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Introduction
Wireless capsule endoscopy of the digestive tract was conceived of by Gabi Iddan and Paul Swain independently [Iddan and Swain, 2004; Iddan et al. 2000]. Instead of competing they decided to join forces. In 1997 Paul Swain swallowed the first wireless capsule endoscope in Israel. The transmitted images were of poor quality but the possibility of wireless transmission from the digestive tract to an outside receiver (recorder) was proven to be possible. This opened the way for a controlled study. Capsule endoscopy of the small bowel was compared with push enteroscopy in patients with occult gastrointestinal bleeding. The capsule outperformed push enteroscopy by a ratio of 2 : 1 [Lewis and Swain, 2002]. Based on these findings the US Food and Drug Administration (FDA) approved this device for investigations of the small bowel in 2001.
Capsule endoscopy was uniquely fit to examine the small bowel. Direct inspection of the mucosa of the small bowel was made possible without invasive tools and laborious challenging procedures, either for the patient or physician.
The developers of capsule endoscopy sought to extend this methodology to the colon. The thinking was that the colonic surface could be inspected without undergoing colonoscopy which is invasive, uncomfortable (air insufflation), requires sedation and carries a small but not negligible risk of complications. Such a device would lend itself to screening the population for colonic polyps and cancer. However, there were major obstacles that had to be overcome.
Evolution of capsule endoscopy
Capsule orientation and camera
The large bowel is anatomically different from the small bowel, and has several challenges. The capsule endoscope has the camera on one end and the radio transmitter unit on the other end. The capsule can enter the small bowel either with the camera or with the radio transmitter leading. Since the small bowel is narrow, the length of the capsule (27 mm) prevents it from turning around. The capsule thus remains oriented in the same direction as it enters the small bowel and transmits images that cover the entire length of the small bowel. However, the colon has a much wider diameter. This allows the capsule to flip around its own axis. Therefore, the camera can change directions: at times the front of the capsule with the camera may be leading and at times the camera may be oriented in the opposite direction. So with a standard capsule there are areas which would be screened twice (when the capsule flips around its axis) and areas that were not to be screened at all.
The engineers solved this problem by adding another camera, so that both ends of the capsule transmit images. This guarantees that the entire surface of the colon is screened no matter how many times the capsule rotates around its own axis in the colon (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3131168/)
What is Capsule Endoscopy?
Capsule Endoscopy lets your doctor examine the lining of the middle part of your gastrointestinal tract, which includes the three portions of the small intestine (duodenum, jejunum, ileum). Your doctor will give you a pill sized video camera for you to swallow. This camera has its own light source and takes pictures of your small intestine as it passes through. These pictures are sent to a small recording device you have to wear on your body.
Capsule Endoscopy lets your doctor examine the lining of the middle part of your gastrointestinal tract, which includes the three portions of the small intestine (duodenum, jejunum, ileum). Your doctor will give you a pill sized video camera for you to swallow. This camera has its own light source and takes pictures of your small intestine as it passes through. These pictures are sent to a small recording device you have to wear on your body.
Your doctor will be able to view these pictures at a later time and might be able to provide you with useful information regarding your small intestine.
Why is Capsule Endoscopy Done?
Capsule endoscopy helps your doctor evaluate the small intestine. This part of the bowel cannot be reached by traditional upper endoscopy or by colonoscopy. The most common reason for doing capsule endoscopy is to search for a cause of bleeding from the small intestine. It may also be useful for detecting polyps, inflammatory bowel disease (Crohn’s disease), ulcers, and tumors of the small intestine.
As is the case with most new diagnostic procedures, not all insurance companies are currently reimbursing for this procedure. You may need to check with your own insurance company to ensure that this is a covered benefit.
Capsule endoscopy helps your doctor evaluate the small intestine. This part of the bowel cannot be reached by traditional upper endoscopy or by colonoscopy. The most common reason for doing capsule endoscopy is to search for a cause of bleeding from the small intestine. It may also be useful for detecting polyps, inflammatory bowel disease (Crohn’s disease), ulcers, and tumors of the small intestine.
As is the case with most new diagnostic procedures, not all insurance companies are currently reimbursing for this procedure. You may need to check with your own insurance company to ensure that this is a covered benefit.
How Should I Prepare for the Procedure?
An empty stomach allows for the best and safest examination, so you should have nothing to eat or drink, including water, for approximately twelve hours before the examination. Your doctor will tell you when to start fasting.
