Behavior of the pulmonary autograft in systemic circulation after the Ross procedure

The purpose of this study was to evaluate performance in systemic circulation following pulmonary autograft aortic root replacement by means of serial postoperative echocardiographic studies.

From November 1997 to November 1999, 30 patients (21 males, 9 females) with a mean age of 29.97 +/- 12.97 years (age range 6-54 years) underwent pulmonary autograft aortic root replacement. Seven of these patients (23.33%) were less than 15 years old. Postoperative echocardiographic measurements of the neo-aortic root were performed within three months of operation, at six months, one year, and annually thereafter. Analysis of this study includes 22 patients with at least three months of follow-up.

Operative mortality was 0%. Compared with preoperative values, the mean autograft annulus diameter exhibited an increase of 8.44% in the first month (1.44 +/- 0.22 cm/m2 vs. 1.55 +/- 0.21 cm/m2, p = 0.0101). An additional aortic annular dilation of 11.33% from baseline preoperative values was observed within the first year (1.41 +/- 0.15 cm/m2 preoperatively vs. 1.57 +/- 0.22 cm/m2, p = 0.0449). After the immediate postoperative period, the pulmonary autograft seemed to adapt to systemic circulation, and there were no differences in aortic annular size between 1-3 months after surgery and the 18-21 month follow-up period (1.60 +/- 0.18 cm/m2 vs. 1.60 +/- 0.27 cm/m2, n = 10). Diameter increase was not associated with the presence of aortic regurgitation. Mean neo-aortic maximal gradient was 7.85 +/- 5.59 mm Hg (3-29 mm Hg). There was a significant decrease in left ventricular size three months after surgery (50.71 +/- 10.20 mm preoperatively vs. 44.98 +/- 7.29 mm, p = 0.0491 in aortic stenosis patients and 68.50 +/- 8.39 mm vs. 59.04 +/- 9.21 mm, p = 0.0017 in aortic insufficiency patients).

Pulmonary autograft annulus increases up to the first year after the Ross procedure but does not appear to progress beyond that time. The pulmonary autograft allows optimal hemodynamic performance without causing substantial aortic regurgitation, thereby permitting normalization of left ventricular dimensions and improvement of left ventricular function early in the postoperative period.