Capsule Endoscopy & Enteroscopy
Diagnosis of Small Intestinal Diseases
The small intestine is 20 feet long and until recently, was a “blind” area for gastroenterologists as there was no way to visualize the mucosa directly. Previously, barium X-rays were used for diagnosis and this was often inaccurate. Frequently, a diagnostic laparotomy (surgery) was required to establish a diagnosis and for treatment. The development of two exciting technologies has led to improved diagnostic and therapeutic capabilities. These are video capsule endoscopy (VCE) and double balloon enteroscopy (DBE). These techniques allow the diagnosis of diseases of the small intestine, including biopsy and results in more accurate planning before making decisions on surgery.
Video Capsule Endoscopy
A video capsule, the size of a large medicine capsule, is designed to house a camera chip, miniature strobe lights, radio wave transmitter and self contained battery with an 8 hour life span (a). The capsule is swallowed (b) and passes through the esophagus and stomach before entering the small intestine. Once inside the small intestine, the capsule is propelled forwards by normal gut contractions. Tens of thousands of snap shots are taken (two every second) until the battery is exhausted. During this time, the capsule emits radio signals that are picked up by electrodes positioned on the abdomen. The electrodes track the movement of the capsule and transfer images to a hard disk carried on a belt by the patient (c,d). The images on the hard disk are downloaded to a computer (e) and analyzed by the doctor. Video capsule endoscopy is a purely diagnostic tool and it is not possible to obtain any tissue biopsy. It is a comfortable technique and is performed on an out-patient basis while the patient continues with his/her normal schedule at home or at the work place. The capsule is eventually passed out in the feces and discarded. Two types of VCE are available for commercial use from the Given and Olympus companies.
Double Balloon Enteroscopy
Enteroscopy involves the insertion of an endoscope through the small intestine. A long thin endoscope developed by Fujinon is the latest device that can be inserted through the entire length of the small intestine.
The device has one balloon mounted at the end of the scope (1) and another balloon mounted on an over tube (2), hence the name “double balloon”.
The examination is performed by two doctors. One turns the knobs that control the tip of the scope and also pushes the endoscope while the other operates the over tube. Using a systematic combination of pushing and withdrawal of the enteroscope and over tube, together with inflation and deflation of the balloons, the small intestine can be drawn over the enteroscope, and insertion through the entire length can be achieved. Insertion can be via the mouth or anus, depending on the likely location of the diseased area. Using the DBE system, diagnostic capability is enhanced by the ability to obtain tissue biopsy of the diseased area. In addition, endoscopic treatment to stop bleeding can be performed using miniature instruments that are inserted through the enteroscope. This is a significant advancement because some cases with bleeding can be treated adequately, without the need for surgery. The procedure is performed under sedation to minimize discomfort.
What are some reasons to use Video Capsule Endoscopy or Double Balloon Enteroscopy?
- To diagnose the location and cause of bleeding from the small intestine. Treatment is also possible with DBE.
- To diagnose inflammatory bowel disease confined to the small intestine.
- To diagnose tumours of the small intestine.
About the author. Dr Yap Chin Kong, is a leading Specialist and Senior Consultant in Gastroenterology, Liver Diseases and Endoscopy. He was awarded a Merit Scholarship to study Medicine at the National University of Singapore and graduated with a Bachelor of Medicine & Bachelor of Surgery degree in 1983. In 1988 he obtained his Masters degree in Medicine (Singapore) and became a Member of the Royal College of Physicians (United Kingdom). He became a Fellow of the Academy of Medicine (Singapore) in 1994 and a Fellow of the Royal College of Physicians (Edinburgh) in 2000. In 1992, he was awarded the Health Manpower Development Program Award by the Ministry of Health to pursue advanced training in therapeutic ERCP (Endoscopic Retrograde Cholangio-Pancreatography) at the Academic Medical Centre in Amsterdam, The Netherlands. After a year of extensive experience he returned in 1993 to develop endoscopy further at the Singapore General Hospital until he left for private practice in 2004. He pioneered the use of endoscopic ltrasonography at SGH for a decade. During this time, he taught many generations of medical students and post-graduate doctors. In 2002, he continued to pursue his interest in early cancers of the stomach and colon and visited the Showa University Hospital in Yokohama, and the National Cancer Centre in Tsukiji, Tokyo. He lectured and taught at workshops locally and internationally, combining the best of Western and Eastern techniques. A Master endoscopist, he developed an innovative cap-fitted gastroscopy technique that is used to help countless patients worldwide. He was President of the Gastroenterological Society of Singapore (1999 to 2003) and was President of the Asia-Pacific Digestive Week in 2003. He is currently in private practice at Mount Elizabeth Medical Centre. His broad specialist experience include advanced endoscopy techniques such as ERCP treatment of bile duct stones and pancreas diseases, endoscopic ultrasound, treatment of esophagus, stomach, colon and liver cancers, viral hepatitis and inflammatory bowel disease. He is Visiting Consultant to the National University Hospital and Kandang Kerbau Womens’ & Childrens’ Hospital where he supervises gastroenterologists-in-training and performs endoscopy for sick children.