Except for Adam Byrum, who doesn't have spina bifida, the other seven children operated on this week needed detethering.

Their parents were told that the All Children's study is a blinded one. That means there is a control group that gets the detethering, but does not get the Xiao procedure. The parents won't know who got what until the study is over. Even Homsy doesn't know which of the spina bifida children are in the control group or the Xiao group.

有没有听见吹2009年3月做了几例？

Beaumont will perform four more Xiao procedures in May.

这个也该有detethering only的control group吧。