Restoring the spiral flow of nature in transposed great arteries

The great arteries are in a non-spiral relationship in their transposition, even after arterial switch operation (ASO) with the Lecompte manoeuvre. We aim to restore the natural spiral great arteries and compare such ASO with conventional ASO with the Lecompte manoeuvre to clarify the functional implications of the spiral great arteries.

The early survivors of ASO (n=130) were included in this retrospective study. In spiral ASO (n=48), the main pulmonary artery ran alongside the aorta and gave rise to its branches posteriorly. Patients who underwent non-spiral ASO with the manoeuvre (n=82) were compared. The survival, re-operation-free ratio and the anatomic details for re-intervention after ASO were reviewed.

Average follow-up was 5.6 + or - 3.4 years (range: 2 months to 11 years). The estimated 10-year survival was similar (92.6% spiral vs 92.1% non-spiral, respectively). Significant pulmonary stenosis (PS) (>40mmHg) was noted in five (10.4%) in the spiral group and seven patients (9.7%) in the non-spiral (p=NS). The re-operation-free survival at 10 years was not significantly different (87.4% vs 90.1%). The reasons for re-operation were subvalvular PS (n=3) and residual defect (n=2) in the spiral group, while supravalvular PS (n=3), neo-aortic regurgitation (n=1) and aortic neo-coarctation (n=2) in the non-spiral group. Supravalvular PS and aortic neo-coarctation that occurred in the non-spiral group were not seen after spiral ASO.

Intermediate-term results of spiral ASO were satisfactory. Transposition is not a mere reversal of the great arteries; therefore, recognition of non-spiral relationship should be appreciated. Spiral reconstruction would be beneficial to reduce supravalvular PS and neo-aortic kinking. Further recognition of spiral function and refined modification might justify the application of spiral ASO in the future.