Patients are randomly assigned to 2 groups, PECS block or surgical infiltration group. Patients assigned to PECS group will receive 30cc of ropivacaine 0,375% where 10cc will be injected between pectoralis major and pectoralis minor and 20cc between pectoralis minor and serratus anterior muscle under ultrasound guidance. Patients assigned to surgical infiltration group will receive 30cc of ropivacaine 0,375% injected by the surgeon. Local aneshetic is administered in both groups after the induction of general anesthesia and before incision. Pain will be assessed at 1, 12, 24h after surgery and at three months after surgery communicating by telephone. Post operative analgesia includes paracetamol 1gr, parecoxib 40 mg (as required) and tramadol as rescue analgesia (1 mg/kg iv up to 3 times daily). Chronic pain will be assessed after 3 months as for prevalence and neuropathic characteristics.