Lucas life changing operation

Lucas Was born with Spastic Quadraplegic Cerable Palsy, which affects all four of his limbs, he is wheel chair bound and unable to move his legs. 
He is a very happy 6 year old but he is now asking why carnt i walk like every one else it breaks our heart to hear this.
Every day things like changing a nappy are becoming impossible due to the Stiffness in his lower limbs. 
He has undergone several courses of Botoz in his legs which helped for a few days. Alder Hey have now said he needs an Selective dorsal rhizotomy operation which is procedure that treats muscle spasticity caused by abnormal communication among the brain, spinal cord, nerves and muscles. Spasticity most commonly affects patients who have cerebral palsy. 
Unfortuanlty this is not funded by the NHS, the Surgeon is telling us that the results will be instant and he could have the operation within a month, if we can find the £16000 shortfall from what the NHS will pay for the procedure.

We are asking for any help to raise the £16000 to enable lucas to have the operation and make him comfortable for once in his life.