Colonoscopy

Other uses of EUS include studying the flow of blood inside blood vessels using Doppler ultrasound and to obtaining tissue samples by passing a special needle, under ultrasound guidance, into enlarged lymph nodes or suspicious tumors. A pathologist can examine the tissue or cells obtained by the needle under a microscope. The process of obtaining tissue with a thin needle is called a fine-needle aspiration (FNA).

Being a relatively new diagnostic tool, the uses for EUS are still being developed, and it is being utilized in the situations mentioned below.

• Staging of cancers of the esophagus, stomach, pancreas, and rectum
• Staging of lung cancer
• Evaluating chronic pancreatitis and other masses or cysts of the pancreas
• Studying bile duct abnormalities, including stones in the bile duct or gallbladder, or bile duct, gallbladder, or liver tumors
• Studying the muscles of the lower rectum and anal canal in evaluating reasons for fecal incontinence
• Studying 'submucosal lesions' such as nodules or 'bumps' that may be hiding in the intestinal wall covered by normal appearing lining of the intestinal tract
• Staging of cancer is becoming an important use of EUS. The prognosis of a cancer victim is related to the stage of cancer at the time of cancer detection. For example, early-stage colon cancer refers to cancer confined to the inner surface of the colon before it is spread to adjacent tissues or distant organs. Therefore early-stage colon cancer can be completely resected with good chances for a cure

However, if cancer is detected at later stages, the cancer tissues have already penetrated the colon wall and invaded neighboring organs, and lymph nodes or have spread to distant organs such as the liver and lungs.

Complete surgical excision becomes highly unlikely. EUS can provide information regarding the depth of penetration of cancer and the spread of cancer to adjacent tissues and lymph nodes. This information is useful for staging.

EUS helps your doctor determine the extent of the spread of certain cancers of the digestive and respiratory systems. EUS allows your doctor to assess cancer’s depth accurately and whether it has spread to adjacent lymph glands or nearby vital structures, such as major blood vessels. In some patients, EUS can be used to obtain a needle biopsy of a lump or lesion to help your doctor determine the proper treatment.

For EUS of the upper gastrointestinal tract, you should not eat or drink, usually for six hours before the examination. Your doctor will tell you when to start this fasting and whether it is advisable to take your regular prescription medications.

For EUS of the rectum or colon, your doctor will instruct you to either consume a colonic cleansing solution or follow a clear liquid diet combined with laxatives or enemas prior to the examination. The procedure might have to be rescheduled if you don’t follow your doctor’s instructions carefully.

When FNA is performed, complications occur more often but are still uncommon (0.5-1.0%). Passing a needle through the gut wall may cause minor bleeding. If unusual bleeding occurs, the patient may be hospitalized briefly for observation, but blood transfusions are rarely needed. Infection is another rare complication of FNA. Infection can occur during the aspiration of fluid from cysts, and antibiotics may be given before the procedure.

If the FNA is performed on the pancreas, pancreatitis (inflammation of the pancreas) can rarely occur. Pancreatitis calls for hospitalization, observation, rest, IV fluid, and medication for abdominal pain. It usually resolves spontaneously in a few days.

If you received sedatives, you would be monitored in the recovery area until most of the sedative effects have worn off. If you had an upper EUS, your throat might be a little sore. You might feel bloated because of the air and water that were introduced during the examination.

Endoscopic retrograde cholangiopancreatography, or ERCP, is a specialized technique used to study the bile ducts, pancreatic duct, and gallbladder. Ducts are drainage routes; the drainage channels from the liver are called bile or biliary ducts. The pancreatic duct is the drainage channel from the pancreas.

During ERCP, your doctor will pass an endoscope through your mouth, esophagus, and stomach into the duodenum (first part of the small intestine). An endoscope is a thin, flexible tube that lets your doctor see inside your bowels.

After your doctor sees the common opening to the ducts from the liver and pancreas, called the major duodenal papilla, your doctor will pass a narrow plastic tube called a catheter through the endoscope and into the ducts. Your doctor will inject a contrast material (dye) into the pancreatic or biliary ducts and will take X-rays.

You should fast for at least six hours (and preferably overnight) before the procedure to make sure you have an empty stomach, which is necessary for the best examination. You should talk to your doctor about medications you take regularly and any allergies you have to medications or to intravenous contrast material (dye).

Inform your doctor about medications you’re taking, particularly aspirin products, arthritis medications, anticoagulants (blood thinners, such as warfarin or heparin), clopidogrel, or insulin. Also, be sure to tell your doctor if you have heart or lung conditions or other major diseases which might prevent or impact the decision to conduct endoscopy.

An anesthesiologist will administer sedation to keep you comfortable during the procedure. Some patients also receive antibiotics before the procedure. You will lie on your abdomen (belly) on an X-ray table. The instrument does not interfere with breathing, but you might feel a bloating sensation because of the air introduced through the instrument.

ERCP is a well-tolerated procedure when performed by doctors who are specially trained and experienced in the technique. Although complications requiring hospitalization can occur, they are uncommon.

Complications can include pancreatitis (inflammation of the pancreas), infections, bowel perforation, and bleeding. Some patients can have an adverse reaction to the sedative used. Sometimes the procedure cannot be completed for technical reasons.

If you have ERCP as an outpatient, you will be observed for complications until most of the effects of the medications have worn off before being sent home. You might experience bloating or pass gas because of the air introduced during the examination. You can resume your usual diet unless you are instructed otherwise.