D-Transposition of great vessels with intact ventricular septum presenting at 3–8 weeks: Should all go for rapid two stage arterial switch or primary arterial switch?

Abstract

Background: Current reports favour primary arterial switch (ASO) in infants with d-transposition of great vessels (d-TGA) with intact ventricular septum (IVS) who present later than 21 days. The premise is that the regressed left ventricle (LV) will still adapt to the systemic circulation.Methods: We compared a retrospective group of 11 infants (group A) who had undergone rapid two stage ASO with those (group B) who had undergone primary ASO (n=15).Results: The age range (25 -70 days), weight (2.5 -4.0 Kg), posterior wall thickness of LV (2.8 mm -4.2 mm) and other pre-operative criteria were similar in both groups. In group A, 3/11 infants died after first stage, one each due to shunt blockade, tight pulmonary artery band, and after emergency Senning operation following cardiac failure. Of the remaining eight who underwent ASO 5 -9 days after first stage, three died, one each due to fungal infection, sepsis and multi-organ failure, and massive haemorrhage from internal mammary artery. Success of LV training was 8/11 (73%) while overall survival was 5/11 (45%). In group B (15 infants), 13 survived (86%), two needing post-operative extracorporeal membrane oxygenator (ECMO) support and two deaths occurred due to immediate post-operative cardiac failure.Conclusions: This study demonstrates that primary ASO can show benefit in infants of d-TGA with IVS presenting between 21 to 60 days of age as compared to rapid two stage ASO. These infants might need more support for the ventriclular function in form of prolonged inotropes and ECMO support. (Ind J Thorac Cardiovas Surg 2006; 22: 5-9)

Midterm Outcome of Primary Arterial Switch Operation Beyond Six Weeks of Life in Children With Transposition of Great Arteries and Intact Ventricular Septum

“…Studies have demonstrated that the LV mass did not necessarily predict good clinical outcomes. 6,13,14 Earlier studies have demonstrated that the initial increase in the cell size and the myocardial mass following pulmonary artery (PA) banding is mostly accounted for by the increase in the volume of mitochondria (power house), enodoplasmic reticulum (synthetic factory) but to a smaller extent by the addition of new myofibrils. 15 The same authors have shown that the microscopic and ultrastructural changes seen in regressed ventricle are similar to the changes that are found in chronic hibernating myocardium.…”

Late Primary Arterial Switch for Transposition of the Great Arteries With Intact Ventricular Septum in an African Population

“…14 In late presenters, the combined early mortality of the rapid 2-stage ASO is higher than that for the late primary ASO (55% vs 14%). 15…”