Selective lymphatic embolization can be a safe and effective treatment for lymphatic conduction disorders in pediatric patients, according to researchers at Children's Hospital of Philadelphia. In Featured Abstract 193, “Selective Lymphatic Embolization for Treatment of Lymphatic Conduction Disorders in Children,” which will be presented on Tuesday, March 7 at 3:18 p.m., in Room 224 of the Phoenix Convention Center, investigators indicate that these selective techniques may also preserve the patency of the thoracic duct.
Lymphatic conduction disorders can be truly debilitating for those afflicted and are marked by lymphatic fluid leaking into the thorax, abdomen or intestine. Leaks can result in significant morbidity. For example, if there is lymphatic leak into the airways, it can result in plastic bronchitis, which can be fatal. In children, these disorders are most often seen in patients who have undergone repairs for congenital heart disease, says Abhay S. Srinivasan, MD, assistant professor at Children's Hospital of Philadelphia. “In these patients, the central venous pressures are nonphysiologic,” Dr. Srinivasan said. “And since the lymphatic system is intimately tied to the venous system, the lymphatic physiology is impacted by that increased central venous pressure.” A smaller subset of patients has primary disorders not associated with congenital heart disease, and disorders in these patients may be a result of a primary dysplasia of lymphatic channels.
Due to the link between conduction disorders and congenital heart disease, Dr. Srinivasan says it’s not uncommon to see patients with these disorders in children’s hospitals. And over the last decade, there have been important advances made for the treatment of these disorders at his institution, due to collaboration between IR and interventional cardiology at the Jill and Mark Fishman Center for Lymphatic Disorders.
According to Dr. Srinivasan, because the thoracic duct is the main thoroughfare of lymphatic fluid within the trunk of the body, standard treatment for conduction disorders has been to embolize the thoracic duct.
“If your lymphangiogram shows leakage from the thorax, you'll see small abnormal channels coming off the thoracic duct and supplying the lungs,” Dr. Srinivasan said. “Then you can see that those are responsible for leaking of the fluid and all the morbidity that comes with it.”
But embolizing the main channel, rather than selecting the branches that are leaking, may increase patient morbidity over time, he said.
“The initial thought of ‘if you see an abnormal duct, to embolize it’ may not be the way to go,” he said. “The more we’ve seen patients with these disorders, the more we’ve come to appreciate the need to be selective in embolizing branches, rather than the entire duct.”
Investigators analyzed the clinical and lymphangiogram records of 39 pediatric patients with thoracic lymphatic disorders. Of those, 36 patients presented with chylothorax and 15 with plastic bronchitis. 90% received selective lymphatic embolization of abnormal branches via microcatheter, and an articulating steerable microcatheter was used for selection in 63% of patients. Other variations in technique included access (antegrade, retrograde or both), the use of a dextrose flood (54%) and direct needle puncture of target channels (31%).
At follow-up (571 days), investigators found that that the presenting symptoms had resolved in 32 of 39 patients (82%).
According to Dr. Srinivasan, he and his team were inspired to explore the different techniques for selective embolization in order to find the best and safest approach.
“We would see patients come from other institutions with a duct embolized, and they would present with more severe problems than they were treated for initially,” he said. “So our main drive behind looking at this data is to raise awareness that—especially in kids—we should give a greater consideration to preserving the duct.”
Through their data and abstract presentation, Dr. Srinivasan and his team hope to expand awareness regarding specific techniques that selectively target problem areas. They hope to also raise awareness of lymphatic interventions in general.
“Lymphatic interventions have kind of seeped out of the IR consciousness for the last few decades,” Dr. Srinivasan said. “But thanks to the diligent efforts of many IRs on both the adult and pediatric sides, it’s been rediscovered. The progress is really encouraging, and we’re all trying to advance awareness of lymphatic disorders and increase appreciation of how morbid they can be.”
