Percutaneous Transhepatic Cholangiography
The commonly used term “PTC” stands for the historic procedure percutaneous transhepatic cholangiography, which is simply the production of an image of the biliary tree by injection of radiological contrast through a needle. This diagnostic procedure has been completely superseded by CT and MRI scanning. However, the term is still in common usage as shorthand for the more complex percutaneous biliary procedures performed today.
Percutaneous biliary procedures encompass a wide range of varying complexity, duration and potential for discomfort. The most common scenario is the re-establishment of an effective biliary drainage channel into the bowel in patients with malignant bile duct obstruction. These cases are often palliative and a completely internalised solution using stents is the aim.
Natural orifice procedures are generally preferred over the percutaneous approach, so it is possible that the patient will have already had an ERCP procedure which did not achieve the desired aim. However, in some scenarios a percutaneous approach is preferable from the start, either because of unfavourable biliary anatomy or because ERCP is impossible due to previous gastric surgery.
More complex cases may involve revision of failed existing stent arrangements, or surgical biliary anastomoses which have developed strictures. Generally speaking, the management of benign biliary obstruction presents more challenges and involves more complexity than malignant causes. In cases of presumed malignant obstruction, brushings and biopsies may be taken from the stricture.
Operator Considerations
Indications: Benign or malignant biliary obstruction.
Contraindications: Specific contraindications include large volume ascites and therapeutic futility, the latter clearly a very individual discussion point.
Planning: The route of access (left lobe vs right lobe), ideal outcome, and bail-out outcomes should all have been determined by the radiologist on the basis of diagnostic imaging and discussion with the clinical team and the patient.
Preparation: Anticoagulation and antiplatelets should be stopped preoperatively. INR should be less than 1.5 and platelet count greater than 50,000 mm3. Treatment with vitamin K or fresh frozen plasma may be required.
Duration: The potential range of procedural variants is very broad. Procedure time may range from 30 minutes to (rarely) two or more hours, but is typically around one hour.
Position: Supine
Access: Percutaneous access may be via the left or the right lobe of the liver, with the radiologist, assistant, and their trolley on the corresponding side of the patient. The C-arm may be on either side of the patient.
Technique: Initial percutaneous access into the biliary tree may be guided by ultrasound, particularly for procedures via left lobe access. Subsequent manoeuvres are all undertaken using fluoroscopic guidance. The radiologist can generally anticipate when they will be doing something which causes pain, such as dilating a stricture. It is helpful if the radiologist tells the anaesthetist that they are about to do something which will likely stimulate the patient.
Complications: Post-procedural pain is common but typically settles within 24 hours. Haemorrhage and systemic sepsis are uncommon but may be sudden and severe. Pancreatitis is relatively rare.
Post-procedure instructions: Patients should be observed closely for several hours for signs of haemorrhage or sepsis. Six hours bed rest is typical.