ENDOSCOPIC PROCEDURES
Summary
Endoscopes and enteroscopes allow your doctor to get a good view of the internal organs without opening you up. These procedures are done for diagnosis and treatment of various problems and conditions affecting the gastrointestinal tract and digestive system. Using only a thin tube-like instrument fitted with a light and camera, known as an endoscope, the inside of the digestive tract can be examined by your physician through the mouth or anus. Endoscopes and enteroscopes also have channels that allow special surgical tools to be passed down them. This equipment can be used to treat whatever is bleeding, to take biopsies, or to mark the location of a problem with a tattoo to aid a surgeon in locating it later.
The most common endoscopic procedures are gastroscopies and colonoscopies. A gastroscopy is done by inserting an endoscope through the mouth down the oesophagus, stomach and small intestine. A colonoscopy, on the other hand, is done by inserting an endoscopy in the anus through to the rectum and large intestine. In rarer cases, a capsule endoscopy, double-balloon enteroscopy, x-ray studies such as enteroclysis and CT enterography or intraoperative enteroscopy may be needed.
Reasons for endoscopic procedures
- Diagnosis and screening of the gastrointestinal tract
- Placement of a stent in the gastrointestinal tract
- Dilatation of strictures in the gastrointestinal tract
- Placement of feeding tubes (PEG)
- Biopsy of benign and malignant lesions
- Endoscopy for staging and palliation of Upper Gastrointestinal malignancy
- To diagnose and treat small bowel bleeding
Types of endoscopic procedures
Once the tool has been passed down to your stomach, your doctor may want to use some air to aid him in the examination. This is done to get a better look at your insides. The gas may make you feel full and bloated. As the instrument passes down your throat and through your stomach, you may feel some mild cramping or a tugging sensation.
The entire procedure should only last 20 minutes but if any abnormalities like ulcers, blockages, growths and tumours, are found they may need to be removed or biopsied at this time. Once the gastroscopy is finished, you will be asked to wait in the room next door until the sedative has worn off and you have passed most of the air that was introduced during the examination.
Instructions for patients undergoing gastroscopy
When undergoing a gastroscopy, your physician will be looking to investigate the upper gastrointestinal tract, including the oesophagus, stomach and small intestine, using a long flexible tube known as an endoscope.
Before this procedure, you will need to prepare by ensuring your stomach is clean and empty for your doctor to make an accurate diagnosis. You will need to stop eating 6 hours before your procedure. Since only the upper part of the digestive system is being examined, there is no need for a laxative to empty your bowels.
Because many patients are apprehensive, Dormicum® and Pethidine® may be given to calm you for the gastroscopy. While this won’t put you to sleep, it will sedate you. (See “Conscious Sedation: What you need to know”). Be sure to tell your physician if you have had any previous problems or reactions to any of these drugs before they are given.
The examination may take anything from 15 – 60 minutes. If polyps are to be removed, it may take longer. A nurse is present to help the doctor and to assist in monitoring the patient’s condition. After the examination is completed, you will be asked to rest for an hour or two in an adjoining room until the effects of the medications have subsided and until you have passed much of the air, which was introduced during the examination. You may need to stay in hospital after the exam based on the findings or if any problems occurred.
Polyps are removed by first locating them with the colonoscope and then placing a wire loop around the base of the polyp. An electric current is used to cut the polyp off at its stalk or base. You will not feel this current.
The specimen is usually retrieved by applying suction to the instrument and catching the polyp on the tip of the instrument. Polyp and instrument are then both withdrawn. If there is more than one polyp, it is necessary to re-insert the instrument to remove the additional polyp.
Instructions for patients undergoing colonoscopy
Your physician has asked that the inside of your colon (large intestine) be inspected by using a long flexible tube (colonoscope) so that he can know what disease, if any, is present.
Proper preparation is extremely important for this examination. The large intestine must be clean and empty for the doctor to make an adequate examination. The preparation requires the use of a clear liquid diet for one day before the examination.
This is achieved by using a laxative known as picoprep; other preparations may be used by your doctor.
Because many patients are apprehensive, Dormicum® and Pethidine® are often given intravenously at the time of the examination to relax the patient. Ask him/her about this. These drugs will not put you to sleep but may cause some lightheadedness. (See "Conscious Sedation: What you need to know") If you have had an unfavourable reaction to any of these drugs, you should tell the examiner before the injection is given.
The small bowel follow-through test is a series of abdominal x-rays that are taken at different times after a patient drinks a white, chalky fluid called barium. This white liquid shows up on x-rays and helps your doctor examine the lining of the intestine for any problems. This test is safe and easy to tolerate, and is good for large abnormalities, but can miss many smaller ones.
