Post-thoracotomy pain syndrome in the era of minimally invasive thoracic surgery

Post-thoracotomy pain syndrome (PTPS) is defined as pain around the wound that persists for more than 2 months after surgery. Persistent pain not only increases the use of analgesics and their side effects but also causes many social problems, such as decreased activities of daily living, decreased quality of life, and increased medical costs. In particular, thoracic surgery is associated with a higher frequency and severity of chronic pain than is surgery for other diseases. The basic principles of postoperative pain treatment, not limited to thoracic surgery, are multimodal analgesic methods (using combinations of several drugs to minimize opioid use) and around-the-clock treatment (administering analgesics at a fixed time and in sufficient doses). Thoracic surgeons must always be aware of the following three points: acute severe postoperative pain is a major risk factor for chronic pain; neuropathic pain due to intercostal nerve injury is a major cause of postoperative pain after thoracic surgery, and its presence must not be overlooked from the acute stage; and analgesics must be administered in sufficient quantities according to dosage and volume. The frequency of PTPS has decreased compared with that in the standard thoracotomy era because of the development of analgesia and the widespread use of minimally invasive procedures such as thoracoscopic surgery and robot-assisted surgery. However, no consistently effective prevention or treatment strategies for PTPS have yet been established. In this review, we focus on PTPS in the era of minimally invasive surgery and discuss the role of thoracic surgeons in its management.