Percutaneous Transhepatic Cholangiography

Anatomy and Physiology

Successful PTC performance and interpretation require an understanding of choledochal anatomy and its variants. The extrahepatic portion of the biliary system consists of the common hepatic, cystic, and common bile ducts.

• The common hepatic duct (CHD) emerges from the liver and travels caudally.
• The cystic duct allows bidirectional flow between the gallbladder and the other 2 ducts.
• The common bile duct (CBD) is simply the continuation of the CHD toward the duodenum beyond the CHD-cystic duct union. The CBD usually enters the pancreas and receives the main pancreatic duct before entering the duodenal wall at the major duodenal papilla.

The sphincter of Oddi, under neurologic and endocrine stimulation, controls bile release from the CBD into the duodenum. Extrahepatic choledochal anatomy is much less variable than intrahepatic choledochal anatomy. Based on its blood supply, the liver can be divided into 8 segments within 2 lobes. The intrahepatic biliary system arises from microscopic bile sinuses that drain into small canals (canaliculi) between hepatocytes. Canaliculi converge to form progressively larger bile ducts, which subsequently develop into 8 segmental ducts, several sectoral ducts, and typically 2 lobar ducts. The right anterior sectoral duct drains segments 5 and 8 and usually courses in a somewhat craniocaudal orientation, whereas the right posterior sectoral duct drains segments 6 and 7 and usually courses more lateromedially. The location where the lobar or sectoral ducts join to form the CHD is called the porta hepatis. The most common configuration near the porta hepatis, seen in about 50% of people, consists of:

• The right lobar duct is formed by the union of an anterior and posterior sectoral duct. 
• Both lobes drain into a single duct, which empties into the CHD.

Congenital variants and anomalies may affect the performance and interpretation of PTC. The most common variant features a right anterior sectoral duct that drains separately into the CHD. Common anomalies include choledochal cysts and diverticula.  

Indications

Because less traumatic alternatives are often available for the diagnosis and treatment of biliary disease, PTC generally is not a first-line procedure. The Cardiovascular and Interventional Radiological Society of Europe, the Society of Interventional Radiology, the Japanese Society of Hepato-Biliary-Pancreatic Surgery, and the Indian College of Radiology and Imaging have published society guidelines specifying when PTC and PTBD are indicated.[1][2][3][4][5][6]

These include:

• Assessing biliary anatomy 
  • PTC can inform a surgeon on the operative approach to take when other imaging exams do not provide sufficient anatomic detail.
• Treating biliary leaks
  • If endoscopic retrograde cholangiopancreatography (ERCP)-guided diagnosis and treatment are not feasible or have failed, then an approach using PTC is the next least invasive option.[7]
• Treating obstructive jaundice from benign or malignant biliary strictures
  • PTC with PTBD can be used to perform cholangioplasty (bile duct dilation) for strictures and obstructions and to place stents or catheters that drain bile internally or externally.
  • Unless surgery is indicated, PTBD becomes the preferred rescue strategy when a peroral method (ie, ERCP) fails or is not feasible,[8][9] such as after a prior bile duct reconstruction like a Kasai portoenterostomy.[10][11]
• Bile duct stone removal and lithotripsy [12]
• Tissue collection via biopsy, aspiration, or brushing
• Foreign body retrieval [13]
• Assisting an endoscopist or surgeon who is having or expects difficulty accessing the bile ducts in retrograde fashion (a rendezvous approach)

Other guidelines for PTC and PTBD have been suggested.[14][15]

Contraindications

Due to its potential risks, PTC can be contraindicated, including when there is:

• The possibility of instead performing ERCP:
  • ERCP should be the first-line therapy for stenoses or obstructions that are reachable via this method, given data showing that ERCP-guided procedures are associated with decreased adverse events, improved survival, and enhanced quality of life.[16]
  • The National Comprehensive Cancer Network recommends ERCP over PTC for extrahepatic duct lesions.[17]
• A nondilated choledochal system: 
  • Attempting PTC when the ducts are not dilated, such as for a planned diversion of bile away from a site of traumatic bile leakage, significantly increases the chance of failed duct access and complications.[18] 
  • PTC should be deferred if there is a possibility that nondilated ducts will expand before significant interval clinical worsening.
• An allergy to contrast material: 
  • Patients with a known contrast allergy should receive preprocedural corticosteroids and antihistamines before undergoing percutaneous transhepatic cholangiography.
• A contraindication to sedation:
  • PTC can be performed with local anesthesia alone. However, most people would be unable to tolerate therapeutic transhepatic procedures if administered local anesthesia only.
• A patient who cannot lie still: 
  • PTC requires a patient to lie still for usually 30 to 60 minutes.
• An anatomical limitation: 
  • Certain anatomical variations or abnormalities (eg, extreme obesity) may make PTC technically challenging or impossible to perform. 
• Early pregnancy: 
  • PTC involves radiation exposure, which can injure a developing fetus. 
• Low life expectancy:
  • The Cardiovascular and Interventional Radiological Society of Europe guidelines advise against performing PTC in persons with a life expectancy of fewer than 30 days, as the procedure risks are likely to outweigh the benefits.
• Any of the following specific diseases/conditions:
  • Ascites, because of the lack of the tamponade effect of solid tissue against the liver capsule, can prevent hepatic puncture site coagulation and result in death.
  • Unstable hemodynamics can worsen PTC.
  • Extensive hepatic disease occurs when bile duct drainage alone will not improve morbidity or mortality, such that urgent liver transplant should be pursued instead.
  • Multifocal intrahepatic segmental stenoses would prevent successful PTBD.
  • Uncontrolled infection, particularly in the area surrounding the liver or biliary tract, can result in sepsis or abscess formation. 
  • This includes coagulopathy or a bleeding disorder.
  • Regarding hemorrhage risk, the Society of Interventional Radiology (SIR)  categorizes PTC as a level 2 procedure.
  • For patients undergoing PTC, the SIR recommends maintaining an international normalized ratio of no 1.5 or less and a platelet count of at least 50,000 cells/μL.

The activity's section on procedure preparation addresses additional issues that could be considered relative contraindications.

Equipment

Essential equipment for PTC includes the following:

• Image guidance machine:
  • The traditional method for percutaneous needle guidance is x-ray fluoroscopy, which produces real-time x-ray video images. Because x-ray fluoroscopy does not show bile duct locations until after a duct has been punctured and filled with contrast, it necessitates a "pin cushion" guesswork approach to the bile duct puncture described below. 
  • Ultrasound (US) can often enable real-time visualization of bile ducts and hepatic arteries, making it a superior method for guiding a needle into a duct and away from arteries, thereby reducing the number of puncture attempts.[19][20]  
  • Computed tomography (CT—particularly CT fluoroscopy) has some data to support its use, as evidenced by an observational head-to-head comparison.[21] 
  • Magnetic resonance imaging and magnetic-guided US access techniques have been performed, but there is a lack of published head-to-head comparison data against other approaches.
• Contrast media and syringes:
  • Usually, water-soluble iodinated contrast is used.
  • A 25% contrast by volume is usually sufficient to visualize the ducts under fluoroscopy, while not obscuring tools placed into the ducts or unnecessarily increasing viscosity in the bile system, which can lead to cholangitis.
• Chlorhexidine, sterile drapes, gowns, and gloves: 
  • These items help maintain aseptic conditions.
  • PTC is considered a clean-contaminated procedure because the bile may already contain enteric bacteria. The goal is not to introduce additional organisms into the body.
• Monitoring equipment:
  • The patient's vital signs should be monitored during the procedure.
• Local anesthetic, sedation, and sedation monitoring equipment:
  • At a minimum, local anesthetic is necessary to enable the patient to tolerate PTC.
  • Transhepatic interventions often are too painful to tolerate without intravenous sedation.
• Needles:
  • Certain needle types, such as 21- to 22-gauge Chiba or Seldinger needles, are suitable for accessing the bile ducts.
  • A shorter 18-gauge coaxial needle can expedite bile duct access by preventing the thinner, more flexible access needle from inadvertent bending and misdirection.
• Guidewires, catheters, and sheaths: 
  • Navigating bile ducts is often best performed using a hydrophilic guidewire.
  • 5 Fr angiographic catheters having short angles (eg, Bern, Berenstein, Kumpe, or reverse internal mammary catheters) may be necessary to navigate the ducts.
  • Such catheters are typically placed through a percutaneous access sheath.
• Most other necessary equipment pertains to therapies performed in conjunction with PTC.

