Main Risk Factor in Long-Term Postoperative Aortic Root Enlargement After Aortic Valve Surgery Associated with...

Dilatation of the aortic root (AR) after aortic valve surgery associated with ascending aorta replacement (AVS+AAR) is an important concern in long-term follow-up (FU). This study aimed to identify factors that may be associated with this late complication.

Two-hundred-sixteen consecutive patients (150 males and 66 females) who underwent AVS+AAR from June 2009 to April 2018 at a single center were retrospectively analyzed. The mean trans-thoracic echocardiographic (TTE) FU was 44.9 ± 22.2 months. An increase of 10% in AR size compared to the pre-operative baseline was the outcome variable. The Student t-test or chi-square test was used as appropriate. For a survival analysis, a Kaplan-Meier curve was computed and a log-rank p-value was calculated. Cox's regression model was used to assess the predictive value of variables over time. A p-value < 0.05 was significant.

No significant differences were observed among patients who underwent aortic valve repair and those who underwent aortic valve replacement (log-rank = 0.917). In patients who underwent valve replacement, AR enlargement was associated with the difference between the diameter of the prosthetic valve and the diameter of the straight vascular prosthesis (OR 0.87, P = 0.024). Based on the difference in diameter between vascular and valve prosthesis, we arbitrarily classified the patients into two groups: a small group (S) (n = 52), in which the difference was ≤ 5 mm, and a large group (L) (n = 34), in which the difference was > 5 mm. Significant AR enlargement was observed in 30.8 % of the S group and 14.7 % of the L group (log-rank = 0.026). A difference of more than 5 mm between the aortic valve prosthesis and the vascular prosthesis protected against AR enlargement in the long-term FU (OR 12.31, P = 0.033), even after adjusting for age and sex (OR 00.32, P = 0.043).

According to our findings, a difference between the size of the aortic valve prosthesis and the vascular prosthesis of less than or equal to 5 mm was the only factor that increased the risk of AR enlargement after AVS+AAR in long-term FU.