Cholelythiasis



Cholelythiasis

1. Cholelythiasis. Clinical picture. Methods of patient examination.

2. Complications of cholelythiasis (mechanical, infectious, degenerative). Treatment.

3. Mechanical jaundice. Differential diagnosis. Treatment.

Cholelithiasis is the formation of gallstones, which are composed of cholesterol, calcium salts, and bile pigments

A gallstone is a crystalline concretion formed within the gallbladder by accretion of bile components. Presence of stones in the gallbladder is referred to as cholelithiasis (from the Greek: chol-, "bile" + lith-, "stone" + iasis-, "process").

Characteristics and composition

Gallstones can vary in size from as small as a grain of sand to as large as a golf ball. The gallbladder may contain a single large stone or many smaller ones. Pseudoliths, sometime referred to as sludge, are thick secretions that may be present within the gallbladder, either alone or in conjunction with fully formed gallstones. The clinical presentation is similar to that of cholelithiasis. The composition of gallstones is affected by age, diet and ethnicity. On the basis of their composition, gallstones can be divided into the following types:

Cholesterol stones

Cholesterol stones vary in color from light-yellow to dark-green or brown and are oval 2 to 3 cm in length, often having a tiny dark central spot. To be classified as such, they must be at least 80% cholesterol by weight (or 70%, according to the Japanese classification system).

Pigment stones are small, dark stones made of bilirubin and calcium salts that are found in bile. They contain less than 20% of cholesterol (or 30%, according to the Japanese classification system).

Mixed stones

Mixed gallstones typically contain 20–80% cholesterol (or 30–70%, according to the Japanese classification system). Other common constituents are calcium carbonate, palmitate phosphate, bilirubin, and other bile pigments. Because of their calcium content, they are often radiographically visible

Cholelithiasis - Causes, Symptoms And Treatment

Diseases of the gallbladder and biliary tract are common and, in many cases, painful conditions that may be life threatening and usually require surgery. They are generally associated with deposition of calculi and inflammation.

Cholelithiasis is the fifth leading cause of hospitalization among adults and accounts for 90% of all gallbladder and duct diseases. Women have two to three times the incidence as men of developing cholelithiasis. The disease may also be more prevalent in persons who are obese, who have high cholesterol, or who are on cholesterol lowering drugs. The prognosis is usually good with treatment unless infection occurs, in which case prognosis depends on its severity and response to antibiotics.

In most cases, gallbladder and bile duct diseases occur during middle age. Between ages 20 and 50, they're six times more common in women, but incidence in men and women becomes equal after age 50. Incidence rises with each succeeding decade.

Causes of Cholelithiasis

Cholelithiasis stones or calculi (gallstones) in the gallbladder. results from changes in bile components. Gallstones are made of cholesterol, caldurn bilirubinate, or a mixture of cholesterol and bilirubin pigment. They arise during periods of sluggishness in the gallbladder due to pregnancy. hormonal contraceptives. diabetes mellitus. celiac disease, cirrhosis of the liver, and pancreatitis.

One out of every 10 patients with gallstones develops Cholelithiasis, or gallstones in the common bile duct (sometimes called common duct stones). This condition occurs when stones pass out of the gallbladder and lodge in the hepatic and common bile ducts. obstructing the flow of bile into the duodenum. Prognosis is good unless infection occurs.

Cholangitis, infection of the bile duct, is commonly associated with choledocholithiasis and may follow percutaneous transhepatic cholangiography or occlusion of endoscopicstents. Predisposing factors may include bacterial or metabolic alteration of bile acids. Widespread inflammation may cause fibrosis and stenosis of the common bile duct. The prognosis for this rare condition is poor without stenting or surgery.

Cholecystitis. acute or chronic inflammation of the gallbladder. is usually associated with a gallstone impacted in the cystic duct, causing painful distention of the gallbladder. Cholecystitis accounts for 10% to 25% of all patients requiring gallbladder surgery. The acute form is most common during middle age; the chronic form occurs most commonly among the elderly. The prognosis is good with treatment.

