Reports indicate that 40 to 60 percent of patients who undergo mastectomy suffer from chronic pain — pain lasting longer than three months. Studies have demonstrated that patients with post-mastectomy pain experience significantly worse quality of life with respect to physical well-being, physical autonomy, relationships, and psychological well-being. Long-term pain contributes to decreased work function, increased healthcare utilization, and increased depression risk. Even breast biopsy, lumpectomy, breast augmentation and breast reconstruction can result in chronic breast and chest pain.
Our experience indicates that post-mastectomy pain can be similar in severity to that experienced by limb amputation patients, with average patient-reported pain scores of 8 out of 10. Therefore, post-mastectomy pain has far-reaching physical and psychological consequences.
Patients with chronic post-mastectomy pain can also experience significant discomfort from even minor sources like clothing, seat belts, or coughing.
Nerve Injury Contributes to Post-Mastectomy Pain
Studies have demonstrated that sensory nerve injury provides a substantial contribution to post-mastectomy pain. This is not surprising, given that multiple small sensory nerves may be injured during breast surgery including mastectomy (the intercostobrachial nerve, pectoral nerves, and segmental intercostal nerves).
When breast tissue is surgically removed from the chest, sensory nerves traveling through these tissues are transected, stretched, or caught up in scar during the healing process. These nerve injuries can lead to chronic pain due to the development of what are known as end neuromas, neuromas-in-continuity, and scar compression. Altered sensation, including "pins and needles", shock-like, burning, or stabbing pain can provide evidence of nerve injury as a cause for the pain. Local anesthetic nerve blocks can confirm that the chronic pain is coming form the injured nerve(s).
Medication Treatments for Nerve Pain Often Not Enough
Opioids, NSAIDs such as ibuprofen, and neuropathic drugs including gabapentin or amitriptyline are sometimes helpful in managing the pain to acceptable levels. However, these treatments are often insufficient due to incomplete pain relief, inconsistent administration, and adverse effects including chronic dependence (opioids), gastrointestinal distress (NSAIDs), and dizziness and fatigue (neuropathic drugs).
Post-Mastectomy Pain and Opioid Dependence
In a very large study of insurance data, over 10 percent of patients who had not previously taken narcotic pain medications continued to use them for more than 3 months after breast surgery. These patients often require opioid doses that approximate those doses taken by chronic opioid users, equal to six tablets of 5-mg hydrocodone per day. These are very concerning statistics which highlight a significant problem!
Nerve Pain Can Be Easily Identified in the Clinic Setting
Our experience shows that injured nerves can be readily identified as the source of pain. During your visit, the surgeon will listen to your description of your pain, and perform an examination designed to pinpoint the location of pain-causing, injured nerves. You may be offered the opportunity to have a small injection of local anesthetic that may relieve the pain for a few hours by blocking the signals from the nerve(s). If successful, you will be able to experience the numbness, which comes as a trade-off for the pain. In cases where the feeling from the local numbing injection is preferable, your surgeon may discuss the potential for surgery to create this situation permanently.
Intercostal Nerves Causing Chronic Pain Can Be Safely Removed
Once nerve injury is identified as the source for the pain, surgical removal of the small, offending nerves can be performed in a straightforward outpatient operation. Small incisions on the flank (directly under the armpit) or just to the side of the breastbone or the spine are used to gain access to small nerves that come out to the skin from between the ribs. The damaged nerves are excised, with the anticipation of resolution of the pain. The side effect is numbness in the area. Most patients welcome this numbness as a welcome trade-off.
Nerve Surgery Helps Relieve Chronic Pain Following Breast Surgery
The majority of patients with chronic pain report significant decreases or complete resolution of their pain. It is uncommon, but there is the possibility of no improvement, or increase in the pain. Most patients describe that the ‘nerve pain feelings’ are improved as soon as the following day. Discomfort from the operation is frequently described as a completely different sensation, which subsides in the next few weeks.
Surgical Treatments for Chronic Nerve Pain Need Improvement
Multiple surgical techniques have been described for addressing neuroma pain. None have proven to be “the best”. Currently, the most frequently performed operation for nerve pain is removal of the nerve end, and burying of the new end of the nerve into the surrounding tissues. A critical limitation to this approach is that these techniques do not do anything to functionally inhibit further, disorganized growth of the cut nerve ends.
RPNI and DSPNI for Prevention of Pain Recurrence
Regenerative Peripheral Nerve Interface (RPNI) and Dermatosensory Peripheral Nerve Interface (DSPNI) are options to prevent pain recurrence.
When the ends of the injured nerves are removed surgically, there is the chance for recurrence of the pain. Several strategies are used to prevent this. One of them, which we use in almost all cases, is RPNI or DSPNI treatment of the nerve ends. The process is simple. The ends of the nerves are wrapped with small pieces of muscle or skin grafts taken from nearby tissues. The goal is to give the new ends of the nerves something to grow into, thereby preventing the recurrence of nerve pain. This novel technique was developed at the University of Michigan Section of Plastic Surgery, and is being taught to surgeons around the world. We have successfully used these techniques in treating nerve pain and phantom pain due to amputations, surgery and injury all over the body.