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

Abstract

INTRODUCTIONObstruction 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.METHODSBilateral 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).RESULTSTwo 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.CONCLUSIONSMRI/MRA/MRV is the only alternative to lymphangiogram in patients with obstruction to lymph flow.