Does Marijuana Hurt a Skin Flap? (photo)

I am going through reconstructive plastic surgery on the left side of my face, My next surgery will be a skin flap, my plastic surgeon said i HAVE to quit smoking cigarettes or she will not perform the surgery, she said she would rather me smoke marijuana(because i smoke both,), but she would still like me to quit smoke marijuana. Does marijuana constrict blood vessel, will the flap fall off, or not heal right? i know it slows down the healing process and wont heal perfect