Percutaneous Cholangiography

Anatomy and Physiology

Successful PC requires an understanding of the intrahepatic and extrahepatic components of the biliary system. The intrahepatic biliary ducts are part of the hepatic lobules portal triad consisting of a biliary duct, hepatic artery, and portal vein. They are typically not easily visualized in traditional imaging studies until pathologically enlarged. The extrahepatic biliary components include the right and left hepatic duct, common hepatic duct, cystic duct, gallbladder, and common bile duct. It is important to understand potential congenital anomalies when performing cholangiography. Pertinent anomalies include aberrant biliary ducts, aberrant cystic duct insertion, choledochal cysts, diverticulum, and the anomalous junction of the biliary ductal and pancreatic ducts.  Choledochal cysts are classified using the Todani system. Type I (80 to 90%) are fusiform cysts in the extrahepatic biliary ducts. Type II (3%) are true diverticulum seen within the intrahepatic and extrahepatic ducts. Type III (5%) is a choledochocele. Type IV cysts are multiple ductal cysts subdivided into type A, both intrahepatic and extrahepatic fusiform cysts, and type B, multiple extrahepatic cysts. Type V is multiple intrahepatic cystic dilations, also known as Caroli disease.[2]

Indications

The role and indication of PC are to obtain access and investigate the biliary system, more so to the proximal than distal. The need for this access varies according to the pathology and planned intervention or assessment. Therefore, indications for PC include identifying and managing biliary obstruction, evaluating cholangitis etiology, evaluating biliary leaks, failed ERCP management, tissue sampling, and post-transplant evaluation of biliary dysfunction.[1][3]  Benign etiologies include biliary stones and inflammatory disorders. Malignant etiologies are biliary obstruction from mass effect or ductal invasion, causing obstruction, most commonly of pancreatic origin.[4] Biliary flow obstruction and its causes are common reasons for the need for this intervention. PTC also permits several therapeutic interventions, including drainage of infected bile in the setting of cholangitis, extraction of biliary tract stones, dilation of benign biliary strictures, or placement of a stent across a malignant stricture.[5]

Contraindications

The situations where PC is contraindicated are mainly when the rate of potential complications is high or when the success chance is low. There are several patient and disease factors that affect the safety and rate of success. The absolute contraindications for PC are irreversible coagulopathy or clopidogrel use that is necessary and cannot stop. The relative contraindications include aspirin use, large volume ascites, and hemodynamic instability. Most patients are severely ill, and clinicians should attempt to reverse any contraindications when possible.

Personnel

PC usually occurs in the interventional radiology suite equipped with imaging, medication administration supplies, and interventional tools and devices. An experienced interventional radiologist (IR) is the primary responsible person in the team. Technician assistants for both imaging and intervention are part of the team. A registered nurse usually provides nursing, monitoring of the patient's condition, and administering medications. Monitoring the patient in the immediate period after the procedure is necessary and accomplished by a registered nurse under the supervision of the radiologist.

Preparation

Before performing any invasive procedure, a thorough evaluation of the patient’s past medical and surgical history is necessary. The patient's current imaging studies should undergo review, and if needed, further cross-sectional imaging ordered as appropriate. To determine risk factors related to coagulopathies encountered during the procedure, the minimum serological workup should include a CBC, platelet count, INR, and aPTT. When clinically appropriate, the INR should be corrected to be less than 1.5, and the target value for platelets should be greater than 50,000 per microliter.[6] Preprocedural antibiotics should be given based on the clinical presentation and serologic workup. The patient should not have anything by mouth following the hospital’s policy for intravenous sedation or general anesthesia.

Technique or Treatment

PC usually takes place in the radiology department with interventional capacity. Interventional radiologists have additional training in placing image-guided percutaneous catheters. Patients needing PC usually have dilated bile ducts due to the pathology and obstructions. This dilatation makes recognizing the biliary ducts on transabdominal ultrasound or with all cross-sectional imaging modalities, including magnetic resonance cholangiopancreatography and computed tomography, easier. There are various ways to access the biliary tree, including a combination of fluoroscopic and ultrasound-guided techniques, based on the physician’s preference.[7] These imaging studies are useful and necessary for planning all the steps of the procedure. When there is no detectable dilatation of the intrahepatic biliary ducts, PC may be technically limited and associated with a higher incidence of complications.

Patient's Position and Preparation

The patient should be in a comfortable supine position allowing appropriate access to the liver. The overlying upper abdomen should be prepped and draped in a sterile fashion. 

