Acute Hepato-Biliary Diseases in Children

Causes of gallstones in childhood

• Hemolytic anemia

• Infection

• Dehydration

• Cirrhosis

• Cystic fibrosis

• Wilson’s disease

• Crohn’s disease and ileal resection

• Parenteral nutrition

• Drugs: furosemide and ceftriaxone

• Biliary tract obstruction (choledochal cyst, sclerosing cholangitis)

• Caroli’s disease

• Obesity

• Familial history

• Metachromatic leukodystrophy

Abdominal US is the key examination as it will demonstrate easily bile ducts dilatation and the presence of stones or sludge in the gallbladder and in the bile ducts. The extrahepatic bile duct diameter varies with age from less than 1.5 mm before the age of 1 year to less than 3.5 mm in teenagers (Fig. 15.1).

Fig. 15.1

Cholelithiasis. Seven-year-old girl presenting with acute abdominal pain and jaundice. (a) US shows a marked dilatation of intra an extra-hepatic bile ducts (head-arrow). (b) With a hyperechoic stone at the end of the common bile ducts (arrow). (c) After spontaneous migration of the stone in the bowel, MRCP performed to search for an underlying bilio-pancreatic malformation shows the normal aspect of the biliary tree and the bilio-pancreatic junction

When US is inconclusive because no stone is visible or when there is a suspicion of underlying biliary malformation (mostly pancreatico-biliary maljunction also called abnormally long common bilio-pancreatic duct), MRCP can be helpful; it may depict small stones localized at the end of the common bile duct and show the bilio-pancreatic duct that should measure less than 5 mm long (Figs. 15.1 and 15.2) [2].

Fig. 15.2

Choledochal cyst. 2.5-year-old boy presenting with intense abdominal pain and jaundice. (a) US shows a marked dilatation of intrahepatic and extrahepatic bile ducts. (b) with sludge at the end of the common bile duct. There was a high suspicion of choledochal cyst with acute obstruction by the sludge (arrow). (c) MRCP confirms the diagnosis showing a pancreatico-biliary maljunction with an abnormally common bilio-pancreatic duct measuring 15 mm (double arrow). (d) Spontaneous resolution of the pain and the jaundice. (d) US control shows the dramatic decrease of the diameter of the common bile duct. Note that the dilatation of the choledochal cyst may be very mild in the absence of obstacle

As in adults, an endoscopic or surgical treatment is applied in symptomatic patients especially those having a predisposing factor.

15.3.1.2 Biliary Malformations-Choledochal Cyst

Biliary malformations may present acutely with abdominal pain, or evidence of pancreatitis and cholestasis. The most frequent malformation is probably the pancreaticobiliary maljunction (PBM) in which the pancreatic and the bile ducts join anatomically outside the duodenal wall with a common pancreatico-biliary duct measuring more than 6 mm. Therefore reciprocal reflux of bile and pancreatic juice occurs resulting in various complications: dilatation of extra-hepatic bile ducts (choledochal cyst) with or without obstruction, biliary stones, abdominal pain, pancreatitis and biliary or pancreatic cancers in older patients [3].

In most cases, the initial US will reveal variable degrees of extra- ± intrahepatic bile ducts dilatation, with or without stones as well as signs of pancreatitis. In some cases, PBM might be demonstrated with US. Still in most cases, MRCP is the key examination to confirm PBM (Fig. 15.2). Furthermore, this technique shows accurately the anatomy of bile ducts before surgery [2]. In doubtful cases, direct transhepatic puncture of the gallbladder can be performed and will allow direct opacification of the biliary tract and of the PBM. During the puncture, the level of amylase can be evaluated and confirm the diagnosis, as it is very elevated in the bile in most cases [4].

