الفهرس 
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Abstract
SUMMARY
Biliary atresia is an idiopathic neonatal hepatobiliary disease characterized by progressive fibrosing obstruction of the extrahepatic biliary tree. The gross appearance of the extrahepatic biliary tract varies from an inflamed, hypertrophic occluded biliary tract to an atrophic remnant. Histologically, the liver has features of portal tract inflammation, with a sbridging fibrosis and ultimately biliary cirrhosis occurs. The lumen of the extrahepatic duct is obliterated at a variable level and this forms the basis for the commonest classification in clinical use - the japanese association of pediatric surgeons classification. Type 3 is the commonest (~90%) type and has the most proximal level of BA, atresia extends up to common bile duct, whereas in type 1 BA, atresia extends up to common hepatic duct level. An important variation is that of cystic change, seen in about 5% of cases, within some part of the extrahepatic biliary tract. Some cysts contain mucus, while others contain bile. If it is bile, there may be diagnostic confusion with that of a true choledochal cyst. In cystic biliary atresia, the wall is invariably thickened, lacks an epithelial lining and communicates poorly
with abnormal non-dilated intrahepatic ducts. This should be evident at operative or percutaneous cholangiography. All patients with BA present with varying degree of jaundice, clay-colored stools and dark yellow urine. The severity of jaundice increases steadily and it is not unusual to find bilirubin levels around 20 mg% at the time of first presentation in developing countries. Failure to thrive, coagulopathy and anemia are also not uncommon. Some will present with signs of advanced disease and cirrhosis such as ascites, umbilical hernia, prominent abdominal veins and respiratory discomfort. In comparison to European or North American experience, most cases in developing countries present late. In a review of BA, only 5% cases were seen below 60 days of age, 40% between two and three months, 30% between three and four months and 25% presented beyond four months of age. Hepatomegaly was seen in all and 60% patients had a palpable spleen. The clinical diagnosis of BA is usually all too obvious in late-presenting cases. However, in infants of <60 days the diagnosis can be difficult. Key investigations include ultrasonography, biochemical liver function tests, viral serology, and a percutaneous liver biopsy. In some centers, duodenal intubation and measurement of intralumenal bile is the routine test for BA. Newer modalities such as ERCP and MRCP have been used at times, although the former is clearly highly operator-dependent and the latter not sufficiently precise in its delineation of infantile biliary anatomy to offer real advantage. Possibly, in most surgical centers, operative cholangiography remains the principal investigation in demonstrating biliary patency. This can also be performed laparoscopicaly with apparently good results. Currently biliary atresia is being managed in two phases: i. First phase: An attempt to preserve the infant’s own liver. This usually involves the Kasai operation which essentially excises all extrahepatic biliary remnants leaving a transected portal plate, followed by biliary reconstruction using a Roux loop onto that plate as a portoenterostomy. ii. Second phase: If bile flow is not restored by Kasai procedure or life-threatening complications of cirrhosis ensue then consideration should be given to liver transplantation. Sometimes this is done as a primary procedure, in those who present late with features of advanced cirrhosis. The major breakthrough in the surgery for biliary atresia was seen hi 1959 when Morio Kasai reported the operative relief of biliary obstruction in infants traditionally considered to have non-correctable biliary atresia. As described by Kasai and modified subsequently by others, the surgical steps of
portoenterostomy starts with opening of the abdomen through a right upper transverse incision, a peroperative cholangiogram (if required) and a wedge liver biopsy (if needed). Once the diagnosis of BA is established the liver should be mobilized fully outside of the abdominal cavity (by division of its suspensory ligaments), to ensure maximal exposure of the porta hepatis and facilitate a detailed dissection. The atretic gall bladder, cystic duct and all the remnant extrahepatic biliary tree are excised up to the level of the porta hepatis. The portal dissection itself must be wide extending from exposure of the origin of the umbilical vein from the left portal vein (in the Rex fossa) to the bifurcation of the right portal vein pedicle. Small veins from the portal vein to the portal remnant should also be divided to expose the caudate lobe posteriorly. The correct level of transaction is flush with the liver capsule, where the plane is usually self-evident. Transgression into actual liver parenchyma, however, adds nothing to the success of surgery. Most transected ductules are found in the marginal areas, recapitulating the normal biliary arrangement, and it is important to allow these to drain into a long (~40 cms) Roux loop of jejunum. Modifications such as an intussusception valve, stomas or implanting the distal end of the Roux into the duodenum have no real advantages in clinical practice and have been discontinued in most centers.
Various technical variants have been proposed according to the anatomical pattern of the biliary remnant. Hepaticojejunostomy may be possible in Type 1 BA although a complete excision and portoenterostomy even in these is probably a better option. If the gallbladder and distal common bile duct are patent then anastomosis of the opened gallbladder to the conduit to the transected portal plate (porto-cholecystostomy) is possible and avoids post-operative cholangitits. The appendix has also been described as a conduit (appendicojejunostomy), although some later series suggests no real advantages. A number of drugs have been suggested to try and improve postoperative results. For instance, there are anecdotal and uncontrolled studies suggesting benefit from corticosteroids, ursodeoxycholic acidl and even Chinese herbs. However, none have been subjected to anything like acceptable scientific scrutiny. The initial results of a randomized double-blind, placebo controlled trial using post-operative prednisolone (2 mg/kg/day) showed a reduction in initial bilirubin levels but no significant difference in ultimate clearance of jaundice or reduction in need for transplantion. Early postoperative complications include: cholangitis, bleeding, leak from anastomosis, prolonged ileus, and intestinal obstruction. Late complications include: cessation of
bile flow, recurrent cholangitis, portal hypertension, ascites, hepato-pulmonary syndrome, and formation of bile lakes in the liver and cirrhosis. A number of malignancies have been reported in the cirrhotic livers of patient with biliary atresia including hepatocellular carcinoma, hepatoblastoma and cholangiocarcinoma. The outcome following the Kasai operation can be assessed in two ways: i. Clearance of jaundice, ii. Proportions of native liver survival, Clearance of jaundice (<2 mg/dL or <34 /miol/L) after Kasai has been reported to be around 60%, whereas five-year survival with native liver ranges from 35% to 64%. Longterm (10 years or greater) survival have been reported in the range of 27%-53%. In our series, only about 15% had true longterm survival without jaundice, normal liver biochemistry and no signs of liver disease or portal hypertension. However, even in this apparently ”cured” group, liver histology still remains abnormal. In the children with a failed Kasai operation, liver transplantation is the only hope. The main problems associated with this major operation are lack of a suitable donor, small size of the recipient abdomen, immunosuppression and a significant postoperative morbidity and even mortality. At present, three-year survival after liver transplantation in good centers is 85-90%.