Hepatic clonorchiasis--a study by endoscopic retrograde cholangiopancreatography

Parasitic and infectious diseases of the biliary tract in migrants and international travelers

In recent years, global and regional crises have led to extraordinary worldwide migration, accompanied by an increase in long-distance travel from Western countries. Both are linked to a rising incidence of rare parasitic and infectious diseases in first world countries, including in the biliary tract. Areas covered: A selective literature research in PubMed was performed to review the most important parasitic and infectious biliary diseases, which are caused by a wide variety of pathogens and may be latent over long periods, with chronic courses leading to cholangitis, hepatic failure or development of cholangiocarcinoma. Parasites such as Ascaris, Fasciola and Clonorchis/Opisthorchis are particularly important and may trigger biliary diseases or predisposition for bacterial superinfections. Viral or protozoal cholangitis is mainly a problem of impaired immunity. Expert commentary: Currently, these entities are still rare in migrants and long-distance travelers. However, a significant increase in Western countries has to be expected. Incidences are most likely underestimated because of protracted clinical latency. Diagnosis depends on the relevant pathogens, the host's immune status and the extent or distribution of biliary obstruction. Modern tomographic methods, ERCP and specific microbiological/parasitological/virological tests are of crucial diagnostic importance. Antimicrobial/antiparasitic/antiviral therapy along with ERCP and interventional sonography/radiology provide effective treatment options.

Parasitic infestations of the biliary tract

Parasitic infestations of the biliary tract are a common cause of biliary obstruction in tropical countries and can lead to such serious complications as cholangitis and cholangiocarcinoma. Endoscopic therapy has helped in the management of biliary complications caused by these parasites. Ascaris lumbricoides organisms, which normally reside in the jejunum, are actively motile and can invade the papilla, thus migrating into the bile duct and causing biliary obstruction. Endoscopic retrograde cholangiopancreatography is a useful diagnostic tool with potential for therapeutic management of biliary ascariasis. Infestation with Clonorchis sinensis organisms can cause such complications as intrahepatic stones, recurrent pyogenic cholangitis, cirrhosis, cholelithiasis, pancreatitis, and cholangiocarcinoma. Opisthorchis viverrini, Opisthorchis felineus, and Dicrocoelium dendriticum are closely related to C. sinensis and can also cause serious biliary complications. Fascioliasis, caused by Fasciola hepatica and F. gigantica, is a zoonotic helminthiasis that can present as acute hepatic or chronic biliary tract infection. CT, MRI, and ultrasound guidance are useful imaging tools for identifying these parasites and their complications.

Multiple hepatic nodules: rare manifestation of clonorchiasis

A 38-year-old man was admitted due to intermittent right upper quadrant pain for 1 month. Leukocytosis with marked eosionphilia and elevated serum alkaline phosphatase were noted. Stool examinations revealed no parasites or ova. Ultrasonography and computed tomography disclosed multiple hepatic tumors. Biopsy of the hepatic tumor was performed due to non-conclusive imaging studies and revealed eosinophil infiltration in portal areas only. Endoscopic retrograde cholangiography showed mild dilatation with irregularity of bilateral intrahepatic ducts, compatible with chronic cholangitis. Bile was aspirated and biliary lavage with normal saline was performed during endoscopy-guided biliary cannulation. Microscopic examination of the aspirate showed the characteristic ova of Clonorchis sinensis. The patient received Praziquantel therapy for 1 day. Abdominal pain reduced in intensity gradually. Eosinophilia and multiple hepatic lesions resolved after adequate treatment of Clonorchis sinensis. The rare manifestation of multiple hepatic tumors in Clonorchis sinensis should be differentiated from other primary or metastatic neoplasms, while biliary lavage for parasite ova is a valuable diagnostic tool when stool examination is negative.

Clonorchiasis: an update

Clonorchis sinensis, the Chinese or oriental liver fluke, is an important human parasite and is widely distributed in southern Korea, China (including Taiwan), Japan, northern Vietnam and the far eastern part of Russia. Clonorchiasis occurs in all parts of the world where there are Asian immigrants from endemic areas. The human and animal reservoir hosts (dogs, pigs, cats and rats) acquire the infection from the ingestion of raw fish containing infectious metacercariae. The first intermediate snail hosts are mainly species of Parafossarulus and Bithynia. Numerous species of freshwater fish serve as the second intermediate hosts of C. sinensis. Extensive studies of clonorchiasis during several decades in Japan, Korea, China and other countries have shown much progress in proving its morphological features including ultrastructure, biology, pathogenesis, epidemiology, clinical manifestations and chemotherapy. The present review deals with mainly current results obtained on the epidemiological, pathological and clinical aspects, as well as control measures in endemic areas. As for the complications of clonorchiasis, formation of calculi in the intrahepatic biliary passages is one of the most characteristic pathological features. It is sometimes accompanied by suppurative cholangitis, cholecystitis, cholangiohepatitis and ultimately can cause cholangiocarcinoma. Experimental results on the relationship to the occurrence of cholangiocarcinoma are presented. Clinical diagnosis by radiological findings including cholangiography, sonography and computerized tomography as well as magnetic resonance imaging for biliary or pancreatic ducts are outlined. Current studies on immunology and molecular biology of C. sinensis were introduced. Praziquantel is the drug of choice for clonorchiasis. The most effective regimen is 25 mg kg(-1) three times daily (total dose, 75 mg kg(-1)) administered orally at 5- to 6-h intervals over a single day. Prevention and control measures are also discussed.

