Overview of Endoscopic Retrograde Cholangiopancreatography
Endoscopic retrograde cholangiopancreatography (ERCP) is a medical procedure that combines endoscopy and fluoroscopy. Simplifying these big terms, let’s say it’s an inspection of your inside organs using a flexible tube/tool called an endoscope, that uses fluoroscopy, a kind of imaging technique that allows doctors to see in real-time what’s happening inside your body. The doctor uses this endoscope to reach a part of your small intestine termed as the duodenum.
Once the endoscope reaches the duodenum, the doctors can then insert different tools into the biliary and pancreatic ducts. These ducts are ‘pipes’ that carry digestive juices from your liver, gallbladder, and pancreas. The doctor can also inject a contrast material in these ducts which makes them visible on an X-ray, and this helps performing therapeutic interventions, if required.
The ERCP started as a way to diagnose conditions by allowing the doctors to view the pancreatic and biliary ducts closely. But, over time, it has become more about treating conditions once they’ve been diagnosed. The doctors try to scope the ducts, and it could be difficult at times. In medical terms, a ‘difficult biliary cannulation’ is when it takes more than 5 minutes or more than five attempts to insert the tool into the duct or if the tool passes through the pancreas at least twice. The direct view of the ducts is obtained using a method called cholangiopancreatoscopy.
Anatomy and Physiology of Endoscopic Retrograde Cholangiopancreatography
The main tube of your pancreas is connected to a duct that helps in the digestion of your food. It typically drains into a small opening in the beginning of your small intestine, called the ampulla of Vater. This process is regulated by a kind of muscular valve called the sphincter of Oddi.
This tube is usually connected with another one that comes from your liver and gallbladder, called the common bile duct. At times, these two ducts can form a common tube, or they may remain separate but emerge at the same spot.
However, in about 10% individuals, their pancreas works slightly different. This is known as pancreas divisum, a harmless natural variation. In these individuals, the main duct and a smaller duct in the pancreas, called the duct of Santorini, do not join together as in most people. Instead, the smaller duct drains into a different part of the small intestine, called the minor duodenal papilla. This area also has a valve, known as the sphincter of Helly.
Remember these are all normal variations in the way your pancreas and liver help in digestion and do not cause any health problems.
Why do People Need Endoscopic Retrograde Cholangiopancreatography
ERCP, short for endoscopic retrograde cholangiopancreatography, is a procedure that doctors use to examine and treat problems in the liver, gallbladder, bile ducts, and pancreas. The doctor uses a long, thin tube called an endoscope to locate certain small openings in your body known as the major and minor papillae. They then insert a small device into these openings and inject a special dye that makes your biliary and pancreatic ducts visible on X-ray images.
During an ERCP, the doctor can also perform other tests to further understand what’s going wrong in your body. They might use a special tool to look directly into your bile and pancreatic ducts, take small samples of tissue for testing (a biopsy), or brush off some cells for testing (brush cytology). They might also use a type of ultrasound, which uses sound waves to create images of the inside of your body.
The ERCP procedure isn’t just for diagnosis; it can also treat a number of illnesses. For example, the doctor might cut a small opening in your bile or pancreatic duct to relieve blockages (this is called a sphincterotomy), place a tiny tube to prop your duct open (stent placement), or remove any stones that may be causing blockages.
The doctor might suggest this procedure for a number of reasons: for example, if your skin or eyes have turned yellow from jaundice, in cases where they need to treat or sample tissue from your biliary or pancreatic ducts, if there’s a chance you could have pancreatic cancer, if it’s unclear why you have inflammation of the pancreas (pancreatitis), or if the doctor needs to measure the pressure inside your sphincter of Oddi (a muscle that controls the flow of juices from the pancreas and gallbladder). It can also help in draining bile, placing a small tube in your bile duct to keep it open in case of any blockages or leaks, or draining pus-filled sacs in your pancreas.
One of the uses, known as a sphincterotomy, is needed when there is a dysfunction or narrowing in your sphincter of Oddi, if they’re having trouble placing a stent or reaching your pancreatic duct, or to treat bile duct stones. It’s also suggested for candidates who can’t undergo surgery because of other health problems and who have a type of cancer in a small opening where the bile and pancreatic ducts empty into the small intestine (ampullary carcinoma). It’s indeed a versatile procedure that helps your doctor make accurate decisions about your health.
