LAUSR

OBJECTIVE We studied the effect of various coronary transfer techniques (CTT) on neo-aortic root size after an arterial switch operation (ASO) in simple transposition by excluding the impact of recognized predisposing factors. METHODS 178 patients with simple transposition were reviewed retrospectively (January 2004-December 2018) and grouped as Punch Hole (n=83/178), Non-Punch Hole (n=65/178; Trapdoor or Standard) and Mixed (n=30/178). Factors predicting the neo-aortic root z-scores- annulus, mid-sinus, and sino-tubular junction (STJ) were analysed by uni/multivariable linear regression. RESULTS Follow-up was 6 years, Interquartile range (IQR) 3.4,10.6. Preoperative aortic (7.4mm, IQR 6.9,8) and pulmonary annulus (7.5mm, IQR 6.8,8.1) sizes were identical (p=0.831). The changes in preoperative, postoperative, and latest median z-scores for neo-aortic annulus (-0.2, IQR -1.2,0.9; 0.0, IQR -0.9,0.9; 0.9, IQR -0.4,2.6; p<0.001), mid-sinus (1.1, IQR -0.1,2; 2.6, IQR 1.6,3.7; 2.9, IQR 1.8,4.3; p<0.001) and STJ (-0.1, IQR -0.8,1.1; 2.1, IQR 0.7,3; 2.4, IQR 1,3.5; p<0.001) were significant. On multivariate analysis, preoperative pulmonary annulus z-score predicted the latest neo-aortic annulus z-score [Beta estimate (BE)= 0.32, 95% confidence interval (CI)= 0.03,0.62; p=0.03] and STJ z-score (BE= 0.45, 95% CI= 0.20,0.70; p<0.0001). CTT did not predict any of the latest neo-aortic z-scores (all p>0.05). Mild plus neo-aortic regurgitation (neoAR) was not significantly different across CTT groups [punch hole 20%(n=15/74), mixed 37%(n=11/30), non-punch hole 21%(n=13/62); Fisher-exact p=0.186], one patient required valve replacement for severe neoAR. CONCLUSIONS The neo-aortic root enlarges significantly over time at all three levels following an ASO in simple transposition, however, this is not significantly influenced by the CTT utilised.