Introduction:
It was in 1999 that capsule endoscopy was performed for the first time, and in 2001, the United States Food and Drug Administration (FDA) approved its use in the United States of America. The capsule with the camera inside it is ingested and transmits images at two to six frames per second over the course of eight to 12 hours until the battery expires. The camera generates high-resolution 512 by 512-pixel images that help in the detailed inspection of the lining of the gastrointestinal tract. The battery life of the camera can be a limiting factor during capsule endoscopies, and a lot of studies are incomplete because of battery expiration.
What Is Capsule Endoscopy?
Capsule endoscopy is a gastrointestinal study that uses a camera fitted inside a vitamin-sized capsule to take images of the intestinal lumen. It is also called video capsule endoscopy or wireless capsule endoscopy. Capsule endoscopy can only be used for localizing lesions in the esophagus, stomach, and small and large intestine, and it cannot be used for biopsy and therapy. Capsule endoscopy is helpful in localizing a lesion prior to surgery, angiography, or further endoscopic procedures. The diagnostic yield of capsule endoscopy is found to be higher than angiography, computed tomographic (CT) enteroclysis, small bowel barium studies, and push enteroscopy.
Why Is Capsule Endoscopy Done?
The doctor might recommend the capsule endoscopy procedure to:
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Diagnose the early signs of gastrointestinal cancer.
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Detect colon polyps, which are small growths found on the inner lining of the large intestine (colon) or rectum.
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Diagnose celiac disease (it is an autoimmune disorder that is triggered by eating gluten).
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Identify Crohn's disease and other inflammatory bowel diseases, which are conditions characterized by inflammation in the gastrointestinal tract.
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Know the cause of abdominal pain.
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Diagnose ulcerative colitis (this condition causes inflammation and ulcers in the gastrointestinal tract).
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Know the cause of unexplained gastrointestinal bleeding.
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Evaluate the esophagus for esophageal varices screening (esophageal varices are the abnormal veins in the lower part of the esophagus running from the throat to the stomach), Barrett’s esophagus screening (esophagus is the change in the cells lining the esophagus), and identification of esophagitis (it is the inflammation that damages the tissues of the esophagus).
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Observe the internal structure of the intestine in individuals who are unable to tolerate sedation or other components of a colonoscopy.
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Do follow-up tests after imaging tests such as X-rays.
In Which Cases Can Capsule Endoscopy Not Be Performed?
There are many contraindications to capsule endoscopy, such as:
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It can not be performed in patients with dementia (loss of memory, language, problem-solving, and other thinking abilities).
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In patients with swallowing disorders.
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In patients with cardiac pacemakers, left ventricular assist devices or defibrillators because of the concern for possible interference between the capsule and cardiac devices.
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It is also contraindicated in pregnant women.
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In patients with suspected strictures, fistula, and obstructions.
What Are the Equipment Required for Capsule Endoscopy?
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There are different types of video capsules available for use. Most of them are used for the diagnosis of lesions of the small bowel, and they transmit two to six images per second. At the same time, some capsules are designed specifically for visualization of the esophageal lumen.
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PillCam ESO has a camera at both ends of the capsule and has a battery life of 20 minutes. It can transmit 18 images per second, and it evaluates the esophagus. PillCam COLON also has a camera at both ends of the capsule, and it activates two hours after ingestion to save battery life. It helps in the visualization of the lumen of the colon.
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The size of the capsules varies in size but is of the size 1.1 by 1.6 centimeters approximately. The size of the colon capsule is slightly larger, measuring 1.1 by 3.2 centimeters in size.
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The data collected by the video capsules is transmitted to a wearable receiver through ultra-high frequency band ratio telemetry or electric field propagation.
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To view the images and for interpretation of the data, a computer with specialized capsule endoscopy software is used. The software has the capability to detect the potential bleeding site by tagging the images that have red pixels.
How Is Capsule Endoscopy Performed?
1) A capsule endoscopy procedure involves:
On the patient's abdomen, adhesive sensors will be placed, and the recording device will be attached to his or her waist with a belt. The patient will be asked to swallow a capsule with water. The patient will not feel the capsule moving through the digestive tract. The capsule, resembling a vitamin pill, contains a wireless camera within it, capturing images while it traverses through the small intestine. The images collected by the camera will be transmitted to the recording device worn on the belt around the waist. The images are saved in this device to be interpreted by the specialist.
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If the Patient Has a Morning Appointment - The patient might be asked to remain at the site during the entire test, depending on his or her medical history. The adhesive sensors and recorder will be removed after about eight hours, and the patient will be discharged immediately.
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If the Patient Has an Afternoon Appointment - The patient would be asked to swallow the capsule and can go home but will have to wear the adhesive sensors and recorder throughout the day and night. The patient will return the next morning to the site to get the equipment removed.
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During the Test - The patient is allowed to drink clear liquids and take medications after two hours of swallowing the capsule and is also allowed to eat after four hours. The patient is instructed to avoid ham radios, metal detectors, and magnetic resonance imaging (MRI) studies while the capsule is still in the digestive tract. The patient is asked not to shower, bathe or swim to keep the equipment dry and is also instructed to avoid strenuous exercise.
What Are the Complications of Capsule Endoscopy?
The most common complication related to capsule endoscopic procedures is capsule retention. It occurs in 1.3% to 1.4% of the patients going through the procedure. Capsule retention is generally asymptomatic and is usually diagnosed after two weeks of capsule ingestion through an abdominal plain film x-ray. The risk of capsule retention is high in patients with strictures, fistulas, or suspected obstructions.
Individuals diagnosed with Crohn's disease face an elevated risk of capsule retention, estimated at approximately 2.6%. Agile patency capsule, which is a dummy capsule, can be used to determine the patency of the lumen of the intestine for the safe use of capsule endoscopy.
Other tests such as radiographic imaging like magnetic resonance enterography or computed tomography can be used to assess the patency of the lumen before the administration of the capsule. Surgical or endoscopic removal of the capsule is suggested in case of symptomatic capsule retention. Additionally, there exists a slight possibility of capsule aspiration or cricopharyngeal impaction during the procedure.
What Happens After Capsule Endoscopy?
Once the procedure for capsule endoscopy is done, the adhesive sensors and recording devices will be removed. The patient can get back to usual activities immediately after the procedure. The patient is not required to retrieve or retain the capsule. The patient might not even feel the capsule passing through the tract. The capsule is safely flushed down the toilet. The results of the procedure would be given by the doctor in about a week. The patient is asked not to have an MRI scan for the next 30 days.
Conclusion:
Capsule endoscopy is an important procedure to evaluate the gastrointestinal tract when traditional endoscopies have failed. It is a painless and safe procedure and does not require sedation. It also has no risk of developing an infection. Capsule endoscopy is best used in combination with other imaging techniques. The only shortcoming of this procedure is the lack of therapeutic capabilities.
