Intercostal nerve block is a procedure used to treat pain in the chest and upper abdomen areas.
The intercostal nerve is found between ribs throughout the thoracic region. Injecting anesthetics, steroids, or other medications inhibits the transmission of pain signals and reduces inflammation of these nerves. This procedure may also be used to diagnose pain and identify the route of the pain signal. Conditions treated with the intercostal nerve block include:
- Neuropathic pain in the chest associated with herpes zoster or shingles
- Postoperative pain of chest or upper abdominal surgery
- Chronic pain after mastectomy
- Rib fracture pain
- Pain related to the formation of scar tissue after surgery
- Somatic pain secondary to metastatic cancer to the ribs
The intercostal nerve communicates pain messages from the muscles, bones, and skin to the brain, and a block can be effective in relieving pain without the side effects of opioid pain medications. The nerve is easy for the physician to access, and the procedure low-risk. A single block may result in permanent pain relief.
AnatomyIntercostal nerves branch out from the first thoracic nerve, traveling along the neck of the rib and into the costal groove. Continuing over the pleura and endothoracic fascia, the nerves go between the innermost and internal intercostal muscles, ending at the internal thoracic vessels. Intercostal means “between the ribs,” and at the beginning of the intercostal space the nerves pass through muscle to the pectoralis major, splitting into the anterior cutaneous branch to innervate the front of the chest.
Other branches of the intercostal nerves supply the abdominal wall and the thoracic wall. These nerves enter the muscles of the abdominal wall, passing in between the rectus abdominis and its posterior sheath wall. These nerves branch out to the rectus and skin. Now thoraco-abdominal nerves, they communicate with the peritoneum, pleura, and diaphragm. The intercostal nerves are effectively distributed to muscles, skin, bones, and pleural space of the chest and upper abdomen. These nerves do not communicate with the viscera, and a block that does not yield pain relief may have diagnostic value pointing to conditions involving the organs or other regions of the body.
ProcedureAn intercostal nerve block may be performed in conjunction with chest and abdominal surgery, or it may be an outpatient procedure done on its own. The injection of the nerve block takes just a few minutes, and after a brief monitoring period, the patient is discharged home.
After checking in to the medical center, consent forms are signed and the procedure is explained to the patient. Vital signs are monitored, and the patient is placed in a position to allow for easy access to the injection site. This procedure can be performed with the patient sitting, lying on their side, or lying on the stomach. The patient is awake for the entire procedure, but local anesthetic is administered to numb the area of the nerve block injection. During the procedure, the patient must remain still since movement makes administering the nerve block difficult. The area for injection is cleaned and injected with anesthetic. Fluoroscope guidance using X-ray helps the doctor determine the correct placement of the needle. Once correct placement is verified, the nerve block injection is administered. A successful block is marked by pain relief. Absence of pain relief indicates either an unsuccessful block administration or that the source of pain is not related to the intercostal nerve. During the procedure, one nerve site may be blocked, or the injection may be performed at different sites along the nerve.
Intercostal nerve block is a short outpatient procedure that is capable of relieving pain of the muscles, bones, and skin in the chest and upper abdomen. Patients suffering from difficult to treat neuropathic or metastatic bone cancer pain may find an intercostal nerve block reduces their pain or relieves it completely. A nerve block is a good alternative to opioid pain medications, which carry side effects the patient may not be able to tolerate. If the procedure is successful, the patient is a candidate for repeat injections to treat recurring pain.
An intercostal nerve block involves insertion of a needle to the rib area, which involves the possibility of certain potential complications, including:
- Pneumothorax, or collapsed lung caused by penetration of the needle
- Nerve damage
- Local anesthetic toxicity
- Spinal anesthesia (very rare)
- Allergic reaction to medications given
The use of fluoroscopy in identifying proper needle placement greatly reduces the risk of pneumothorax and damage to surrounding tissues.
The first nerve block functions as a test as well as a possible treatment for pain. If the block results in pain relief, the physician can identify the role of the intercostal nerve in the patient’s condition. If no pain relief is achieved from the nerve block, other avenues of treatment need to be explored, and it’s possible that the intercostal nerve is not involved in the patient’s condition. After a successful block, pain relief varies from patient to patient. Those being treated for acute pain tend to respond better to the nerve block than chronic pain sufferers. The anesthetic provides immediate pain relief that lasts a few hours. It takes longer for the steroid component to reduce inflammation and relieve pain. The steroid takes effect in about three to five days and can continue to provide pain relief for weeks or months. Patients who respond positively to treatment may receive repeat injections over time to prolong pain relief. Once the role of the intercostal nerve is identified, a permanent ablation may be performed to provide long-term pain relief.
The procedure is relatively low risk. Less than 1% of patients experience pneumothorax. This minimally-invasive treatment for pain that is often resistant to other medical interventions is easy for the patient to tolerate with minimal discomfort. An intercostal nerve block reduces the patient’s dependence on opioid pain medications. If effective, the block allows patients to be more physically active in activities of daily living and improves quality of life.
- Ronan O’Rahilly. The Thoracic Wall and Mediastinum. Retrieved from http://www.dartmouth.edu/~humananatomy/part_4/chapter_20.html
- Intercostal Nerve Blocks. Retrieved from http://www.thepainmds.com/intercostal.html
- Intercostal Nerve Block. Retrieved from http://www.lahey.org/Departments_and_Locations/Departments/Pain_Management_Center/Nerve_Blocks/Intercostal_Nerve_Block.aspx
- A.M.-H. Ho, M.D, Karmakar, M.D. (March 15, 2012). Intercostal Nerve Block. Retrieved from http://www.nysora.com/peripheral_nerve_blocks/nerve_stimulator_techniques/3098-Intercostal-Nerve-Block.html
- Intercostal Nerve Block. Retrieved from http://www.medcentral.org/Main/IntercostalNerveBlock.aspx