percutaneous transhepatic cholangiography

Percutaneous Transhepatic Cholangiography 

Definition

Percutaneous transhepatic cholangiography (PTHC) is an x-ray test used to identify obstructions either in the liver or bile ducts that slow or stop the flow of bile from the liver to the digestive system.

Purpose

Because the liver and bile ducts are not normally seen on x rays, the doctor injects the liver with a special dye that will show up on the resulting picture. This dye distributes evenly to fill the whole liver drainage system. If the dye does not distribute evenly, this is indicative of a blockage, which may be caused by a gallstone or a tumor in the liver, bile ducts, or pancreas.

Precautions

Patients should report allergic reactions to:

• anesthetics
• dyes used in medical tests
• iodine
• shellfish

PTHC should not be performed on anyone who has cholangitis (inflammation of the bile duct), massive ascites, a severe allergy to iodine, or a serious uncorrectable or uncontrollable bleeding disorder. Patients who have diabetes should inform their doctor.

Description

PTHC is performed in a hospital, doctor's office, or outpatient surgical or x-ray facility. The patient lies on a movable x-ray table and is given a local anesthetic. The patient will be told to hold his or her breath, and a doctor, nurse, or laboratory technician will inject a special dye into the liver as the patient exhales.

The patient may feel a twinge when the needle penetrates the liver, a pressure or fullness, or brief discomfort in the upper right side of the back. Hands and feet may become numb during the 30-60 minute procedure.

The x-ray table will be rotated several times during the test, and the patient helped to assume a variety of positions. A special x-ray machine called a fluoroscope will track the dye's movement through the bile ducts and show whether the fluid is moving freely or if its passage is obstructed.

PTHC costs about $1,600. The test may have to be repeated if the patient moves while x rays are being taken.

Preparation

An intravenous antibiotic may be given every 4-6 hours during the 24 hours before the test. The patient will be told to fast overnight. Having an empty stomach is a safety measure in case of complications, such as bleeding, that might require emergency repair surgery. Medications such as aspirin, or non-steroidal anti-inflammatory drugs that thin the blood, should be stopped three-seven days prior to taking the PRHC test. Patients may also be given a sedative a few minutes before the test begins.

Aftercare

A nurse will monitor the patient's vital signs and watch for:

• itching
• flushing
• nausea and vomiting
• sweating
• excessive flow of saliva
• possible serious allergic reactions to contrast dye

The patient should stay in bed for at least six hours after the test, lying on the right side to prevent bleeding from the injection site. The patient may resume normal eating habits and gradually resume normal activities. The doctor should be informed right away if pain develops in the right abdomen or shoulder or in case of fever, dizziness, or a change in stool color to black or red.

Risks

Septicemia (blood poisoning) and bile peritonitis (a potentially fatal infection or inflammation of the membrane covering the walls of the abdomen) are rare but serious complications of this procedure. Dye occasionally leaks from the liver into the abdomen, and there is a slight risk of bleeding or infection.

Normal results

Normal x rays show dye evenly distributed throughout the bile ducts. Obesity, gas, and failure to fast can affect test results.

Abnormal results

Enlargement of bile ducts may indicate:

• obstructive or non-obstructive jaundice
• cholelithiasis (gallstones)
• hepatitis (inflammation of the liver)
• cirrhosis (chronic liver disease)
• granulomatous disease
• pancreatic cancer
• bile duct or gallbladder cancers

Resources

Books

Komaroff, A. L. The Harvard Medical School Family Health Guide. New York: Simon & Schuster, 1999.

Periodicals

Cieszanowski, A., et al. "Imaging Techniques in Patients with Biliary Obstruction." Medical Science Monitor 6 (November-December 2000): 1197-202.

Other

Percutaneous Transhepatic Cholangiography. 〈http://207.25.144.143/health/Library/medtests/〉.

Percutaneous Transhepatic Cholangiography (PTHC). 〈http://www.uhs.org/frames/health/test/test3554.htm〉.

Test Universe Site: Percutaneous Transhepatic Cholangiography. http://www.testuniverse.com/mdx/MDX-3055.html.

Key terms

Ascites — Abnormal accumulation of fluid in the abdomen.

Bile ducts — Tubes that carry bile, a thick yellowish-green fluid that is made by the liver, stored in the gallbladder, and helps the body digest fats.

Cholangitis — Inflammation of the bile duct.

Fluoroscope — An x-ray machine that projects images of organs.

Granulomatous disease — Characterized by growth of tiny blood vessels and connective tissue.

Jaundice — Disease that causes bile to accumulate in the blood, causing the skin and whites of the eyes to turn yellow. Obstructive jaundice is caused by blockage of bile ducts, while non-obstructive jaundice is caused by disease or infection of the liver.

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percutaneous transhepatic cholangiography (PTC),

the radiographic examination of the structure of the bile ducts. A contrast medium is injected through a needle passed directly into a hepatic duct.

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percutaneous transhepatic cholangiography

GI disease A technique used to evaluate the gall bladder and intra- and extahepatic bile ducts; diagnostic success rate is 95% for dilated bilie ducts, 75% when ducts are normal or sclerosed Cons No anatomic information Contraindications Radiocontrast dye allergies, ↑ bleeding time Complications Allergic reactions, bile peritonitis due to spillage post injection, < 5%–eg, sepsis, hemorrhage due to puncture of blood vessel, death. See Percutaneous transhepatic biliary drainage. Cf ERCP-endoscopic retrograde cholangiopancreatography.