This study prospectively evaluates the incidence of Horner's syndrome after thoracic epidural anesthesia following continuous thoracic epidural analgesia for mastectomy. The incidence was 1.36% and the mechanism of Horner's syndrome was cephalic spread of the local anesthetic.

Transient Horner's syndrome has been recognized rare complication of epidural anesthesia and the incidence is not exactly well-known in thoracic epidural anesthesia. Therefore, this study prospectively evaluates the incidence of Horner's syndrome after thoracic epidural anesthesia following continuous thoracic epidural analgesia for mastectomy.

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.

Inclusion Criteria:

• Patients, who scheduled for mastectomy with/without breast reconstruction

Exclusion Criteria:

• The patients who had more than one abnormal preoperative clotting parameter either clinical signs of potential bleeding disorders suggested by bruising
• Petechiae, or ecchymosis, or anatomic or neurologic abnormalities
• That is, significant scoliosis or kyphosis, radyculopathy or ptosis
• Unsuccessful catheter placement (impossible to insert a catheter at two vertebral levels)
• Unsuccessful epidural anesthesia (not checkable sensory block)
• Dural perforation or intravascular catheterization

Patients, who scheduled for mastectomy with/without breast reconstruction