Cholesterolosis. polyps or crystal deposits of cholesterol in the gallbladder's submucosa, may result from bile secretions containing high concentrations of cholesterol and insufficient bile salts. The polyps may be localized or speckle the entire gallbladder. Cholesterolosis the most common pseudotumor. isn't related to widespread inflammation of the mucosa or lining of the gallbladder. The prognosis is good with surgery.

Biliary cirrhosis. ascending infection of the biliary system, sometimes follows viral destruction of liver and duct cells. but the primary cause is unknown. This condition usually leads to obstructive jaundice and involves the portal and periportal spaces of the liver. It's nine times more common among women ages 40 to 60 than among men. The prognosis is poor without liver transplantation.

Gallstone ileus results from a gallstone lodging at the terminal ileum; it's more common in the elderly. The prognosis is good with surgery.

Postcholecystectomy syndrome commonly results from residual gal1stones or stricture of the common bile duct. It occurs in 1 % to 5 % of all patients whose gallbladders have been surgical1y removed and may produce right upper quadrant abdominal pain, biliary colic, fatty food intolerance, dyspepsia. and indigestion. The prognosis is good with selected radiologic

procedures, endoscopic procedures, or surgery.

Acalculous cholecystitis is more common in critical1y ill patients, accounting for about 5% of cholecystitis cases. It may result from primary infection with such organisms as Salmollella typhi. Escherichia coli, or Clostridium or from obstruction of the cystic duct due to lymphadenopathy or a tumor. It appears that ischemia usually related to a low cardiac output. also has a role in the pathophysiology of this disease. Signs and symptoms of acalculous cholecystitis include unexplained sepsis, right upper quadrant pain, fever, leukocytosis, and a palpable gallbladder.

Cholelithiasis Symptoms and Signs

Although gallbladder disease may produce no symptoms. acute cholelithiasis, acute cholecystitis, choledocholithiasis. and cholesterolosis produce the symptoms of a classic gallbladder attack. Attacks commonly follow meals rich in fats or may occur at night. suddenly awakening the patient. They begin with acute abdominal pain in the right upper quadrant that may radiate to the back. between the shoulders. or to the front of the chest; the pain may be so severe that the patient seeks emergency department care. Other features may include recurring fat intolerance. biliary colic. belching. flatulence, indigestion. diaphoresis. nausea. vomiting. chills. low-grade fever. jaundice (if a stone obstructs the common bile duct). and clay-colored stools (with choledocholithiasis).

Clinical features of cholangitis include a rise in eosinophils, jaundice, abdominal pain. high fever. and chills; biliary drrhosis may produce jaundice, related itching, weakness, fatigue. slight weight loss. and abdominal pain. Gallstone ileus produces signs and symptoms of small bowel obstruction - nausea. vomiting, abdominal distention, and absent bowel sounds if the bowel is completely obstructed. Its most telling symptom is intermittent recurrence of colicky pain over several days. Each of these disorders produces its own set of complications.

Diagnosis and testing information

Differential diagnosis is essential in gallbladder and biliary tract disease because gallbladder disease can mimic other diseases (myocardial infarction. angina. pancreatitis. pancreatic head cancer. pneumonia, peptic ulcer, hiatal henda, esophagitis. and gastritis). Serum amylase distinguishes gallbladder disease from pancreatitis. With suspected heart disease. serial cardiac enzyme tests and electrocardiogram should precede gallbladder and upper GI diagnostic tests. Tests used to diagnose gallbladder and biliary tract disease include:

• Ultrasound reflects stones in the gallbladder with 96% accuracy. It's also considered the primary tool for diagnosing cholelithiasis.

• Percutaneous trashepatic cholangiography. done under fluoroscopic control. distinguishes between gallbladder or bile duct disease and cancer of the pancreatic head in patients with jaundice.

• Endoscopic retrograde cholangiopancreatography (ERCP) visualizes the biliary tree after insertion of an endoscope down the esophagus into the duodenum, cannulation of the common bile and pancreatic ducts, and injection of contrast medium.

• HIDA scan of the gallbladder detects obstruction of the cystic duct.

• Computed tomography scan, although not used routinely, helps distinguish between obstructive and non obstructive jaundice.

• Flat plate of the abdomen identifies calcified, but not cholesterol. stones with 15% accuracy.

