But those damages isn't as severe. Part of their lungs still works and are able to get oxygen. Also their heart still works which means it can distribute the remaining oxygen in the blood to the brain.Sasuke had his entire chest cavity evacuated by bee's lariat and he survived long enough for juugo to chansfer the flesh of his body into his chest and restore his organs without oxygen deprivation or any apparent negative side effects at all. I understand this is more extreme, but tsunade's seal is also passive, making it activate immediately upon impact, and is also a better agent of healing than juugo's CS transfer.
Also kisame's chest was blown out by bee and it was healed within 2 panels i believe by chakra alone. I feel the same principle applies here and the only difference is that in tsunade's case it would take much more chakra. But given the proper time for chakra to accumulate, i think it's possible.
She's half senju, half uzumaki. I think her chakra levels are fine.
In tsunades case she has to recreate many organs such as lungs, heart, nerves, blood cells, etc just to carry out a functioning circulatory and respiratory system, to avoid oxygen depravation. That will definitely take more time, than what decapitated Tsunade is allowed to.
So logically speaking, it is not possible
