It is believed that many patients with chest disease who have undergone open-heart surgery (and also thoracoscopic surgery) are more or less plagued with a follow-up problem – the annoying chronic pain around the incision. It often manifests itself as a dull or burning pain that persists along the peri-incisional area and remains stubbornly present 2 months after the surgery, or diminishes but lingers; it is triggered and exacerbated by coughing, lifting the hands (shoulders), resting in bed, and changes in weather, and is particularly pronounced in some elderly female patients due to the pulling of the sagging breast. The medical term for this nuisance is “post-thoracotomy pain syndrome”. Here, as a thoracic surgeon, I will analyze its occurrence, its causes, and how to prevent and treat it.
I. Is it common? What are the trends or effects?
I am very sorry to inform you that open-heart surgery, together with amputation, is considered the most common procedure that causes chronic postoperative pain. According to the literature, the incidence of chronic pain after open-heart surgery is as high as 52% (of which 32% are mild, 16% are moderate and 4% are severe). In layman’s terms, if 10 people have open-chest surgery, more than half will experience chronic postoperative incisional pain. However, with time, some patients’ symptoms can disappear or reduce on their own, mostly six months to one year after surgery, while a few of them can be haunted by pain for up to 4-5 years. Chronic pain can be triggered by emotions, weather changes, and changes in body position, and can severely affect the movement of the affected upper extremity, and can also lead to mental disorders such as anxiety and depression, causing negative changes in the patient’s mood and behavior, significantly affecting the patient’s quality of life after surgery. Therefore, including thoracic surgeons, anesthesiologists, patients and their families, it is very necessary to pay more attention to chronic pain after open-heart surgery and take various measures, including medication, active prevention, and even necessary humanistic care, in order to alleviate the many disturbances it brings.
Second, what are the causes of it?
1. Intercostal neuroma secondary to intercostal nerve injury: it is currently considered the most important cause of pain. The abnormal sensation and spontaneous burning or dull pain that many patients experience, distributed in a semi-circular pattern along the chest incision, is typical of neuropathic pain and is caused by a neuroma formed by the healing of an injured intercostal nerve cutaneous branch (sensory nerve); damage to the intercostal nerve is partly related to the technique of closing the chest, such as interrupted intercostal sutures that trap the intercostal nerve and compress the nerve causing persistent pain.
2, healing rib fracture or bone fracture (intraoperative rib injury due to lesion invasion or overpropulsion of the spreader)
3, local infection and pleurisy: due to the intensive and special sensitivity of pleural nerve distribution, inflammatory adhesions or pleurisy formed on the surface of the pleura can cause pain symptoms for a considerable period of time, characterized by intermittent, sometimes good and sometimes bad, pain in a fixed area in a deeper location, in the patient’s own words, “inside the chest, giggling and pulling pain, persistent “.
4, rib chondritis and rib cartilage dislocation: also mostly related to excessive rib support, rib cartilage is located in the anterior chest, so the pain is often located in the chest wall against the front side.
5, “myofascial pain syndrome”: the reason is due to poor repair of muscle and fascia tissue around the incision after injury, i.e., local inflammation, ectopic nerve proliferation and scar formation. The pain is characterized by a fixed location and obvious tenderness points on the surface of the chest wall, and slight stroking can bring about a pinprick or burning-like pain.
6.Genetic susceptibility and psychological reasons: It is found that each person has different physical sensitivity to pain, which is manifested as lower pain threshold and strong reaction to pain; in addition, psychological factors such as female and anxious personality may also affect patients’ subjective feeling of postoperative pain to different degrees.
7. Local recurrence of tumor: The growth of tumor will directly invade the chest wall, ribs and pleura, compressing the intercostal nerve and stimulating the periosteum, causing continuous and progressively aggravated pain, which also needs to cause sufficient attention and vigilance.
How to carry out prevention and treatment?
1.Treatment
a. Oral analgesic drugs: There are many kinds of oral analgesic drugs, which need to be selected individually according to the patient’s pain level and drug side effects. When applying, refer to the three-step principle: ① Non-steroidal analgesics can be preferred when the pain is mild, such as fenbid, anti-inflammatory pain, ploctazone, diclofenac sodium, etc., together with neurotrophic drugs (such as Micropod) taken at the same time. These drugs are non-addictive and can be taken for a long time, but the analgesic effect is limited, and attention should be paid to the effects on the stomach and intestines (use with caution in patients with chronic stomach disease and ulcer disease). ② For mild to moderate pain, weak opioids, such as codeine, should be used, which also have cough suppressant effect; in addition, they can be used in combination with the above non-steroidal drugs, for example, if you are distracted by many activities during the day, you should take weak non-steroidal drugs regularly, and if you are sensitive to pain at night, you can take weak opioids in appropriate amount, so that the combination of dynamic-static and strong-weak can have satisfactory effect on some patients. If the pain is moderate to severe or above, or the effect of the above drugs is still not good, strong opioid central analgesic drugs can be used moderately, such as oxycodone (tylenol), morphine (mescaline), dulcolax, etc.; tramadol hydrochloride (chimantin) also has certain effect for moderate pain or above, and the addiction is relatively weak, and patients who have concerns about opioid narcotics can take them at their discretion, etc.