• Oral cholecystography, which is rarely used, shows stones in the gallbladder and biliary duct obstruction.

Elevated icteric index, total bilirubin, urine bilirubin, and alkaline phosphatase support the diagnosis. White blood cell count is slightly elevated during a cholecystitis attack.

Cholelithiasis treatment

Cholecystectomy (gallbladder removal) has a 99% chance of eliminating the recurrence of cholelithiasis. Only symptomatic patients must be indicated to surgery. The lack of a gallbladder may have no negative consequences in many people. However, there is a portion of the population — between 10 and 15% — who develop a condition called postcholecystectomy syndrome which may cause gastrointestinal distress and persistent pain in the upper-right abdomen, as well as a 10% chance of developing chronic diarrhea.

Surgery, usually elective, is the treatment of choice for gallbladder and biliary tract diseases and may include open or laparoscopic cholecystectomy, cholecystectomy with operative cholangiography and, possibly, exploration of the common bile duct.

There are two surgical options for cholecystectomy:

• Open cholecystectomy: This procedure is performed via an incision into the abdomen (laparotomy) below the right lower ribs. Recovery typically consists of 3–5 days of hospitalization, with a return to normal diet a week after release and normal activity several weeks after release.

Laparoscopic cholecystectomy: This procedure, introduced in the 1980s, is performed via three to four small puncture holes for a camera and instruments. Post-operative care typically includes a same-day release or a one night hospital stay, followed by a few days of home rest and pain medication. Laparoscopic cholecystectomy patients can, in general, resume normal diet and light activity a week after release, with some decreased energy level and minor residual pain continuing for a month or two. Studies have shown that this procedure is as effective as the more invasive open cholecystectomy, provided the stones are accurately located by cholangiogram prior to the procedure so that they can all be removed.

Obstruction of the common bile duct with gallstones can sometimes be relieved by endoscopic retrograde sphincterotomy (ERS) following endoscopic retrograde cholangiopancreatography (ERCP).

Other treatments include a low-fat diet to prevent attacks and vitamin K for itching, jaundice, and bleeding tendendes due to vitamin K deficiency. Treatment during an acute attack may include insertion of a nasogastric tube and an I.V.line and, possibly, antibiotic and analgesic administration. A non surgical treatment for choledocholithiasis involves placement of a catheter through the percutaneous transhepatic cholangiographic route. Guided by fluoroscopy, the catheter is directed toward the stone. A basket is threaded through the catheter,opened, twirled to entrap the stone, closed, and withdrawn. This procedure can be performed endoscopically.

Ursodiol (Actigall), which dissolves radiolucent stones, provides an alternative for patients who are poor surgical risks or who refuse surgery. however, use of urdodiol is limited by the need for prolonged treatment, the high incidence of adverse effects, and the frequency of stone formation after the treatment ends.

Extra corporeal shock wave lithotrillsy (ESWL) has also been adapted for the treatment of gallstones. ESWL Is a non surgical procedure used to ('rush stones inside the gallbladder. Gallstones can be broken up using a procedure called extracorporeal shock wave lithotripsy (often simply called "lithotripsy"), which is a method of concentrating ultrasonic shock waves into the stones to break them into tiny pieces that can pass out of the gallbladder through the cystic duct and common bile duct into

the small intestine.

Jaundice - (jôn`dĭs, jän`–), abnormal condition in which the body fluids and tissues, particularly the skin and eyes, take on a yellowish color as a result of an excess of bilirubin. During the normal breakdown of old erythrocytes (red blood cells), their hemoglobin is converted into bilirubin. Normally the bilirubin is removed from the bloodstream by the liver, which passes from the liver into the intestines. There are several conditions that may interrupt the elimination of bilirubin from the blood and cause jaundice.

Prehepatic jaundice is caused by an increased content of free bilirubin circulating in the blood, formed as a result of increased decomposition of the erythrocytes (hemolytic jaundice), or of congenital or acquired deficiency of enzymes that participate in binding bilirubin with glucuronic acid. Hemolytic jaundice appears in hemolytic disease of the new-born and in poisoning with hemolytic toxins; it is characterized by increased excretion of the products of bilirubin metabolism in the urine (urobilin) and feces (stercobilin, which causes the saturated pigmentation of the feces). Other types of jaundice caused by disruption in the capture and bonding of bilirubin and proceeding without substantive affection of liver cells are physiological jaundice of the new-born, nuclear jaundice, and juvenile jaundice.

