What are the risks of surgery complications caused smoking?

Everything. From infection, poor / non healing, incision / repair breakdown to higher risk of cardiopulmonary complications are all reported with tobacco use. However, good outcomes are also noted with patients who quit tobacco use before surgery and do not resume smoking till their healing is complete. If you can't or don't want to quit for good - at least take a break around the time of your surgery.
Stop Smoking. Nicotine behaves as a vasoconstrictor of vessels thereby decreasing blood flow to tissues ( that need to receive blood flow to heal after surgery).  a decrease in this blood flow may result in wound healing problems and/or tissue death. Patients should avoid all forms of nicotine ( smoking, gum, patches), especially prior to procedures involving flaps such as breast lifting, tummy tuck, facelifts.