Background/Aims: Thromboprophylaxis is recommended for hospitalized patients with inflammatory bowel disease (IBD) in Western countries, although it is selectively administered to high-risk patients in East Asia. A central venous catheter (CVC) is commonly placed in patients with IBD. Although CVC placement is considered a risk factor for venous thromboembolism (VTE), the degree of increased risk in patients with IBD is uncertain. This study aimed to identify the risk of VTE with CVC placement in hospitalized Japanese patients with IBD without thromboprophylaxis. Methods: This retrospective cohort study included patients with ulcerative colitis or Crohn’s disease who were admitted for disease flares at Keio University Hospital between January 2016 and December 2020. Patients who already had thrombosis or were administered any antithrombotic treatment on admission were excluded. VTE development during the hospitalization was surveyed, and VTE risk associated with CVC indwelling was estimated using propensity score matching and inverse probability of treatment weighting analyses. Results: Altogether, 497 hospitalized patients with IBD (ulcerative colitis, 327; Crohn’s disease, 170) were enrolled. VTE developed in 9.30% (12/129) of catheterized patients and in 0.82% (3/368) of non-catheterized patients. The propensity score matching yielded 127 matched pairs of patients. The catheterized group demonstrated higher odds for VTE than the non-catheterized group (odds ratio, 13.15; 95% confidence interval, 1.68–102.70). A similar result was obtained in the inverse probability of treatment weighting analysis (odds ratio, 11.02; 95% confidence interval, 2.64–46.10). Conclusions CVC placement is a major risk factor for VTE among hospitalized Japanese patients with IBD without thromboprophylaxis.

Background/Aims: The evaluation of small bowel lesions of Crohn’s disease (CD) using balloon-assisted enteroscopy (BAE) is crucial because mucosal healing is associated with a good prognosis. However, BAE procedures are invasive, requiring sedation or analgesia to reduce the patient’s pain.This study evaluated the clinical usefulness of a novel ul-trathin single-balloon enteroscopy (SBE) procedure for CD. Methods: This single-center retrospective study included 102 CD patients who underwent trans-anal SBE between Janu-ary 2012 and May 2018. Of these patients, 82 underwent enteroscopy using conventional SBE, while 20 underwent ultrathin SBE. Patients were analyzed using propensity score matching, with 20 patients per group. The median duration of the examination, terminal ileum intubation rate, median cecum intubation time, median insertion depth, adverse events, and sedated dose in each group were compared. Results: Before propensity score matching, the conventional SBE group had a larger number of surgical history patients than the ultrathin SBE group (p=0.05). After matching, the two groups did not significantly differ clinically. There were no significant differences in the mean duration of the examina-tion, cecum intubation time, or terminal ileal intubation rate between ultrathin SBE and conventional SBE. The mean in-sertion depth of ultrathin SBE tended to be deeper than that of conventional SBE (p=0.09). The use of ultrathin SBE also reduced the sedative dose during needed for enteroscopy compared with conventional SBE (p=0.005). Conclusions Novel ultrathin SBE may be less painful for CD patients than conventional SBE.