Chylothorax
Encyclopedia
A chylothorax is a type of pleural effusion
. It results from lymphatic fluid (chyle) accumulating in the pleural cavity
.
or one of the main lymphatic vessels that drain to it. The most common causes are lymphoma
and trauma
caused by thoracic surgery. If the patient is on a normal diet, the effusion can be identified by its white and milky appearance, as it contains high levels of triglycerides. This chyle composition of triglycerides is mostly in the form of chylomicrons.
The condition is rare but serious, and appears in all mammals. In animals, chylothorax usually results from diseases that cause obstruction to the thoracic duct, preventing lymph from draining normally into the venous system. Examples include tumors, heartworm disease, right-sided cardiac failure, or idiopathic lymphangiectasia
.
are options: the leaking of lymphatic fluids is stopped by irritating the lungs and chest wall, resulting in swelling and closure of the pleural space. The medication octreotide
has been shown to be beneficial and in some cases will stop the chylothorax after a few weeks.
In animals, the most effective form of treatment until recently has been surgical ligation of the thoracic duct combined with partial pericardectomy.
Pleural effusion
Pleural effusion is excess fluid that accumulates between the two pleural layers, the fluid-filled space that surrounds the lungs. Excessive amounts of such fluid can impair breathing by limiting the expansion of the lungs during ventilation.-Pathophysiology:...
. It results from lymphatic fluid (chyle) accumulating in the pleural cavity
Pleural cavity
In human anatomy, the pleural cavity is the potential space between the two pleura of the lungs. The pleura is a serous membrane which folds back onto itself to form a two-layered, membrane structure. The thin space between the two pleural layers is known as the pleural cavity; it normally...
.
Causes
Its cause is usually leakage from the thoracic ductThoracic duct
In human anatomy, the thoracic duct of the lymphatic system is the largest lymphatic vessel in the body. It is also known as the left lymphatic duct, alimentary duct, chyliferous duct, and Van Hoorne's canal....
or one of the main lymphatic vessels that drain to it. The most common causes are lymphoma
Lymphoma
Lymphoma is a cancer in the lymphatic cells of the immune system. Typically, lymphomas present as a solid tumor of lymphoid cells. Treatment might involve chemotherapy and in some cases radiotherapy and/or bone marrow transplantation, and can be curable depending on the histology, type, and stage...
and trauma
Physical trauma
Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
caused by thoracic surgery. If the patient is on a normal diet, the effusion can be identified by its white and milky appearance, as it contains high levels of triglycerides. This chyle composition of triglycerides is mostly in the form of chylomicrons.
The condition is rare but serious, and appears in all mammals. In animals, chylothorax usually results from diseases that cause obstruction to the thoracic duct, preventing lymph from draining normally into the venous system. Examples include tumors, heartworm disease, right-sided cardiac failure, or idiopathic lymphangiectasia
Lymphangiectasia
Lymphangiectasia is a pathologic dilation of lymph vessels. When it occurs in the intestines of dogs, and more rarely humans, it causes a disease known as "intestinal lymphangiectasia." This disease is characterized by lymphatic vessel dilation, chronic diarrhea and loss of proteins such as serum...
.
Treatment
Since the mechanism behind chylothorax is not well understood, treatment options are limited. Drainage of the fluid out of the pleural space is essential to obviate damage to organs, especially the inhibition of lung function by the counter pressure of the chyle. Another treatment option is pneumoperitoneal shunting (creating a communication channel between pleural space and peritoneal cavity). By this surgical technique loss of essential triglycerides that escape the thoracic duct can be prevented. Omitting fat (in particular FFA) from the diet is essential. Either surgical or chemical pleurodesisPleurodesis
Pleurodesis is a medical procedure in which the pleural space is artificially obliterated. It involves the adhesion of the two pleura.- Uses :Pleurodesis is done to prevent recurrence of pneumothorax or recurrent pleural effusion...
are options: the leaking of lymphatic fluids is stopped by irritating the lungs and chest wall, resulting in swelling and closure of the pleural space. The medication octreotide
Octreotide
Octreotide is an octapeptide that mimics natural somatostatin pharmacologically, though it is a more potent inhibitor of growth hormone, glucagon, and insulin than the natural hormone...
has been shown to be beneficial and in some cases will stop the chylothorax after a few weeks.
In animals, the most effective form of treatment until recently has been surgical ligation of the thoracic duct combined with partial pericardectomy.
External links
- University of Wisconsin: http://www.vetmed.wisc.edu/dss/ChyloThoraxTrial/page5.php
- Morris Animal Foundation: http://www.morrisanimalfoundation.org/ada_studies.php?col=study&val=179