A second x-ray test, called the enteroclysis study, is similar to the small bowel follow-through in that it uses barium (the chalky white liquid) to visualize the inner wall of the small bowel. The enteroclysis study is more invasive though because it requires a small tube called a catheter to be slowly moved from the nose down the oesophagus, through the stomach, and into the small bowel. Through this catheter, the barium and air can be inserted into the small bowel. The advantage of this study is that pictures from enteroclysis have better resolution, so abnormalities missed by the small bowel follow-through test may be detected easier. A disadvantage of the enteroclysis study is that it can be an uncomfortable examination due to the presence of the catheter and the use of air to distend the small bowel while taking pictures. In some cases, a CT scan is used instead of regular x-rays. This allows for even more detail to be seen.
The third test is known as a CT enterography. A CT enterography is done the same way a normal CT scan is done. The patient drinks an oral contrast solution (often diluted barium), while also receiving intravenous (IV) contrast. Then numerous, very detailed images are taken to spot abnormalities and problems. A CT enterography differs from a standard CT scan in that the type of contrast that the patient drinks are designed to allow for a more detailed inspection of the lining of the small bowel.
While none of these tests is perfect at finding abnormalities, the advantage of these tests is that they can sometimes find bleeding sources that are out of reach of a standard enteroscope. The major limitations of these studies are that they cannot detect abnormal arteries and veins (AVMs), and if an abnormality is seen, there is no way to apply immediate treatment to stop the bleeding, to take biopsies to confirm a diagnosis, or to mark the location of the lesion with a tattoo. In addition, some patients are allergic to the IV contrast that is used as part of the CT scan.
In about 15% of exams, the capsule does not view the entire small bowel prior to the battery running out and may need to be repeated. This is sometimes the case for those who aren’t regular.
Like x-rays, the capsule cannot be used to take biopsies, apply therapy, or mark abnormalities for surgery. Moreover, the capsule cannot be controlled once it has been swallowed, so once it has passed a suspicious area, it cannot be slowed to better look at the area. Despite these limitations, capsule endoscopy is frequently the test of choice for finding a source of small bowel bleeding if standard endoscopy has failed to do so because it is able to look at the whole small bowel and is an easy test for most people to do.
Overall, for those with occult bleeding (blood that is microscopically present in the stool, but the stool looks normal), capsule endoscopy finds a cause of bleeding in up to 67% of patients. In cases of overt bleeding (blood is seen in the stool, or the stool is black and tarry), the results are highly variable. If the bleed happened in the past, the yield may be as low as 6%. If, however, the doctor believes that there is active bleeding occurring at the time of the test, the yield is > 90%.
The capsule is generally safe and easy to take; however, rarely the capsule can get stuck in the small intestine. This may happen if there has been prior abdominal surgery causing scarring or other conditions that cause narrowing of the small intestine. If this happens and the capsule becomes stuck, endoscopic or surgical removal will need to be done. In most cases, there is a good chance that the capsule is stuck at the place where the bleeding is coming from, and thus removing the capsule may also mean your doctor can treat the problem, at the same time.
In some cases, by doing the test through both the mouth and through the anus, it is possible to examine the entire length of the small bowel, though this is not always possible.
A double-balloon enteroscopy test often takes a couple of hours to perform, as opposed to 20 minutes for standard endoscopy. Because an examination using a double-balloon enteroscopy is much more involved than standard endoscopy, it is usually only used if a bleeding site is found on either an x-ray or capsule endoscopy and is out of reach of a standard enteroscope. In one study, double-balloon enteroscopy was able to locate a bleeding source in 74% of patients.
Because the test is done with an endoscope if a source of bleeding is found, it may be possible to treat it, take biopsies, or mark the area with a tattoo. If a source is found, it can be treated in about 60 to 70 per cent of people.
In addition to double-balloon enteroscopy, there are two other options for deep small bowel enteroscopy. One is single balloon enteroscopy, which is a test similar to double-balloon enteroscopy, though in this case there is only one balloon attached to the scope. A second option is deep small bowel enteroscopy using a special spiral tube that fits over the scope and allows the endoscope to be advanced into the deep small bowel.
Because it is an invasive, surgical procedure, however, intraoperative enteroscopy is usually only used when other methods have failed to find or treat the source of bleeding. Overall, it is effective in treating the source of bleeding in approximately 70% of the patients who require the procedure.
Risks of endoscopic procedures
There are certain risks to this procedure:
- There is a very small risk of perforation of the colon. If, however, this should happen, surgery may be required for repair.
- Following the removal of a polyp, there is a small chance/risk of bleeding from the site. This may settle spontaneously, require re-examination or, rarely, surgical intervention. A blood transfusion may be required.
- X-ray screening may be used during the procedure, so it is important to inform the doctor if you suspect you might be pregnant.
It is important to note that, if you are concerned regarding any symptoms which develop following this procedure, you should contact your doctor. He/she will most likely request that you present for assessment without delay.