Automatic assessment of bowel preparation by an artificial intelligence model and its clinical applicability.

BACKGROUND AND AIM: Reliable bowel preparation assessment is important in colonoscopy. However, current scoring systems are limited by laborious and time-consuming tasks and interobserver variability. We aimed to develop an artificial intelligence (AI) model to assess bowel cleanliness and evaluate its clinical applicability. METHODS: A still image-driven AI model to assess the Boston Bowel Preparation Scale (BBPS) was developed and validated using 2361 colonoscopy images. For evaluating real-world applicability, the model was validated using 113 10-s colonoscopy video clips and 30 full colonoscopy videos to identify "adequate (BBPS 2-3)" or "inadequate (BBPS 0-1)" preparation. The model was tested with an external dataset of 29 colonoscopy videos. The clinical applicability of the model was evaluated using 225 consecutive colonoscopies. Inter-rater variability was analyzed between the AI model and endoscopists. RESULTS: The AI model achieved an accuracy of 94.0% and an area under the receiver operating characteristic curve of 0.939 with the still images. Model testing with an external dataset showed an accuracy of 95.3%, an area under the receiver operating characteristic curve of 0.976, and a sensitivity of 100% for the detection of inadequate preparations. The clinical applicability study showed an overall agreement rate of 85.3% between endoscopists and the AI model, with Fleiss' kappa of 0.686. The agreement rate was lower for the right colon compared with the transverse and left colon, with Fleiss' kappa of 0.563, 0.575, and 0.789, respectively. CONCLUSIONS: The AI model demonstrated accurate bowel preparation assessment and substantial agreement with endoscopists. Further refinement of the AI model is warranted for effective monitoring of qualified colonoscopy in large-scale screening programs.

Risk factors for the failure of endoscopic balloon dilation to manage anastomotic stricture from colorectal surgery: retrospective cohort study.

BACKGROUND: An anastomotic stricture after colorectal surgery is principally managed by endoscopic balloon dilation (EBD). Although this intervention is effective, however, subsequent procedures or surgical interventions are often required. This study aimed to assess the long-term outcomes of EBD for anastomotic stricture arising from colorectal cancer surgery. MATERIALS AND METHODS: We analyzed 173 patients who received curative surgery for colorectal cancer at our hospital between January 2000 and December 2022 and had undergone EBD to manage anastomotic stricture. The medical records of these cases were retrospectively reviewed to assess the outcomes and risk factors for restenosis and permanent stoma. RESULTS: Of the 173 study patients, 41 (23.7%) presented with restenosis with a median time to recurrence of 49 [37-150] days. The restenosis group was significantly younger (55.6 years versus 60.8 years), with a more prominent rectal location (80.5% versus 57.6%), a higher incidence of hand-sewn anastomosis (24.4% versus 5.3%), and a higher percentage of neoadjuvant radiotherapy (34.1% versus 5.3%, P < 0.001). Multivariable analysis indicated neoadjuvant radiotherapy (adjusted HR 2.48; 95% CI 1.03-5.95) and cerebral vascular disease (adjusted HR 6.97; 95% CI 2.15-22.54) as independent prognostic factors for restenosis. Fourteen patients (8.1%) required a permanent stoma due to treatment failure. All cases needing a permanent stoma were male (14 patients, 100%, P = 0.007) and this group had a higher rate of neoadjuvant radiotherapy, adjuvant chemotherapy, and hand-sewn anastomosis. CONCLUSION: Patients receiving neoadjuvant radiotherapy are most prone to restenosis after an EBD intervention to manage an anastomotic stricture. Neoadjuvant radiotherapy is also a strong risk factor for requiring a permanent stomas due to treatment failure.

Efficacy and safety of oral sodium sulfate tablet compared with 1-L polyethylene glycol plus ascorbate: a prospective, randomized, endoscopist-blinded trial.

