Because it is impossible to see what's going on inside a patient's stomach, small intestine and colon, diagnosing gastrointestinal problems has been challenging for physicians.
Advances in imaging technology have made it easier, in recent years, for physicians to detect and treat conditions in the digestive tract. Over the past three decades, endoscopes have been used to diagnose and treat problems in the esophagus, stomach, the top of the small intestine, and colon. In the past several years, a technique called push enteroscopy uses long scopes equipped with video cameras to examine the upper third of a patient's small intestine. However, even with this imaging tool, about 10 feet to 15 feet of the small intestine remains hidden from view. X-rays are required to obtain a picture of that extensive region.
According to Dr. Michael Kimmey, professor of medicine, head of gastroenterology, and director of endoscopy at UW Medical Center, new technologies are making it possible to check previously inaccessible portions of the intestinal tract. These procedures do so in ways that are more comfortable for a patient.
One such technology is called capsule endoscopy, often dubbed the "video pill." With this procedure, a patient swallows a capsule that is about the size of a large vitamin pill. The capsule contains a miniature, battery-operated camera and light. As the pill travels through the gastrointestinal tract, it sends video images to a small antenna worn on a belt on the patient's abdomen. Patients carry on with their normal activities for about seven hours. Afterwards their doctor downloads and studies the video images on a computer.
"The video pill allows us to examine the entire small intestine in great detail," said Kimmey. "However, unlike push enteroscopy, the pill is useful only as a diagnostic device. Surgery or some other form of treatment is still required if a bleeding site or tumor is found."
The video pill is used to diagnose the cause of intestinal bleeding when traditional endoscopic procedures can't locate the source of the problem. With push enteroscopy, the detection rate is about 30 percent. The video pill increases that success rate to about 70 percent.
Another new technology, called CT colonography (or virtual colonoscopy), offers promise of a non-invasive way to screen for colon cancer. In this procedure, the colon is inflated with air and a CT scan is taken of the area. A computer reconstructs what the colon would look like had an actual colonoscopy been performed. No sedation is necessary and most patients feel very little discomfort. However, according to Kimmey, virtual colonoscopy in its current form has drawbacks, including a significant rate of false positives and false negatives.
"It's a great idea," he said. "With future refinements, as well as advances that reduce the patient's need for extensive bowel preparation procedures, it could be the next step forward in screening for colon cancer."
Kimmey pointed out that other new technologies already are helping physicians make difficult diagnoses. Endoscopic ultrasound allows physicians to look under the surface of the gastrointestinal tract lining to measure the extent of a variety of digestive cancers and to direct treatment. This procedure couples ultrasound with an endoscope to gather information about the structure of the gastrointestinal tract and surrounding organs, such as the pancreas, that are hard to view using only external devices. UW Medicine physicians are pioneering the use of this technique and other endoscopic procedures to identify pre-cancerous conditions in patients who have a family history of pancreatic cancer.
A new Digestive Disease Center in the UW Surgery Pavilion will have state-of-the-art endoscopic equipment, along with the capabilities for physicians to integrate advances in endoscopy with surgical procedures.
"In this new facility, our patients will benefit from the most advanced diagnostic and therapeutic endoscopic procedures. A patient comes into the Digestive Disease Center, has the procedure performed, and returns home a few hours later," said Kimmey.
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