Biliary system obstruction

Enzyme changes occur in several gastrointestinal conditions, such as intestinal infarction or obstruction, parasitic infections, obstruction of the biliary system, and contraction of the sphincter of Oddi by drugs such as morphine, withdrawal of food, and age-related changes. 

These closely related trematodes exist in the Far East (C. sinensis, the Chinese liver fluke, and O. viverrini) and parts of Eastern Europe (O. felineus). Metacercariae releasedfrom poorly cooked infected fish mature into adult flukes that inhabit the human biliary system. Heavy infections can cause obstructive liver disease, inflammatory gallbladder pathology associated with cholangio-carcinoma, and obstructive pancreatitis. One-day therapy with praziquantel is highly effective. 

If it is difficult to identify the bile duct, as can be the case in very young children, an alternative approach is to drain the biliary system via the gallbladder. This can of course only be done in cases of a distal obstruction (Fig. 7.11). 

Hyoty MK,NordbackIH (1990) Biliary stent or surgical bypass in unresectable pancreatic cancer with obstructive jaundice. Acta Chir Scand 156 391-396 Jasche W, Klose KJ, Strecker EP (1992) A new balloon - expandable tantalum stent (Strecker-stent) for the biliary system preliminary experience. Cardiovasc Intervent Radiol 15 356-359... 

Sung, JJ, Chung, SC, Tsui, CP et al (1994. Omitting side-holes in biliary stents does not improve drainage of the obstructed biliary system a prospective randomized trial. Gastrointest Endosc 40 321-325... 

When duodenal obstruction occurs without jaundice and a biliary stent is not in situ, subclini-cal biliary obstruction must be excluded before duodenal stent placement. Careful assessment of the biliary system is important so that impending bile duct obstruction can be treated. Where ERCP is precluded by the duodenal tumour, information from CT may be complemented by ultrasound or magnetic resonance cholangio-pancreatography (MRCP). If the patient s liver function tests are abnormal in the absence of hepatic metastases, this should be assumed to reflect biliary obstruction and a biliary stent placed. It is wise to place a metal biliary stent first, either endoscopically or transhepati-cally before placing a duodenal stent. 

MRCP visualises the biliary and pancreatic system and is used to identify obstruction. It uses MRI and the inherent contrast properties of bile and pancreatic fluids to produce the image, and therefore does not require the injection of contrast media. It is used as an alternative to ERCP as it is non-invasive and can be used for patients with a history of allergy to iodine. 

Bile acid sequestrants Choiestryamine Colestipoi Colesevalam Bind to bile acids in gut LDLi t5%"30% HDL t 30% TG no change or t Gl constipation, bloating, abdominal pain None(not system ically absorbed) i, bioavai lability of coadministered drugs separate other drugs at least 1 hr before or 4-6 hr after Complete biliary obstruction severely elevated TG... 

Hepatobiliary transporters are affected by both systemic inflammation (e.g., arising from an infection) and inflammation intrinsic to the liver (e.g., acute inflammatory cholestasis caused by drug or alcohol abuse). As described above, endotoxin or turpentine are used to trigger systemic inflammation in rodents. Other rodent models of cholangitis include ethinylestradiol (oral contraceptive-induced cholestasis/cholestasis of pregnancy), alpha-naphthylisocyanate (vanishing bile duct syndrome), and common bile duct ligation (extrahepatic biliary obstruction) [87, 88]. 

Measurement of serum y-GT activity has clinical significance. The enzyme is present in all tissues, but the highest level is in the kidney however, the serum enzyme originates primarily from the hepatobiliary system. Elevated levels of serum y-GT are found in the following disorders intra- and posthepatic biliary obstruction (elevated serum y-GT indicates cholestasis, as do leucine aminopeptidase, 5 -nucleotidase, and alkaline phosphatase) primary or disseminated neoplasms some pancreatic cancers, especially when associated with hepatobiliary obstruction alcohol-induced liver disease (serum y-GT may be exquisitely sensitive to alcohol-induced liver injury) and some prostatic carcinomas (serum from normal males has 50% higher activity than that of females). Increased activity is also found in patients receiving phenobarbital or phenytoin, possibly due to induction of y-GT in liver cells by these drugs. 

The excretion theory is now thoroughly discounted and there is considerable evidence to suggest that in hepatobiliary disease, the eirculating alkaline phosphatase comes from the liver and/or the bile passages (H15a, K7, P19, R21, S24). It now appears established that biliary obstruction leads to increased synthesis of alkaline phosphatase in the hepatobiliary system (K6) and that the newly synthesized enzyme then reaches the blood via canalicular-sinusoidal connections (R23). 

Cholestyramine resin also is helpful for the relief of pruritus associated with partial biliary obstruction and in conditions such as primary biliary cirrhosis. Cholestyramine increases fecal excretion of bile acids and reduces circulating and eventually systemic levels with relief of pruritus in -1-3 weeks. 

The patient with acute intermittent porphyria suffers a severe acute abdominal pain not definitely localized and without rigidity or tenderness of the abdominal wall. Moderate fever and leukocytosis develop. If the physician is not aware of the porphyria, he is likely to be confused and suspect appendicitis, renal or biliary colics, pancreatitis, perforated ulcer, acute bowel obstruction or another common cause of abdominal pain. The differential diagnosis of porphyria and bowel obstruction is further complicated because the attacks of porphyria hepatica are often associated with severe constipation. Abdominal X-rays of porphyric patients show colonic distension. The pathogenesis of the abdominal symptoms is not known. They could result either from a direct effect of porphobilinogen or porphyrin on the intestinal mucosa or be the consequence of an increased excitability of the autonomic system. 

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