Brave new world or the unfortunate natural history of "lethal" disease: when to push the envelope?

We recently witnessed a neonatal intensive care unit infant succumb to tracheal agenesis and noticed, at the same time, in the news headlines of adults being “saved” by “labmade tracheas” [1]. This stimulated our curiosity to review recent developments in tissue engineering and stem cell research that may challenge prior authors' claims that tracheal agenesis is “uniformly fatal” [2]. Although prior tracheal reconstructive efforts have not had long-term success [2], what our review found seems to bring science fiction (Aldous Huxley's Brave New World, 1931) into reality and allows the creation of a new trachea using the child's umbilical cord stem cells. Prior attempts at repair have typically used the native esophagus, but this is usually complicated with the need for positive pressure to keep the esophagus from collapsing [3]. Other problems such as esophageal stenosis, ulceration, pneumonia, and aspiration after esophageal reconstruction may plague the child and result in an untimely demise [4]. No long-term data are available on recent attempts to use external esophageal stenting and donor aortas with a vascular stent [5]. Devising a “new” repair that would not require long-term reliance on positive pressure ventilation and would preserve the native esophagus seems warranted. Elements of this trachea repair strategy would include a prenatal diagnosis of tracheal agenesis and screening for coexisting anomalies, use of both an ex utero intrapartum treatment (EXIT procedure) to extracorporeal membrane oxygenation (ECMO), and obtaining a suitable trachea replacement or growing the patient a new trachea using stem cells in a laboratory. Improvements in high-resolution ultrasonography have now allowed for prenatal detection of tracheal agenesis [6]. According to a 2009 report by Zhou et al [6], hyperechoic lungs, a dilated trachea and bronchi without fluid flow, a flattened or inverted diaphragm, and compression of the heart are sonographic suggestions that a trachea agenesis may exist. Because there is an association with other lifethreatening VACTERL abnormalities, a complete evaluation