United States Constitution, Article IV, Section I, "Full faith and credit shall be given in each state to the public acts, records, and judicial proceedings of every other state. And the Congress may by general laws prescribe the manner in which such acts, records, and proceedings shall be proved, and the effect thereof."
"... Congress may by general laws ..." --> There are already general laws against aggravated battery that culminates with mayhem, or permanent disfigurement and permanent loss of normal function, by definition of the very procedure that causes it; thus strict liability applies; only the primary features of the act must be proved; proof of intent is not necessary.
Because the right to bodily integrity is at the core of every malum in se crime against the person, it is easy to see that it is in fact one of the fundamental and inalienable rights protected by Amendment IX or X. Thus, a crime committed against this right may be prosecuted under Title 18 USC S241, S242 (unless the crime against rights is considered to be a lesser included charge? I'm new at this...) Note that those laws authorize the death penalty when the victim dies during commission of a crime against rights. There is no reason to change that because there is not a mandatory sentencing guideline, and so judges and juries can make a determination regarding fair sentencing according to the severity of the offense and character of the culpable mental state of the perpetrator.