Tell your doctor in advance about any medications you take including iron, aspirin, bismuth subsalicylate products and other over-the-counter medications. You might need to adjust your usual dose prior to the examination.
Discuss any allergies to medications as well as medical conditions, such as swallowing disorders and heart or lung disease.
Tell your doctor of the presence of a pacemaker or defibrillator, previous abdominal surgery, or previous history of bowel obstructions in the bowel, inflammatory bowel disease, or adhesions.
An empty stomach allows for the best and safest examination, so you should have nothing to eat or drink, including water, for approximately twelve hours before the examination. Your doctor will tell you when to start fasting.
Tell your doctor in advance about any medications you take including iron, aspirin, bismuth subsalicylate products and other over-the-counter medications. You might need to adjust your usual dose prior to the examination.
Discuss any allergies to medications as well as medical conditions, such as swallowing disorders and heart or lung disease.
Tell your doctor of the presence of a pacemaker or defibrillator, previous abdominal surgery, or previous history of bowel obstructions in the bowel, inflammatory bowel disease, or adhesions.
Your doctor may ask you to do a bowel prep/cleansing prior to the examination.
What Can I Expect During Capsule Endoscopy?
Your doctor will prepare you for the examination by applying a sensor device to your abdomen with adhesive sleeves (similar to tape). The pill-sized capsule endoscope is swallowed and passes naturally through your digestive tract while transmitting video images to a data recorder worn on your belt for approximately eight hours. At the end of the procedure you will return to the office and the data recorder is removed so that images of your small bowel can be put on a computer screen for physician review.
Your doctor will prepare you for the examination by applying a sensor device to your abdomen with adhesive sleeves (similar to tape). The pill-sized capsule endoscope is swallowed and passes naturally through your digestive tract while transmitting video images to a data recorder worn on your belt for approximately eight hours. At the end of the procedure you will return to the office and the data recorder is removed so that images of your small bowel can be put on a computer screen for physician review.
Most patients consider the test comfortable. The capsule endoscope is about the size of a large pill. After ingesting the capsule and until it is excreted you should not be near an MRI device or schedule an MRI examination.
What Happens After Capsule Endoscopy?
You will be able to drink clear liquids after two hours and eat a light meal after four hours following the capsule ingestion, unless your doctor instructs you otherwise. You will have to avoid vigorous physical activity such as running or jumping during the study. Your doctor generally can tell you the test results within the week following the procedure; however, the results of some tests might take longer.
You will be able to drink clear liquids after two hours and eat a light meal after four hours following the capsule ingestion, unless your doctor instructs you otherwise. You will have to avoid vigorous physical activity such as running or jumping during the study. Your doctor generally can tell you the test results within the week following the procedure; however, the results of some tests might take longer.
What are the Possible Complications of Capsule Endoscopy?
Although complications can occur, they are rare when doctors who are specially trained and experienced in this procedure perform the test. There is potential for the capsule to be stuck at a narrowed spot in the digestive tract resulting in bowel obstruction. This usually relates to a stricture (narrowing) of the digestive tract from inflammation, prior surgery, or tumor. It’s important to recognize obstruction early. Signs of obstruction include unusual bloating, abdominal pain, nausea or vomiting. You should call your doctor immediately for any such concerns. Also, if you develop a fever after the test, have trouble swallowing or experience chest pain, tell your doctor immediately. Be careful not to prematurely disconnect the system as this may result in loss of pictures being sent to your recording device.
Although complications can occur, they are rare when doctors who are specially trained and experienced in this procedure perform the test. There is potential for the capsule to be stuck at a narrowed spot in the digestive tract resulting in bowel obstruction. This usually relates to a stricture (narrowing) of the digestive tract from inflammation, prior surgery, or tumor. It’s important to recognize obstruction early. Signs of obstruction include unusual bloating, abdominal pain, nausea or vomiting. You should call your doctor immediately for any such concerns. Also, if you develop a fever after the test, have trouble swallowing or experience chest pain, tell your doctor immediately. Be careful not to prematurely disconnect the system as this may result in loss of pictures being sent to your recording device.
Capsule endoscopy may also be called:
- capsule enteroscopy
- wireless capsule endoscopy
Capsule endoscopy allows for examination of the small intestine, which cannot be easily reached by traditional methods of endoscopy. (http://www.asge.org/patients/patients.aspx?id=390)
This is a photo of Camera Capsule
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