Hepatogenic jaundice (parenchymatous jaundice) is a function of organic (infectious, parasitic, or toxic) affection of the liver itself and is conditioned by the formation of an anastomosis between blood and bile capillaries and also by intrahepatic stasis of bile during inflammations of the liver. There appear, along with other symptoms of liver affection, a saturated pigmentation of the urine and faintly colored feces.

Posthepatic, or, Mechanical biliary obstruction. Such obstruction may have a malignant or benign origin. Choledocholithiasis is found in about 15% of patients with gallbladder stones. The clinical presentation ranges from mild right upper quadrant pain with minimal elevation of liver enzymes to ascending cholangitis. Ultrasonography is as sensitive as CT for the detection of choledocholithiasis. ERCP is also highly accurate in the diagnosis of biliary obstruction, with a sensitivity of 89% to 98% and a specificity of 89% to 100%. ERCP can also be used for therapeutic interventions, including stone removal and endobiliary stent placement.

Biliary obstruction may also be caused by parasitic infections (as with Ascaris lumbricoides); on endoscopy, the organisms can sometimes be seen protruding from the ampulla.

Malignant causes include carcinoma of the pancreas or gallbladder, ampullary carcinoma, and cholangiocarcinoma. ERCP facilitates procedures such as diagnostic brushings or biopsy in cholangiocarcinoma and ampullary cancer, as well as the placement of an endobiliary stent to temporarily relieve the obstruction. Jaundice in PSC is typically a result of end-stage liver disease; however, occasionally a dominant nonmalignant extrahepatic biliary stricture is the cause, and this condition is treatable with endobiliary stent placement.

In a number of instances, a yellow coloring of the skin and other body tissues may be caused by pigments in food (for example, the carotene contained in carrots) or medications (acrichin).

Choledocholithiasis

If gallstones migrate into the ducts of the biliary tract, the condition is referred to as choledocholithiasis (from the Greek: chol-, "bile" + docho-, "duct" + lith-, "stone" + iasis-, "process").

Signs and symptoms

A positive Murphy's sign is a common finding on physical examination. Jaundice of the skin or eyes is an important physical finding in biliary obstruction. Jaundice and/or clay-colored stool may raise suspicion of choledocholithiasis or even gallstone pancreatitis. If the above symptoms coincide with fever and chills, the diagnosis of ascending cholangitis may also be considered.

Causes

While stones can frequently pass through the common bile duct (CBD) into the duodenum, some stones may be too large to pass through the CBD and may cause an obstruction. One risk factor for this is duodenal diverticulum.

Pathophysiology

This obstruction may lead to jaundice, elevation in alkaline phosphatase, increase in conjugated bilirubin in the blood and increase in cholesterol in the blood. It can also cause acute pancreatitis and ascending cholangitis.

Diagnosis

Common bile duct stone impacted at ampulla of Vater seen at time of ERCP

Choledocholithiasis (stones in common bile duct) is one of the complications of cholelithiasis (gallstones), so the initial step is to confirm the diagnosis of cholelithiasis. Patients with cholelithiasis typically present with pain in the right-upper quadrant of the abdomen with the associated symptoms of nausea and vomiting, especially after a fatty meal. The physician can confirm the diagnosis of cholelithiasis with an abdominal ultrasound that shows the ultrasonic shadows of the stones in the gallbladder.

The diagnosis of choledocholithiasis is suggested when the liver function blood test shows an elevation in bilirubin. The diagnosis is confirmed with either an Magnetic resonance cholangiopancreatography (MRCP), an ERCP, or an intraoperative cholangiogram. If the patient must have the gallbladder removed for gallstones, the surgeon may choose to proceed with the surgery, and obtain a cholangiogram during the surgery. If the cholangiogram shows a stone in the bile duct, the surgeon may attempt to treat the problem by flushing the stone into the intestine or retrieve the stone back through the cystic duct.

