Endoscopy is a procedure which permits the gastroenterologist to look inside the patient's intestine, take pictures, take samples and, at times, perform therapy. Endoscopy is carried out with a long tube about the diameter of your little finger. This long tube is inserted into the esophagus through the mouth while the patient is under deep sedation or general anesthesia. The lining of the esophagus can be examined. If the esophagus is inflamed (esophagitis), the esophagus will look thick and sore. In a patient with chronic liver disease with portal hypertension (high pressures in the portal vein leading to the liver), large veins called varices can be seen sticking out of the walls of the esophagus. At times these may break open and cause the child to throw up blood. The scope can examine the stomach and look for ulcers, prominent veins from portal hypertension (portal hypertensive gastropathy) and even Helicobacter pylori infection. The small intestine can also be examined either for abnormalities of the lining or for abnormal blood vessels.
The endoscope can sometimes be used to correct problems. If there is a bleeding ulcer in the stomach, the scope can be used to burn the blood vessel that is causing the bleeding; the scope can also be used to inject epinephrine into the bleeding ulcer. If the child is bleeding from varices (large veins) in the esophagus, two therapies can be undertaken. Esophageal banding is a procedure where a rubber band is placed through the scope around the varix (remember that the varix is a large vein in the esophagus). The rubber band chokes off the blood supply to the varix making it shrink down and clot off. Alternatively, sclerotherapy can be carried out. In sclerotherapy, an irritating substance is injected into the varix blood vessel. This will make it scar down and also stop or prevent bleeding. Esophageal banding or sclerotherapy can be complicated by causing bleeding, causing ulceration or even causing narrowing of the esophagus due to scar tissue. These complications are not common. Even less common are reactions to the process in other organ systems such as heart or lungs. The patient requires careful monitoring during and after endoscopic management of esophageal varices. Several sessions of band ligation or sclerotherapy separated by a few weeks are usually necessary to eliminate the varices.
ERCP (Endoscopic Retrograde Cholangiopancreatography)
Endoscopic retrograde cholangiopancreatography or ERCP may be ordered when the doctor is concerned that there may be a disease affecting the bile ducts or pancreas. This test is performed with a special fiber optic instrument called an endoscope. While the child is deeply sedated or under general anesthesia, the scope is advanced through mouth into the esophagus, stomach, and into the small intestine. In the small intestine, the ampulla of Vater (which is a little opening where juices from the liver and pancreas spill into the intestine to help digest food) is identified. A tiny catheter is advanced from the scope into the bile duct. Dye is then injected into the bile duct which fills the entire branching network of bile ducts that is present in the liver. If there is a narrowing or irregularity to the ducts, it can be seen on the X-ray pictures that are taken during the ERCP. If a stone is stuck in the bile duct, the endoscopist may be able to use balloons and baskets to pull the stone out. This sometimes requires cutting to enlarge the ampulla of Vater. This cutting is called a "sphincterotomy."
ERCP is commonly performed by adult GI endoscopists, with assistance from their pediatric colleagues. This is because the procedure is not needed often in children, whereas adult endoscopists build up much experience doing this procedure. Sometimes a special tiny infant scope must be borrowed from the manufacturer and may take several days to acquire. Antibiotics are typically given at the time of the ERCP to prevent infection of the bile ducts when the dye is squirted in. Like in any procedure, there is a small risk of reaction to anesthetic or sedation, of making a hole in the intestine, and of bleeding. The most important risk of ERCP is the fact that pancreatitis, inflammation of the pancreas causes abdominal pain and vomiting, can develop in as many as 5% of patients who undergo the procedure, with severe pancreatitis developing in 0.5%. Because of this risk, patients are sometimes observed overnight after undergoing ERCP.
A liver biopsy may be recommended to further evaluate the child's liver disease. During this procedure, a small fragment of the liver is removed, preserved, stained, and looked at under the microscope. This sample of the liver may provide further information to explain the patient's symptoms or blood test results. There are several ways to do a liver biopsy. The first and most common way is called a "percutaneous liver biopsy." This means that the biopsy is done with a needle inserted through the skin of the ribcage. This kind of biopsy, which can be done by an interventional radiologist/gastroenterologist or a surgeon, does not require a large incision or stitches. Liver biopsy can also, under certain circumstances, be done through a vein or through a surgical incision (see below).
Preparation for the Biopsy
Your child will be asked not to eat or drink for several hours before the biopsy. This is done to make sure the stomach is empty so the child will not throw up and choke. Laboratory studies are done before the biopsy to make sure the clotting times (PT/PTT) and platelets are normal enough to help prevent bleeding from the biopsy. Your child should not receive aspirin or ibuprofen two weeks before the procedure (discuss this with the doctor who placed your child on aspirin).
In adults, percutaneous liver biopsy is done without sedation. A local anesthetic (numbing medicine) is just injected into the skin where the biopsy will take place. Young children usually require sedation or anesthesia. Your doctor may choose to sedate the child with intravenous medicines that result in "conscious sedation." This means that the child is awake and breathing on his own but is not aware and will not remember the experience. The child is carefully monitored during such a procedure. At some institutions the liver biopsy is done under general anesthesia. That means an anesthesiologist puts the child completely to sleep. Depending on the kind of anesthetic used, this may involve the child briefly having a breathing tube during the procedure.
Percutaneous Liver Biopsy
Once the child is sedated or asleep, an area in the lower right ribcage over the liver is selected. Under special circumstances, ultrasound may be used to pick the right spot. The area is sterilized with some iodine and alcohol and a tiny nick is made in the skin over one of the ribs. The needle is then inserted into the liver, the sample is obtained, and the needle is withdrawn. This may be done more than once if multiple samples are needed. The fragment of liver removed is very small, about the size of the inside of a needle.
