Computational Study of Pulmonary Flow Patterns after Repair of Transposition of Great Arteries

TL;DR

This study uses computational fluid dynamics and MRI data to analyze pulmonary flow patterns after arterial switch surgery for transposition of great arteries, revealing abnormal flow features linked to post-operative anatomy.

Contribution

It combines MRI and CFD to identify flow abnormalities in post-ASO patients, providing insights for surgical planning and long-term management.

Findings

Presence of shear layer instabilities and vortical structures in patients

Flow remains mostly laminar in healthy controls

Altered flow patterns are linked to pulmonary bifurcation curvature

Abstract

Patients that undergo the arterial switch operation (ASO) to repair transposition of great arteries (TGA) can develop abnormal pulmonary trunk morphology with significant long-term complications. In this study, cardiovascular magnetic resonance was combined with computational fluid dynamics to investigate the impact of the post-operative layout on the pulmonary flow patterns. Three ASO patients were analyzed and compared to a normal control. Results showed the presence of anomalous shear layer instabilities, vortical and helical structures, and turbulent-like states in all patients, particularly as a consequence of the unnatural curvature of the pulmonary bifurcation. Streamlined, mostly laminar flow was instead found in the healthy subject. These findings shed light on the correlation between the post-ASO anatomy and the presence of altered flow features, and may be useful to improve surgical planning as well as the long-term care of TGA patients.