On a different pathway, the physician may choose to proceed with ERCP before surgery. The benefit of ERCP is that it can be utilized not just to diagnose, but also to treat the problem. During ERCP the endoscopist may surgically widen the opening into the bile duct and remove the stone through that opening. ERCP, however, is an invasive procedure and has its own potential complications. Thus, if the suspicion is low, the physician may choose to confirm the diagnosis with MRCP, a non-invasive imaging technique, before proceeding with ERCP or surgery.

Treatment

Treatment involves removing the stone using ERCP. Typically, the gallbladder is then removed, an operation called cholecystectomy, to prevent a future occurrence of common bile duct obstruction or other complications

CHOLANGITIS

acute ascending cholangitis (from the Greek: chol-, "bile + ang-, "vessel" + itis-, "inflammation"), a serious infection of the bile ducts.

Cholangitis is inflammation of the bile duct. The most common cause is a bacterial infection, and the problem is then an ascending cholangitis. However, there are other types of cholangitis as well.

Types of cholangitis

Ascending cholangitis

Ascending cholangitis is caused by bacteria, and causes pain, jaundice, and fever. The bacteria usually originate from a preceding choledocholithiasis and is ascending from the intestines. Typical bacteria is; - Aerobic: E. Coli, Klebsiella, Pseudomonas (post ERCP), streptococcus faecalis and Enterobacter - Anaerobic: Bacteroides fragilis, Clostridium perfringens. Both aerobic and anaerobic infection can be present at the same time. Gallstones obstructing the common bile duct are a risk factor for developing ascending cholangitis.

Primary sclerosing cholangitis

Primary sclerosing cholangitis is a cholangitis with autoimmune origin. Primary sclerosing cholangitis (PSC) is a chronic liver disease caused by progressive inflammation and scarring of the bile ducts of the liver. The inflammation impedes the flow of bile to the gut, which can ultimately lead to liver cirrhosis, liver failure and liver cancer. The underlying cause of the inflammation is believed to be autoimmunity; and more than 80% of those with PSC have ulcerative colitis. The definitive treatment is liver transplantation.

Secondary sclerosing cholangitis

Secondary sclerosing cholangitis is a cholangitis with other causes.

Recurrent pyogenic cholangitis

Recurrent pyogenic cholangitis (a.k.a. cholangiohepatitis) is a condition that most commonly affects humans of East Asian origins. It is characterized by recurrent bouts of cholangitis in association with intrahepatic pigment stones and intrahepatic biliary obstruction. It is also a common liver disease in cats.

PATHOPHYSIOLOGY

Acute inflammation of the biliary tree secondary to obstruction, complicated by infection,and is a surgical emergency being potentially lethal

Obstruction, increased pressure, bacterial infection from duodenum, lymphatics, or portal vein

Incomplete obstruction more common than complete obstruction

Sepsis from increased biliary tree pressure pushes bugs into portal vein

Bugs: Ecoli, Klebsiella, Proteus, Enterococcus

Etiology

CBD stone

Stricture: post op, sclerosing cholangitis

Neoplasms

Signs and symptoms

A person with cholangitis may complain of abdominal pain (particularly in the right upper quadrant of the abdomen), fever, rigors (uncontrollable shaking) and a feeling of uneasiness (malaise). Some may report jaundice (yellow discoloration of the skin and the whites of the eyes).

Physical examination findings typically include jaundice and right upper quadrant tenderness. Charcot's triad is a set of three common findings in cholangitis: abdominal pain, jaundice, and fever. This was assumed in the past to be present in 50–70% of cases, although more recently the frequency has been reported as 15–20%. Reynolds' pentad includes the findings of Charcot's triad with the presence of septic shock and mental confusion. This combination of symptoms indicates worsening of the condition and the development of septicemia, and is seen less commonly still.

In the elderly, the presentation may be atypical; they may directly collapse due to septicemia without first showing typical features. Those with an indwelling stent in the bile duct (see below) may not develop jaundice.

