Background: The thoracic duct plays an important role in fluid balance, lipid absorption, and transport of immunologically active cells. The thoracic duct is difficult to access but is readily identified by EUS. The present study assessed the feasibility of EUS identification and EUS-guided puncture of the thoracic duct in a swine model.
Methods: Transesophageal EUS-guided thoracic duct puncture was attempted in 3 animals under fluoroscopy. In two animals, the thoracic duct was identified by cutdown in the neck; in the third animal, EUS-guided puncture was performed under fluoroscopy alone. In one animal, the thoracic duct was opacified by injecting contrast medium. In the second animal, thoracic duct was injected with patent blue and contrast medium.
Observations: Thoracic duct was identified and punctured successfully in all 3 animals. In the first animal, contrast medium containing lymph was aspirated. In the second animal, lymph containing patent blue was aspirated, and, in the third animal, successful puncture was confirmed by obtaining a lymphangiogram.
Conclusions: This pilot study in an animal model demonstrates that transesophageal EUS-guided puncture of the thoracic duct is feasible and that the technique can be used for lymph sampling and/or lymphangiography.