The AA describe two particular complications of arteriovenous fistula for chronic hemodialysis in pediatric age: a king king and a stenosis. In these cases are necessary angiographic studies of the vessels and then, if it is possible, the AA prefer a surgical repair of the same arteriovenous fistula. The other alternatives in these cases are an extensive patch, a new angioaccess or a percutaneous transluminal angioplasty.