Personnel

The healthcare professionals working together to enable PTC usually include:

• A clinician trained in interventional radiology or hepatic surgery
• An imaging technologist
• An anesthesiologist, nurse anesthetist, or nurse dedicated to administering sedation
• A "circulator" who is free to move about to obtain supplies on an as-needed basis

Preparation

Imaging before PTC enables an informed approach to the procedure, such as whether a right- or left-lobe approach should be pursued initially. Cross-sectional imaging (CT, MRI, or US) can reveal the patient's duct anatomy and dilation distribution, the location of an obstruction, and possibly the obstructive cause. Imaging confirmation of a bile duct leak is often best performed using radionuclide scintigraphy (nuclear imaging), such as an iminodiacetic acid scan.[22]

The operator should plan an upper limit for hepatic punctures (transgressing the liver capsule) and passes (moving the needle deeper into the parenchyma without necessarily re-entering the liver itself), as well as a systemic approach for redirecting the needle after each unsuccessful puncture. Prospective observational data collected by the same investigator in different patient groups found a required average number of punctures to vary between 3 and 6.[23][24] When there is no ability to visualize a target duct with US, sometimes the planned upper limit of punctures is reached with no successful duct access, even using a limit of 50.[24] The same investigator concluded that greater than 5 punctures or 10 passes are thresholds where the odds of hemorrhagic events start to double; a puncture number to clinical complication relationship curve from a controlled trial has not yet been published. The patient's autonomy should be preserved via informed consent.[25]

Antibiotic prophylaxis, regardless of whether the patient is symptomatic, should cover gram-negative bacteria. A reduced rate of sepsis after PTC has been found with prophylactic gram-negative bacterial therapy, even in persons for whom there is no evidence of biliary tract retrograde contamination with enteric flora.[26] Some clinicians also cover gram-positive and anaerobic bacteria. For PTC only, a single dose of a third-generation cephalosporin may be considered. When therapy is also planned, the Society of Interventional Radiology recommends intravenous administration of 1 g of ceftriaxone or 1.5 g of ampicillin-sulbactam.[27]

Steps should be taken to correct modifiable risk factors, such as coagulopathy and sedation-related risks. Patients referred for PTBD are often dehydrated, posing a risk of procedure-induced hepatorenal failure; hydration should be provided even when hemodynamic instability findings are absent. The patient should be placed in a comfortable position that still allows access to the intended region of the liver selected for puncture. A sterile field should be created around that site. 

Technique or Treatment

Mastery of the PTC technique is essential for ensuring diagnostic accuracy and procedural safety. The following section outlines the step-by-step approach to performing PTC.

Needle Insertion and Duct Cannulation

There is no prospective randomized data regarding access location and image guidance technique. The access location and image guidance technique should be determined based on anatomy identified on pre-PTC cross-sectional images, the expected goal of PTC, and any planned adjunct procedures. When only x-ray fluoroscopy is used for initial image guidance, such as in a nondilated intrahepatic duct system, the most common approach is to access a right lobe bile duct by inserting a needle slightly ventral to the midaxillary line caudal to the tenth rib, with the needled angled craniad to the expected location of the porta hepatis and toward the midclavicular line. This approach can: keep the needle out of the thoracic cavity, create an angle conducive to passing instruments into the bile ducts, and keep the operator's body out of the x-ray beam. Options for bile duct access using fluoroscopic guidance also include the left lobe and the gallbladder. 

Ultrasound guidance should be used when a bile duct is large enough to be visualized with this technology, as it can yield faster and more accurate duct targeting and reduce radiation exposure.[19][28] Results from a retrospective, noncontrolled study supported the use of ultrasonographic guidance via a left lobe approach. Still, they found no advantage compared with conventional fluoroscopic guidance for a right lobe approach.[20] Further, a longstanding technique involves aspirating bile and injecting contrast during needle withdrawal, indicating that the needle has traversed and re-entered a duct—a method referred to as the double-wall puncture technique. However, results from a randomized, noncontrolled trial found no difference in outcomes between single-wall and double-wall puncturing techniques.[29]

Sufficient contrast must be injected to diagnose blockages and strictures, but excessive injection should be avoided. PTC can, in some cases, be performed with a needle only. When injection through a needle alone is insufficient to visualize enough of the biliary tract for diagnostic purposes, the Seldinger technique is used to exchange the needle for a catheter to navigate the ducts. 

