Chyle (from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word χυλός ''chylos'', "juice") is a milky

bodily fluid Body fluids, bodily fluids, or biofluids, sometimes body liquids, are liquids within the human body. In lean healthy adult men, the total body water is about 60% (60–67%) of the total body weight; it is usually slightly lower in women (52-55%). ...

consisting of

lymph Lymph (from Latin, , meaning "water") is the fluid that flows through the lymphatic system, a system composed of lymph vessels (channels) and intervening lymph nodes whose function, like the venous system, is to return fluid from the tissues to ...

and emulsified

fat In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food. The term often refers spec ...

s, or free

fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, fr ...

s (FFAs). It is formed in the

small intestine The small intestine or small bowel is an organ in the gastrointestinal tract where most of the absorption of nutrients from food takes place. It lies between the stomach and large intestine, and receives bile and pancreatic juice through the p ...

during digestion of fatty foods, and taken up by lymph vessels specifically known as lacteals. The lipids in the chyle are

colloid A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others extend ...

ally suspended in

chylomicron Chylomicrons (from the Greek χυλός, chylos, meaning ''juice'' (of plants or animals), and micron, meaning ''small particle''), also known as ultra low-density lipoproteins (ULDL), are lipoprotein particles that consist of triglycerides (85 ...

Clinical significance

A chyle

fistula A fistula (plural: fistulas or fistulae ; from Latin ''fistula'', "tube, pipe") in anatomy is an abnormal connection between two hollow spaces (technically, two epithelialized surfaces), such as blood vessels, intestines, or other hollow or ...

occurs when defect(s) of lymphatic vessel(s) result in leakage of lymphatic fluid, typically accumulating in the thoracic (pleural) or abdominal (peritoneal) cavities, leading to a chylous pleural effusion (

chylothorax A chylothorax is an abnormal accumulation of chyle, a type of lipid-rich lymph, in the space surrounding the lung. The lymphatics of the digestive system normally returns lipids absorbed from the small bowel via the thoracic duct, which ascend ...

) or chylous ascites, respectively. Diagnosis of a chyle fistula may be accomplished by analysis of pleural/peritoneal fluid. Identifying the source (localizing the lymphatic defect) is often challenging, but may be accomplished with lymphangiography, which is occasionally associated with a serendipitous therapeutic effect (resolution of the leak), thought to be secondary to a sclerosant effect of the lymphangiography contrast. Due to the extreme

friability Friability ( ), the condition of being friable, describes the tendency of a solid substance to break into smaller pieces under duress or contact, especially by rubbing. The opposite of friable is indurate. Substances that are designated hazardous, ...

of the lymphatic vessels, direct repair of defects is impractical. Therefore, treatment of chyle fistulae relies upon either decreased production of lymphatic fluid to allow for healing of lymphatic defect(s) or permanent diversion of lymphatic fluid away from lymphatic defect(s). Decreased production of lymphatic fluid may be accomplished by dietary restriction (or complete replacement of oral intake with

total parenteral nutrition Parenteral nutrition (PN) is the feeding of nutritional products to a person intravenously, bypassing the usual process of eating and digestion. The products are made by pharmaceutical compounding companies. The person receives a nutritional mix ...

), as well as by the medications

octreotide Octreotide, sold under the brand name Sandostatin among others, 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. It was ...

(a synthetic analogue of the hormone

somatostatin Somatostatin, also known as growth hormone-inhibiting hormone (GHIH) or by several other names, is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G protein-couple ...

){{Cite journal, pmid=15830574, year=2005, last1=Mincher, first1=L, last2=Evans, first2=J, last3=Jenner, first3=MW, last4=Varney, first4=VA, title=The successful treatment of chylous effusions in malignant disease with octreotide, volume=17, issue=2, pages=118–21, journal=Clinical Oncology, doi=10.1016/j.clon.2004.06.016 and

orlistat Orlistat, sold under the brand name Xenical among others, is a medication used to treat obesity. Its primary function is preventing the absorption of fats from the human diet by acting as a lipase inhibitor, thereby reducing caloric intake. It ...

(a lipase inhibitor that decreases absorption of dietary fats). Permanent diversion of lymphatic fluid may be accomplished by

thoracic duct In human anatomy, the thoracic duct is the larger of the two lymph ducts of the lymphatic system. It is also known as the ''left lymphatic duct'', ''alimentary duct'', ''chyliferous duct'', and ''Van Hoorne's canal''. The other duct is the right ...

embolization (a needle-based procedure to occlude the duct by depositing glue/embolic material into it) or by thoracic duct ligation (an open surgical procedure to occlude the duct by suturing tightly around it).

Clinical significance

See also