When a Person Should Avoid Endoscopic Retrograde Cholangiopancreatography
Sometimes, ERCP (a procedure used to diagnose problems of the bile and pancreatic ducts) is not the right choice. This might be the case if there is no clear proof of a problem with the bile or pancreatic ducts. It’s also not a good idea to use ERCP when there are other, safer ways to figure out what’s wrong. If a person has pain in their belly but the doctors aren’t sure why, ERCP might not be the right choice. Lastly, there’s no point in doing ERCP if knowing the results won’t change how the doctors plan to treat the person. These situations help ensure that the procedure is only used when it’s most helpful and safe.
Equipment used for Endoscopic Retrograde Cholangiopancreatography
In an ERCP procedure, a tool called a side-viewing duodenoscope is typically used because it gives a good view of a part of the small intestine called the major duodenal papilla. This makes it easier to insert a tube or catheter, a process known as cannulation. However, for patients who have had certain types of surgeries, like the Billroth II gastrectomy or Roux-en-Y operation, the structure of their intestines has been changed. The entrance to a loop in the intestine might be hidden and set at a sharp angle, it could be longer, and the position of the papilla might be reversed.
In circumstances like these, the side-viewing endoscope may not provide a clear enough view. This makes it harder to insert a tube into the loop of the intestine, which can risk causing injuries. An alternative might be to use a forward-viewing endoscope, which could make it easier to insert a tube into the loop. However, deceptively inserting a tube into the papilla might still be more challenging because of its altered position. It doesn’t necessarily get easier with either the side-viewing or forward-viewing scopes.
There is another technique called double-balloon enteroscopy that uses two balloons to guide the forward-viewing endoscope through the intestine. This involves repeatedly inflating and deflating the balloons to progress through the intestine.
A dual lumen forward-viewing endoscope is another possibility. This type of instrument would even allow for the use of other surgical tools. For instance, a tool called an Allis forceps could be used to hold the papilla in position. Additionally, using a stiffer endoscope along with manual compression or an instrument like a polypectomy snare might make the cannulation process less challenging.
Who is needed to perform Endoscopic Retrograde Cholangiopancreatography?
The procedure requires one or two expertly trained doctors who specialize in using an endoscope. An endoscope is a flexible tube with a light and camera attached to it so the doctors can look inside your body. There also needs to be medical staff available who are trained to administer anesthesia, which is medication that will keep you comfortable and pain-free during the procedure.
Preparing for Endoscopic Retrograde Cholangiopancreatography
The American Society for Gastrointestinal Endoscopy (ASGE) provides guidelines on the types of tests a patient needs before undergoing a procedure called an endoscopy. They argue that healthy individuals don’t usually need extra tests like X-rays, heart checks, or blood tests before an endoscopy. However, certain tests might be needed based on a patient’s health and the risk factors of the procedure itself.
For instance, if there’s a chance a woman could be pregnant, a pregnancy test might be needed. If a patient has anemia, is prone to bleeding, or if blood loss is anticipated during the examination, tests to check blood levels and blood type may be conducted. Patients with bleeding disorders, diseases related to the bile ducts (tubes that carry bile from the liver to the gut), or those with poor nutrition might need tests to check the blood’s ability to clot. A chest X-ray might be required if a patient has symptoms related to the heart or lungs. Other tests could be necessary, depending on the individual patient’s medical history. Just like most procedures that use sedatives, a patient needs to avoid eating before the endoscopy.
In most cases, antibiotics aren’t given proactively before an ERCP (a procedure to examine the ducts (tubes) that drain the liver). Antibiotics are given, however, to patients who have had a liver transplant or have a blocked bile duct. These antibiotics specifically target bacteria found in the bile and should be continued after the procedure if the bile isn’t draining properly.
How is Endoscopic Retrograde Cholangiopancreatography performed
ERCP is a procedure that uses a flexible tube with a camera and light at the end, to examine your digestive system. The tube, called a duodenoscope, has multiple features that allow your doctor to perform many different tasks. These may include removing small growths, placing small drains, taking samples of tissue for further testing, releasing built-up fluid, and examining or removing certain stones from the passages that connect your gallbladder, liver, and pancreas to your intestine.
This procedure starts with the doctor inserting the duodenoscope through a mouthguard and sliding it down through the stomach into the first part of your small intestine (called the duodenal bulb). The doctor then needs to spot a small mound in the intestine, called the major duodenal papilla. From there, another thin and flexible wire is guided through the duodenoscope into either your bile duct or pancreas. The doctor will know they are in the right spot by using X-ray, before they inject a contrast liquid that helps to better see these areas.
