4 years college 4 years medical school, how many years after that to become a board certified cardio thoracic surgeon? How about a bc plastic surgeon?

7 years. After medical school is 5 years of a general surgery residency, followed by at least two years of cardiothoracic training. Sometimes, it can be even longer, but that is the timetable to be eligible for board certification.
BC Plastic Surgeon. After college and medical school it will take at least six years of training to become a board certified plastic surgeon.
Several. General surgery 5-7 years cardiothoracic 2-3 more plastic 5-7 depending on program there is a book listing all the programs.