The International Association for the Study of Pain defines post-mastectomy pain syndrome (PMPS) as persistent or chronic pain following mastectomy or lumpectomy that affects the anterior thorax, axilla, and/or medial upper arm – and the syndrome is reported affect 30-80% of women who undergo breast surgery. There is no specific therapy for this disorder, and patients report consistent levels of pain over time despite medication, physical therapy, spinal injections, psychological intervention, and/or acupuncture. It is largely agreed that damage to the intercostobrachial nerve (ICBN) during surgery, scar tissue formation about the ICBN after surgery, or neuroma formation involving the ICBN, are the primary contributor(s) to the symptoms of this disorder. In addition, short term interventions such as steroid/anesthetic injections under ultrasound guidance to the ICBN have shown to improve pain in the corresponding distribution. The ICBN is readily accessible with CT. It arises from the lateral cutaneous branch of the second intercostal nerve, pierces the external intercostal muscle and serratus anterior, then crosses the axilla to the medial side of the arm – making it vulnerable during breast interventions, particularly axillary dissection. Cryoablation affects nerves specifically through 1) ice-crystal mediated vasa vasorum damage and endoneural edema, 2) Wallerian degeneration, 3) direct physical injury to axons, and 4) dissolution of microtubules resulting in cessation of axonal transport. The cumulative end point of these routes of neuronal damage is decreased pain sensation resulting from conduction cessation, activation of descending inhibition, blockade of excitatory transmitter systems, and/or generalized sodium channel blockade. This study is enrolling patients to study the effect of cryoablation on the ICBN in this setting.