The authors of the study ‘Outcome after extracorporeal membrane oxygenation therapy in Norwood patients before the bidirectional Glenn operation’ should be congratulated for their very good results of Norwood surgery for patients with hypoplastic left heart syndrome and variants implementing extracorporeal membrane oxygenation (ECMO) into postoperative care [1]. Since the first use of this technique in 2007 they were able to reduce hospital mortality to 26 (8.5%) of their 306 patients. I am not aware of high volume, i.e. very experienced Norwood centres, which were able to report a comparably low hospital mortality before ECMO was available.

The low hospital mortality is even more remarkable as 9 patients with total anomalous pulmonary venous connection (TAPVC) and pulmonary venous obstruction were treated. Their extremely poor prognosis is well documented in the literature, and they did not benefit from ECMO in this series. Therefore, this condition may even be seen as an exclusion criterion for surgery, as the pulmonary vascular bed is irreversibly damaged before birth and unsuitable for a Fontan circulation.