Gastroenterology and Hepatology Board Review: Pearls of Wisdom, Third Edition

Section VI GALLBLADDER, BILE DUCTS, AND PANCREAS

CHAPTER 32. Gallbladder, Bile Duct, and Pancreatic Infectious Disorders

David W. McFadden, MD, MBA and Denise McCormack, MD

Image What organism is most commonly associated with recurrent pyogenic cholangitis?

Clonorchis sinensis.

Image What parasite can predispose to intrahepatic gallstones?

Ascaris lumbricoides.

Image What is the intermediate host for Fasciola hepatica?

Lymnaeca trunculata—snail. Patients are infected by eating infected watercress.

Image Eosinophilia, elevated alkaline phosphatase, and cholangiography findings of filamentous filling defects with blunted tips in the bile duct suggest what infection?

C. sinensis, the Chinese liver fluke, or F. hepatica, the common or sheep liver fluke.

Image When is surgical treatment indicated for patients with infestation of the biliary tract by C. sinensis (Chinese liver fluke)?

Surgical treatment is reserved for complications, such as biliary obstruction, due not only to the parasites themselves but also to secondary formation of stones and acute cholangitis. Some patients present with pancreatitis, presumably caused by passage of the stones or the worms. In addition to cholecystectomy and clearing the bile ducts of stones and flukes, improved biliary drainage by choledochoduodenostomy, hepaticojejunostomy, or transduodenal sphincteroplasty is thought to reduce the rate of recurrent biliary obstruction, which otherwise exceeds 40%.

Image What class of antibiotic has been shown to achieve therapeutic concentrations in bile and is useful in treating cholangitis?

Fluoroquinolones.

Image What antibiotic may lead to the development of biliary sludge?

Ceftriaxone precipitates a calcium salt that has the ultrasonic appearance of biliary sludge.

Image Which of the following primary duct stones has the highest positive culture rate for bacteria—black, brown, or cholesterol?

Brown.

Image What factors are associated with the development of black pigment stones?

Chronic hemolysis, as can occur in hereditary spherocytosis, thalassemia and the presence of mechanical heart valves, cirrhosis, total parenteral nutrition, and advanced age.

Image What bacterial infection and anatomical deformity play a role in the formation of brown pigment stones?

Escherichia coli and a juxtapapillary duodenal diverticulum.

Image What bacterial enzyme is responsible for hydrolysis of conjugated bilirubin and may play a role in the development of pigment stones?

Bacterial beta-galactosidase, which is homologous to human beta-glucuronidase.

Image What bacterium may cause acute cholecystitis and also be nonpathogenic in a carrier state?

Salmonella.

Image Name two nonbacterial infectious entities that predispose to acute cholecystitis in an immunocompromised host.

Cytomegalovirus (CMV) and Cryptosporidium.

Image What are the three most common organisms isolated from blood cultures in patients with acute ascending cholangitis?

E. coliKlebsiella, and Pseudomonas. Anaerobes are isolated in approximately 15%.

Image What is the mechanism of biliary obstruction in tuberculosis?

Obstructive jaundice is a rare complication of tuberculosis. The obstruction is caused by tuberculous infection involving lymph nodes in the porta hepatis or the retroduodenal area that compresses the bile duct.

Image Charcot’s triad plus what other two clinical features define Reynold’s pentad?

Hypotension and altered mental status.

Image In Oriental cholangitis, which side of the hepatic ductal system most commonly develops strictures and intrahepatic stones?

The left hepatic ductal system, presumably due to its more acute angle at the bifurcation.

Image Bacillary angiomatosis with peliosis is caused by what organism?

Bartonella henselae or Bartonella quintana.

Image What is the treatment of bacillary angiomatosis with peliosis in a patient with fever, abdominal pain, and elevated liver tests?

Antibiotic therapy with erythromycin or doxycycline.

Image What species of Microsporidia is responsible for causing AIDS cholangiopathy?

Enterocytozoon bieneusi.

Image True/False: The signs and symptoms of an acute pancreatic infection differ from those that occur with acute pancreatitis.

False. Epigastric pain, fever, nausea, and/or vomiting are frequent symptoms. Signs include leukocytosis and elevations in serum amylase and lipase.

Image What are the most common viral infections of the pancreas?

Mumps, rubella, coxsackievirus B, Epstein–Barr virus (EBV), CMV, herpes simplex virus (HSV), HIV, and hepatitis A, B, and C.

