LYMPHATIC SYSTEM: A FORGOTTEN AREA?

Abstract

Development of new methods of visualization of the lymphatic system and in the treatment of several pathologies associated with impaired lymph fl ow. The lymphatic system is an integral part of the circulation. One of the main functions of the lymphatic system is to transport residual interstitial fl uid from the tissue back to the venous system. Despite growing recognition of the role of the lymphatic system in many disease processes, the techniques for imaging and interventions on the lymphatic system have lagged behind the well-developed methods for imaging and interventions on the cardiovascular systems. This is primarily due to small size and variability in anatomy of the lymphatic vessels, and diffi culty of introducing contrast into lymphatic ducts. Due to lack of imaging and intervention options, the fl ow function of the lymphatic system was relatively ignored over the last few decades. Recently, there has been resurgence in the interest in the fl ow function of the interventions on the lymphatic system with the development of percutaneous minimally invasive techniques, such as thoracic duct embolization, to treat life threatening lymphatic leaks. Our group recently introduced two new methods of lymphatic imaging: intranodal lymphangiography and dynamic contrast MR lymphangiography. These methods have allowed further understanding of lymphatic anatomy, pathophysiology, lymphodynamics, as well as provi???ded guidance for novel minimally invasive lymphatic interventions. Using new techniques, the group discovered the causes and then developed treatments for several fatal conditions effecting single ventricle patients including plastic bronchitis and protein loosing enteropathy. Treatment for other conditions has evolved as well including congenital lymphodysplasia, chylothorax, and chylous ascites. The study of the liver lymphatic system has been little explored despite its signifi cant relevance as exampled in ascites formation in association with cirrhosis, one of the most recognized clinical manifestations of lymphatic vascular system disorders. Liver lymphangiogram is an additional minimally invasive technique that allows visualization of the liver lymphatics. Embolization of the liver lymphatic system has been proven to be curative for liver lymphorrea. Due to the lack of the imaging ability of the lymphatic system the understanding of these relationships lacked. Intranodal lymphangiogram, and liver lymphangiograms are one of the fi rst steps in attempt to understand these relationships. Embolization of the lymphatic system provides the opportunity to treat the abnormal lymphatic fl ows in conditions such as pulmonary lymphatic perfusion syndrome, liver cirrhosis, cardiac failure.