BACKGROUND AND AIM: Low-volume bowel preparation solutions, including 1-L polyethylene glycol plus ascorbate (PEG-A), have been developed to improve tolerability. The oral sodium sulfate tablet (OST) is a new agent with simethicone as a preloaded component. We investigated the efficacy, safety, and tolerability of OST compared to 1-L PEG-A. METHODS: A single-center, prospective, controlled study was performed with randomization into the OST (group A) and 1-L PEG-A (group B) groups. Bowel preparation efficacy was assessed on the Boston Bowel Preparation Scale (BBPS) and Bubble Scale. Safety and tolerability were evaluated using a questionnaire and laboratory examination. RESULTS: Final analysis was performed on 171 patients (group A: 87, group B: 84). The proportion of bowel preparation success (BBPS ≥ 2 for each colonic segment) in group A was not inferior compared to group B (95.4% vs 96.4%, P = 0.736, 1-sided 97.5% lower confidence limit -7.0%). The adenoma detection rate was not different (59.6% vs 41.9%; P = 0.087). The bubble scale was better in group A (0.2 ± 0.9 vs 1.9 ± 1.7, P < 0.001). All adverse events were mild in both groups. Nausea was less frequent in group A (14.9% vs 38.1%, P = 0.001). Overall satisfaction was better in group A (8.1 ± 2.1 vs 6.4 ± 2.8, P < 0.001). No clinically significant laboratory abnormality developed in both groups. These findings were similarly shown in old patients ≥65 years. CONCLUSIONS: Both OST and 1-L PEG-A were efficacious, safe, and tolerable for bowel preparation of colonoscopy. The OST showed fewer bubbles and slightly better tolerability.

Influence of endoscopists' expertise level on clinical outcomes after bridge-to-surgery stenting in obstructive colorectal cancer.

BACKGROUND AND AIM: This study aimed to investigate the effect of stenting-related factors, including endoscopists' expertise, on clinical outcomes after bridge-to-surgery (BTS) stenting for obstructive colorectal cancer (CRC). METHODS: We analyzed BTS stenting-related factors, including stenting expertise and the interval between stenting and surgery, in 233 patients (63 [13] years, 137 male) who underwent BTS stenting for obstructive CRC. We evaluated the influence of these factors on post-BTS stenting clinical outcomes such as stent-related complications and cancer recurrence. RESULTS: The interval between stenting and surgery was ≤ 7 days in 79 patients (33.9%) and > 7 days in 154 patients (66.1%). BTS stenting was performed by endoscopists with ≤ 50, 51-100, and > 100 prior stenting experiences in 94, 43, and, 96 patients, respectively. The clinical success rate of BTS stenting was 93.1%. Stent-related and postoperative complications developed in 19 (8.2%) and 20 (8.6%) patients, respectively. Cancer recurrence occurred in 76 patients (32.6%). Short BTS interval of ≤ 7 days increased the risk of postoperative complications (odds ratio [OR], 2.61 [1.03-6.75]; P = 0.043). Endoscopists' stenting experience > 100 showed greater clinical success of stenting (OR, 5.50 [1.45-28.39]; P = 0.021) and fewer stent-related complications (OR, 0.26 [0.07-0.80]; P = 0.028) compared with stenting experience ≤ 50. BTS stenting-related factors did not affect long-term oncological outcomes. CONCLUSION: Greater expertise of endoscopists was associated with better short-term outcomes, including high stenting success rate and low rate of stent-related complications after BTS stenting for obstructive CRC. An interval of > 7 days between BTS stenting and surgery was required to decrease postoperative complications.

Impact of Sarcopenia on Clinical Course of Inflammatory Bowel Disease in Korea.

BACKGROUND AND AIMS: Reduced body muscle mass is a poor prognostic factor for inflammatory bowel disease (IBD). In this study, we investigated the prevalence of sarcopenia at diagnosis and its clinical significance in Korean patients with IBD. METHODS: The prevalence of sarcopenia in IBD patients between June 1989 and December 2016 was investigated using a well-characterized referral center-based cohort. Abdominopelvic computed tomography within six months from IBD diagnosis was used for the evaluation. Sarcopenia was defined as an L3 skeletal muscle index of < 49 cm2/m2 for male and < 31 cm2/m2 for female. The clinical characteristics and outcomes were evaluated with respect to sarcopenia. RESULTS: A total of 1,027 patients (854 Crohn's disease [CD]; 173 ulcerative colitis [UC]) were evaluated. Sarcopenia was found in 56.8% of the population (CD, 57.5%; UC, 53.2%), and male were more likely to be sarcopenic (CD, 94.3%; UC, 91.6%). There were no significant differences in the cumulative risk of using steroids, immunomodulators, biologics, and bowel resections (or colectomy) with or without sarcopenia during follow-up (median: CD, 5.8 years; UC, 3.7 years). In sarcopenic patients with CD, there was a significantly higher cumulative risk of perianal surgeries than in non-sarcopenic patients with CD (Log-rank test; P = 0.001). However, the risk of perianal surgeries was not significant in multivariate analysis (Odds ratio 1.368; 95% confidence interval 0.782-2.391; P = 0.272). CONCLUSION: Sarcopenia at diagnosis may have no significant prognostic value for medical treatment and bowel resection, but it may be associated with perianal CD.

