The Effect of Ultrasound Guided Superficial, Deep Serratus Plane Blocks and Thoracic Epidural in Thoracotomy

The aim of thoracotomy surgery is to explore the thoracic cavity and manage different pathologies including pulmonary, diaphragmatic, mediastinal, esophageal and vascular pathologies. It can be performed posterolaterally, anterolaterally or even anteriorly. Pain after thoracotomy is known to be sever acute pain that is resulted from retraction, resection or fracture of ribs and dislocation of costovertebral joints; injury of intercostal nerves or even irritation of the pleura by chest tubes inserted at the end of surgery. This pain increases post-operative morbidity and if not properly managed peri-operatively, chronic post thoracotomy pain syndrome may develop. Different methods are described to manage post thoracotomy pain. Intravenous (IV) drugs such as opioids and non-steroidal anti-inflammatory drugs (NSAIDS), infiltration of local anesthetics to the wound and regional anesthetic techniques such as thoracic epidural analgesia (TEA), paravertebral block, intercostal block and intra/extra pleural block are methods frequently used to relieve post thoracotomy pain. Thoracic epidural analgesia is believed to be the corner stone in the peri-operative care for thoracotomy providing the most effective analgesia. However, thoracic epidural analgesia is associated with serious complications such as hypotension, dural puncture with the needle or the catheter, post-dural puncture headache, respiratory depression with adding opioids, spinal cord injury and anterior spinal artery syndrome. The serratus muscle is a superficial and easily identified muscle that is considered a true landmark to implement thoracic wall blocks because the intercostal nerves pierce it.Serratus anterior plane (SAP) block has recently been described as a regional anesthetic technique to provide analgesia for breast and thoracic wall surgeries. During SAP block, local anesthesia are deposited in the fascial plane either superficial to the serratus muscle or deep to the serratus anterior muscle in the mid-axillary line .Serratus anterior block provides analgesia to a hemithorax by blocking the lateral branches of the intercostal nerves.SAP block is also expected to avoid autonomic blockade associated with TEA and other complications involving the pleura and central neuraxial structures. Ultrasound imaging made the practice of regional anesthesia easier in visualization and identification of usual and unusual position of nerves , blood vessels , needle during its passage through the tissues, as well as deposition and spread of local anesthetics in the desired plane and around the desired nerve.