Congenital anomalies of the biliary tract: causes, symptoms, diagnosis, treatment

Most congenital anomalies of the biliary tract can be associated with a failure of the initial budding from the primary foregut or with a failure of the reopening of the lumen of the dense gallbladder and biliary diverticulum.

The liver and bile ducts are formed from a kidney-shaped outgrowth of the ventral wall of the primary foregut, located cranial to the yolk sac. The right and left lobes of the liver are formed from two dense cell sprouts, and the hepatic and common bile ducts are formed from an elongated diverticulum. The gallbladder is formed from a smaller cell cluster in the same diverticulum. Already in the early stages of intrauterine development, the bile ducts are passable, but subsequently the proliferating epithelium closes their lumen. Over time, a reopening of the lumen occurs, which begins simultaneously in different areas of the dense rudiment of the gallbladder and gradually spreads to all the bile ducts. By the 5th week, the formation of the cystic, common bile and hepatic ducts is completed, and by the 3rd month of the intrauterine period, the fetal liver begins to secrete bile.

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Classification of congenital anomalies of the biliary tract

Anomalies of the outgrowth of the primary foregut

• Lack of growth
• Absence of bile ducts
• Absence of gallbladder
• Additional outgrowths or splitting of outgrowth
• Accessory gallbladder
• Bipartite gallbladder
• Accessory bile ducts
• Migration of the growth to the left (normally to the right)
• Left-sided location of the gallbladder

Anomalies in the formation of the lumen from a dense bile outgrowth

• Violation of the formation of the lumen of the bile ducts
• Congenital obliteration of the bile ducts
• Congenital obliteration of the cystic duct
• Choledochal cyst
• Violation of the formation of the lumen of the gallbladder
• Rudimentary gallbladder
• Diverticulum of the bladder fundus
• Serous type of "Phrygian cap"
• Hourglass shaped gallbladder

Preservation of the cystic hepatic duct

• Diverticulum of the body or neck of the gallbladder

Preservation of the intrahepatic gallbladder

Anomalies of the rudiment of the gallbladder

• Retroserous type of "Phrygian cap"

Additional folds of the peritoneum

• Congenital adhesions
• Wandering gallbladder

Anomalies of the hepatic and cystic arteries

• Additional arteries
• Abnormal position of the hepatic artery relative to the cystic duct

These congenital anomalies are usually of no clinical significance. Sometimes, bile duct anomalies cause bile stasis, inflammation, and gallstone formation. This is important for radiologists and surgeons who operate on the bile ducts or perform liver transplants.

Bile duct and liver anomalies may be associated with other congenital anomalies, including heart defects, polydactyly, and polycystic kidney disease. The development of bile duct anomalies may be associated with viral infections in the mother, such as rubella.

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Absence of gallbladder

There are two types of this rare congenital anomaly.

Type I anomalies are associated with impaired origin of the gallbladder and cystic duct from the hepatic diverticulum of the foregut. These anomalies are often associated with other anomalies of the biliary system.

Type II anomalies are associated with a disturbance in the formation of the lumen in the dense rudiment of the gallbladder. They are usually combined with atresia of the extrahepatic bile ducts. The gallbladder is present, but only in a rudimentary state. These anomalies are detected in infants with signs of congenital biliary atresia.

In most cases, such children also have other serious congenital anomalies. Adults usually have no other anomalies. In some cases, pain in the right upper quadrant of the abdomen or jaundice are possible. Failure to detect the gallbladder during ultrasound is sometimes regarded as a gallbladder disease and the patient is referred for surgery. The physician should be aware of the possibility of agenesis or ectopic localization of the gallbladder. Cholangiography is of the utmost importance for establishing the diagnosis. Failure to detect the gallbladder during surgery cannot serve as evidence of its absence. The gallbladder may be located inside the liver, hidden by pronounced adhesions, or atrophied due to cholecystitis.

Intraoperative cholangiography should be performed.

Double gallbladder

A double gallbladder is very rare. During embryonic development, small pockets often form in the hepatic or common bile duct. Sometimes these persist and form a second gallbladder, which has its own cystic duct, which can pass directly through the liver tissue. If the pocket is formed from the cystic duct, the two gallbladders share a common Y-shaped cystic duct.

A double gallbladder can be detected using various imaging methods. Pathological processes often develop in the additional organ.

Bipartite gallbladder is an extremely rare congenital anomaly. During the embryonic period, the rudiment of the gallbladder is doubled, but the original connection is preserved and two separate independent bladders with a common cystic duct are formed.

The anomaly has no clinical significance.

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Accessory bile ducts

Accessory bile ducts are rare. The accessory duct usually belongs to the right liver and joins the common hepatic duct between its origin and the cystic duct. However, it may join the cystic duct, the gallbladder, or the common bile duct.

The cystic hepatic ducts are formed as a result of the preservation of the existing connection of the gallbladder with the liver parenchyma in the fetus with a violation of the recanalization of the lumen of the right and left hepatic ducts. The outflow of bile is provided by the cystic duct, which flows directly into the preserved hepatic or common hepatic duct or into the duodenum.

The presence of additional ducts must be taken into account during biliary tract surgery and liver transplantation, since accidental ligation or intersection of these ducts may result in strictures or fistulas.

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Left-sided location of the gallbladder

In this rare anomaly, the gallbladder is located under the left lobe of the liver to the left of the falciform ligament. It is formed when, during the embryonic period, the rudiment from the hepatic diverticulum migrates not to the right, but to the left. At the same time, independent formation of a second gallbladder from the left hepatic duct is possible with developmental disorders or regression of the normally located gallbladder.

When transposing internal organs, the normal relative positions of the gallbladder and liver, located in the left half of the abdomen, are maintained.

The left-sided location of the gallbladder has no clinical significance.

