Key Points

• Chylothorax is an accumulation of lymphatic fluid within the pleural space secondary to injury or obstruction of the thoracic duct or an associated or accessory ductal branch.
• Chylothorax is characterized by rapid accumulation of milky fluid after the patient begins a normal diet.
• A pleural fluid triglyceride level > 110 mg/dl is diagnostic.
• The most common causes of chylothorax are iatrogenic injury to the thoracic duct system or spontaneous duct rupture from a neoplastic process.
• The basics of conservative therapy include drainage of the effusion and initiation of a low triglyceride diet or nothing by mouth (nil per os; NPO) with total parenteral nutrition (TPN).
• Interventional radiologic thoracic duct coil embolization is an effective option prior to surgery.
• Prompt surgical ligation of the thoracic duct needs to be performed if nonsurgical modalities fail.
• Modern techniques of thoracic duct identification using indocyanine green (ICG) fluorescence have been proposed to avoid iatrogenic chylothorax.