The Concept of the Arch Window in the Spiral Switch of the Great Arteries.

Abstract

When the arterial switch operation includes the Lecompte maneuver, the arterial trunks are reconnected in parallel, rather than the spiral fashion observed in the normal heart. Thus, although the ventriculo-arterial connections are hemodynamically corrected, the anatomic arrangement cannot be considered normal. We hypothesized that, if feasible, it would be advantageous to restore a spiral configuration for the arterial trunks. In 58 patients, we reconstructed the arterial trunks such that, postoperatively, the pulmonary channel spirals round the aorta, passing to either the right or the left, and branches posteriorly. We compared the outcomes with those in 95 patients undergoing a standard non-spiraling operation over the same period. Average follow-up was 8.2±4.5years. The estimated 10-year survival was similar in the cohorts, at 94.7% for those with spiraling trunks, as compared to 90.4% for those with parallel outflow tracts. Reoperation-free survival at 10years was not significantly different (87.6 vs. 90.5%). Supravalvar pulmonary stenosis, aortic neo-coarctation, or left bronchial stenosis, however, was encountered in one-eighth of those undergoing a standard operation. None of these complications occurred in those patients who, postoperatively, had spiraling outflow tracts (P=0.002). Reconstruction of spiraling trunks after the arterial switch has, thus far, avoided the complications of supravalvar pulmonary stenosis, neo-aortic kinking, or bronchial stenosis. The spiraling arrangement prevents compression of the pulmonary vessels and bronchial tree by the aorta, since it provides a wide window in the new aortic arch.