Abstract P4-11-01: A simple intervention for long-term relief of chronic post mastectomy pain
Authors: Keane HJ , Khoury AL , Hosseini A , Varghese FP , Mukhtar R , Eder SE , Wong J , Esserman LJ 
Published: May 2019

Abstract
Background: Post-mastectomy pain syndrome (PMPS) is a common and often debilitating condition. One common cause likely results from injury to the T4 and T5 sensory nerves during breast surgery, with resulting neuroma formation. It manifests as a pain syndrome diagnosed by “trigger points” that reproduce exquisite pain upon palpation. Pain specialists have found a combination of corticosteroids and local anaesthetic given through perineural infiltration, at other sites, effective in alleviating these neuromas or trigger points. Utilizing this principle, we initiated a quality improvement project to treat PMPS. This perineural injection led to remarkable, long-lasting relief of the first few patients, we therefore continued treating patients with clinical symptoms suggestive of a neuroma. We report on long-term pain relief after trigger point injections (TPI) for women with PMPS.
Methods: An observational cohort study of women with PMPS and clinical evidence of neuroma was undertaken. Patients were examined by breast surgeons at a single institution. We injected a 2mL mixture of equal parts 0.5% bupivacaine and 4 mg/mL dexamethasone into each trigger point. Demographics, type of breast and axillary surgery, duration of pain, history of surgical complications, adjuvant radiotherapy, number of injections required, location of trigger points and dates of injection were obtained from the electronic medical record. Patients were surveyed via telephone interview for long-term resolution of pain. Descriptive statistics are reported, univariate and bivariate analyses were conducted using Stata 12 (College Station, TX).
Results: We identified 89 trigger points on 61 breasts in 53 patients with PMPS. Patient age ranged from 30-92 years. Mean number of surgeries prior to injection was 2.2 (range 1-8). In this cohort, we found mastectomy was the most frequent surgical procedure preceding the development of a neuroma (41 breasts), followed by reduction mammoplasty with or without concurrent partial mastectomy (16 breasts), and least frequently lumpectomy alone (4 breasts). The time from the onset of neuropathic pain to the first trigger point injection varied from as early as 1 week post-operatively to 132 months (mean 22.2 months). Effectiveness of the TPI was assessed by physical examination immediately (1-3 minutes) after the injection, then with telephone interview (at &gt;/=3 months post TPI). All 53 patients had long-term follow-up data (≥3 months). Long-term relief was achieved in 84 of 89 trigger points (94.4%) or 54 of 61 breasts (88.5%). Trigger point injections were well tolerated by all patients and no complications were reported.
Discussion: Perineural infiltration with bupivacaine and dexamethasone is a safe, simple, and effective treatment option for PMPS with an associated trigger point. Our data suggest this significant problem can easily be resolved in an outpatient setting. All breast specialists should inquire about the presence of symptoms consistent with PMPS and understand the value of intervention to eliminate neuropathic pain. This technique should be added to the armamentarium of all surgeons who perform breast surgery.
Citation Format: Keane HJ, Khoury AL, Hosseini A, Varghese FP, Mukhtar R, Eder SE, Wong J, Esserman LJ. A simple intervention for long-term relief of chronic post mastectomy pain [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-11-01.