Anesthesia

The procedure involves painful steps that include a percutaneous catheter traversing the skin, intercostal muscles, and the liver capsule. Therefore the procedure should be performed using local anesthesia and moderate sedation. When additional steps like biopsies or stenting are needed, sedation becomes particularly important.

Antibiotic Prophylaxis

Gram-negative bacteria and enterococcal antibiotic coverage are necessary for the obstructive biliary system.

Access and Cannulation

The most preferred approach to limit complications is accessing the right bile duct from a slightly anterior approach, at the midaxillary line, below the tenth rib. Other approaches include a left-sided epigastric approach or a trans-gallbladder approach.  The method utilized should be determined based on the expected pathology. A sequence of wire and catheter exchanges are performed until access into the biliary tree is obtained. Once biliary access is confirmed, drainage of the bile is the next step, followed by contrast injection into the biliary tree to evaluate the biliary anatomy and pathology. A catheter can then be inserted and advanced across an obstruction into the duodenum. The drainage in this way will be both internally and externally. The external end of the catheter can be caped to enhance internal drainage and preserve the enterohepatic bile salt circulation.

The cholangiographic findings will then direct the management of the defined pathology. Management may include biliary drainage placement, biliary dilation, and/or stent placement.[8] Further discussion on these techniques is outside the scope of this article.

Complications

The complication rate for only percutaneous cholangiography is very low, with major complications being under 2%. There are four major complications described, and medical practitioners should be aware of potential complications that may arise. 

1. Hemorrhage is the most concerning complication related to the technical difficulty of the procedure.[9] It can be subcapsular or intraperitoneal. Another form of bleeding is hemobilia resulting from the communication of the tract with a major vascular structure. The chance of severe hemobilia ranges from 0.2 to 4 percent.[10] Most hemorrhage is self-limited, but if the patient becomes unstable, another procedure may be necessary. The typical management of a hypotensive patient related to hemorrhage after a percutaneous cholangiogram would be embolization. Hepatic arteriography is useful to identify the source of bleeding, and transcatheter embolization can effectively stop the bleeding. If necessary, embolization should be selective to preserve as much functioning hepatic tissue as possible. 

2. Infection and bacteremia, which include cellulitis, cholangitis, and sepsis. To reduce infection risk, patients should receive the appropriate preprocedural antibiotics before the procedure begins.[3] Cholangitis is more common in ERCP than the percutaneous approach related to crossing the pancreatic ampulla, allowing enteric bacteria into the biliary system. Cholangitis overall is more common in obstructive diseases related to malignant etiologies.[11][12] Cellulitis and cholangitis usually receive treatment with oral antibiotics. Sepsis may require hospitalization with culture and sensitivities for intravenous antibiotics.

3. Biliary leaks are another complication, subdivided into peritoneal or pleural biliary leaks.

4. Pneumothorax can occur with a right-sided approach. Management includes sequential chest X-rays. If the patient remains stable, observation may be adequate; if not, a chest tube may be necessary.[3]

Other significant complications may arise when performing percutaneous biliary work but are usually related to the management of biliary pathology.

Clinical Significance

Percutaneous cholangiography is an essential adjunct to diagnosing and treating patients with biliary disease. Patients who present clinically with jaundice or symptoms of obstructive biliary disease should be considered for ERCP and/or percutaneous cholangiography, depending on the clinical presentation. Percutaneous cholangiography can be critical in assisting with the diagnosis and may direct further patient management.

Enhancing Healthcare Team Outcomes

Patients who present with jaundice, fever, and right upper quadrant pain should undergo evaluation for obstructive biliary disease utilizing serology and cross-sectional imaging. If a diagnosis is not possible with cross-sectional imaging, the interprofessional team should consider whether or not ERCP or percutaneous cholangiography is more appropriate. It is important to determine the overall goal of patient management based on the patient’s clinical presentation and comorbidities. Collaboration with all members of the health care team is essential to ensure that successful diagnosis and the appropriate management take place. A radiology nurse can prepare the patient for the procedure and provide post-procedural care and monitoring, reporting to the clinicians of any changes in status. Interprofessional cooperation will enhance the effectiveness of hepatic cholangiography and improve the process as well as the subsequent care through accurate diagnosis leading to better-targeted treatment. [Level 5]

Nursing, Allied Health, and Interprofessional Team Monitoring

A registered nurse usually provides monitoring of the patient's general condition with particular attention to the consequences of the procedure. Nursing also includes administering medications and monitoring the patient in the immediate period after the procedure. Close monitoring in a dedicated holding area in the vicinity of the interventional suite is essential. Direct intervention can then take place; this is not commonly needed, but it should be available.