Porcine Model of the Arterial Switch Operation: Implications for Unique Strategies in the Management of Hypoplastic Left Ventricles

Anthony Azakie,Michelle J Doyle,Cindy M Martin,Richard W Bianco,Rajat Kalra,John P Carney,Matthew T Lahti

doi:10.1007/s00246-020-02507-8

Anthony Azakie, Michelle J Doyle + Show 5 more

Open Access

https://doi.org/10.1007/s00246-020-02507-8

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Abstract

There are no reports on the performance of the arterial switch operation (ASO) in a normal heart with normally related great vessels. The objective of this study was to determine whether the ASO could be performed in a healthy animal model. Cardiopulmonary bypass (CPB) and coronary translocation techniques were used to perform ASO in neonatal piglets or a staged ASO with prior main pulmonary artery (PA) banding. Primary ASO was performed in four neonatal piglets. Coronary translocation was effective with angiograms confirming patency. Piglets could not be weaned from CPB due to right ventricle (RV) dysfunction. To improve RV function for the ASO, nine piglets had PA banding. All survived the procedure. Post-banding RV pressure increased from a mean of 20.3 ± 2.2 mmHg to 36.5 ± 7.3 mmHg (p = 0.007). At 58 ± 1 days post-banding, piglets underwent cardiac MRIs revealing RV hypertrophy, and RV pressure overload with mildly reduced RV function. Catheterization confirmed RV systolic pressures of 84.0 ± 6.7 mmHg with LV systolic pressure 83.3 ± 6.7 mmHg (p = 0.43). The remaining five PA banded piglets underwent ASO at 51 ± 0 days post-banding. Three of five were weaned from bypass with patent coronary arteries and adequate RV function. We were able to successfully perform an arterial switch with documented patent coronary arteries on standard anatomy great vessels in a healthy animal model. To our knowledge this is the first time this procedure has been successfully performed. The model may have implications for studying the failing systemic RV, and may support a novel approach for management of borderline, pulsatile left ventricles.

Highlights

The arterial switch operation (ASO) has become the standard of care for D-transposition of the great arteries even in the setting of unusual coronary artery patterns [1,2,3,4]
We report the successful completion of the arterial switch operation in a novel porcine model, in a normal heart
Furosemide 40 mg twice daily was administered to assist with volume status optimization. 7–8 weeks following main pulmonary artery (MPA) banding, five animals were anesthetized for cardiac imaging and five animals were anesthetized for the arterial switch operation as described

Summary

Introduction

The arterial switch operation (ASO) has become the standard of care for D-transposition of the great arteries even in the setting of unusual coronary artery patterns [1,2,3,4]. Translocation of the left coronary artery may result in hairpin looping of the left main to the left anterior descending coronary artery axis Due to this difficulty in both human and animal models, experimental models of the arterial switch presented in the literature merely replicate the anastomoses required in an arterial switch without chronically switching the subpulmonic and systemic ventricles [5, 6]. The study provides the first animal model of the ASO, it demonstrates that the coronary arteries in normally related great vessels are “switchable” This first report of the ASO in a normal heart may provide a potentially novel approach to the management of variants of hypoplastic left heart syndrome (HLHS) where the left ventricle has borderline size or function. An arterial switch in a heart with non-apex forming, but pulsatile, left ventricle may be an initial step for palliation of HLHS variants

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