Stop smoking before surgery

Studies have shown conclusively that patients who stop smoking before surgery have fewer complications and heal faster than those who continue to smoke.
Smoking and surgical outcomes
2011 study finds increased mortality among surgical patients who smoke

The surgical outcomes of current smokers and never smokers were examined in a large US cohort comparison involving a sample of 520,795 non-cardiac surgical patients. The researchers found that smoking was associated with a 40% greater chance of 30-day mortality and a 30-100% greater chance of major morbidity including surgical site infection, pneumonia, unplanned intubation and septic shock.

Turan A, Mascha EJ, Roberman D, et al. Smoking and perioperative outcomes. Anesthesiology 2011; 114: 837-46.