Improved adenoma detection by a novel distal attachment device-assisted colonoscopy: a prospective randomized controlled trial.

BACKGROUND AND AIMS: WingCap (A&A Medical Supply LLC, Seongnam, South Korea) is a novel distal attachment device for colonoscopy that combines a cap and an existing mucosal exposure device, such as Endocuff Vision (Arc Medical Design Ltd, Leeds, UK) and AmplifEYE (Medivators Inc, Minneapolis, Minn, USA). We aimed to investigate whether WingCap-assisted colonoscopy can improve the adenoma detection rate (ADR) and adenoma per colonoscopy (APC) and simultaneously shorten cecal intubation time compared with standard colonoscopy. METHODS: We conducted a single-center, prospective, randomized controlled trial for outpatients aged ≥18 years undergoing colonoscopy. The primary outcome was ADR differences with the assistance of WingCap. Secondary outcomes were APC and other colonoscopy quality indicators, such as cecal intubation and withdrawal times. RESULTS: In total, 537 patients were randomized for WingCap-assisted or standard colonoscopy. Their mean age was 59.3 years, and 48.5% were men. ADR was significantly higher in the WingCap group than in the control group (37.2% vs 26.6%, P = .012). APC was greater with WingCap than with standard colonoscopy (.72 ± 1.34 vs .45 ± 0.97, P = .008), prominently for nonpedunculated (.65 ± 1.25 vs .42 ± .95, P = .015) and diminutive (.42 ± .94 vs .20 ± .64, P = .002) adenomas. With WingCap, ADR and APC significantly increased for beginner endoscopists, whereas a modest increase was seen for experienced endoscopists. There were no differences in cecal intubation and withdrawal times between the 2 arms. No serious adverse event was associated with the use of WingCap. CONCLUSIONS: WingCap-assisted colonoscopy was tolerable and efficacious for improving ADR and APC compared with standard colonoscopy, especially for nonpedunculated and diminutive adenomas and for beginner endoscopists. (Clinical trial registration number: KCT0005214.).

Immune profile by multiplexed immunohistochemistry associated with recurrence after chemoradiation in rectal cancer.

BACKGROUND AND AIM: Evidence has emerged that a pretreatment immune profile in rectal cancer is associated with response to chemoradiotherapy (CRT) and recurrence after CRT. However, few studies have evaluated the immune profile differences after CRT regarding recurrence and nonrecurrence. METHODS: We included patients with advanced rectal cancer treated with CRT and surgery with recurrence within 1 year in a recurrence group. After sex and age matching with the recurrence group, patients with no recurrence for 3 years after CRT were included in a nonrecurrence group. We extracted the immune profile, including CD3 and CD8, from the surgical specimen after CRT using multispectral fluorescence immunohistochemistry and compared the two groups. RESULTS: The immune profiles of 65 patients with rectal cancer were assessed; 30 were included in the recurrence group and 35 were included in the nonrecurrence group. CD3+ and CD8+ T lymphocyte densities were significantly higher in the nonrecurrence group than in the recurrence group (CD3+ ; P < 0.001, CD8+ ; P = 0.003) in the primary tumor. Consistent results were found in epithelial and stromal cells. Compared with the recurrence group, the distinct profiles of co-expressed immune markers in the nonrecurrence group were revealed (CD3+ CD8+ , P = 0.001; CD3+ CD8+ PD-L1- , P = 0.001; CD3+ CD8+ FOXP3- PD-L1- , P = 0.001). CONCLUSIONS: Vigorous CD3+ and CD8+ T cell priming post-CRT was prominent in the nonrecurrence group compared with that of the recurrence group. This finding suggests that differences in immune profiles may have clinical significance even after CRT.

Sessile serrated lesions in patients with adenoma on index colonoscopy do not increase metachronous advanced adenoma risk.

