S.C.
B.,
The Family Medical Leave act allows a person time off, without pay, for medical emergencies for themselves or a dependent family member, without worry you will lose your job for taking extended time off. Please correct me if I am wrong but it does not require that your employer pay you during this time. It only guarantees your job will be waiting when you return because of events beyond your control. I'm about 99.9% certain you cannot use this for elective, cosmetic surgery unless it is life threatening.
Were that the case it could be used for almost anything and put a business at a terrible disadvantage. You should check with your companies HR department about their policies regarding FML. You don't need to tell them why you are asking so if you need to take vacation time for your surgery no one will be the wiser.
Best regards,
S.