re-growth of sciatic nerve?? Help pl?

Hi!
A friend of ours (in his late 30s) was involved in a serious car accident almost three months ago. His entire left leg was involved - and the amazing surgeons where able to "fix" the hip and knee during a difficult 10 hour operation. From the knee downwards, unfortunately there does´nt seem to be much improvement and it "seems"to be paralysed. He cannot move his ankle, foot, toes and lower leg. The docs have mentioned that the sciatic nerve was cut thru (?) and needs to grow back - they say if he´s lucky this would take a year at least.
[[ I´ve never heard of sciatic nerve re-joining - so I may have mis-understood this part :( we don´t speak the language fluently yet. ]]
Our question dear Doc is: would there be any natural ways for him to encourage the re-growth of this nerve... any homepathic remedies or other supplements he can take, exercises he could do? Whatever else you may see fit to recommend?
His wife will be delivering a baby soon (their first!!)- God willing - so he´s impatient to be on his toes and about as soon as is possible. Yes - he complains about his impatience.
Pl help!!! and thank you in advance. Tweet