Ductal Stenting to Retrain the Involuted Left Ventricle in d-Transposition of the Great Arteries

BACKGROUND: Ductal stenting is performed to retrain involuted left ventricles (LVs) in patients with d-transposition of the great arteries and intact ventricular septum (TGA-IVS). However, its efficacy is largely unknown. This study aimed to determine the safety and efficacy of ductal stenting in retraining of the involuted LV in patients with TGA-IVS.

METHODS: This was a single-center, retrospective study. Echocardiographic assessment of the LV geometry, mass, and free wall thickness was performed before stenting and before the arterial switch operation. Patients then underwent the arterial switch operation, and the postoperative outcomes were reviewed.

RESULTS: There were 11 consecutive patients (male, 81.8%; mean age at stenting, 43.11 ± 18.19 days) with TGA-IVS with involuted LV who underwent LV retraining by ductal stenting from July 2013 to December 2017. Retraining by ductus stenting failed in 4 patients (36.3%). Two patients required pulmonary artery banding, and another 2 had an LV mass index of less than 35 g/m2. Patients in the successful group had improved LV mass index from 45.14 ± 17.91 to 81.86 ± 33.11g/m2 (p = 0.023) compared with 34.50 ± 10.47 to 20.50 ± 9.88 g/m2 (p = 0.169) and improved LV geometry after ductal stenting. The failed group was associated with an increased need for extracorporeal support (14.5% vs 50%, p = 0.012). An atrial septal defect-to-interatrial septum length ratio of more than 0.38 was associated with failed LV retraining.

CONCLUSIONS: Ductal stenting is an effective method to retrain the involuted LV in TGA-IVS. A large atrial septal defect (atrial septal defect-to-interatrial septum length ratio >0.38) was associated with poor response to LV retraining.