If the obstruction is complete or associated with infection or major pain, biliary drainage may be indicated prior to surgery (see Sect. 15.4.2). Surgery consists of complete resection of the extrahepatic bile duct and the gallbladder with hepatico-jejunostomy. This surgery is also performed in order to prevent tumoral transformation. In most cases, the prognosis is good. Stenosis of the bilio-digestive anastomosis may happen; postoperative US follow-up is mandatory to detect postoperative bile ducts dilatation.

The main differential diagnosis of biliary tract malformation during childhood is cholelithiasis without underlying malformation (see15.3.1.1).

15.3.1.3 Varia: Extrinsic Compression, Cholangitis

In exceptional cases, initial imaging will reveal an intra-biliary tumor (rhabdomyosarcoma), an extrinsic compression by a mass (tumor, duodenal duplication, etc.) or diffuse abnormalities of the bile ducts that may reveal sclerosing cholangitis (especially in the context of inflammatory bowel disease, Langerhans cells histiocytosis, immunodeficiency disorders or autoimmune hepatitis, IgG4 syndrome) (Fig. 15.3). In case of sclerosing cholangitis, subsequent MRCP will be very useful to search for irregular dilatation of bile ducts and thickening of bile ducts. The prognosis is usually poor leading to biliary cirrhosis.

Fig. 15.3

Biliary rhabdomyosarcoma. Four-year-old boy presenting acute acholic stools and jaundice. (a) US shows the marked dilatation of intra and extrahepatic bile ducts with solid tissue (arrows) visible at the end of the common bile duct. (b) US shows the extension in the cystic duct as well (arrow). (c) MRCP shows the presence of abnormal tissue in the extrahepatic bile duct with a high signal intensity on T2-weighted imaging

15.3.1.4 Gallbladder Abnormalities

Usually revealed by right upper quadrant pain, acute abnormality of the gallbladder is usually first confirmed on US.

Hydrops of the gallbladder consists in an acute distension without any mechanical obstruction of the cystic duct. On US, the gallbladder appears distended, with thin walls and anechoic content. It may be associated with numerous disorders such as scarlet fever, streptococcus, salmonella and Shigella infection, Kawasaki disease, leptospirosis, extensive burning, polyarteritis nodosa, familial paroxysmal polyseritis and prolonged parenteral nutrition. Spontaneous resolution is the usual outcome. Perforation is rare but may occur (Fig. 15.4).

Fig. 15.4

Hydrocholecystis and acalculous acute cholecystitis, aspects on US. (a) Distended gallbladder with thin walls and anechoic content consistent with a hydrocholecystis associated with Kawasaki disease. (b) and (c) Thickened and hypervascularized gallbladder walls consistent with an acalculous acute cholecystitis in a context of autoimmune hepatitis. (d) Collection revealing the spontaneous perforation of hydrocholecystis associated with hepatitis A

Acute acalculous cholecystitis is usually revealed by abdominal pain of the right upper quadrant and fever. It is defined by the presence of a large gallbladder with at least two of the following three criteria on US: increased gallbladder wall thickening (>3.5–4 mm), pericholecystic fluid and the presence of sludge. It is the most frequent type of cholecystitis in children. It may develop in previously healthy and non-critically ill children. It is related in most cases to viral infection: hepatitis A virus (HAV) and Epstein Barr virus (EBV) hepatitis in most cases. The prognosis is good. Association with Kawasaki disease is also reported; the hepatobiliary involvement is associated with coronary artery disorders (see Sect. 15.3.2.5). Acalculous cholecystitis can develop also in critically ill children or post-surgery patients or be associated with severe bacterial infection. Conservative treatment is the rule. Percutaneous cholecystostomy can be proposed in selected cases. In very exceptional cases, rupture may happen (Fig. 15.4).

Thickening of the gallbladder wall may also be encountered in association with ascites, hypoalbuminemia, portal hypertension, and cardiac failure [5, 6].

15.3.2 Acute Hepatobiliary Disease

15.3.2.1 Acute Liver Failure

Acute liver failure is very rare in infants and children. Patients present with aspecific symptoms such as nausea, vomiting, weakness, anorexia, jaundice, pruritus, and fever. In severe cases, seizure and encephalopathy may develop.