Image What virus is the most common cause of infection-related pancreatitis in children?

Mumps.

Image What fungal infections can involve the pancreas and/or cause pancreatitis?

Candida species, Torulopsis glabrata, and Cryptococcus are the most common. Aspergillus fumigatus, Coccidioides immitis, Paracoccidioides brasiliensis, Histoplasma capsulatum, and Pneumocystis jiroveci may also be involved.

Image What appears to be the most effective treatment for fungal infections involving the pancreas?

Amphotericin B. Drainage and debridement of infected necrosis are also important.

Image What is the most common type of parasitic infection of the pancreas?

A. lumbricoides, the giant roundworm. Other parasitic infections include Echinococcus granulosisGiardia lambliaPlasmodium falciparumC. sinensis and Strongyloides stercoralis.

Image True/False: The most common bacteria that cause pancreatic infections are Gram-negative enteric organisms.

True. Gram-negative enteric bacteria, anaerobes, and Candida species are most common pathogens; however, Staphylococcus aureus is also frequently isolated.

Image True/False: Pancreatic abscess is a frequent complication of acute pancreatitis.

False. Pancreatic abscess complicates about 5% of cases of acute pancreatitis and occurs about 2 to 6 weeks after the initial attack.

Image What is the treatment of pancreatic abscess?

External (percutaneous) catheter drainage and broad-spectrum antibiotics. If this fails, surgical debridement is usually needed.

Image Describe the pathogenesis of infected pancreatic necrosis in a patient with acute necrotizing pancreatitis.

Infected pancreatic necrosis develops as a result of transmural, transductal, lymphatic, or hematogenous spread of infectious organisms to necrotic regions of the pancreas. It usually occurs less than four weeks after the initial onset of pancreatitis.

Image What is the gold standard for establishing a diagnosis of infected pancreatic necrosis?

CT-guided percutaneous aspiration with Gram stain and culture is indicated in patients who exhibit signs and symptoms suggestive of infected pancreatic necrosis.

Image A visiting shepherd from South America is transferred to your service with fever, weight loss, and diarrhea. A CT scan of the abdomen reveals a large calcified cyst with fenestrations in the pancreas and several smaller cysts nearby. What is your diagnosis?

Hydatid cysts of the pancreas.

Image What organism is responsible for hydatid cyst disease?

Echinococcus granulosus, or occasionally E. multilocularis, a parasitic worm that normally resides in the intestine of dogs.

Image What are the intermediate hosts in hydatid disease?

Man, sheep, and cattle.

Image How is the diagnosis of hydatid disease made?

Diagnosis is based on history of exposure from endemic areas and characteristic radiographic findings including evidence of daughter cysts within larger primary cysts. A negative serologic test does not necessarily exclude the diagnosis.

Image What is the treatment of hydatid cysts of the pancreas?

Surgical excision, if technically possible without major pancreatic resection, or infusion of scolicidal agents (eg, 95% ethanol and hypertonic saline) and high-dose mebendazole or albendazole are the mainstays of treatment.

Image How does the HIV affect the pancreas?

Indirectly through secondary infections, infiltrative processes (lymphoma, Kaposi’s sarcoma), or drugs used in its treatment (eg, 2′, 3′ dideoxyinosine).

Image What is the most common opportunistic infection of the pancreas in AIDS patients?

CMV. Others include CryptococcusToxoplasma gondiiCryptosporidiumM. tuberculosis and M. avium complex.

• • • SUGGESTED READINGS • • •

Trikudanathan G, Navaneethan U, Vege SS. Intra-abdominal fungal infections complicating acute pancreatitis: a review. Am J Gastroenterol. 2011;106:1188-1192.

Behrman SW, Bahr MH, Dickson PV, Zarzaur BL. The microbiology of secondary and postoperative pancreatic infections: implications for antimicrobial management. Arch Surg. 2011 May;146(5):613-619.

Devarbhavi H, Sebastian T, Seetharamu SM, Karanth D. HIV/AIDS cholangiopathy: clinical spectrum, cholangiographic features and outcome in 30 patients. J Gastroenterol Hepatol. 2010 Oct;25(10):1656-1660.

Julka K, Ko CW. Infectious diseases and the gallbladder. Infect Dis Clin North Am. 2010 Dec;24(4):885-898.