St sb1

Push enteroscopy (Olympus SIF-Q260, Olympus Medical Systems Corp) or single-balloon enteroscopy (SBE) was performed for the management of acute overt OGIB. SBE was performed by using the Olympus SIF-Q260 enteroscope and disposable overtube (ST-SB1, Olympus Medical Systems Corp). All enteroscopic procedures were performed by two experienced endoscopists (CM Tseng and CM Tai). If the CTA showed that the potential source of bleeding was in the distal duodenum or proximal jejunum, push enteroscopy via the oral route was performed first. Otherwise, we used SBE for deep small-bowel examination.
The choice of route of insertion for SBE was also dependent on the results of CTA. If the CTA identified a lesion that was a plausible source of bleeding, we chose the route of insertion accordingly. If CTA was negative, the insertion route depended on the color of the stool: the oral route for melena and the anal route for hematochezia. If SBE failed to detect the source of bleeding from one route, tattooing was performed at the deepest point, and an additional session of SBE was performed from the other route.

Patients treated between April 2011 and April 2018 at our hospital were retrospectively reviewed. Maneuverability and indication were confirmed on preoperative endoscopy (CF‐HQ290ZI or CF‐H260AZI; Olympus, Tokyo, Japan), with magnifying function, in 400 consecutive cases of colorectal ESD performed during the study period. Poor maneuverability comprised paradoxical movement of the endoscope,10 poor control with adhesion after abdominal surgery, and redundant colon. Of the 125 cases judged as having poor maneuverability, 36 cases of sigmoid colon without the use of BAE, 2 cases of incomplete total colonoscopy, and 4 cases with the use of a single balloon overtube for the small intestine (ST‐SB 1; Olympus) were excluded. Finally, 83 deep colon cases judged as having poor maneuverability were included. Among these, 54 cases underwent BAE, introduced in March 2015 at our hospital (group B), and 29 cases underwent conventional procedures before BAE was introduced (group C) (Fig. 1). This study was approved by our Institutional Review Board (No. F2018C12); all patients were provided with the opportunity to opt out of the study.

We used four models of enteroscopes: SIF-Y0004, SIF-Y0004-V01, and SIF-Y0015, which were prototype enteroscopes, and SIF-H290S, which was a commercially available model (Olympus Medical Systems, Tokyo, Japan). All enteroscopes had a working length of 1520 mm, a working channel diameter of 3.2 mm, and a distal end outer diameter of 9.2 mm. With the exception of SIF-Y0004, all enteroscopes had passive bending and high force transmission functions. A sliding tube with a working length of 880 mm was used (ST-SB1S, Olympus Medical Systems). A tip cap (D-201-10704, Olympus Medical Systems) was used in all patients.

A single-balloon enteroscope (SIF-H290S; Olympus Medical, Tokyo, Japan), a distal attachment (D-201-10704; Olympus Medical) and an overtube (ST-SB1S; Olympus Medical) was used as a BAE in this study. This enteroscope has a 9.2 mm distal end diameter, a 152 cm working length and a 3.2 mm working channel. A 6 Fr or 7.2 Fr END tube (SilkyPass; Boston Scientific, Marlborough, MA, USA) was used for external drainage. A 7 Fr double-pigtail stent (Through & Pass; Gadelius Medical, Tokyo, Japan, Zimmon Biliary Stent Sets; Cook Medical, Bloomington, IN, USA) was used when a plastic stent was selected for internal drainage. Several types of uncovered SEMS with 9 Fr delivery systems were used depending on the time of study period: Niti-S Colonic stent (TaeWoong Medical, Gyeonggi-do, South Korea), Niti-S Pyloric/Duodenal stent (TaeWoong Medical), HANAROSTENT Naturfit DUO stent (Boston Scientific), JENTLLY NEO Duodenal stent (Japan Lifeline, Tokyo, Japan), and NEXENT duodenal stent (Next Biomedical, Incheon, South Korea). The diameter of Niti-S Colonic stemt was 18 mm, while all other SEMS had diamaters of 22 mm. The lengths of uncovered SEMS were 60, 80, 100, 120 mm.