Small bowel endoscopy

Abstract

Evaluation of the small bowel has been one of the last frontiers of GI endoscopy. Outside of large referral medical centers, it is not common to find patients with obscure GI bleeding whose work-up and endoscopic investigations failed to find the cause of GI blood loss and for whom all other standard investigations are unrewarding as well. A questionnaire was sent to members of the International Editorial Board who were able to share their experiences with small bowel endoscopy at the beginning of the 21st century. Dr. Goh: I use a pediatric colonoscope and perform an examination in the small bowel about 5 times a year. Celiac disease is almost never diagnosed among Asians, and Crohn's disease is relatively uncommon. I do not find a significant yield of pathology, and the usual indication is a search for obscure GI bleeding. Dr. Armengol-Miro: The major indication is bleeding of unknown origin or after capsule endoscopy to search for a lesion identified. I do not often find pathology, however. Dr. Wang: I perform about 2 cases a month and find significant pathology in about one third of all enteroscopies. Dr. Novis: The main indication is a suspected small bowel source for undiagnosed GI bleeding or a small bowel lesion seen on radiograph. I use a video colonoscope and perform about 30 cases a year. In about 30% of examinations, I find either angiodysplasias or mass lesions. Dr. Hassall: From a pediatric standpoint, I have rarely had the occasion to use push enteroscopy, but I have done intraoperative enteroscopy with a surgeon helping to advance a colonoscope through an enterotomy. This was in a patient before small bowel transplant to identify the extent of small bowel mucosal destruction. As for assessment of the depth of insertion beyond the ligament of Treitz, Dr. Armengol-Miro feels that he passes it 270 cm beyond Treitz, Dr. Novis about 70 cm, Dr. Wang between 60 and 100 cm, and Dr. Goh estimates about 20 cm. Other than gastric erosions, none of the respondents reported any complications with the technique. Dr. Armengol-Miro takes biopsy specimens when there is an abnormal appearance of the mucosa, and takes 4 to 5 nonoriented specimens. Dr. Goh either performs biopsies on a specific lesion or when malabsorption is suspected. The number of biopsies is approximately 4 to 6, and he feels that when taking 2 to 3 biopsy specimens with one pass of the forceps, there is crush artifact, which may distort the specimen. Orientation of specimens on a filter paper is attempted. Dr. Wang performs biopsy only for mucosal pathology and takes 4 to 5 specimens in different parts of mucosa, but feels that it is acceptable to take 2 specimens within one pass of the forceps. Dr. Novis usually takes 4 to 6 nonoriented biopsy specimens in patients when pathology is seen or where malabsorption is suspected. His pathologist has no complaints when he takes multiple biopsy specimens with one pass of the biopsy forceps. Dr. Hassall states that as a pediatric gastroenterologist, he routinely take biopsy specimens during upper GI endoscopy, and these are usually taken for chronic abdominal pain or for diarrhea. The biopsy specimens are taken beyond the ampulla of Vater or from the duodenal bulb when there is suspected acid peptic disease. He takes only one biopsy specimen with each pass of the forceps. Nurses orient all specimens, placing them on mesh. However, he feels that orientation of specimens is best performed by flattening out the submucosal surface, never by rubbing a mounting pick over the mucosal surface, which will denude or damage the epithelium. Dr. Armengol-Miro feels that biopsy specimens for sprue should be taken in the third portion of the duodenum and not from the duodenal bulb. None of these members of the International Editorial Board take specimens of the ileum on retrograde ileostomy during colonoscopy. Dr. Goh uses a standard gastroscope to take a biopsy specimen in the duodenum when sprue is suspected and feels that specimens of the bulb are not representative of histology of the small intestine. Dr. Wang feels that specimens of the bulb are not worthwhile for making the diagnosis of sprue and likes to use an enteroscope when malabsorption is suspected to take specimens of the proximal jejunum. Dr. Novis takes specimens with the gastroscope in the second or third portion of the duodenum when malabsorption is suspected. Because of Brunner gland artifacts and acid peptic-related duodenitis or ulcer disease, the biopsy specimens are not taken from the duodenal bulb. He does not feel that it makes any difference whether one performs biopsy on the duodenum or jejunum when small bowel disease is expected. Dr. Armengol-Miro has used this on 12 patients and feels that it is a good technique, but feels that more studies are necessary to assess its proper use in the diagnostic schema of small bowel diseases. Dr. Goh states that he has viewed a demonstration of the capsule and thinks that it is too time consuming to even view it. Dr. Wang and Dr. Novis have no experience with the capsule. Dr. Hassall (pediatrics) feels that the major circumstances where they would like to have a “small bowel diagnosis” is Crohn's disease, but he is reluctant to use the capsule because of the possibility of getting it caught at a stricture. He feels that in those few occasions when there is no diagnosis at all, laparoscopic evaluation and full thickness biopsy would have a higher and more specific diagnostic yield. Dr. Waye: The era of small bowel enteroscopy was begun several years ago by Drs. Tada and Kawai in Japan. The technique of passing a peristalsis-driven 9-foot instrument through the small bowel over the course of several hours did not obtain many advocates in endoscopy. The procedure was tedious, and outside of large medical centers, was not used. When push enteroscopy became fashionable, many abandoned the long enteroscope for the push technique and found it to be quite useful, rapid, and diagnostic. The latest way to view the small intestine is with the wireless capsule. The capsule does have limitations in that it purely diagnostic, with no therapeutic capabilities. For patients with persistent anemia requiring blood transfusions and when the bleeding site cannot be found by standard repeated endoscopies, the capsule endoscope does not seem to be the instrument of choice. These patients need control of bleeding and should probably have intraoperative enteroscopy where the entire small bowel can be directly inspected and treatment rendered. If, on the other hand, the patients are severely ill or debilitated, an exploratory laparotomy with intraoperative enteroscopy should only be performed if there is a high probability of finding a lesion. In these patients, the capsule enteroscope would be an ideal diagnostic procedure which, if positive, would mandate a surgical approach in spite of comorbidities.