Biliary atresia

Case contributed by Francis Fortin
Diagnosis certain

Presentation

Elevated liver enzymes and cholestasis found on blood work in a context of left inguinal ovarian hernia.

Patient Data

Age: 8 weeks
Gender: Female
ultrasound

Findings:

Small gallbladder measuring 23 x 2 mm with finely echogenic walls (accessible for puncture).

Echogenic cord in front of the right portal branch 3 mm thick, not fulfilling the 4 mm cutoff for the triangular cord sign but still suspicious.

Dilation of the hepatic artery at the hilum (3.3 mm), nearly as large as the portal vein. Permeable portal and hepatic veins.

Slightly heterogeneous echogenicity of the liver parenchyma, with smooth contours.

No visibility of the extrahepatic bile ducts.

Mild splenomegaly at 6.2 cm (no polysplenia).

Partially visible portions of the pancreas are normal. Normal relationship of mesenteric vessels.

Normal kidneys. No mass effect in the adrenal regions.

Bladder, uterus and right ovary normal. Left ovary not seen in the pelvic cavity.

Conclusion:

High suspicion for biliary atresia.

Percutaneous transhepatic gallbladder puncture was requested by pediatric hepatology and surgery teams to confirm the diagnosis prior to surgery.

Gallbladder puncture

Fluoroscopy

Technique:

Under sterile conditions and general anesthesia, ultrasound-guided gallbladder puncture with a 22-gauge spinal needle passing through the liver. Cholangiography with iodinated contrast medium.

Afterwards, local anesthesia with 1.5 ml of ropivacaine 0.2%. Small incision in the skin. Hepatic biopsy under the ribs with a semi-automatic 16 gauge system. Manual compression for 10 minutes. No hemoperitoneum or traumatic intrahepatic vascular lesion on post-compression ultrasound.

Compression dressing performed.

Findings:

Cholangiography demonstrates an irregular, microlobulated gallbladder, a cystic duct that progressively dilates upon injection, and a network of very fine irregular bile ducts in the hepatic hilum (appearance of cholangiolar proliferation) with progressive enhancement of extensive periportal fibrosis. No opacification of a common bile duct.

The liver biopsy specimen appeared macroscopically adequate, greenish-brownish.

Conclusion:

Transhepatovesicular cholangiography confirming biliary atresia.

Liver biopsy without complication.

Patient underwent Kasai procedure and bilateral inguinal hernia repair.

On surgery, the liver was enlarged and had an obvious cholestatic appearance but remained soft and smooth. The gallbladder was hypoplastic. The exploration of the common bile duct showed the absence of an internal lumen, but there still seemed to be a small communication upstream confirming the diagnosis of partial biliary atresia.

Biopsy and surgical pathology confirmed biliary atresia and F3 liver fibrosis.

Case Discussion

Characteristic ultrasound and cholangiography images of biliary atresia. The combination of several ultrasound findings increases the likelihood of a positive imaging diagnosis, such as in this case with a triangular cord sign (though less than the usual 4 mm cutoff), hepatic artery enlargement, a small and irregular gallbladder with echogenic walls, heterogeneous liver texture and splenomegaly. Though the absence of a visible gallbladder is suggestive of biliary atresia in the appropriate clinical context, it can also represent isolated gallbladder atresia. Likewise, the presence of a gallbladder in no way rules out biliary atresia.

In children with cholestasis, one should have a very high degree of suspicion for biliary atresia, seeing as it is the most common cause of cholestasis requiring emergent surgery and delay in diagnosis results in poorer outcomes.

If a gallbladder is present, percutaneous transhepatic gallbladder puncture can be performed for preoperative confirmation of the diagnosis. Findings are variable and can include (1) a visible gallbladder with no communication with the biliary tree, (2) visible common bile duct, but no reflux into the common hepatic duct and (3) visible common hepatic duct but no visible common bile duct. As in this case, some patients may have irregular lace-like biliary structures in the liver hilum and ill-defined enhancement which is thought to represent fibrosis and cholangiolar proliferation.

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