Occasionally, it might be tough for your doctor to guide the wire into the right spot due to certain factors such as a small pocket of tissue diverting the normal path, a biliary stone that’s blocking the way, or narrowing or growths in the bile duct or pancreas. Very rarely, the doctor might need to guide their wire into a minor mound, or minor papilla, in the cases of frequent unexplained inflammation of the pancreas or a condition known as pancreas divisum.
To perform a cholangiopancreatoscopy, a procedure that uses a thin tube to visually examine the bile and pancreatic ducts, there are three main ways including a two-person method, a method called SpyGlass, and direct per-oral method.
In the two-person method, there are two doctors involved where one controls the main duodenoscope and the other controls a smaller device, with a tip that can only move up and down.
In the SpyGlass method, a single doctor uses a four-lane tube with a tip that can move in all four directions.
The direct per-oral method uses very thin tube-like devices that allow for digital imaging and are most commonly used in cases where the common bile duct is dilated. It uses water or “carbon dioxide” to inflate the area and minimize the risk of air bubbles entering the bloodstream.
In all methods, tiny tubes are passed through the duodenoscope into the bile duct. These tiny tubes vary in size, with widths from 1 to 4 millimeters. The working lengths range from 65 to 220 centimeters. This method allows for various devices to be passed into these tubes, such as tiny forceps for taking samples or devices for breaking up stones in the bile duct.
Possible Complications of Endoscopic Retrograde Cholangiopancreatography
About 6.8% of people might face problems after a specific procedure called ERCP (Endoscopic Retrograde Cholangiopancreatography), a type of medical exam that helps doctors look at the ducts (tubes) that carry bile from the liver to the gallbladder and from the gallbladder to the small intestine. And for about a quarter of these people, the problems might be severe and might lead to interventions like more prolonged hospital stay or blood transfusions.
The most common complication after ERCP is called post-ERCP pancreatitis (PEP), an inflammation of the pancreas, which happens in about 3.5% of people. Most of the time, the inflammation caused by this is mild to moderate. Other problems like infections of the bile ducts (cholangitis) and gallbladder (cholecystitis) can happen about 1.4% of the time, while bleeding in the stomach or intestines happens about 1.3% of the time. Even though it’s rare, duodenal and biliary perforations (holes in the first part of the small intestine and bile ducts, respectively) are the most concerning as they have the highest death rates among ERCP-related problems.
Other problems account for 1.3% of overall complications and may include issues related to anesthesia, conditions involving air trapped in the chest or abdominal cavity, damage to the liver or spleen, obstruction of the small intestine, and complications connected with the removal of bile duct stones.
Some factors can increase the risk of getting pancreatitis after an ERCP, which include hard-to-reach bile ducts, multiple insertions of a guide wire into the pancreas, a history of pancreatitis, female gender, young age and using certain techniques during the procedure.
To reduce these risks, doctors may prescribe drugs known as NSAIDs (Nonsteroid anti-inflammatory drugs), encourage hydration, and use alternative methods if NSAIDs are not suitable. Patients are regularly monitored after the procedure by measuring enzyme levels in their blood to ensure the pancreas is working correctly. It’s important to be aware that not all medications are effective in reducing the risk of pancreatitis, so your doctor will determine the most appropriate preventive measures.
Some procedure-related precautions that doctors follow to decrease the risk of complications include minimizing the number of attempts to access the ducts, using softer contrast materials to get clearer images, and the use of a special technique for duct access. They may also use carbon dioxide instead of air to inflate the stomach or intestines, which reduces post-procedure abdominal pain. For high-risk patients, doctors may place a temporary stent (small tube) in the pancreas duct to help prevent pancreatitis.
Hopefully, this explanation helps in understanding the ERCP procedure better and what doctors do to reduce the risks of complications.
What Else Should I Know About Endoscopic Retrograde Cholangiopancreatography?
ERCP, or Endoscopic Retrograde Cholangiopancreatography, was originally used as a test procedure to examine the pancreas and gallbladder. However, over time its usage has changed. Now, it’s mostly used as a treatment tool rather than for diagnosis. Because ERCP is an invasive procedure, meaning it requires entering the body via natural openings or small incisions, there’s a considerable chance of complications. These complications are why doctors don’t use this procedure unless it’s necessary.