The aims of imaging the liver must be to look for (Fig. 15.5):

Signs of chronic liver disease that may suggest an underlying unknown disease,
Involvement of other organs indicative of some specific diagnosis: for instance, enlarged lymph nodes suggestive of a hemopathy,
Signs of portal hypertension such as persistent patent ductus venosus, thickened small omentum with or without direct visualization of the left gastric vein that may be enlarged with hepatofugal flow, hepatofugal portal flow, splenomegaly, etc. [1].

Fig. 15.5

Acute liver failure revealing underlying chronic liver disease (Wilson disease) in two different patients. (a) Examination with curvilinear probe shows a hyperechoic liver probably steatotic with normal size and regular margins. (b) High-resolution examination with high frequency probe shows that the parenchyma is heterogeneous. (c) Irregular margins of the liver clearly visible along the gallbladder. (d) Spontaneous spleno-renal shunts consistent with portal hypertension. (e) Thickened small omentum consistent with portal hypertension

Whatever the etiology, common findings on imaging will be: enlarged liver, ascites and thickened gallbladder wall.

Usual etiologies and suggestive patterns on abdominal imaging are listed in Table 15.2 [7].

Table 15.2

causes of acute liver failure and suggestive patterns on imaging [7]

			Imaging suggestive patterns
Infants	Infectious	Hepatitis A, hepatitis B, NANB hepatitis, HSV	Acalculous cholecystitis
	Drugs and toxins	Acetaminophen, valproate, isoniazid
	Metabolic	Hereditary fructose intolerance, mitochondrial disorders, tyrosinemia	Large kidneys
	Immune	Autoimmune hepatitis, macrophage activation syndrome, hemophagocytic syndrome
	Abnormal perfusion	Congenital heart disease, myocarditis, severe asphyxia, vascular or anatomic abnormality	Dilatation of hepatic veins, obstruction of hepatic veins or portal veins, heterogeneity of liver parenchyma
	Other	Malignancy	Mass, lymph nodes, liver may be homogeneous
Children	Infectious	Acute viral hepatitis A/B, NANB hepatitis, EBV	Acalculous cholecystitis
	Drugs and toxins	Acetaminophen, valproate, isoniazid
	Immune	Autoimmune hepatitis, macrophage activation syndrome, hemophagocytic syndrome
	Abnormal perfusion	Budd-Chiari syndrome, congenital heart disease, myocarditis, severe asphyxia, vascular or anatomic abnormality	Stenosis or thrombosis of hepatic or portal veins Dilatation of portal vein Abnormal pulsed-Doppler pattern Signs of chronic liver disease
	Metabolic	Wilson’s disease	Large gallbladder Sludge, stones
	Other	Malignancy, hyperthermia	Mass, lymph nodes may be homogeneous

15.3.2.2 Infection

Liver infections are severe conditions that usually present acutely and may be fatal. Viral hepatitis is the most common diffuse infection of the liver in otherwise healthy children. Imaging plays a role in severe presentations or in complications. Bacterial liver infection may present as pyogenic abscess, granulomatous disease or diffuse infection. Parasitic infections are also possible and may involve the biliary tree (ascariasis) or the parenchyma (echinococcosis or amebiasis). Immunocompromised patients are more susceptible to other infectious agents especially fungus. Imaging plays a key role in the early detection, characterization, and management of these severe conditions.

Viral Hepatitis

Most viral hepatitis in infants and children are caused by Hepatitis viruses or EBV. However a number of other viruses have been implicated in childhood hepatitis such as mumps, measles, Varicella zoster virus, herpes simplex virus, and cytomegalovirus.

The diagnosis relies on clinical data and biology.