Bile Sampling

Aspirated bile should be assessed for its color and odor to guide decisions prior to ending the procedure. If doing so reveals evidence of infectious cholangitis, then a sample should be tested for microbes.

Image Documentation

Images should be recorded to show key portions of the procedure and the information needed for the next steps in management. True lateral views are often not possible using a conventional fluoroscope, but images can still be taken in multiple planes, such as supine oblique views. Newer x-ray fluoroscopes can also create CT images when needed.

Procedure Conclusion

A hemostatic patch can be placed along the liver capsule via the needle or sheath; however, there are currently no studies with results demonstrating that this approach reduces complications. Once the tools (needle, catheter, and/or sheath) are removed, dermal pressure and a bandage should be applied to promote superficial hemostasis and prevent skin contact with bile, a chemical irritant. The patient should be monitored for a period to manage any complications or until it is reasonable to assume that no severe complications have occurred. 

Complications

The Society of Interventional Radiology in 2020 reported complication rates for PTC and PTBD of between 2% and 10% based largely on retrospective selected case series.[3] However, in more recent large prospective cohorts, PTC and PTBD were reported as having higher complication rates than those reported by the societies that have published guidelines for these procedures.[26][30] Hemobilia and/or melena occur in approximately 10% of cases and are generally considered expected outcomes rather than true complications. Similarly, postprocedural pain requiring analgesia is a common adverse effect and not classified as a complication in itself. The most common complications associated with PTC are listed below in descending order of frequency.[1][14][31]

• Infections:
  • Bacteremia/sepsis, cholangitis, liver abscess, and/or infection may occur at the body wall puncture site.
  • A review of different studies' results found varying overall infection rates: 67 of 343 patients (19.5%), 46 of 152 patients (30%), and 83 of 193 patients (43%).[26]
• Bile-related inflammation:
  • Perforation of the bile ducts and the liver capsule can leak bile into the peritoneal space, resulting in sterile or chemical peritonitis and abscess formation; leaks can also occur in the pleural space, resulting in sterile/chemical pleuritis and empyema.
  • Bilomas are noninfected bile collections. Because they typically resolve independently, percutaneous drainage is reserved for cases where a collection remains unbearably painful despite medication or exhibits additional signs of infection.
• Damage to adjacent organs and spaces:
  • Of these, the risk of pneumothorax is highest, especially in cases where the abdominal puncture site is close to the diaphragm. According to a review, transpleural punctures were associated with pneumothoraces at rates ranging from 8% to 22%.[32]
  • The needle may inadvertently puncture the lung, gallbladder, or bowel. Catheter manipulation to the level of the pancreatic duct can cause pancreatitis.
• Bleeding: 
  • In addition to hemobilia and melena, bleeding may occur in the form of subcapsular hepatic hematoma, hemothorax, hemoperitoneum, pseudoaneurysm, fistula, and/or hemorrhage from the body wall at the catheter/drain site. Hemorrhage following PTC/PTBD may result from arterial, portal, and/or hepatic venous injury.[33] 
  • Hepatic artery bleeding is marked by bright red (occasionally pulsatile) blood, a large drop in hematocrit levels, or hemodynamic instability. Portal vein bleeding should be suspected when dark blood is present, without significant hemodynamic instability or a drop in hematocrit.
  • Nonoperative treatment options may include PTBD drain repositioning, stent graft placement, and embolization. Stent graft placement across the injury site is feasible only with a central injury and favorable anatomy. Arterial embolization is more common, typically performed using coils via femoral or radial artery access.
  • The Society of Interventional Radiology recommends performing a practice review if more than 5% of patients have experienced bleeding significant enough to warrant a second invasive procedure.[3]
• Death:
  • As discussed in the sections above, PTC with PTBD is often performed on those who have significant comorbidities with little reserve for additional hemodynamic instability or infection.
  • In the setting of malignant obstructions, one retrospective study's results showed a statistically significant greater risk of death from PTC and attempted PTBD compared to endoscopic retrograde cholangiopancreatography and attempted endoscopic drainage.[34]

