To assess safety and efficacy of the regional anesthetic technique paravertebral block for operative treatment of breast cancer, and to compare postoperative pain, nausea, vomiting, and length of hospital stay in patients undergoing breast surgery using paravertebral block and general anesthesia. General anesthesia is currently the standard technique used for surgical treatment of breast cancer. Increasing hospital costs have focused attention on reducing the length of hospital stay for these patients. However, the side effects and complications of general anesthesia preclude ambulatory surgery for most patients undergoing breast surgery.Paravertebral block can be used to perform major operations for breast cancer with minimal complications and a low rate of conversion to general anesthesia. Paravertebral block markedly improves the quality of recovery after breast cancer surgery and provides the patient with the option of ambulatory discharge