Like any procedure, liver biopsy has its risks. There is always a risk associated with sedating or anesthetizing anyone. These risks include allergic reactions to medication, breathing difficulty and physical injury. The biopsy itself can result in significant bleeding, since there are many blood vessels in the liver. The chance of bleeding enough to require a blood transfusion is about 1 to 2% in children. Life-threatening bleeding can occur in less than one in 1,000 cases. Injury to the lung, gallbladder or intestine can also occur, and could even require surgery. A few patients have some pain after the biopsy. Since most problems occur within the first few hours after the biopsy, children are observed closely those first few hours, laying on their right side. At some institutions they are kept overnight for observation, and in others they are discharged after a few hours if the heart rate and blood pressure are stable and a repeat blood count is good. You should call your doctor if excessive pain, breathing difficulty, pallor or dizziness occur after biopsy.
Transjugular Liver Biopsy
When abnormal blood clotting or low platelet counts make standard biopsy unsafe, Interventional Radiology can biopsy "from the inside" with a large IV placed in a neck vein. During this procedure, done with the patient sedated or asleep, a very long tube with a needle goes through the neck vein, into the large inferior vena cava, into a liver vein. The liver is biopsied through that internal vein so that any bleeding can be confined. The procedure is typically done under anesthesia.
Open Liver Biopsy
An "open liver biopsy" is done when the risk of bleeding is very high. It may be planned when blood clotting or platelets are abnormal, making percutaneous biopsy unsafe. Open biopsy is also done when a large piece of liver is needed for special tests. Sometimes, when another surgery is already taking place, an open biopsy is done while the abdomen is open. This procedure, done under general anesthetic, requires that a surgeon make a one or two inch cut in the skin, clip off a piece of the liver, and either stitch or burn the edge so that it does not bleed. An open biopsy is also done under general anesthesia.
Tests on the Liver Biopsy
A number of tests can be done on the tissue obtained during a liver biopsy depending on the child's underlying condition. Most commonly, standard stains including "H & E" and other stains are done so that the liver can be looked at under the microscope. There, inflammation (immune cells from the body may be attacking the liver) can be seen. Abnormalities in the liver cells themselves can also be seen. Bile ducts can be looked at and evaluated, as can blood vessels. Special stains can show how much scar tissue is present in the liver. Sometimes these tests can give a lot of information about a possible diagnosis. Other times, however, the results are simply descriptive: they will describe what the pathologist saw without telling you exactly what your child has. In some specialized situations, the liver biopsy is sent for electron microscopy. This special microscope does a real "close-up" on the liver cells looking for rare and specific metabolic or infectious problems. Special stains can also be done on a liver biopsy if a disease is suspected which involves storage of copper, iron, fat or other substances. If an infection is suspected, a tiny piece of the biopsy can be cultured for viruses, bacteria or fungus. These infections are very rare, and many hepatitis viruses cannot be cultured easily; CMV virus, which is especially important in transplant patients, can be cultured this way. Lastly, a piece of liver can be frozen immediately in very cold temperatures. Later, special metabolic tests can be done on these samples if the activity of a certain enzyme or chemical needs to be assessed. Frozen tissue will preserve these specimens and allow these specialized tests to be done. This is especially important for some metabolic diseases where there are abnormalities in the body's chemistry.
After the Biopsy
It may take from one to several weeks for results of the biopsy to be available, depending on which tests are ordered.
Some patients with liver disease have a large amount of fluid called "ascites" in their abdomen outside the organs. A procedure called paracentesis can be used to obtain some fluid, either to check for infection or to make the patient more comfortable. A small needle is inserted into the abdominal wall and fluid is pulled out.
PTC (Percutaneous Transhepatic Cholangiogram)
Sometimes, physicians need a detailed look at the bile ducts in a patient in whom ERCP is not possible (see above). Some babies are too small for ERCP to be practical. Some patients have had previous surgery on their bile ducts, which would make them difficult to reach through a scope of this sort. When another approach to taking pictures of the bile ducts is needed, PTC is sometimes arranged. This procedure is carried out by an interventional radiologist, with the patient usually under general anesthetic or deep sedation. A small needle is introduced into the liver, typically between the ribs, and advanced into the liver until it enters a bile duct. Dye is then injected allowing an X-ray to take a picture of the bile ducts and their branches. If a narrowing or leak is noticed, the area can be balloon-dilated (opened up) or a long tube (stent) can be placed through the skin into the liver through the abnormal area and out into the intestine. While this procedure does not run the risk of causing pancreatitis like ERCP does, it has the potential to cause serious bleeding or injury to other organs. Children are observed for several hours or overnight after a PTC.
TIPS (Transjugular Portosystemic Shunt)
TIPS is used to treat complications of portal hypertension. Portal hypertension occurs when blood flow from the intestine, flowing into the portal vein, cannot get into the liver because the liver is scarred or cirrhotic. The blood backs up into veins in the esophagus called varices, which can break open and lead to massive bleeding. The TIPS is a shunt that can relieve this backup of pressure. With the patient sedated, an interventional radiologist inserts a long catheter into the neck vein and advances it into the liver. There, the radiologist uses special equipment to make a shunt connection between blood entering and leaving the liver so blood does not back up. Unfortunately, these shunts often clot off over time; they have to be checked by ultrasound and often repaired. While they are very effective at stopping bleeding that results from portal hypertension, they can lead to worsening of encephalopathy (confusion that can come with portal hypertension) or of liver function. Patients usually do well but are monitored closely.