Friends who have read Romance of the Three Kingdoms may not be familiar with the name Hua Tuo. Hua Tuo went to Cao Cao's camp to treat Cao Cao, and the suspicious Cao Cao thought Hua Tuo was going to take the opportunity to kill him and avenge Guan Yu, so he ordered his left and right to put Hua Tuo in jail and torture him, which resulted in a generation of miraculous doctors succumbing to death in prison. If he had been allowed to cut open Cao Cao's head, would he really have been able to cure Cao Cao's headaches?
I think this has to be taken into account if the actual situation, Hua Tuo could not do a successful craniotomy. The brain is very complex, modern medicine to do craniotomy, but also a technical difficulty of the operation, but also to assist the CT and other modern medical equipment. There was no comparison in terms of tools. At the time, Hua Tuo's suggestion of splitting it open with an axe was a bit of a non-starter. The problem was that he didn't have a successful case, it was a first, and Cao Cao himself had a shadow over it, so there was no way Cao Cao would agree to this!
The technology and level of craniotomy is still a high-risk surgery, before the invention of penicillin tetanus is incurable, if in that era, even if the craniotomy does not die will die of infection, and then on that era of how much research on the brain, and so far today, the brain tissue is still a forbidden area of medical research, who knows that Hua Tuo will be moved to a piece of the nerves Cao Cao directly hang, so all things considered, Cao Cao will be the first one to be able to do so.
There are many people who would give their lives to someone they are not sure of, so all things considered, Cao Cao will definitely hang.
Even if he had taken Hua Tuo's advice I think he would have died during the operation. Even if Hua Tuo's medical skills were higher at that time under those conditions it would have been impossible to complete the operation. Even in today's society the risk of doing open heart surgery is not low. Also at that time, who in their right mind would believe that open heart surgery could be done.
If Cao Cao agreed, his men would not. Because Hua Tuo would have been more of an object of political struggle. It is more likely to be swayed by external factors. Anti-Cao forces and internal fighting within the Cao family would become more intense and even publicized. Ministers loyal to Cao Wei would oppose it without question, even killing Hua Tuo outright would be possible.
Best laid plans, Cao Cao and his men agreed to the operation and Hua Tuo successfully cured Cao Cao. Then there should be nothing left for Sima Yi after that, because as long as Cao Cao is around Sima Yi can only remain subservient to Cao Cao not daring to make any other moves. With Cao Cao's talent and so many strategists and generals working for him, it's only a matter of time before the Three Kingdoms are unified. Then Zhuge Liang and Zhou Yu would not be as famous as they are now. But this is just a hypothesis that will never become reality.
Of course, history can't be changed, and we can only envision things in the modern world, based on recorded history, folks, if Hua Tuo wanted to give you open-heart surgery at that time, would you agree?