Comparison of pulmonary arterial flow phenomena in spiral and Lecompte models by computational fluid dynamics.

OBJECTIVES: The transposed great arteries are simply reversed by means of a conventional arterial switch operation with the Lecompte maneuver without resumption of their spiral relationship. We seek to clarify the functional implications of the spiral relationship of the great arteries by means of mathematic modeling.

METHODS: Computational fluid dynamics is used to compare flow phenomena of the spiral and Lecompte (nonspiral) models under various body surface areas.

RESULTS: The velocity profile and wall-shear stress distribution are more uniform for the spiral than for the Lecompte model. The pressure drop and power loss ratio are smaller for the spiral than the Lecompte model for all the body surface areas investigated. The power loss ratio increases abruptly starting from 0.43 m2 of body surface area for the Lecompte model. At that specific stage, after arterial switch operation with the Lecompte maneuver, suprapulmonary stenoses occur most frequently.

CONCLUSIONS: Reconstructing the great arteries in spiral fashion might be recommended because the blood flow patterns are more streamlined than those of the Lecompte maneuver. Initiation of stenosis might be minimized to some extent.