Imaging can search for a cause of hepatic failure and for complications. US may show an enlarged heterogeneous liver with periportal hyperechogenicity related to peri-portal edema. The wall of the gallbladder may be thickened. Lymphadenopathies may be present along the hepatic pedicle (Fig. 15.4).

CT or MR imaging should be performed in severe cases especially if liver transplantation is planned. They can show peri-portal hypodensity/hyperintensity on T2-weighted imaging and heterogeneous liver parenchyma. Sometimes the whole liver will appear hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging [8].

Bacterial Infection

Liver Abscess

Pyogenic abscesses are rare in children. The pathogenesis of liver abscesses is multifactorial; they can result from ascending cholangitis, hematogenous dissemination from a gastrointestinal infection (via the portal vein) or from disseminated (via the hepatic artery), or through contiguous spread.

Hepatic abscesses have mainly been reported in immunocompromised children with chronic granulomatous disease, bone marrow transplant, immunosuppressive chemotherapy congenital or acquired immunodeficiency, or in children with intraabdominal infection. Yet, liver abscess can occur without any predisposing factor.

Clinical presentation is not specific but may include hepatomegaly with tenderness, fever (70–90% of patients) and biological signs of infection.

In most patients, the infection is usually polymicrobial aero- or anaerobic. Infective organisms are usually Staphylococcus aureus (50% of the cases), Streptococcus, Escherichia coli, Enterococcus faecalis, Klebsiella, Enterobacter, Pseudomonas organisms, and salmonellae [9].

Abdominal US is the first examination to perform and will show in most cases a solitary mass with variable patterns ranging from a well-defined, homogeneous, hypoechoic or fluid containing mass to a poorly defined, heterogeneous mass. Pleural effusion with lung condensation may be associated. On CE-CT, the typical aspect is the “double target sign” with a central low attenuation fluid-filled area surrounded by a high attenuation inner ring and a low-attenuation outer ring. The inner layer shows early contrast enhancement that persists on the delayed phase whereas the outer ring enhances only during the delayed phase.

On MR imaging, hepatic abscesses typically show central low T1-weighted and high T2-weighted signal intensity. The double target sign on T2-weighted appears as an isohypointense inner layer and a hyperintense outer layer. Enhancement is similar to the one observed on CT. Perilesional edema can appear as high signal intensity on T2-weighted. High intensity on DWI with decrease of apparent diffusion coefficient (ADC) is usually seen.

On dynamic CT and MR imaging, a transient, early, wedge shaped or circumferential segmental region of hepatic enhancement, which equilibrates in late phase, can be associated with liver abscess and reflects perfusion disorders of the surrounding liver probably related to the compression or thrombosis of adjacent portal veins (Fig. 15.6) [8].

Fig. 15.6

Liver abscesses: 4-year-old girl presenting with acute abdominal pain and fever. (a) Initial US examination shows two hypoechoic rather well-defined hepatic nodules consistent with liver abscesses in the context. (b) Color Doppler demonstrates patency of the surrounding vessels. (c) CE-CT shows a well-defined isoattenuating central area with a hypoattenuating appearance of its peripheral wall (target-appearance). Note the associated wedge-shaped segmental region of hepatic enhancement, highly suggestive of liver abscess. Puncture and drainage of the largest abscess confirmed the diagnosis and showed the presence of Staphylococcus aureus. (d) US after direct puncture of one abscess that confirmed the diagnosis of liver abscesses with the presence of Staphylococcus aureus. Further investigation revealed chronic granulomatous disease

The different complementary examinations must search for an infection at the origin of or associated with the liver abscess. If no source is discovered, an underlying predisposing disorder such as immunodeficiency must be searched.

Gas can be present within the mass and may raise the possibility of a gastrointestinal fistula or anaerobic infection (Fig. 15.10).

Management of pyogenic liver abscesses includes antibiotic therapy and percutaneous drainage if the abscess is large enough (>5 cm) [10] (see Sect. 15.4.3).

Only gold members can continue reading. Log In or Register to continue