Prospective Randomized Trial of Anterograde Single Balloon Versus Spirus Enteroscopy in Patients With Suspected Small Bowel Disease
We currently perform both spiral enteroscopy (SE) and single balloon enteroscopy (SBE) in
Johns Hopkins Hospital. The decision as to which procedure to use is determined by the
endoscopist performing the procedure, with currently approximately 60% being performed with
SE and 40% performed with SBE. We wish to perform a prospective, randomised trial, to
assess the differences between these two procedures. The question of what differences there
are between these two techniques, in terms of depth of insertion, diagnostic and therapeutic
yields, time required for the procedure and the sedation requirements, are important
questions to answer, and depending on the results, would affect the investigators approach
to patients with small bowel disease.
The small bowel is poorly suited to standard endoscopy techniques due to its anatomical
differences from the colon and the upper gastrointestinal tract. The small bowel has an
average length of 6.7 m, with a free mesentery that resists standard "push to advance"
endoscopy techniques. New developments in overtubes, which are placed over an enteroscope,
have revolutionized the investigators ability to deeply intubate the small bowel. The first
of these new techniques to be described was double balloon enteroscopy (DBE) (Fujinon,
Wayne, NJ) in 2001. The next development was single balloon enteroscopy (SBE) (Olympus
America, Center Valley PA), an iteration of DBE that simply forgoes the second balloon at
the tip of the endoscope, and also allows for deep enteroscopy which has been available in
the United States since 2007. Spiral enteroscopy (SE) was introduced soon after SBE in 2007,
and consists of a spiral overtube (Spirus Medical Inc., Stoughton, Massachusetts, USA) which
pleats the small bowel onto the enteroscope.
DBE has the largest amount of published data, with more than 1370 patients and 2591
examinations. Data regarding the efficacy of SBE and SE are more limited than DBE. SBE and
SE have only been available in the United States since 2007, and therefore have less
published data than DBE. There are two published series of SBE, with several more
publications in abstract form. A total of 362 cases have been reported, with diagnostic
yields ranging between 30% to 76%, with therapeutic intervention performed in up to 55%.
There are 6 reports of SE procedures, with one large series of 1750 cases documenting side
effects of SE. The overall diagnostic yield ranged from 24% to 51% with similar treatment
success rates. SBE has been compared with DBE in patients with suspected small bowel
disease in three studies reported in abstract form. SE has been compared with push
enteroscopy and DBE, however there have been no studies comparing SBE and SE.
The risks associated with augmented enteroscopy (DBE, SBE, SE) are similar to those
associated with routine endoscopy and include sedation-related complications, aspiration
pneumonia, and respiratory infections. In addition, there have been complications
specifically related to augmented enteroscopy. Abdominal discomfort can occur due to
trapped gas. DBE has been associated with intestinal cramping in 2% to 20% of patients.
The use of CO2, which the investigators routinely use in Johns Hopkins, decreases post
procedure abdominal cramping. Minor small bowel contusion can occur. The incidence of
gastrointestinal haemorrhage does not seem to be increased in augmented enteroscopy compared
with standard endoscopic procedures. Pancreatitis occurred in 6 (0.2%) of cases reported in
a multicenter United States study of DBE. There have been no reports of pancreatitis
associated with SBE or SE enteroscopy. Intestinal perforation is a rare but serious event.
Perforation has been reported in 5 (0.2%) of 2591 DBE examinations. In SBE, one perforation
was reported in a series of 37 patients, with a case report of a perforation in a patients
with jejuna ulceration from metastatic adenocarcinoma of unknown primary. A mucosal tear,
requiring endoscopic clip esophageal or gastric perforation, severe bleeding requiring
transfusion, cardio-pulmonary arrests or deaths. There were 7 (0.4%) severe complications.
Six were small bowel perforations (0.34%).
In Johns Hopkins there has been one perforation using SBE and one using SE one of which
occurred in a patient with small bowel Crohns disease (SBE) and the other in a patient with
altered anatomy (SE) (personal communication Dr PI Okolo). This latter group of patients
are known to be at increased risk of perforation during endoscopic procedures and will be
excluded from this study. There have had no other serious complication associated with
either SE or SBE enteroscopy. All of the individuals who will participate in this study are
already scheduled to have an augmented enteroscopy. Therefore, there is no additional risk
incurred by the patient by participating in this study, over and above the risk of an
augmented enteroscopy which is part of the routine clinical care for these patients.
Observational Model: Case-Only, Time Perspective: Prospective
Comparison of the depth of insertion into the small bowel of SBE compared with SE from the pylorus.
The depth of insertion was defined as the maximum distance the enteroscope was inserted past the pylorus. In SBE, the endoscopist estimates in 10cm increments from 0 to 40 cm the length of small bowel released during each insertion of the overtube and pulling back of the enteroscope and overtube. The net advancement is defined as the DMI for SBE. For SE the DMI is calculated by counting the length of bowel examined in 10-cm increments upon withdrawal of the enteroscope and overtube.
At the time of procedure
Patrick Okolo, MD
Johns Hopkins University
United States: Institutional Review Board
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