Rokitansky-Aschoff sinuses

Rokitansky-Aschoff sinuses are hernia-like protrusions of the mucous membrane of the gallbladder through the muscular layer (intramural diverticulosis), which are especially pronounced in chronic cholecystitis, when the pressure in the lumen of the bladder increases. On oral cholecystography, Rokitansky-Aschoff sinuses resemble a crown around the gallbladder.

Folded gallbladder

The gallbladder, as a result of a sharp bend in the area of the bottom, is deformed in such a way that it resembles the so-called Phrygian cap.

The Phrygian cap is a conical cap or hood with a curved or forward-sloping top, worn by the ancient Phrygians; it is called a "liberty cap" (Oxford Dictionary). There are two varieties of the anomaly.

1. The fold between the body and the fundus is the retroserous "Phrygian cap". Its cause is the formation of an abnormal fold of the gallbladder inside the embryonic fossa.
2. The bend between the body and the funnel is the serous "Phrygian cap". Its cause is an abnormal bend of the fossa itself in the early stages of development. The bend of the gallbladder is fixed by fetal ligaments or residual septa formed due to the delay in the formation of the lumen in the dense epithelial rudiment of the gallbladder.

The emptying of the folded gallbladder is not impaired, so the anomaly has no clinical significance. It should be known in order to correctly interpret the cholecystography data.

Hourglass gallbladder. This anomaly is probably a variation of the "Phrygian cap", presumably of the serous type, only more pronounced. The constancy of the position of the fundus during contraction and the small size of the communication between the two parts of the gallbladder indicate that this is a fixed congenital anomaly.

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Diverticula of the gallbladder and ducts

Diverticula of the body and neck may originate from the remaining cystic hepatic ducts, which normally connect the gallbladder to the liver during the embryonic period.

Diverticula of the fundus are formed by incomplete re-formation of the lumen in the dense epithelial rudiment of the gallbladder. When the incomplete septum constricts the area of the fundus of the gallbladder, a small cavity is formed.

These diverticula are rare and have no clinical significance. Congenital diverticula should be distinguished from pseudodiverticula, which develop in gallbladder diseases as a result of its partial perforation. In this case, the pseudodiverticulum usually contains a large gallstone.

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Intrahepatic location of the gallbladder

The gallbladder is normally surrounded by liver tissue until the 2nd month of intrauterine development; later, it occupies a position outside the liver. In some cases, the intrahepatic location of the gallbladder may persist. The gallbladder is located higher than normal and is surrounded by liver tissue to a greater or lesser extent, but not completely. Pathological processes often develop in it, since its contractions are difficult, which contributes to infection and the subsequent formation of gallstones.

Congenital adhesions of the gallbladder

Congenital adhesions of the gallbladder are very common. They are sheets of peritoneum that form during embryonic development by stretching the anterior mesentery, which forms the lesser omentum. Adhesions can extend from the common bile duct laterally over the gallbladder to the duodenum, to the hepatic flexure of the colon, and even to the right lobe of the liver, probably closing the omental foramen (Winston foramen). In less severe cases, adhesions extend from the lesser omentum through the cystic duct and anteriorly to the gallbladder or form a mesentery of the gallbladder (a "wandering" gallbladder).

These adhesions have no clinical significance and should not be mistaken for inflammatory adhesions during surgical interventions.

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Wandering gallbladder and gallbladder torsion

In 4-5% of cases, the gallbladder has a supporting membrane. The peritoneum encloses the gallbladder and converges in two sheets, forming a fold or mesentery that anchors the gallbladder to the undersurface of the liver. This fold may allow the gallbladder to "hang" 2-3 cm below the surface of the liver.

A mobile gallbladder can rotate, which leads to its torsion. In this case, the blood supply to the bladder is disrupted, which can lead to a heart attack.

Torsion of the gallbladder usually occurs in thin, elderly women. As we age, the fat layer of the omentum decreases, and the decrease in muscle tone of the abdominal cavity and pelvis leads to a significant displacement of the abdominal organs in the caudal direction. The gallbladder, which has a mesentery, can twist. This complication can develop at any age, including childhood.

Torsion manifests itself as sudden, severe, constant pain in the epigastric region and right hypochondrium, radiating to the back and accompanied by vomiting and collapse. A tumor-like formation resembling an enlarged gallbladder is palpated, which may disappear within a few hours. Cholecystectomy is indicated.

Relapses of incomplete torsion are accompanied by acute episodes of the symptoms described above. With ultrasound or CT, the gallbladder is localized in the lower abdomen and even in the pelvic cavity, held by a long, downwardly curved cystic duct. Cholecystectomy is indicated in early life.

Anomalies of the cystic duct and cystic artery

In 20% of cases, the cystic duct does not immediately join the common hepatic duct, being located parallel to it in one connective tissue tunnel. Sometimes it spirally wraps around the common hepatic duct.

This anomaly is of great importance to surgeons. Until the cystic duct is carefully separated and its junction with the common hepatic duct is identified, there is a risk of ligation of the common hepatic duct with catastrophic consequences.

The cystic artery may arise not from the right hepatic artery, as is normal, but from the left hepatic or even from the gastroduodenal artery. Additional cystic arteries usually arise from the right hepatic artery. In this case, the surgeon must also be careful when isolating the cystic artery.

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Benign bile duct strictures

Benign bile duct strictures are rare, usually following surgery, especially laparoscopic or “open” cholecystectomy. They can also develop after liver transplantation, primary sclerosing cholangitis, chronic pancreatitis, and abdominal trauma.

Clinical signs of bile duct strictures are cholestasis, which may be accompanied by sepsis, and pain. The diagnosis is established using cholangiography. In most cases, the cause of the disease can be determined based on the clinical picture.

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