Diagnosis

Blood tests

Routine blood tests show features of acute inflammation (raised white blood cell count and elevated C-reactive protein level), and usually abnormal liver function tests (LFTs). In most cases the LFTs will be consistent with obstruction: raised bilirubin, alkaline phosphatase and γ-glutamyl transpeptidase. In the early stages, however, pressure on the liver cells may be the main feature and the tests will resemble those in hepatitis, with elevations in alanine transaminase and aspartate transaminase.[1]

Blood cultures are often performed in people with fever and evidence of acute infection. These yield the bacteria causing the infection in 36% of cases,[6] usually after 24–48 hours of incubation. Bile, too, may be sent for culture during ERCP (see below). The most common bacteria linked to ascending cholangitis are gram-negative bacilli: Escherichia coli (25–50%), Klebsiella (15–20%) and Enterobacter (5–10%). Of the gram-positive cocci, Enterococcus causes 10–20%. A small proportion of cases, especially in the elderly and those who have undergone previous surgery of the biliary system, is due to anaerobic organisms such as Clostridium and Bacteroides. In the developing world, cholangitis may also be caused by parasites such as Ascaris lumbricoides and Clonorchis sinensis. In people with AIDS, a large number of opportunistic organisms has been known to cause AIDS cholangiopathy, but the risk has rapidly diminished since the introduction of effective AIDS treatment.[1]

Medical imaging

Cholangiogram through a nasobiliary drain showing the common bile duct in black (diagonally from top left to bottom right in the center) with an interruption in the contour due to a large gallstone.

Given that ascending cholangitis usually occurs in the setting of bile duct obstruction, various forms of medical imaging may be employed to identify the site and nature of this obstruction. The first investigation is usually ultrasound, as this is the most easily available.[1] Ultrasound may show dilation of the bile duct and identifies 38% of bile duct stones; it is relatively poor at identifying stones further down the bile duct. Ultrasound can help distinguish between cholangitis and cholecystitis (inflammation of the gallbladder), which has similar symptoms to cholangitis but appears differently on ultrasound. A better test is magnetic resonance cholangiopancreatography (MRCP), which uses magnetic resonance imaging (MRI); this has a comparable sensitivity to ERCP. Smaller stones, however, can still be missed on MRCP depending on the quality of the hospital's facilities.

The gold standard (best possible) test for biliary obstruction is still endoscopic retrograde cholangiopancreatography (ERCP). This involves the use of endoscopy (passing a tube through the mouth into the esophagus, stomach and thence to the duodenum) to pass a small cannula into the bile duct. At that point, radiocontrast is injected to opacify the duct, and X-rays are taken to get a visual impression of the biliary system. On the endoscopic image of the ampulla, one can sometimes see a protuberant ampulla from an impacted gallstone in the common bile duct, or the frank extrusion of pus from the common bile duct orifice. On the X-ray images (known as cholangiograms), gallstones are visible as nonopacified areas in the contour of the duct. For diagnostic purposes, ERCP has now generally been replaced by MRCP. ERCP is only used first-line in critically ill patients in whom delay for diagnostic tests is not acceptable; however, if the index of suspicion for cholangitis is high, an ERCP is typically done to achieve drainage of the obstructed common bile duct.[1]

If other causes rather than gallstones are suspected (such as a tumor), computed tomography and endoscopic ultrasound (EUS) may be performed to identify the nature of the obstruction. EUS may be used to obtain biopsy (tissue sample) of suspicious masses.[1] EUS may also replace diagnostic ERCP for stone disease, although this depends on local availability.

Causes

Bile duct obstruction, which is usually present in acute cholangitis, is generally due to gallstones. 10–30% of cases, however, are due to other causes such as benign stricturing (narrowing of the bile duct without an underlying tumor), postoperative damage or an altered structure of the bile ducts such as narrowing at the site of an anastomosis (surgical connection) and various tumors (cancer of the bile duct, gallbladder cancer, cancer of the ampulla of Vater, pancreatic cancer or cancer of the duodenum).[8] Cholangitis may also complicate medical procedures involving the bile duct, especially ERCP. To prevent this, it is recommended that those undergoing ERCP for any indication receive prophylactic (preventative) antibiotics.[3]

The presence of a permanent biliary stent (e.g. in pancreatic cancer) slightly increases the risk of cholangitis, but stents of this type are often needed to keep the bile duct patent under outside pressure.

