Six hundred thirty three Patients, who scheduled for mastectomy with/without breast reconstruction, were eligible for this prospective observational study from September 2010 to December 2013. Thoracic epidural anesthesia performed using 0.375% or 0.5% ropivacaine 15mL followed by sedation consisting of propofol without muscle relaxation. After the operation, thoracic epidural analgesia continued; supplemented by a continuous epidural infusion of ropivacaine 0.15%, 2 ml/h with fentanyl 8mcg/h. At 1 hour, 2hour, 1 day, 2 day and 3 day after the operation, postoperative surveillance consisted of the occurrence of symptoms of Horner's syndrome (miosis, ptosis, and hyperemia) were performed by anesthesiologists.