In a ground-breaking procedure, doctors in France have performed the world’s first double face transplant.

The man, who is in his 40s but hasn’t been named, received a face transplant seven years ago, The Telegraph reported. In November, his body started to reject the new face, so doctors placed him in an induced coma while contemplating the next step.

Last week, physicians in Paris performed the second transplant. It will still be several weeks before they can say with any certainty whether or not it was successful.