Cholangioscopy- Applications, Limitations, and how it differs from standard ERCP

Peroral Cholangioscopy, Cholangioscopy, Single Operator Cholangioscopy, bile duct diagnosis, ERCP, ERCP vs. Cholangioscopy

Cholangioscopy is a noninvasive endoscopic method used for both direct visual diagnostic evaluation and simultaneous therapeutic intervention of the bile ducts.

Cholangioscopy- Applications, Limitations, and how it differs from standard ERCP

What Is Cholangioscopy?

Cholangioscopy is a procedure where your gastroenterologist or physician wants to inspect your bile ducts more closely and see hard-to-reach areas that can’t be visualized using other diagnostics. Cholangioscopy can be both diagnostic and therapeutic, meaning that it can diagnose and treat diseases of the bile duct.

The same instrument that is used to visualize the bile ducts can also be used to inspect the pancreas during the endoscopy, however, this procedure is called pancreatoscopy.

The procedure is used in conjunction with endoscopic retrograde cholangiopancreatography (ERCP), which uses endoscopy and X-ray technology to examine the bile ducts, pancreas, liver, and gallbladder. ERCP has its limitations, and your physician may not be able to clearly visualize parts of the bile ducts.. If your physician feels the need to get a more clearer look in or obtain biopsy samples from the bile ducts, they may use ERCP and cholangioscopy combined or cholangioscopy as a standalone diagnostic.

Why Is Cholangioscopy Performed?

The primary reason cholangioscopy is performed is to evaluate biliary structures and to diagnose and remove bile stones. It is often used when ERCP is insufficient and direct visualization is necessary. In addition to its primary purposes, cholangioscopy is performed for other reasons as well. Some reasons diagnostic cholangioscopy is performed include:

Evaluation of fungal infections, parasitic infections, and cytomegalovirus
Biopsy (sampling of tissue for evaluation)
Visual evaluation of eosinophilic cholangitis (disorder of the biliary tract), and other biliary issues
Diagnosing hemobilia (bleeding in the biliary tract)
Diagnosing cholangiocarcinoma (cancer of the bile ducts)
Evaluating primary sclerosing cholangitis (inflammatory and stricturing disease of the bile ducts)

Cholangioscopy can also be therapeutic, which means the procedure is used to treat a condition. Some types of therapeutic cholangioscopy include:

Photodynamic therapy for cholangiocarcinoma (cancer of the bile ducts)
Cystic duct stent replacement
Biliary stone extraction

When cholangiopancreatoscopy is used (inspection of the bile ducts and pancreas), it can diagnose and remove pancreatic stones, diagnose and potentially remove pancreatic duct tumors, diagnose chronic pancreatitis, and diagnose and potentially treat autoimmune pancreatitis.

How Is Cholangioscopy Performed?

Currently available cholangioscopy equipment can be broadly classified into a ‘two-operator system’ or a ‘single-operator system’. The two-operator system includes the conventional “mother and baby” system and needs the active participation of two endoscopists.

Innovation in direct peroral cholangioscopy led to the recent development of single-operator cholangioscopy (SOC) systems. The catheter-based system attaches to an ERCP endoscope and is preferred over previous methods due to its improved visualization and durability, in addition to being a single-operator system. The currently available fiberoptic baby scopes have an external diameter of 2.8 mm to 3.4 mm with a working channel varying from 0.5 mm to 1.2 mm. They have a single plane tip deflection (up-down) of approximately 90°. These systems are widely available, allow tissue biopsy and can be used for therapeutics. The electronic baby scopes have a charge-coupled device (CCD) video chip which is mounted at the distal tip of the scope.

Single-operator cholangioscopy systems are designed to overcome the limitations of the standard 'mother‑baby' cholangioscopy procedure. As well as needing only a single operator, the SOC system has a 4‑way tip deflection and a single‑use baby endoscope for access and delivery. These systems allow users to visually examine the biliary ducts, take biopsy samples and treat large biliary stones by either electrohydraulic or laser lithotripsy.

When SOC cholangioscopy is performed, a fiber optic probe attached to a small camera is inserted using endoscopy. The probe allows your examiner to visualize areas not seen with ERCP. It is an endoscopic procedure, so the patient will have twilight sedation and will be awake. A mouthpiece is placed in your mouth, and the physician may use local sedation to prevent gagging or choking. A single person can perform this procedure, so either the physician or gastroenterologist will insert the endoscope into your mouth and down through your throat and digestive tract. The endoscope has a tiny camera with a fiber optic probe. Using the camera and probe, the physician is able to see bile ducts or other areas not previously seen in ERCP. Depending on the reason for the procedure, the doctor may perform cholangioscopy and ERCP concurrently.

ERCP vs. Cholangioscopy

ERCP can demonstrate the anatomy of the biliary tract and reveal anatomical abnormalities, strictures and intraductal filling defects. However, this technique does not always differentiate the biological nature of bile duct lesions and can fail to determine their intraluminal extension. Furthermore, it is unable to provide information about biliary mucosal lesions that do not project into the biliary lumen.

Peroral cholangioscopy as an adjunct to ERCP is a promising procedure that provides direct visualization of the biliary tree. It has been shown to have value in treating difficult-to-remove biliary stones, assessing indeterminate biliary strictures and distinguishing between different intraductal lesions of the biliary tree.

How Do I Prepare for Cholangioscopy?

Before your procedure, you will sit down with your physician and review your current and past medical history. You should let your doctor know if you have allergies, what medications you are on, and supplements you take. You will be asked to fast for 8 to 12 hours prior to your procedure. If you are on blood thinners, it is imperative to let your physician know, as you should stop taking certain medications at a certain point before your procedure.

What Happens After Cholangioscopy?

After your procedure, you’ll be taken to a recovery room where you’ll be monitored. Be sure to have someone to drive you home. Your doctor may advise you not to eat for the next 24 hours, and then you can resume normal activity. You may experience some side effects after the procedure, such as:

Sore throat, particularly if the endoscope was guided into the esophagus
Abdominal cramps
Gas
Reactions to sedatives, such as drowsiness, nausea, and vomiting

If these side effects persist or seem severe, let your physician know right away.

Are There Any Complications After Cholangioscopy?

Cholangioscopy is a minimally invasive procedure that is relatively low risk, however, some patients can experience complications afterward. Some of these include: