The purpose of this study is to compare the clinical profiles of two currently acceptable analgesia techniques. The most common regional block used to achieve postoperative analgesia following mastectomy is the paravertebral block, during which local anesthetic is injected into the paravertebral space which contains the thoracic spinal nerves, between the costotransverse ligament and the pleura. At our institution there has been recent interest in an alternative regional block. The pectoral nerve block is performed by injecting anesthetic between the pectoralis major and the pectoralis minor (PECs I) or between the pectoralis minor and the serratus anterior (PEC II).
The proposed advantage of the pectoral nerve block for regional anesthesia during breast surgery is equal analgesic efficacy with fewer potential complications.