Mastectomy, a surgical procedure involving the removal of breast tissue, is a common and often life-saving treatment for breast cancer. While highly effective in disease management, like any major surgery, it can lead to various side effects. Among these, nerve injury is a recognized complication that can significantly impact a patient’s quality of life. This article focuses on the most common nerve injury associated with mastectomy.
The Intercostobrachial Nerve and Its Vulnerability
The intercostobrachial nerve (ICBN) is the nerve most frequently affected during mastectomy, particularly when axillary lymph node dissection is performed. This sensory nerve originates from the second (T2) and third (T3) intercostal nerves, emerging from the chest wall. It then traverses the axilla (armpit), providing sensation to the skin of the upper inner arm, the axillary region, and a portion of the lateral chest wall.
The ICBN’s anatomical course makes it susceptible to injury during axillary surgery. During a mastectomy, particularly when lymph nodes are removed, the nerve can be stretched, compressed, or even transected (cut). Its superficial location and close proximity to lymph node areas contribute to this vulnerability. While other nerves, such as the long thoracic or thoracodorsal nerves, can also be injured, the ICBN is involved in most nerve-related complications due to its consistent presence in the surgical field.
Recognizing Nerve Injury Symptoms
Injury to the intercostobrachial nerve results in sensory disturbances in the areas it supplies. Patients often describe symptoms such as numbness, tingling, or burning discomfort in the upper inner arm, armpit, or along the side of the chest wall. Some individuals may experience sharp, shooting pains or a sensation like “pins and needles” in these regions.
The intensity and consistency of these sensations vary among individuals, being constant or intermittent. Diagnosis of ICBN injury is primarily clinical, relying on patient history and a physical examination to assess sensation in the affected areas. Imaging tests like MRI or ultrasound are not typically used to diagnose ICBN injury directly, but may exclude other causes of pain or discomfort.
Approaches to Management
Managing symptoms associated with intercostobrachial nerve injury often begins with conservative measures to alleviate discomfort. Over-the-counter pain relievers, such as nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, can help reduce mild pain and inflammation. For more persistent or severe neuropathic pain, prescription medications are frequently used, including gabapentin, pregabalin, or certain tricyclic antidepressants like amitriptyline. These medications work by modulating nerve signals to reduce pain perception.
Topical creams containing lidocaine or capsaicin can also provide localized relief by desensitizing nerve endings in the affected skin. Physical therapy plays a role in management, focusing on techniques like desensitization, where textures and temperatures are gradually introduced to the sensitive area to reduce hypersensitivity. Additionally, physical therapy can help maintain or improve arm mobility and range of motion. In cases of intense, localized pain, nerve blocks involving local anesthetic injections may offer temporary relief, though the duration of effect varies. While symptoms can be persistent, many patients experience gradual improvement over several months to a year.
Minimizing Risk and Recovery
Surgical techniques during mastectomy aim to minimize the risk of intercostobrachial nerve injury, though complete preservation is not always feasible. Surgeons use careful dissection and identification of the nerve within the axillary field to avoid trauma. Despite these efforts, the primary objective of surgery is complete removal of cancerous tissue, which sometimes requires transection of the nerve for adequate oncological clearance.
Patient education before and after surgery is important, informing individuals about the potential for post-mastectomy pain syndrome (PMPS) and altered sensation due to nerve involvement. While some numbness or altered sensation in the upper inner arm or axilla may be permanent, significant pain often diminishes over time with appropriate management. Most patients regain a good quality of life as symptoms improve and they adapt to any lasting sensory changes.