Can Chronic Post-surgical Pain be Reduced by Preserving Intercostobrachial Nerve During Axillary Lymph Node Dissection? : A Randomized Controlled Trial

Intercostobrachial nerve (ICBN) is a cutaneous nerve that provides sensation to the lateral chest, upper medial arm and axilla. It arises from the second intercostal nerve and leave intercostal space at the level of midaxillary line. It then pierces the serratus anterior muscle and enters axilla. Intercostobrachial nerve is encountered during axillary lymph node dissection (ALND) while mobilizing axillary contents laterally off the chest wall and tends to tether axillary contents to the lateral chest wall. Many surgeons routinely sacrifice it as doing so makes mobilization easier and allow exposure of long thoracic neve. Currently there is no consensus on the usefulness of preserving intercostobrachial nerve. According to a 2020 systemic review and meta-analysis, prevalence of CPSP/ PPSP following breast cancer surgery ranged from 2% to 78% and pooled prevalence was found to be 35%. Higher prevalence was associated with ALND. Several risk factors have been identified which contribute to the development of PPSP. These include; Preexisting pain, preoperative opioid exposure, genetics, psychological factors such as anxiety, depression or catastrophizing, intensity of acute postoperative pain and nerve injury during surgery. As a result of nerve injury, damaged and non-damaged nerve fibers start generating action potential spontaneously. These are considered ectopic inputs as they do not arise from peripheral terminals. These inputs lead to the development of central sensitization, which is a state of exaggerated functional response of neurons involved in the pain pathway. This increased sensitization results due to increased membrane excitability, enhanced synaptic efficacy and decreased inhibition. The aim of the present trial is to investigate the effect of ICBN preservation on chronic/ persistent post surgical pain (CPSP/ PPSP). This will be achieved through a randomized control trial with CPSP/ PPSP as a primary outcome measure. Secondary outcome measures will include Health Related Quality of Life (HRQoL), operating time, lymph node yield, functional status of ipsilateral shoulder, post-operative complications and post-operative use of opioid analgesics.