- tograft tissue in children is predicated on the ade- quate growth of that tissue because of the need for somatic growth of the patient. Growth of autologous pulmonary tissue in the systemic circulation has been previously described in patients with d-transposition of the great arteries, who have undergone the arterial switch procedure. 1,2 Earlier studies have also sug- gested neoaortic root growth in patients who have undergone pulmonary autograft replacement of their aortic valves. 3,4 The results of these studies have been variable, with the surgical approach appearing to play a role in the rate of growth of the neoaortic root. The goals of this study were (1) to identify serial changes in neoaortic root size, (2) to establish variance of patient root size from that of the normal population, and (3) to describe changes in hemodynamic variables that may play a role in the observed pattern of growth. METHODS Subjects: From October 1993 through February 1997, 33 patients underwent the Ross procedure at our institution. Echocardiographic data were available for analysis in 30 of these patients. The patients were predominantly males (24 male, 6 female). Their ages were 3.1 to 31.4 years (median 16.3) at the time of the Ross procedure, with a body surface area (BSA) of 0.6 to 2.4 m 2 . Most (27 of 30) had a congenitally abnor- mal bicuspid aortic valve. Moderate aortic stenosis, with mean Dopper gradients of 50 mm Hg, was present in 5 patients, moderate to severe aortic regur- gitation in 19, and both moderate aortic stenosis and regurgitation in 3 patients. The 3 remaining patients had anatomically normal aortic valves but developed severe aortic valve regurgitation secondary to pre- sumed rheumatic heart disease (n = 1), a small resid- ual ventricular septal defect after surgical closure with aortic cusp prolapse (n = 1), and progressive aortic valve deformation from a small ventricular septal de- fect and subaortic membrane (n = 1). The control population comprised 217 healthy in- dividuals who were referred for various reasons to the Pediatric Cardiology Clinic or Echocardiography Lab- oratory and were found to have a normal heart by their studies, which included an echocardiogram. Their ages were 1 day to 17 years (median 4.0) with a BSA of 0.1 to 2.2 m 2 . Surgical technique: Pulmonary autograft replace- ment of the aortic valve was performed using the root replacement technique, as described by Walters et al. 5 The pulmonary root was confirmed to be normal by visual inspection and was then excised. 6 The right and left coronary arteries were mobilized with generous aortic buttons and the aortic root removed. The pul- monary autograft was implanted as a free root into the aortic position followed by implantation of the coro- nary artery buttons into their respective sinuses. Right ventricular outflow tract reconstruction was then per- formed using a pulmonary artery homograft. From the Department of Pediatrics/Division of Cardiology; and De- partment of Cardiovascular Surgery, Wayne State University School of Medicine, Children’s Hospital of Michigan, Detroit, Michigan. Manu- script received June 5, 1998; revised manuscript received and ac- cepted October 23, 1998. Address for reprints: M. Victoria T. Tantengco, MD, Division of Pediatric Cardiology, Children’s Hospital of Michigan, 3901 Beaubien Boulevard, Detroit, Michigan 48201. 915 ©1999 by Excerpta Medica, Inc. 0002-9149/99/$–see front matter All rights reserved. PII S0002-9149(98)01062-5