Fibrosis and Scarring of the Brachial Plexus as Displayed by MRI/MRA/MRV

Abstract

Bilateral rounding of the shoulders (laxity) associated with kyphosis of the thoracic spine causes costoclavicular venous compression and brachial plexopathy. This form of thoracic outlet syndrome is usually not amenable to surgical treatment in older patients, particularly in severe kyphosis of the thoracic spine. The objective of this presentation is to display the sites of landmark anatomy compressing the brachial plexus that decreases venous return to the nerves causing a shortage of oxygen and glucose needed for cellular metabolism causing fibrosis and scarring of the soft tissues marginating the brachial plexus. Magnetic resonance imaging (MRI) is the only modality that displays fibrosis and scarring of fascial plane anatomy obstructing venous and lymphatic return, not possible with Ultrasound and/or Computerized Axial Tomography (CAT).The longer venous obstruction, transient ischemia or permanent obstruction ischemia if unrelieved, progressively affect the nerve fibers in increasing numbers and to an increasing degree. Pathology develops with edematous swelling and vascular congestion. If the pressure is unrelieved and continues to increase, the nerve(s) suffer a first degree or a conduction block injury. Compression ischemia with degeneration and fibrosis develop. In absence of relief, the endoneurial tubes and funniculi atrophy and with increasing ischemia, fibrosis becomes marked.This presentation displays costoclavicular compression of the brachial plexus with fibrosis and scarring in two patients. One patient post resection of the scalene triangle complicated by laceration of the second division of right subclavian artery and the second patient with bilateral scalenectomy with incomplete first rib resection.Monitored bilateral MRI, MRA and MRV of the brachial plexus is the only modality of choice to display costoclavicular compression and fibrosis and scarring of the brachial plexus.