Serratus Anterior Plane Block for Recovery After Minimally Invasive CABG

Coronary artery bypass grafting (CABG) is an effective revascularization method for treating severe coronary heart disease. Traditional CABG uses a midline thoracotomy approach, providing sufficient exposure of the surgical field. However, sternotomy can cause severe postoperative pain, affecting patients' coughing, expectoration, and early activities, and increasing the risk of pulmonary complications and chronic pain. In recent years, with the deepening of the concept of minimally invasive surgery, minimally invasive direct coronary artery bypass grafting (MIDCABG) has been widely used in clinical practice due to its advantages of less trauma, less blood loss, and faster recovery. However, MIDCABG uses a small incision on the left chest for entry, and the surgery involves rib opening, pulling of chest wall muscles and intercostal nerve, and can still cause severe incision pain and chest wall pain after the operation. Its pain management is not easier than traditional thoracotomy surgery.

Opioid analgesia has always been used as the main method for postoperative pain management in cardiac surgery, but its related side effects (such as nausea, vomiting, respiratory depression, and urinary retention) affect the patient's recovery, so the postoperative accelerated recovery (ERAS) guidelines recommend incorporating regional block techniques into the multimodal analgesia plan for cardiac surgery. From a mechanism perspective, regional block can not only effectively control acute pain but also block pain transmission, reduce the dosage of opioids, thereby reducing opioid-induced hyperalgesia, and may prevent the occurrence of CPSP. However, thoracic paravertebral block and epidural anesthesia are operationally difficult and risky, especially in anticoagulated patients. In this context, the simpler and safer fascial plane block is considered a better choice. Among them, the serratus anterior plane block (SAPB) can effectively block the lateral branches of the intercostal nerves by injecting local anesthetic into the superficial or deep fascial space of the serratus anterior muscle, providing precise pain relief for the anterior lateral chest wall. The value of SAPB in thoracic surgery analgesia has been confirmed by multiple studies, but its clinical effect in MIDCABG is controversial. In conclusion, in the specific surgical scenario of MIDCABG, SAPB, as a key component of multimodal analgesia, its clinical efficacy and application strategies still require in-depth verification through well-designed randomized controlled studies. Based on the above background, this research intends to conduct a randomized controlled trial to systematically evaluate the impact of ultrasound-guided SAPB on the postoperative recovery quality of patients undergoing MIDCABG, with the aim of providing higher-level evidence-based medical evidence for optimizing the perioperative analgesic plan of MIDCABG.