Cholangiography, Percutaneous Transhepatic(redirected from Percutaneous cholecystogram)
Cholangiography, Percutaneous Transhepatic
Synonym/acronym: Percutaneous cholecystogram, PTC, PTHC.
To visualize and assess biliary ducts for causes of obstruction and jaundice, such as cancer or stones.
Area of applicationBiliary system.
ContrastRadiopaque iodine-based contrast medium.
Percutaneous transhepatic cholangiography (PTC) is a test used to visualize the biliary system in order to evaluate persistent upper abdominal pain after cholecystectomy and to determine the presence and cause of obstructive jaundice. The liver is punctured with a thin needle under fluoroscopic guidance, and contrast medium is injected as the needle is slowly withdrawn. This test visualizes the biliary ducts without depending on the gallbladder’s concentrating ability. The intrahepatic and extrahepatic biliary ducts, and occasionally the gallbladder, can be visualized to determine possible obstruction. In obstruction of the extrahepatic ducts, a catheter can be placed in the duct to allow external drainage of bile. Endoscopic retrograde cholangiopancreatography (ERCP) and PTC are the only methods available to view the biliary tree in the presence of jaundice. ERCP poses less risk and is probably done more often.
This procedure is contraindicated for
- Patients who are pregnant or suspected of being pregnant, unless the potential benefits of a procedure using radiation far outweigh the risk of radiation exposure to the fetus and mother.
- Patients with conditions associated with adverse reactions to contrast medium (e.g., asthma, food allergies, or allergy to contrast medium). Although patients are still asked specifically if they have a known allergy to iodine or shellfish, it has been well established that the reaction is not to iodine, in fact an actual iodine allergy would be very problematic because iodine is required for the production of thyroid hormones. In the case of shellfish the reaction is to a muscle protein called tropomyosin; in the case of iodinated contrast medium the reaction is to the noniodinated part of the contrast molecule. Patients with a known hypersensitivity to the medium may benefit from premedication with corticosteroids and diphenhydramine; the use of nonionic contrast or an alternative noncontrast imaging study, if available, may be considered for patients who have severe asthma or who have experienced moderate to severe reactions to ionic contrast medium.
- Patients with conditions associated with preexisting renal insufficiency (e.g., renal failure, single kidney transplant, nephrectomy, diabetes, multiple myeloma, treatment with aminoglycocides and NSAIDs) because iodinated contrast is nephrotoxic.
- Elderly and compromised patients who are chronically dehydrated before the test, because of their risk of contrast-induced renal failure.
- Patients with bleeding disorders or receiving anticoagulant therapy because the puncture site may not stop bleeding.
- Patients with cholangitis; the injection of the contrast medium can increase biliary pressure, leading to bacteremia, septicemia, and shock.
- Aid in the diagnosis of obstruction caused by gallstones, benign strictures, malignant tumors, congenital cysts, and anatomic variations
- Determine the cause, extent, and location of mechanical obstruction
- Determine the cause of upper abdominal pain after cholecystectomy
- Distinguish between obstructive and nonobstructive jaundice
- Biliary ducts are normal in diameter, with no evidence of dilation, filling defects, duct narrowing, or extravasation.
- Contrast medium fills the ducts and flows freely.
- Gallbladder appears normal in size and shape.
Abnormal findings related to
- Anatomic biliary or pancreatic duct variations
- Biliary sclerosis
- Common bile duct cysts
- Gallbladder carcinoma
- Nonobstructive jaundice
- Sclerosing cholangitis
- Tumors, strictures, inflammation, or gallstones of the common bile duct
Factors that may impair clear imaging
- Gas or feces in the gastrointestinal (GI) tract resulting from inadequate cleansing or failure to restrict food intake before the study.
- Retained barium from a previous radiological procedure.
- Metallic objects within the examination field, which may inhibit organ visualization and cause unclear images.
- Inability of the patient to cooperate or remain still during the procedure because of age, significant pain, or mental status.
- The procedure may be terminated if chest pain or severe cardiac arrhythmias occur.
- Failure to follow dietary restrictions and other pretesting preparations may cause the procedure to be canceled or repeated.
- Consultation with a health-care provider (HCP) should occur before the procedure for radiation safety concerns regarding younger patients or patients who are lactating. Pediatric & Geriatric Imaging Children and geriatric patients are at risk for receiving a higher radiation dose than necessary if settings are not adjusted for their small size. Pediatric Imaging Information on the Image Gently Campaign can be found at the Alliance for Radiation Safety in Pediatric Imaging (www.pedrad.org/associations/5364/ig/).
- Risks associated with radiation overexposure can result from frequent x-ray procedures. Personnel in the examination room with the patient should wear a protective lead apron stand behind a shield, or leave the area while the examination is being done. Personnel working in the examination area should wear badges to record their level of radiation exposure.
Nursing Implications and Procedure
- Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
- Patient Teaching: Inform the patient this procedure can assist in assessing the bile ducts of the gallbladder and pancreas.
- Obtain a history of the patient’s complaints or clinical symptoms, including a list of known allergens, especially allergies or sensitivities to latex, anesthetics, contrast medium, or sedatives.
- Obtain a history of the patient’s gastrointestinal and hepatobiliary systems, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
- Ensure that this procedure is performed before an upper GI study or barium swallow.
- Record the date of the last menstrual period and determine the possibility of pregnancy in perimenopausal women.
