Balloon Assisted or “Deep” Enteroscopy
The small bowel is approximately 20 feet in length and, historically was an inaccessible part of the gastrointestinal tract. In 2001 the FDA approved the use of the first wireless video capsule endoscopy system which allowed unprecedented visualization of lesions and abnormalities in the small bowel. This technology created the need for therapeutic intervention in the small bowel, and the deep enteroscopy systems were developed to allow non-surgical treatment and biopsy of small bowel pathology. Through this new technique, many treatments of the small bowel are now possible including stricture dilation, polyp removal, tissue sampling, and various hemostatic procedures to stop active blood loss or destroy bleeding lesions. In some instances, therapy with a balloon assisted enteroscope may allow patients to avoid surgical intervention on the small bowel.
The balloon system consists of a 200 cm endoscope and an overtube. There are one or two inflatable balloons attached to the scope and/or overtube. The technique allows the scope to advance through the length of the small bowel via the process of inflating and deflating the balloon(s), which grip the walls of the small intestine. With a series of ‘reductions,’ the process pleats the small bowel over the overtube, like a curtain over a rod, and advances the scope. The spiral overtube technique works by pleating the small bowel over the tube, allowing passage of a small caliber enteroscope deep into the small bowel. Accessories such as biopsy forceps, dilating devices, and cautery probes can be passed through channels in the scope in order to treat abnormal findings in the small intestine.
Balloon assisted or deep enteroscopy can be performed in an outpatient or inpatient setting and may require several hours, depending on the therapy required. It is often performed with general anesthesia, although some patients may require only moderate sedation. Fluoroscopy, or the use of X-ray, may be employed during the procedure. Most procedures are performed through the mouth (antegrade), although the retrograde approach, through the rectum, may allow better access to lesions in the lower part of the small bowel.
The risks of the procedure are similar to those for colonoscopy and upper endoscopy (EGD) and include bleeding, perforation, and complications of sedation. Unique to balloon enteroscopy are the risks of ileus (transient slowing of the bowel) and pancreatitis, which occur in less than one percent of procedures.
The indications for balloon assisted enteroscopy include the need for treatment of small intestinal lesions found on other gastrointestinal exams, such as capsule endoscopy or CT scan. The procedure is not used as a first line therapy and is performed only after careful evaluation by a specially trained gastroenterologist. Most procedures are done for bleeding lesions seen on capsule endoscopy, worrisome lesions or masses seen by other modalities, polyps in patients with hereditary syndromes, retained foreign objects, and small bowel strictures.
As noted above, therapies include treatment of bleeding lesions such as angioectasias, dilation of strictures using a hydrostatic balloon dilator, removal by snare or biopsy of polyps or small bowel masses, retrieval and removal of foreign objects or retained capsules, and biopsy of abnormal tissue. Balloon assisted enteroscopy has also been used in gaining access to parts of the gastrointestinal tract in patients with surgically altered anatomy.
Patients who are not medically stable should not undergo balloon assisted enteroscopy. Those who have had extensive abdominal surgeries may be poor candidates because of adhesions or altered anatomy which may prevent the scope from advancing.