Pathogenesis

Bile is produced by the liver, and serves to eliminate cholesterol and bilirubin from the body, as well as emulsifying of fats to make them more soluble in water and aid in their digestion. Bile is formed in the liver by hepatocytes (liver cells) and excreted into the common hepatic duct. Part of the bile is stored in the gall bladder because of back pressure (exerted by the sphincter of Oddi), and may be released at time of digestion. The gall bladder also concentrates the bile by absorbing water and dissolved salts from it. All bile reaches the duodenum (first part of the small intestine) through the common bile duct and the ampulla of Vater. The sphincter of Oddi, located at the junction of the ampulla of Vater and the duodenum, is a circular muscle that controls the release of both bile and pancreatic secretions into the digestive tract.

The biliary tree is normally relatively free of bacteria because of certain protective mechanisms. The sphincter of Oddi acts as a mechanical barrier. The biliary system normally has low pressure (8 to 12 cmH2O)[9] and allows bile to flow freely through. The continuous forward flow of the bile in the duct flushes bacteria, if present, into the duodenum, and does not allow establishment of an infection. The constitution of bile—bile salts and immunoglobulin[2] secreted by the epithelium of the bile duct also has a protective role.

Bacterial contamination alone in absence of obstruction does not usually result in cholangitis. However increased pressure within the biliary system (above 20 cmH2O) resulting from obstruction in the bile duct widens spaces between the cells lining the duct, bringing bacterially contaminated bile in contact with the blood stream. It also adversely affects the function of Kupffer cells, which are specialized macrophage cells that assist in preventing bacteria from entering the biliary system. Finally, increased biliary pressure decreases production of IgA immunoglobulins in the bile. This results in bacteremia (bacteria in the blood stream) and gives rise to the systemic inflammatory response syndrome (SIRS) comprising fever (often with rigors), tachycardia, increased respiratory rate and increased white blood cell count; SIRS in the presence of suspected or confirmed infection is called sepsis.[1] Biliary obstruction itself disadvantages the immune system and impairs its capability to fight infection, by impairing the function of certain immune system cells (neutrophil granulocytes) and modifying the levels of immune hormones (cytokines).

In ascending cholangitis, it is assumed that organisms migrate backwards up the bile duct as a result of partial obstruction and decreased function of the sphincter of Oddi.[1] Other theories about the origin of the bacteria, such as through the portal vein or transmigration from the colon, are considered less likely.

Treatment

Fluids and antibiotics

Cholangitis requires admission to hospital. Intravenous fluids are administered, especially if the blood pressure is low, and antibiotics are commenced. Empirical treatment with broad-spectrum antibiotics is usually necessary until it is known for certain which pathogen is causing the infection, and to which antibiotics it is sensitive. Combinations of penicillins and aminoglycosides are widely used, although ciprofloxacin has been shown to be effective in most cases, and may be preferred to aminoglycosides because of fewer side effects. Metronidazole is often added to specifically treat the anaerobic pathogens, especially in those who are very ill or at risk of anaerobic infections. Antibiotics are continued for 7–10 days. Drugs that increase the blood pressure (vasopressors) may also be required to counter the low blood pressure.[2]

Endoscopy

The definitive treatment for cholangitis is relief of the underlying biliary obstruction.[1] This is usually deferred until 24–48 hours after admission, when the patient is stable and has shown some improvement with antibiotics, but may need to happen as an emergency in case of ongoing deterioration despite adequate treatment, or if antibiotics are not effective in reducing the signs of infection (which happens in 15% of cases).