- Obtain a list of the patient’s current medications, including anticoagulants, aspirin and other salicylates, herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus). Such products should be discontinued by medical direction for the appropriate number of days prior to a surgical procedure. Note time and date of last dose.
- If iodinated contrast medium is scheduled to be used in patients receiving metformin (Glucophage) for non–insulin-dependent (type 2) diabetes, the drug should be discontinued on the day of the test and continue to be withheld for 48 hr after the test. Iodinated contrast can temporarily impair kidney function, and failure to withhold metformin may indirectly result in drug-induced lactic acidosis, a dangerous and sometimes fatal side effect of metformin related to renal impairment that does not support sufficient excretion of metformin.
- Review the procedure with the patient. Address concerns about pain and explain that there may be moments of discomfort and some pain experienced during the test. Inform the patient that the procedure is usually performed in the radiology department by an HCP, with support staff, and takes approximately 30 to 60 min.
- Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
- Explain that an IV line may be inserted to allow infusion of IV fluids such as normal saline, antibiotics, anesthetics, sedatives, or emergency medications. Patients who will undergo percutaneous bile drainage may have infected bile and as such should have an antibiotic administered at least 1 hr before the procedure in order to avoid spreading the infection to other parts of the body. Explain that the contrast medium will be injected, by catheter, at a separate site from the IV line.
- Type and screen the patient’s blood for possible transfusion.
- Inform the patient that a laxative and cleansing enema may be needed the day before the procedure, with cleansing enemas on the morning of the procedure depending on the institution’s policy.
- Instruct the patient to remove all external metallic objects from the area to be examined.
- Instruct the patient to fast and restrict fluids for 8 hr prior to the procedure and to avoid taking anticoagulant medication or to reduce dosage as ordered prior to the procedure. Protocols may vary among facilities.
- Make sure a written and informed consent has been signed prior to the procedure and before administering any medications.
- Potential complications:
PTC is an invasive procedure and has potential risks that include allergic reaction related to contrast reaction, bleeding, septicemia, bile peritonitis, and extravasation of the contrast medium.
- Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient.
- Ensure that the patient has complied with dietary, fluid, and medication restrictions for 8 hr prior to the procedure.
- Ensure the patient has removed all external metallic objects from the area to be examined.
- Assess for completion of bowel preparation according to the institution’s procedure.
- Administer ordered prophylactic steroids or antihistamines before the procedure. Use nonionic contrast medium for the procedure if the patient has a history of allergic reactions to any relevant substance or drug.
- Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
- Have emergency equipment readily available.
- Instruct the patient to void prior to the procedure and to change into the gown, robe, and foot coverings provided.
- Instruct the patient to cooperate fully and to follow directions. Instruct the patient to remain still throughout the procedure because movement produces unreliable results.
- Record baseline vital signs, and continue to monitor throughout the procedure. Protocols may vary among facilities.
- Establish an IV fluid line for the injection of saline, sedatives, or emergency medications.
- Place the patient in the supine position on an examination table.
- A kidney, ureter, and bladder (KUB) or plain film is taken to ensure that no barium or stool will obscure visualization of the biliary system.
- An area over the abdominal wall is anesthetized, and the needle is inserted and advanced under fluoroscopic guidance. Contrast medium is injected when placement is confirmed by the free flow of bile.
- A specimen of bile may be sent to the laboratory for culture and cytological analysis.
- At the end of the procedure, the contrast medium is aspirated from the biliary ducts, relieving pressure on the dilated ducts.
- If an obstruction is found during the procedure, a catheter is inserted into the bile duct to allow drainage of bile.
- Maintain pressure over the needle insertion site for several hours if bleeding is persistent.
- Observe/assess the needle site for bleeding, inflammation, or hematoma formation.
- Establish a closed and sterile drainage system if a catheter is left in place.
- Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
- Instruct the patient to resume usual diet, fluids, medications, and activity, as directed by the HCP. Renal function should be assessed before metformin is restarted.
- Monitor vital signs and neurological status every 15 min for 1 hr, then every 2 hr for 4 hr, and as ordered. Take temperature every 4 hr for 24 hr. Monitor intake and output at least every 8 hr. Compare with baseline values. Notify the HCP if temperature is elevated. Protocols may vary among facilities.
- Monitor for reaction to iodinated contrast medium, including rash, urticaria, tachycardia, hyperpnea, hypertension, palpitations, nausea, or vomiting.
- Observe/assess the puncture site for signs of bleeding, hematoma formation, ecchymosis, or leakage of bile. Notify the HCP if any of these is present.
- Advise the patient to watch for symptoms of infection, such as pain, fever, increased pulse rate, and muscle aches.
- Recognize anxiety related to test results. Discuss the implications of abnormal test results on the patient’s lifestyle. Provide teaching and information regarding the clinical implications of the test results, as appropriate.
- Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP. Answer any questions or address any concerns voiced by the patient or family.
- Depending on the results of this procedure, additional testing may be needed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.
- Related tests include ALT, amylase, AMA, AST, biopsy liver, cancer antigens, cholangiography postoperative, cholangiopancreatography endoscopic retrograde, CT abdomen, GGT, hepatitis antigens and antibodies (A, B, C), hepatobiliary scan, KUB studies, laparoscopy abdominal, lipase, MRI abdomen, peritoneal fluid analysis, pleural fluid analysis, and US liver and biliary tract.
- Refer to the Gastrointestinal and Hepatobiliary systems tables at the end of the book for related tests by body system.
Handbook of Laboratory and Diagnostic Tests, © 2013 Farlex and Partners