OAK BROOK, Ill. October 31, 2008 A study by researchers in Japan concludes that Double Balloon Endoscopy™ (DBE) was very useful in the diagnosis of obscure gastrointestinal (GI) bleeding and had a therapeutic impact on the majority of patients. The study appears in the October issue of GIE: Gastrointestinal Endoscopy, the monthly peer-reviewed scientific journal of the American Society for Gastrointestinal Endoscopy (ASGE).
Endoscopy is a procedure that uses an endoscope - a thin, flexible tube with a light and a lens on the end to look into the esophagus, stomach, duodenum, small intestine, colon, or rectum, in order to diagnose or treat a condition. There are many types of endoscopy, including colonoscopy, sigmoidoscopy, gastroscopy, enteroscopy, and esophogogastroduodenoscopy (EGD). Capsule endoscopy (CE) uses a pill- sized video capsule, which has its own lens and light source that the patient swallows for examination of the small intestine. The balloon assisted enteroscopy technique is a new method that advances the scope through the small intestine by inflating and deflating balloons, and pleats the small bowel over a tube like a curtain rod. This technique allows for diagnosis and treatment of small intestinal disorders. Balloon assisted enteroscopy can be performed with one or two balloons. When two balloons are used, the technique is referred to as Double Balloon Endoscopy™.
"The source of GI bleeding can be identified in most cases by conventional upper-GI and lower-GI endoscopy, but approximately five percent of all GI bleeding remains undiagnosed," said study lead author Shu Tanaka, MD, Nippon Medical School, Tokyo, Japan. "Until now, there has been no in-depth analysis about the diagnostic yield of DBE in patients with obscure GI bleeding. Our study showed that the sensitivity of DBE was 92.7 percent in the diagnosis of small intestinal lesions in patients with obscure GI bleeding and overall diagnostic yields were similar to those of capsule endoscopy."
Patients and Methods
This study examined 108 patients at the Nippon Medical School, Tokyo, Japan from July 2003 to February 2007 who had been referred for evaluation of obscure GI bleeding. Obscure GI bleeding was defined as overt GI bleeding or anemia in combination with stool test positive for blood of unknown cause despite negative upper and lower endoscopy. A stool blood test or fecal occult blood test (FOBT) is used to find small amounts of hidden (occult) blood in the stool. A sample of stool is tested for traces of blood.
The patients were classified into three groups before a DBE was performed: patients seen with active bleeding were classified as the overt-ongoing group (13 patients); patients with previous episodes though not active bleeding, were the overt-previous group (76 patients); and patients with positive fecal occult blood and a decrease in Hb level more than 2 g/dL comprised the occult group (19 patients). Researchers noted that during the study time frame, capsule endoscopy was introduced to the hospital. Therefore 36 of the 108 patients underwent both capsule endoscopy and DBE examinations, though DBE examination in this group, regardless of CE results, focused on the diagnostic precision of DBE for obscure GI bleeding.
Preparation for the DBE examination included a 12-hour overnight fast. Diagnostic biopsies or therapeutic procedures were performed during a DBE as necessary for any lesions discovered. Erosions or red spots that did not bleed during the examination were not considered the bleeding source. All patients were followed-up every two months until the end of the study for a period of at least nine months. The aims of the study investigators were to evaluate the diagnostic yield of DBE for obscure bleeding and assess the impact of DBE on the ultimate diagnosis and treatment plan.
DBE demonstrated a diagnostic yield of 54.2 percent. However, DBE when examined in the context of symptomatic indication, gave a diagnosis for bleeding in 100 percent of patients with overt-ongoing bleeding, 48.4 percent of patients with overt-previous bleeding, and 42.1 percent of patients with occult bleeding. The difference in diagnostic yields between the overt-ongoing group and the two other groups was statistically significant (P < .005).
54.2 percent of patients had a potential source of small intestinal bleeding identified, while 45.8 percent of patients had a negative DBE. The most common sources of bleeding were ulcers (21/108 patients) and tumors (19/108). There were no serious complications encountered. Follow-up data was available for 93 patients. Eight patients (7.4 percent), four from the positive DBE and four from the negative DBE group, had recurrent bleeding during the mean follow-up period of 28.5 months. Sensitivity, specificity, positive, and negative predictive values of DBE in the diagnoses of small intestinal lesions in patients with obscure GI bleeding were 92.7 percent, 96.4 percent, 98.1 percent, and 87.1 percent, respectively.
The authors show that identification of a bleeding source in obscure GI bleeding is most likely when DBE is performed during or soon after a bleeding episode; similar conclusions have been reached on studies of CE. The authors propose that patients with obscure overt-ongoing bleeding ought to be examined by a DBE first for concurrent diagnosis and endoscopic hemostasis. In cases of overt-previous or occult obscure GI bleeding, the priority should be given to the less invasive CE. Future prospective studies should consider clinical outcomes such as cost-effectiveness, length of hospitalization, and the amount of blood transfusion, to clarify the role of CE and DBE in the diagnosis and management of obscure GI bleeding with overt-ongoing bleeding.
|Contact: Anne Brownsey|
American Society for Gastrointestinal Endoscopy