The thoracic duct (TC) is the largest lymphatic vessel in the body. It originates in the region of the upper lumbar vertebral bodies, ascends along the thoracic spine, and empties into the systemic venous system around the confluence between the left subclavian vein and the left internal jugular vein through a unidirectional valve. There are many anatomical variations of the TD such as duplications and atypical locations, but in most cases, they are functionally normal. Failure of the TD to properly empty into the jugulo-subclavian confluent can occur due to the following reasons: 1) congenital obstructions (the TD is dysplastic and either ends before reaching the thoracic inlet or it ends in an atretic segment that has no functional opening into the vein; Figure 1), 2) acquired obstructions (the TD is accidentally ligated or injured during a thoracic operation, resulting in either a complete obstruction or an abnormal extravasation of the lymphatic fluid), or 3) functional obstructions (the TD communicates with a central systemic venous system that is thrombosed due to previous instrumentation [e.g., ECMO cannulation] or a central venous system that is hypertensive due to a variety of congenital cardiac anomalies such as hypoplastic left heart syndrome post Fontan repair). Failure of the TD to empty properly leads to a conglomerate of severe, often life-threatening clinical consequences. Patients with congenital anomalies tend to present signs before birth and have the most severe clinical presentations. Recent developments in the imaging of the central lymphatic system allow us now not only to understand the anatomy of the TD with incredible precision but to also understand the dynamic aspect of the progression of lymphatic fluid, or lack thereof, within the TD. These new imaging modalities developed in the last ten years opened the possibility of accessing and manipulating the TD percutaneously, which in turn led to the creation of several surgical procedures that were not considered feasible in the past.