Hi welcome to Healthcare Magic ,
From what you have said it seems your nephew has a form of esophageal atresia. The unfortunate thing is that the gap between the ends being too long , and surgery being difficult. As far as my knowledge goes they can use a stent
to fill the gap between the ends and reconstruct the food pipe or the only other way is a gastrostomy i.e bypass the esophagus(food pipe) and create a direct conduit ,direct connection to the stomach.U can consult a gastro surgeon and get his opinion on this issue.