Endoscopic retrograde cholangiopancreatography (ERCP) is the most common approach in unblocking the bile duct. This involves endoscopy (passing a fiberoptic tube through the stomach into the duodenum), identification of the ampulla of Vater and insertion of a small tube into the bile duct. A sphincterotomy (making a cut in the sphincter of Oddi) is typically done to ease the flow of bile from the duct and to allow insertion of instruments to extract gallstones that are obstructing the common bile duct; alternatively or additionally, the common bile duct orifice can be dilated with a balloon. Stones may be removed either by direct suction or by using various instruments, including balloons and baskets to trawl the bile duct in order to pull stones into the duodenum. Obstructions that are caused by larger stones may require the use of an instrument known as a mechanical lithotriptor in order to crush the stone prior to removal. Obstructing stones that are too large to be removed or broken mechanically by ERCP may be managed by extracorporeal shock wave lithotripsy. This technique uses acoustic shock waves administered outside the body to break down the stones.[14] An alternative technique to remove very large obstructing stones is electrohydraulic lithotripsy, where a small endoscope known as a cholangioscope is inserted by ERCP to directly visualize the stone. A probe uses electricity to generate shock waves that break down the obstructing stone. Rarely, surgical exploration of the common bile duct (termed choledochotomy), which can be performed with laparoscopy, is required to remove the stone.

Narrowed areas may be bridged by a stent, a hollow tube that keeps the duct open. Removable plastic stents are used in uncomplicated gallstone disease, while permanent self-expanding metal stents with a longer lifespan are used if the obstruction is due to pressure from a tumor such as pancreatic cancer. A nasobiliary drain may be left behind; this is a plastic tube that passes from the bile duct through the stomach and the nose and allows continuous drainage of bile into a receptible. It is similar to a nasogastric tube, but passes into the common bile duct directly, and allows for serial x-ray cholangiograms to be done to identify the improvement of the obstruction. The decision on which of the aforementioned treatments to apply is generally based on the severity of the obstruction, findings on other imaging studies, and whether the patient has improved with antibiotic treatment. Certain treatments may be unsafe if blood clotting is impaired, as the risk of bleeding (especially from sphincterotomy) is increased in the use of medication such as clopidogrel (which inhibits platelet aggregation) or if the prothrombin time is significantly prolonged. For a prolonged prothrombin time, vitamin K or fresh frozen plasma may be administered to reduce bleeding risk.

It may be difficult to obtain endoscopic access to the obstruction located higher (proximal) up in the biliary system, or when it is due to a stricture in the priorly performed anastomosis between the bile duct (surgically joining) with the duodenum or jejunum.[2] When this happens, percutaneous transhepatic cholangiography (PTC) may be needed to relieve pressure. This involves identifying the bile duct by ultrasound and then passing a tube through the skin (percutaneous).[3] PTC is generally performed by radiologists. PTC has potential complications, so occasionally further attempts at ERCP by more experienced doctors are preferred.

Continual contamination of bile duct by indwelling stents (as may occur in chronic conditions like tumor of the head of pancreas) requires monitoring by repeated radiologic tests and changing of the stents.

Cholecystectomy

Not all gallstones implicated in ascending cholangitis actually originate from the gallbladder, but cholecystectomy (surgical removal of the gallbladder) is generally recommended in people who have been treated for cholangitis due to gallstone disease. This is typically delayed until all symptoms have resolved and ERCP or MRCP have confirmed that the bile duct is clear of gallstones.[1][2][3] Those who do not undergo cholecystectomy have an increased risk of recurrent biliary pain, jaundice, further episodes of cholangitis, and need for further ERCP or related procedures; the risk of death is also significantly increased.

Prognosis

Acute cholangitis carries a significant risk of death, the leading cause being irreversible shock with multiple organ failure (a possible complication of severe infections).[8] Improvements in diagnosis and treatment have led to a reduction in mortality: before 1980, the mortality rate was greater than 50%, but after 1980 it was 10–30%.[8] Patients with signs of multiple organ failure are likely to die unless they undergo early biliary drainage and treatment with systemic antibiotics. Other causes of death following severe cholangitis include heart failure and pneumonia.

Risk factors indicating an increased risk of death include older age, female gender, a history of liver cirrhosis, biliary narrowing due to cancer, acute renal failure and the presence of liver abscesses. Complications following severe cholangitis include renal failure, respiratory failure (inability of the respiratory system to oxygenate blood and/or eliminate carbon dioxide), cardiac arrythmia, wound infection, pneumonia, gastrointestinal bleeding and myocardial ischemia (lack of blood flow to the heart, leading to heart attacks).

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download