OBJECTIVES: Post-polypectomy surveillance intervals should be determined based on index colonoscopy findings. However, the risk of metachronous lesions, resulting from the coexistence of adenoma and sessile serrated lesions (SSLs), has rarely been addressed. We evaluated the impact of synchronous SSL on the risk of metachronous lesions within similar adenoma risk groups. METHODS: We retrieved individuals with one or more adenomas on index colonoscopy in a single-center retrospective cohort and stratified them into four groups depending on the presence of SSL and low-risk/high-risk adenoma (LRA/HRA). Participants who underwent surveillance colonoscopies at least 12 months apart were included. We compared the risks of metachronous lesions including HRA, advanced adenoma (AA), or SSL within similar adenoma risk groups according to the presence of SSL. RESULTS: Overall 4493 individuals were included in the analysis. The risk of metachronous HRA/AA was not significantly higher in the adenoma with SSL group compared with the adenoma without SSL group, irrespective of LRA (HRA, 6/86 vs. 231/3297, P = 1.00; AA, 0/86 vs. 52/3297, P = 0.64) or HRA (HRA, 11/64 vs. 240/1046, P = 0.36; AA, 3/64 vs. 51/1046, P = 1.00). However, the risk of metachronous SSL in individuals with synchronous SSL was higher than that in those without SSL for both LRA (15/86 vs. 161/3297, P < 0.001) and HRA groups (11/64 vs. 61/1046, P = 0.002). CONCLUSION: The presence of synchronous SSL did not increase the risk of metachronous HRA/AA, compared with isolated adenoma, but increased the risk of metachronous SSL.

Atopic Diseases Are Associated With Development of Inflammatory Bowel Diseases in Korea: A Nationwide Population-based Study.

BACKGROUND & AIMS: The association between atopic diseases and inflammatory bowel diseases (IBD) is unclear. We conducted a nationwide population-based study in Korea to investigate the effect of atopic diseases on the development of IBD. METHODS: A total of 9,923,521 participants, who received a medical check-up in 2009, were included and followed through 2017. The presence of any atopic diseases, including atopic dermatitis (AD), allergic rhinitis (AR), and asthma, was evaluated. Patients who developed IBD, including Crohn's disease (CD) and ulcerative colitis (UC), were identified using claims data from National Health Insurance; the association between atopic diseases and the risk of IBD was evaluated using Cox proportional hazard models, and presented as adjusted hazard ratios (aHRs) with 95% CIs. RESULTS: During a mean follow-up period of 7.3 years, 1419 patients (0.014%) developed CD and 5897 patients (0.059%) developed UC. The incidences of CD (per 100,000 person-years) were 3.756, 2.248, and 2.346 in patients with AD, AR, or asthma, respectively. The incidences of UC were 11.952, 9.818, and 9.358 in patients with AD, AR, or asthma, respectively. Multivariable analysis revealed that the aHRs for incident CD in patients with AD, AR, or asthma were 2.02, 1.33, and 1.60 (95% CIs, 1.118-3.663, 1.149-1.529, and 1.193-2.136, respectively) compared with controls. The risks of incident UC in patients with AD, AR, or asthma were 1.51, 1.32, and 1.29 (95% CIs, 1.082-2.104, 1.229-1.410, and 1.115-1.491, respectively) compared with controls. Moreover, an increase in the number of atopic diseases gradually increased the risk for CD and UC; for 1 or 2 or more atopic diseases, the aHRs for CD were 1.35 and 1.65 (95% CIs, 1.171-1.560 and 1.146-2.376), and the aHRs for UC were 1.30 and 1.49 (95% CIs, 1.211-1.392 and 1.249-1.774), respectively. CONCLUSIONS: Based on a nationwide population-based study in Korea, patients with any atopic disease, including AD, AR, or asthma, have an increased risk for CD and UC. The risk for IBD increases with the increase in the number of atopic diseases.

Risk and characteristics of tuberculosis after anti-tumor necrosis factor therapy for inflammatory bowel disease: a hospital-based cohort study from Korea.

BACKGROUND: Anti-tumor necrosis factor (TNF) treatment for inflammatory bowel disease (IBD) increases the risk of tuberculosis (TB) infection. In the present study, we analyzed the clinical characteristics and risks of TB in Korean patients with IBD who received anti-TNF treatment. METHODS: The study included patients with IBD who were treated using anti-TNF agents between January 2001 and June 2018 at the Asan Medical Center. Overall, 1434 patients with ulcerative colitis or Crohn's disease were enrolled. We calculated the incidence of active TB infection after anti-TNF treatment and compared the clinical characteristics of the TB group with those of the non-TB group. RESULTS: Twenty-one patients (1.46%) developed active TB infection, and the incidence rate of active TB was 366.73 per 100,000 person-years. In total, 198 patients (14.9%) were positive for latent tuberculosis infection (LTBI), of whom only eight (4%) did not complete LTBI treatment. The age at which the anti-TNF therapy was started was significantly higher in the TB group than in the non-TB group (HR 1.041, 95% CI 1.014-1.069, p = 0.002), and as age increased, so did the incidence rate of active TB infection (linearity p < 0.001). There was no significant difference in the incidence rate of LTBI between the TB and non-TB groups (HR 0.896, 95% CI 0.262-3.066, p = 0.862). CONCLUSIONS: In patients with IBD, the incidence rate of TB increased with age at anti-TNF therapy initiation. Active treatment of LTBI may lower the incidence of TB in patients with IBD who are to undergo anti-TNF therapy.