Clinical Significance

PTC is most commonly used during the management of the following conditions:

• Bile duct obstruction due to malignant disease:
  • Pancreatic cancer
  • Cholangiocellular carcinoma
  • Hepatocellular carcinoma
  • Metastatic disease
• Bile duct obstruction due to benign disease:
  • Cholangiolithiasis
  • Iatrogenic injury to the biliary tract 
  • Primary sclerosing cholangitis
• Cholangitis due to ischemic or infectious causes

Technical Success of PTC and PTBD

The Cardiovascular and Interventional Radiological Society of Europe (CIRSE) has defined technical success as follows:

• For PTC: Diagnostic opacification of bile ducts.
• For PTBD: Placement of a drainage catheter.

Although success rates are likely to vary by practice, CIRSE guidelines reported that technical success for these procedures based on published retrospective reviews is:

• Rates of 90% or higher when there are dilated biliary ducts
• Rates of 80% or higher when there are nondilated biliary ducts [1]

As with all procedures, clinical success rates also depend on the patient's overall clinical condition and operator skill.

PTC versus Other Diagnostic and Therapeutic Options

For disease diagnosis, PTC has been largely replaced by magnetic resonance cholangiopancreatography, endoscopic ultrasound, and endoscopic retrograde cholangiopancreatography because PTC has higher morbidity and lacks comparative cost-effectiveness.[5][35][36] For tissue sampling, percutaneous or endoscopic biopsy is generally performed instead of PTC-guided biopsy. However, cholangiographic-guided biopsy may improve the accuracy of specimen diagnosis in unusual circumstances.[37][38]

For relief of bile duct obstruction, PTC is the first step for PTBD or percutaneous stenting, which is the second most common approach for treating obstructive jaundice after endoscopic retrograde cholangiopancreatography (ERCP)-guided drainage or stenting.[16][39] The success rates of both procedures are similar for obstructions near or caudal to the porta hepatis. However, PTBD has a higher overall success rate for isolated intrahepatic obstructions.[40] 

Results from a prospective noncontrolled study of 30 patients showed that the only advantage of PTC over ERCP was the treatment of bile fistulas.[41] In the West, only data from nonrandomized studies is available. A randomized trial comparing percutaneous versus endoscopic bile duct interventions was attempted in the United States but failed to recruit enough patients over a 3-year period; future attempts in Europe have been proposed.[28][42] A prospective randomized study from China (not published in English) reported that PTBD is more cost-effective than an endoscopic approach when performed for end-of-life palliation.[43]

Enhancing Healthcare Team Outcomes

Patients undergoing PTC require the collaboration of several healthcare professionals to ensure patient-centered care that prioritizes safety and outcomes in line with the patient's goals. Interventional radiologists or hepatobiliary surgeons are the physicians who most commonly perform PTC and PTBD. Collaboration with hepatologists, transplant surgeons, hospitalists, and other clinical specialists is important for addressing contraindications and alternatives before proceeding with PTC/PTBD. Imaging technologists help with PTC/PTBD technical performance. Advanced care clinicians, nurses, and pharmacists assist with patient monitoring, medication administration, and education. 

Creating an interprofessional team that meets regularly to review previous cases and discuss performance feedback can help identify areas for improvement and implement strategies to enhance team performance.[44] Healthcare teams making an effort to conduct shared decision-making with patients have been shown in 2 meta-analyses of randomized trials, both in nonsurgical and surgical settings, to:

• Reduce patient decision regret (0.29, 95% CI 0.07 to 0.51; 1 study; N= 326), and
• Reduce consultation length (0.51, 95% CI 0.21 to 0.81; 1 study, N= 175).[45]
• Reduce decision conflict (0.4, 95% CI 0.33 to 0.46; 24 studies),
• Reduce patient decision regret (0.2, 95% CI significant but not reported; 6 studies),
• Reduce patient decision anxiety (0.4, 95% CI 0.55 to 0.46; 4 studies), and
• Increase patient decision satisfaction (0.7, 95% CI significant but not reported; 9 studies).[46]

Note: These values are reported as: odds ratio, 95% confidence interval; number of studies +/- number of patients.