The clinical and cholangiographic picture of hepatic clonorchiasis

BACKGROUND

Hepatic clonorchiasis is endemic in areas of the Far East, including Taiwan, where people commonly eat raw or partially cooked freshwater fish.

GOALS

To analyze and explore the cholangiographic findings of hepatic clonorchiasis with respect to the clinical data.

STUDY

From February 1990 to May 1999, 64 patients were diagnosed with hepatic clonorchiasis in the Kaoshiung Veterans General Hospital. Eighteen of the 64 patients were indicated for endoscopic retrograde cholangiopancreatography (ERCP). The final diagnosis was confirmed by identification of ova in bile or worms in the biliary tract.

RESULTS

Fifteen (83%) of 18 patients had history of raw fish consumption and seven patients (39%) came from an endemic area. Clinically, cholangitis (8 of 18) was the most frequent indication for ERCP. All of the patients were diagnosed by the presence of ova in bile. Only seven (39%) patients had peripheral eosinophilia, and seven (39%) had ova in stool. The most characteristic cholangiographic finding of hepatic clonorchiasis in ERCP is filamentous or elliptic filling defects of the biliary tract (16 of 18).

CONCLUSION

When presented with biliary symptoms, a history of raw fish consumption in an endemic area should arouse suspicion of hepatic clonorchiasis. Filamentous filling defects in ERCP with bile analysis may confirm the diagnosis.

Endoscopic cholangiopancreatography in hepatic clonorchiasis--a follow-up study

Cholangiographic changes of the biliary system in 16 patients with proven hepatic clonorchiasis, diagnosed by positive stool or bile ova isolates, were studied. All patients presented with epigastric pain. Other symptoms included jaundice in 31% (5 of 16) and fever in 12.5% (2 of 16). Praziquantel given at 25 mg/kg for three doses in 1 day were administered. Three consecutive stool tests were performed 3 months after treatment and were negative in 87.5% (14 of 16). ERCP studies were repeated at a mean interval of 31.6 months (range, 8 to 69 months). Measurements of the bile ducts on retrograde cholangiograms before and after treatment were compared using the paired Student's t test. Filling defects and blunting of the terminal bile ducts seen on the initial cholangiogram, interpreted as the presence of adult worms, disappeared after treatment. However, there was no significant change between pre- and post-treatment measurement of bile duct caliber. Bile duct dilation, irregularities, and ductal proliferation persisted despite eradication of the parasite.

Biliary papillary hyperplasia with clonorchiasis resembling cholangiocarcinoma

Infection by the liver fluke Clonorchis sinensis is very common in the Far East. It causes low grade inflammatory changes and proliferation in the biliary tree. Initially there is desquamation of the biliary epithelium, followed by hyperplasia and adenomatous proliferation. Cholangiocarcinomas are potential long term complications. We present a case of biliary papillary hyperplasia with clonorchiasis resembling cholangiocarcinoma in a 69-yr-old Korean man. Early recognition of biliary hyperplasia and treatment of Clonorchis sinensis is important to prevent development of cholangiocarcinoma, especially in the Far East.

Hepatolithiasis and biliary parasites

Hepatolithiasis, or the presence of intrahepatic stones, is prevalent in East Asia and is characterized by the finding of stones within the intrahepatic bile ducts proximal to the confluence of the right and left hepatic ducts. Bile stasis and bacterial infection have been incriminated as the major aetiopathogenic factors. Clinical features include recurrent pyogenic cholangitis, multiple liver abscesses, secondary biliary cirrhosis and cholangiocarcinoma. The goals of management include accurate localization of pathologies, control of biliary sepsis and the elimination of stones and stasis. Ultrasonography, computed tomography and direct cholangiography complement each other in defining the stones, strictures and degree of liver damage. Non-operative biliary decompression by endoscopy and interventional radiology is effective in controlling the infection, but surgery remains the mainstay for the treatment of stones and strictures. Intra-operative ultrasound and flexible choledochoscopy, combined with percutaneous transhepatic cholangioscopy and intraductal lithotripsy, facilitate stone removal. Balloon dilatation and biliary stenting serve to open the bile duct strictures. The creation of a hepaticocutaneous jejunostomy after conventional surgery allows atraumatic access to the biliary system for the removal of recurrent stones. The management of biliary parasites begins with conservative measures, including analgesics and anti-helminthic therapy. In refractory cases or patients with acute cholangitis, endoscopic biliary drainage and the extraction of worms may be necessary. Improvement in sanitation plays a crucial role in the epidemiological control of these biliary diseases.