Hepatolithiasis (Oriental Cholangiohepatitis)

              Hepatolithiasis, previously known as Oriental cholangiohepatitis, recurrent pyogenic cholangitis, and primary intrahepatic stones, is most often encountered in patients from East Asia, with only an occasional non-Oriental patient reported. Prevalence in East Asia varies considerably between countries. The hallmark of this condition is intrahepatic bile duct stones proximal to the confluence of right and left hepatic ducts. The etiology of hepatolithiasis is not clear. Bile stasis and bacterial infection probably play a role. Some believe that infestation with the parasites Clonorchis sinensis or Ascaris lumbricoides results in an inflammatory reaction that starts a cycle of stasis, stone formation, and strictures, but evidence for such an association is not convincing. In Japan, a congenital basis for these strictures has been raised, with some patients having congenital common bile duct dilation.
                Multiple strictures develop and calculi and debris form proximal to these strictures. Both intra- and extrahepatic bile ducts eventually dilate, but stones form intrahepatically, more often in the left lobe rather than right lobe ducts. These stones tend to be composed of calcium bilirubinate; they tend to be soft, adhere to the duct wall, and vary in size. Their number ranges from several to multiple, in some patients filling most of the visualized bile ducts. In fact, often not all bile ducts are visualized by cholangiography because of segmental obstruction by stones.

This is radiology images of Oriental cholangiohepatitis. Computed tomography reveals stones (arrows) within dilated intrahepatic bile ducts.

              This condition is progressive and not curable. Involved liver segments tend to atrophy. Untreated, recurrent cholangitis, liver abscesses, cirrhosis and eventual portal hypertension develop. Clinically, the diagnosis is readily missed in countries with a low prevalence. Liver enzymes often are only mildly elevated, and the initial ERCP findings are subtle; early on, the extrahepatic ducts tend to appear normal, while a tight intrahepatic stricture prevents visualization of a more proximal stone in a dilated duct.
                In some patients the sphincter of Oddi is destroyed, with reflux of gas and intestinal content into bile ducts. At times orally ingested contrast refluxes into the bile ducts. Stones and air bubbles can be confused with each other. Computed tomography can suggest the diagnosis by detecting dilated intrahepatic bile ducts and stones. Once the diagnosis is suspected, ERC defines the underlying anatomy using, if necessary, a balloon catheter to dilate and obtain adequate filling of intrahepatic ducts. At times percutaneous cholangiography is necessary to outline the full extent of hepatolithiasis.
               Adequate antibiotic coverage is necessary for these procedures because these patients are prone to cholangitis and sepsis. Not all strictures in oriental cholangitis are benign. These patients are at increased risk for a cholangiocarcinoma. Because of distortion and obstruction by stones, an intrahepatic cholangiocarcinoma is readily overlooked. This tumor infiltrates diffusely and mimics a benignappearing stricture. Imaging in patients with cholangiocarcinoma in a setting of hepatolithiasis reveales irregular ductal strictures or obstruction and lobar atrophy; tumors and stones tend to be located in the same lobe. Some
of these patients have an intraductal papillary tumor and mucin hypersecretion. Generally, the initial therapy of these patients is surgical. Stone extraction, various biliary drainage procedures, and, at times, partial hepatectomy are performed. Liver resection is recommended by some surgeons for patients with intrahepatic segmental or subsegmental biliary stenoses. Some perform a partial left lobe resection if bilateral hepatolithiasis and strictures are found; they believe a lobectomy simplifies future treatment and may decrease complications. At times a Roux-en-Y hepaticojejunostomy is performed in order to clear stones. It is important at surgery to ensure that all stones are located and removed. Intraoperative US-guided transhepatic lithotomy is useful to detect residual stones; stones are located by US, and a surgical path is then chosen using US guidance. 
                A number of endoscopic and percutaneous transhepatic techniques have been developed to deal with these intrahepatic strictures and stones.At times a temporary surgical cutaneous stoma is created, allowing endoscopic access for cholangiography, stricture dilation, and stone removal. Some patients undergo exploration of extrahepatic bile ducts, any accessible stones are removed and a T-tube is inserted; using the Ttube tract for access, strictures are then dilated, stones removed, or electrohydraulic lithotripsy performed. The aim of therapy is complete stone clearance, although stone recurrence is common. An alternative approach in some patients is percutaneous transhepatic cholangioscopy and lithotripsy. As needed, percutaneous or endoscopic stricture dilation and stone extraction are performed. Smaller intrahepatic stones can be pushed into more central ducts, whilelarger stones are crushed. Stones can also be fragmented using extracorporeal shockwave lithotripsy.

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