Percutaneous Transhepatic Cholangiography

Percutaneous transhepatic cholangiography is the fluoroscopic examination of the biliary ducts after injection of an iodinated contrast medium directly into a biliary radicle. This test is especially useful for evaluating patients with persistent upper abdominal pain after cholecystectomy and for evaluating patients with severe jaundice.

Although computed tomography scan or ultrasonography is usually performed first when obstructive jaundice is suspected, percutaneous transhepatic cholangiography may provide the most detailed view of the obstruction; however, this invasive procedure carries a potential risk of complications that include bleeding, septicemia, bile peritonitis, extravasation of the contrast medium into the peritoneal cavity, and subcapsular injection.

Purpose

• To determine the cause of upper abdominal pain following cholecystectomy
• To distinguish between obstructive and nonobstructive jaundice
• To determine the location, the extent, and often the cause of mechanical obstruction

Patient preparation

• Explain to the patient that this procedure allows examination of the biliary ducts through X-ray films taken after a contrast medium is injected into the liver.
• Instruct him to fast for 8 hours before the test.
• Describe the test, including who will perform it, where it will take place, and its duration (about 30 minutes).
• Inform the patient that he'll be placed on a tilting X-ray table that rotates into vertical and horizontal positions during the procedure.
• Assure him that he'll be adequately secured to the table and assisted to supine and side-lying positions throughout the procedure.
• Warn him that injection of the local anesthetic may sting the skin and produce transient pain when it punctures the liver capsule.
• Advise him that injection of the contrast medium may produce a sensation of pressure and epigastric fullness and may cause transient upper back pain on his right side.
• If appropriate, advise him that a sedative will be administered just before the procedure begins, and tell him that he must rest for at least 6 hours after the procedure.
• Make sure the patient or a responsible family member has signed a consent form.
• Check the patient's history for hypersensitivity to iodine, seafood, contrast media used in other diagnostic tests, and the local anesthetic. Describe the possible adverse effects of contrast medium administration, such as nausea, vomiting, excessive salivation, flushing, urticaria, sweating and, rarely,anaphylaxis; tachycardia and fever may accompany intraductal injection.
• Check the patient's history for normal bleeding, clotting, and prothrombin times, and a normal platelet count. If prescribed, administer 1 g of ampicillin I.V. every 4 to 6 hours for 24 hours before the procedure.
• Just before the procedure, administer a sedative, if prescribed.

Procedure and posttest care

• After the patient is placed in a supine position on the X-ray table and is adequately secured, the right upper quadrant of the abdomen is cleaned and draped; the skin, subcutaneous tissue, and liver capsule are infiltrated with a local anesthetic.
• While the patient holds his breath at the end of expiration, the flexible needle is inserted under fluoroscopic guidance through the eighth or ninth intercostal space in the midaxillary line and into the liver.
• The needle is passed deeply into the liver substance and then slowly withdrawn, injecting the contrast medium to locate a biliary radicle. When fluoroscopy reveals placement in a radicle, the needle is held in position and the remaining contrast medium is injected. When the contrast medium enters a biliary radicle, it begins to outline the biliary tree.
• Using a fluoroscope and television monitor, the opacification of the biliary ducts is observed, and spot films of significant findings are taken with the patient in supine and lateral recumbent positions. When the required films have been taken, the needle is removed.
• Apply a sterile dressing to the puncture site.
• Check the patient's vital signs until they're stable.
• Enforce bed rest for at least 6 hours after the test, preferably with the patient lying on his right side, to help prevent hemorrhage.
• Check the injection site for bleeding, swelling, and tenderness. Watch for signs of peritonitis: chills, temperature of 102° to 103° F (38.8° to 39.4°C), and abdominal pain, tenderness, and distention.
• Tell the patient that he may resume his usual diet.

Precautions

• Percutaneous transhepatic cholangiography is contraindicated in patients with cholangitis, massive ascites, uncorrectable coagulopathy, or hypersensitivity to iodine.

Normal findings

The biliary ducts are of normal diameter and appear as regular channels homogeneously filled with contrast medium.

Abnormal findings

Distinguishing between obstructive and non obstructive jaundice hinges on whether biliary ducts are dilated or of normal size. Obstructive jaundice is associated with dilated ducts; nonobstructive jaundice, with normalsized ducts. When ducts are dilated, the obstruction site may be defined. Obstruction may result from cholelithiasis, biliary tract carcinoma, or carcinoma of the pancreas or papilla of Vater that impinges on the conunon bile duct, causing deviation or stricture.

When ducts are of normal size and intrahepatic cholestasis is indicated, liver biopsy may be performed to distinguish among hepatitis, cirrhosis, and granulomatous disease.

Interfering factors

• Marked obesity or gas overlying the biliary ducts (possible poor imaging).