Surgical management and indication of left ventricular retraining in arterial switch for transposition of the great arteries with intact ventricular septum

Objective: Arterial switch is the operation of reference for the surgical t reatment of transposition of the great arteries. In cases of late referral. perinatal complications or early left ventricular (LV) dysfunction, the on e stage arterial switch is contra indicated. Anatomical repair remains poss ible in these patients following a LV retraining. Methods: From January 199 2 to January 2000, a LV retraining was attempted in 22 patients with transp osition of the great arteries with intact ventricular septum (TGA IVS), whe reas 470 direct arterial switch and 2 Senning were performed. Indication fo r LV retraining was based on a combination of factors including: an age old er than 3 weeks, a 'banana shape' aspect of the inter-ventricular septum an d mainly a LV mass < 35G/m(2). Results: The mean age at LV retraining was 3 .2 months ranging from 9 days to 8 months. Usually conducted by sterntomy, it associated a loose PA banding with a LV/RV at 65% with a systemico-pulmo nary shunt. The first stage was associated with frequent LV dysfunction and the LV retraining was discontinued in two patients in favor of one Senning and one early switch followed by ECMO. One patient died at first stage fro m a mediastinitis. Nineteen patients underwent a second stage arterial swit ch that was performed when the LV mass had reached 50 G/m(2) after a mean d elay of 10 days, ranging from 5 days to 6 weeks. After a mean follow up of 25 months, there was one non-cardiac late death. The 17 patients followed a nd leaving with an arterial switch are in NYHA class I, with a mean LV shor tening fraction of 39%. Conclusions: Arterial switch following LV retrainin g in TGA IVS is a satisfactory option. The inferior limit of 35 G/m(2) adop ted, to indicate LV retraining, seems a safe landmark. The quality of the m yocardium generated and the respective roles played by the LV afterload, LV wall shear stress, LV inflow and outflow to induce the LV remodeling remai n under debate. (C) 2001 Elsevier Science B.V. All rights reserved.