b. Sedative and tranquilizing drugs: some patients have emotional instability, insomnia, anxiety and depression due to long-term pain, these drugs can be applied at the same time as painkillers to stabilize mood, improve sleep and relieve tension and anxiety, such as Valium and Librium at bedtime; patients with anxiety or depression should take the drugs under the guidance of a specialist. In addition, some Chinese medicinal preparations such as Zhen Huang An Gong Tablets, Ginseng Astragalus Wu Wei Zi and An Shen Tonic Heart Pills can also be taken as appropriate (used under the guidance of Chinese pharmacists).
c. Topical patches: transdermal pain patches are applied locally with good permeability and long duration of analgesic effect, and can reduce the systemic side effects of painkillers. At present, there are two kinds of clinical common, flurbiprofen babu cream (Depakote, Zephyr) and fentanyl transdermal pain patches (Doregis), the former is non-steroidal, the effect is mild and long-lasting, also has efficacy for rheumatoid arthritis; the latter has obvious analgesic effect, the effect lasts up to 72 hours, good for severe chronic pain and advanced cancer patients, but belongs to morphine drugs, should be used with caution.
d. Acupuncture and local care. Acupuncture and physiotherapy are effective for some people and can be tried if necessary; for pain induced by sagging and pulling of the breast, custom-made individualized bras, supplemented with silicone pads or water bladders, etc. can be considered.
e. Invasive treatment: nerve block and surgery. Among all patients with chronic pain after open-heart surgery, a small percentage of them belong to severe pain (about 4%), which is not effective with all the above treatments, and the degree and frequency of pain seriously affect their sleep and daily life, leading to mental anxiety or depression. In such cases, intercostal nerve block or even surgical removal of the intercostal nerve is needed to block the abnormal discharge of pain transmission according to the characteristics of the condition and the patient’s own wishes.
In general, although there are many treatments for postoperative chronic pain, the results are often unsatisfactory, and the side effects and addictive nature of pain medications limit the possibility of long-term use by patients, so the focus remains on how to prevent it.
2.Prevention
a. Effective postoperative analgesia: domestic and foreign studies have shown that epidural analgesia in the thoracic segment given as early as possible after surgery can effectively control acute pain within 2 weeks after surgery and can significantly reduce the incidence of chronic pain. In layman’s terms, the control of acute pain can effectively prevent and reduce the occurrence of chronic pain. Therefore, the effectiveness of postoperative analgesia is crucial and requires adequate technical support from anesthesiologists in the perioperative period. Some patients and their families also need to correct the misconceptions about the use of anesthetics, that is, they think it will affect wound healing and inhibit the so-called brain and intelligence, so they adopt the resistant attitude of “tolerate as much as possible and use no (less) painkillers” to postoperative pain, which increases the incidence of postoperative chronic pain to a certain extent. On the contrary, the short-term and adequate application of analgesics after surgery will neither induce addiction nor cause damage to the nervous system, but will help reduce chronic pain, reduce pulmonary infection and promote postoperative functional recovery.
b. Intraoperative intercostal nerve protection: Since intercostal nerve injury is the most important cause of chronic pain after open-heart surgery, the importance of protecting the intercostal nerve cannot be overstated. In practice, the “small intercostal nerve protection incision” technique adopted by the Department of Thoracic Surgery of Peking University First Hospital can effectively prevent the occurrence of chronic pain, and most patients do not complain of chronic pain around the incision after discharge; even if some patients have symptoms, they are mild. The reason for this is that this incision not only rarely interrupts the muscles, but also allows intraoperative identification of the intercostal nerve cutaneous branches under direct vision, avoiding damage during incision and rib spreading. Moreover, great attention is paid to the protection of the intercostal nerve under the incision when closing the chest, and the sutures are wrapped under the periosteum of the rib as much as possible to avoid trapping the nerve in the knot, thus greatly reducing the incidence of chronic postoperative pain.
c. For some women and people with anxious or sensitive personalities, it is necessary to strengthen preoperative education and tips to help patients relieve tension and be psychologically prepared to deal with pain; give adequate follow-up and treatment guidance after surgery, understand the scope and degree of pain in time, analyze the causes and make timely targeted treatment to avoid physiological and psychological barriers caused by long-term pain.
In conclusion, the prevention of chronic pain is a multifaceted and comprehensive treatment system that requires the joint efforts and full attention of thoracic surgeons, anesthesiologists, pain specialists, patients and their families. With sufficient attention and understanding of the rules of its occurrence, the reduction and prevention of chronic pain after open-heart surgery will surely be within reach.