An accessory

bile duct A bile duct is any of a number of long tube-like structures that carry bile, and is present in most vertebrates. Bile is required for the digestion of food and is secreted by the liver into passages that carry bile toward the hepatic duct. It ...

is a

conduit Conduit may refer to: Engineering systems * Conduit (fluid conveyance), a pipe suitable for carrying either open-channel or pressurized liquids * Electrical conduit, a protective cover, tube or piping system for electric cables * Conduit curre ...

that transports

bile Bile (from Latin ''bilis''), or gall, is a dark-green-to-yellowish-brown fluid produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is produced continuously by the liver (liver bile ...

and is considered to be

supernumerary Supernumerary means "exceeding the usual number". Supernumerary may also refer to: * Supernumerary actor, a performer in a film, television show, or stage production who has no role or purpose other than to appear in the background, more commonl ...

or auxiliary to the

biliary tree The biliary tract, (biliary tree or biliary system) refers to the liver, gallbladder and bile ducts, and how they work together to make, store and secrete bile. Bile consists of water, electrolytes, bile acids, cholesterol, phospholipids and co ...

. It may be described by its location relative to the

gallbladder In vertebrates, the gallbladder, also known as the cholecyst, is a small hollow organ where bile is stored and concentrated before it is released into the small intestine. In humans, the pear-shaped gallbladder lies beneath the liver, although ...

as supravesicular (superior to the gallbladder body) or subvesicular (inferior to the gallbladder body).

Duct of Luschka

In the surgical literature, the term duct of Luschka is used to refer to an accessory bile duct. They are small ducts that distinctly enter the gallbladder bed, or small tributaries of minor intrahepatic radicals of the right hepatic ductal system. Originating from the hepatic parenchyma the accessory bile duct may enter a large bile duct or the gallbladder at any location. Rarely it is found to be connected directly to the GIT. They may not always drain bile and sometimes can have blind distal ends. One study showed them originating from the liver parenchyma of the right anterior inferior dorsal subsegment or from the connective tissue of the gallbladder bed. The study showed the distal connections ending at the hepatic right anterior inferior dorsal branch, hepatic right anterior branch, right hepatic duct, or common hepatic duct. The term ''duct of Luschka'' is ambiguous, as it may refer to supravesicular or subvesicular ducts. Supravesicular ducts are typically in the gallbladder bed. A 2012 review suggested that the term ''duct of Luschka'' should be abandoned because of this ambiguity and replaced by the more specific term ''subvesical bile duct''. As well, the exact origin and drainage locations of the relevant duct(s) varied greatly between patients.

Clinical significance

Although they may not drain any liver

parenchyma Parenchyma () is the bulk of functional substance in an animal organ or structure such as a tumour. In zoology it is the name for the tissue that fills the interior of flatworms. Etymology The term ''parenchyma'' is New Latin from the word π ...

, they can be a source of a bile leak or biliary

peritonitis Peritonitis is inflammation of the localized or generalized peritoneum, the lining of the inner wall of the abdomen and cover of the abdominal organs. Symptoms may include severe pain, swelling of the abdomen, fever, or weight loss. One part or ...

after

cholecystectomy Cholecystectomy is the surgical removal of the gallbladder. Cholecystectomy is a common treatment of symptomatic gallstones and other gallbladder conditions. In 2011, cholecystectomy was the eighth most common operating room procedure performed i ...

in both adults and children. If an accessory bile duct goes unrecognized at the time of the gallbladder removal, 5–7 days post-operative the patient will develop bile

, an easily treatable complication with a morbidity rate of 44% if left untreated. Often diagnosed by

HIDA scan Cholescintigraphy or hepatobiliary scintigraphy is scintigraphy of the hepatobiliary tract, including the gallbladder and bile ducts. The image produced by this type of medical imaging, called a cholescintigram, is also known by other names depe ...

, a bile leak from an accessory bile duct post-op can be treated with a temporary biliary stent to redirect the bile from the liver into the intestine and allow the accessory duct to spontaneously seal itself or using a drainage guided by radiology.

Eponym

The term is named after German anatomist

Hubert von Luschka Hubert is a Germanic masculine given name, from ''hug'' "mind" and ''beraht'' "bright". It also occurs as a surname. Saint Hubertus or Hubert (c. 656 – 30 May 727) is the patron saint of hunters, mathematicians, opticians, and metalworkers. ...

(1820-1875) who described the first case in 1863.

References

{{Digestive glands Hepatology General surgery Accessory body parts