Infectious causes are also observed, most often in developing countries. The most common cause of an infectious chylothorax is a complication of tuberculous lymphadenitis. Other possible causative infections include aortitis, histoplasmosis, and filariasis. Chylothorax can also be congenital, and may co-occur with other lymphatic malformations like lymphangiectasis and lymphangiomatosis. Other conditions like tuberous sclerosis, congenital heart disease, trisomy 21 (Down syndrome), Noonan syndrome, or Turner syndrome (missing X chromosome) are also possible causes of congenital chylothorax. Other, more rare causes of congenital chylothorax include Castlemans disease, yellow nail syndrome, Waldenströms macroglobulinemia, sarcoidosis, venous thrombosis, thoracic radiation, macroglobulinemia, amyloidosis, and a goiter. These diseases cause chylothorax by obstructing or destroying the thoracic duct. Also, parenteral nutrition has been a possible cause; a quick dose of total parenteral nutrition can overwhelm the thoracic duct, causing the chyle to leak into the surrounding pleural space. Traumatic
Iatrogenic chylothorax after surgery is the most common variety of chylothorax. It is a common and serious complication of a pneumonectomy. It is especially common in surgeries requiring mediastinal dissection. The probability of chylothorax depends on the type of surgery. The surgery with the highest risk of chylothorax is an esophagostomy, with a 5-10% risk of chylothorax. Lung resection and mediastinal node dissection have the second highest risk, with 3-7% risk. Other operations like mediastinal tumor resection, thoracic aneurysm repair, sympathectomy, and any other surgeries that take place in the lower neck or the mediastinum can lead to chylothorax.
Surgical
Surgery is indicated if the case is post-traumatic, iatrogenic, or refractory to other treatments, in which cases surgery reduces mortality by 40%. One invasive surgical intervention called a thoracic duct ligation involves closing off the thoracic ducts. Surgical pleurodesis is another option and can be undertaken if the affected person fails to respond to conservative treatment and is not a candidate for surgical intervention.Another treatment option is pleuroperitoneal shunting (creating a communication channel between the pleural space and peritoneal cavity). Since surgery to close the leak is not reliable, talc pleurodesis is recommended; in a case study of 19 people with refractory malignant chylothorax due to lymphoma, it resulted in success for all affected individuals. Chemical pleurodesis is an option, since the leaking of lymphatic fluids is stopped by irritating the lungs and chest wall, resulting in a sterile inflammation. This causes the lung and the chest wall to fuse together, thus preventing lymphatic fluids from leaking into the pleural space. Prognosis
The morbidity and mortality rates associated with chylothorax have declined as treatments have improved. Malignant, bilateral, and chronic chylothoraces have an inferior prognosis to other types. Currently, the mortality and morbidity rates are about 10% if treated surgically. If cases are post-operative and treated conservatively, mortality rates approach 50%. Complications
Complications of chylothorax include malnutrition, immunosuppression, dehydration, and respiratory distress. The severity of the complications depends on how quickly the chylothorax accumulated, its size, and its chronicity. Epidemiology
Chylothoraces are rare and usually occur as a complication of surgeries in the neck and mediastinum.