Fibrosis And Scarring of The Brachial And Sacral Plexus as Displayed by MRI/MRA/MRV

Bilateral rounding of the shoulders (laxity) associated with kyphosis of the thoracic spine causes costoclavicular 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. Surgery alters fascial planes within the thorax and pelvis that causes fibrosis and scarring of the blood supply to the brachial and sacral plexus.

The objective of this presentation is to display the sites of landmark anatomy compressing the brachial plexus that decreases venous return supply 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 and sacral 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 or Computerized Axial Tomography (CAT).

The longer venous obstruction transient ischemia or permanent obstruction ischemia if unrelieved, progressively affect the nerve fibers increasing numbers 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 increasing ischemia, fibrosis becomes marked. This presentation displays costoclavicular compression of the brachial and sacral plexus with fibrosis and scarring in two patients. One patient post multiple fractures of the thorax and pelvis complicated by thoracic outlet syndrome post pelvic hardware, and the second patient post cervical fusion and bilateral total shoulder and hip replacement with foot drop.

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.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Surgery to Relieve Thoracic Outlet Syndrome Complaints Should Have Preoperative Imaging:MRI/MRA/MRV

INTRODUCTION

Thoracic Outlet Syndrome (TOS) patients are normally managed conservatively with physical therapy (PT) and may undergo scalenectomy and first rib resection without imaging. Bilateral multiplanar magnetic resonance imaging and 2D time of flight magnetic resonance angiography and venography (MRA/MRV) of the brachial plexus display costoclavicular compression of the draining veins within the neck, supraclavicular fossae, and neurovascular bundles as the diagnostic cause of thoracic outlet syndrome.

METHODS

Bilateral MRI/MRA/MRV displays sites of obstruction of the draining veins of the neck and the subclavian and axillary arteries with binding nerve roots. Monitored multiplanar images are acquired on a 1.5 Tesla GE Signa LX unit, 44 cm field of view, 512 × 256 matrix with saline water bags to enhance signal to noise ratio.

SUMMARY

The case selected for this presentation was diagnosed with left TOS and left pectoralis minor syndrome. Her surgeon convinced her that there was no need for imaging. However, she developed postoperative complaints and sought evaluation by a neurologist. Thereafter, bilateral imaging of the brachial plexus was requested displaying the surgical alteration of landmark anatomy, costoclavicular compression of binding nerves to the subclavian and axillary arteries, obstruction to venous drainage, scarring and fibrosis from the resected lymphatics marginating veins within the pectoralis minor muscle adhering the pectoralis major muscle to the anterior chest wall.

CONCLUSION

Nerves, arteries, veins and lymphatics are within the fascial planes marginating muscles. Health professionals should be aware that resection of the pectoralis minor muscle tendon (tenotomy) at the coracoid process disrupts lymph drainage precipitating fibrosis and scarring of those structures within. Baseline plain radiographs and MRI of the brachial plexus should be obtained prior to all surgical intervention.

Obstruction of the thoracic duct(s) causes chronic lymphedema of the upper limb in patients presenting with symptoms of thoracic outlet syndrome: MRI/MRA/MRV

INTRODUCTION

Obstruction of the thoracic duct(s) causes chronic upper extremity lymphedema. Lymphatics have bicuspid valves like the venous system. Metaplastic fibrosis resulting from obstruction of lymph drainage in the upper extremities impedes vertebral venous plexus / Batson’s plexus circulation. The upper limb undergoes painful swelling into the axilla and compresses the brachial plexus. Patients present with tingling/numbness and weakness of the affected arm; lightheadedness; blurred vision and floaters in the visual fields, and tinnitus with whooshing sounds in the ear on the affected side and increased hair growth and nail changes in the affected limb.

METHODS

Bilateral MRI/MRA/MRV displays the sites of obstruction of lymphatics, draining veins of the neck and the subclavian and axillary arteries with binding nerve roots. Monitored multiplanar images are acquired on a 1.5 Tesla GE Signa LX unit, 44 cm field of view, 512 × 256 matrix and saline water bags to enhance signal to noise ratio and Fast Spin Echo (FSE) to display lymphedema (JNMA 1999; 91:333–341).

SUMMARY

Two patients were selected: one with acquired obstruction of the thoracic lymph duct with lipoma extending into the left hemithorax, the other with developmental fibrosis of the right thoracic duct complicated by pulmonary emboli. Cannulation of the lymphatics could not be performed because of obstructed lymphatic flow.

CONCLUSION

MRI/MRA/MRV is the only alternative to lymphangiogram in patients with obstruction to lymph flow.