Patients can now swallow pill-sized, disposable cameras to help gastroenterologists diagnose and evaluate diseases of the esophagus, or swallowing tube. This new diagnostic tool is a further modification of capsule endoscopy, which has been used clinically since late 2001 to examine the small intestines.
The United States Food and Drug Administration (FDA) cleared the first version of the esophageal device (PillCam(TM) ESO, manufactured by Given Imaging, Israel and marketed by InScope, a division of Ethicon Endo-Surgery, a Johnson & Johnson company, Cincinnati) on Nov. 29 of last year.
This new esophageal capsule endoscope is a smooth plastic capsule about the size of a large vitamin pill that has tiny video cameras at each end. A patient lies on his or her back and swallows the pill with water. The pill then glides down the esophagus taking about 2,600 color pictures, which are transmitted to a recording device worn by the patient. After 20 minutes, the doctor has enough video images to make a careful evaluation and even make a diagnosis. The disposable capsule is passed naturally, usually within 24 hours.
The esophageal capsule will be utilized to screen patients with suspected esophageal diseases such as GERD and Barrett's esophagus, a pre-cancerous condition. However, it is important to note that the capsule endoscope is not to be used for patients who have swallowing difficulties, who wear a pacemaker or who have or are suspected of having gastrointestinal obstruction, strictures or fistulas in their digestive tract.
Traditional endoscopy uses a long, thin flexible tube, called an endoscope, to go through the sedated patient's mouth and down the throat into the esophagus. The endoscope has a tiny camera with a light, so the physician can view close-up images of the esophagus lining. The tube also contains cables for control and channels that permit the passage of devices to biopsy (sample) tissue for examination.
New information presented at the meeting of the International Conference on Capsule Endoscopy (ICCE) last week indicates this technology is useful in screening and surveillance in patients with elevated pressure in the blood vessels of the esophagus due to a condition referred to as portal hypertension which is most often associated with liver cirrhosis. Presentations at the 4th annual ICCE confirmed the potential utility of the capsule endoscope to detect esophagitis and Barrett's esophagus. In addition an international multi-center pilot trial demonstrated that this tool could be used for screening of patients with cirrhosis, esophageal varices (enlarged veins) and other related changes of the stomach (called portal hypertensive gastropathy). This 32- patient trial compared diagnostic accuracy of capsule endoscopy versus traditional upper endoscopy. All cases of esophageal varices and portal hypertensive gastropathy seen on endoscopy were detected on blinded capsule endoscope readings. A large scale validation trial will begin soon. "Utilizing capsule endoscopy to screen patients with liver disease may increase adherence to screening and decrease sedation-related complications in this patient group," noted Glenn Eisen, MD, ASGE Governing Board member and presenter at ICCE.
It is expected that the new capsule endoscopy will be used together with traditional endoscopy in the case management of esophageal diseases. Blair Lewis, MD, Clinical Professor of Medicine, The Mount Sinai Medical Center, NY, stated that the esophageal capsule endoscope could be used as a screening device to determine if a patient was "at risk" for cancer, while traditional endoscopy could be used to gather tissue or remove polyps.
If the patient was "at risk" for cancer, further surveillance by traditional endoscopy with tissue biopsies would be done every three years.
"There were about 7,000 new cases of cancer of the esophagus in the United States last year, which is small in comparison to the cases of colon, prostate and lung cancer," stated Dr. Lewis. "However, while the incidences of the other cancers are dropping, esophagus cancer, on a per capita basis, is growing in numbers."
According to David J. Bjorkman, MD, president of the American Society for Gastrointestinal Endoscopy and Dean of the University of Utah School of Medicine, "The incidence of esophageal cancer is increasing faster than any other malignancy in the U.S. and much of it has to do with the fact that only 5-10 percent of patients suffering from chronic GERD actually get screened for pre-cancerous conditions."
Here are some statistics to put esophageal diseases in perspective. There are 60 million people in the U.S. who experience acid indigestion at least once per month, and some studies suggest there are 15 million daily sufferers who take over-the-counter or prescription remedies. Annually, 19 million people will be diagnosed with GERD.
Of the 10 million Americans who are considered at risk for cancer in the U.S., about one million (10%) will develop Barrett's esophagus, a pre-cancer condition. And, since Barrett's esophagus is twice as common in men as women, deaths due to cancer of the esophagus are higher among men. About 4% of all male deaths due to all types of cancer last year were attributed to cancer of the esophagus.
"While endoscopy has been the gold standard for detecting digestive tract abnormalities," Dr. Bjorkman said, "many patients have been reluctant to go through the procedure due to the time commitment involved, and as a result, do not get checked regularly. Capsule endoscopy could present a more attractive solution to these patients, and eventually lead to increased rates of compliance."
Dr. Lewis stated that the goal of gastroenterologists is to get more adults over 50 screened for pre-cancer conditions of the esophagus that could lead to cancer and need to be monitored. "We hope this new patient-friendly, less intimidating capsule endoscopy procedure will increase the numbers of those willing to be screened, thus reducing the risk of cancer of the esophagus."