Risk factors for rebleeding in Crohn's disease patients with acute severe lower gastrointestinal bleeding: With special reference to the role of anti-tumor necrosis factor therapy.

BACKGROUND AND AIM: Acute severe lower gastrointestinal bleeding (LGIB) in patients with Crohn's disease (CD) is uncommon; however, it is a potentially life-threatening complication, and its recurrence is common. We thus aimed to identify the predictors for rebleeding in CD patients with acute severe LGIB and particularly focused on whether anti-tumor necrosis factor (TNF) therapy lowers the risk of rebleeding compared with conventional medical therapy (CMT) or surgery. METHODS: The risk of rebleeding was analyzed in 131 CD patients with acute severe LGIB. Patients were classified into the CMT group (n = 99), anti-TNF therapy group (n = 22), and surgery group (n = 10). No patients in the surgery group received anti-TNF therapy. RESULTS: During the median follow-up of 98 months after the first episode of acute severe LGIB, rebleeding occurred in 50.5%, 18.2%, and 30.0% of the CMT group, anti-TNF therapy group, and surgery group, respectively (P = 0.015). The cumulative risks of rebleeding at 1 and 10 years were 20.0% and 64.7% in the CMT group, 13.6% and 18.4% in the anti-TNF therapy group, and 0% and 40.7% in the surgery group, respectively (P = 0.020). Multivariable Cox regression analysis showed that anti-TNF therapy was associated with a lower risk of rebleeding compared with CMT (hazard ratio, 0.303; 95% confidence interval, 0.108-0.849; P = 0.023). CONCLUSIONS: In CD patients with acute severe LGIB, anti-TNF therapy may reduce the risk of rebleeding compared with CMT. Although surgery is considered effective in preventing early rebleeding, concomitant anti-TNF therapy may be helpful in further lowering the long-term risk of rebleeding.

Chronic Viral Hepatitis Is Associated with Colorectal Neoplasia: A Systematic Review and Meta-Analysis.

BACKGROUND: Chronic viral hepatitis is associated with a wide range of extrahepatic diseases; however, evidence on a link between chronic viral hepatitis and colorectal neoplasia is still lacking. AIMS: To analyze the association between chronic viral hepatitis and prevalence of colorectal neoplasia. METHODS: A systematic review of articles published in the MEDLINE, EMBASE, and Cochrane Library between 2000 and 2020 was performed. Subgroup analyses based on the types of colorectal neoplasia and the etiology of chronic viral hepatitis were conducted. RESULTS: Twelve eligible studies with 48,428 hepatitis B virus (HBV) patients and 46,561 hepatitis C virus (HCV) patients were included. Chronic viral hepatitis was significantly associated with an increased risk of both colorectal adenoma (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.16-2.02; I2 = 83%) and colorectal cancer (CRC) (OR, 1.32; 95% CI, 1.08-1.61; I2 = 94%). The etiology of chronic viral hepatitis was an independent factor related to heterogeneity for CRC subgroup analysis revealed an increased risk of CRC in both HBV (OR, 1.18; 95% CI, 1.09-1.27; I2 = 37%) and HCV (OR, 1.88; 95% CI, 1.78-1.97; I2 = 0%). HCV was associated with an increased risk of colorectal adenoma (OR, 1.48; 95% CI, 1.22-1.79; I2 = 0%); however, HBV was not associated with an increased risk of colorectal adenoma and had considerable heterogeneity (OR, 1.65; 95% CI, 0.88-3.09; I2 = 90%). CONCLUSION: Our meta-analysis showed that chronic viral hepatitis is associated with an increased risk of colorectal neoplasia. The strategy of stricter screening colonoscopy may benefit from patients with chronic viral hepatitis.

Clinical Course of COVID-19 in Patients with Inflammatory Bowel Disease in Korea: a KASID Multicenter Study.

In 2020, the novel coronavirus disease 2019 (COVID-19) began to spread worldwide and remains an ongoing medical challenge. This case series reports on the clinical features and characteristics of patients with inflammatory bowel disease (IBD) and confirmed COVID-19 infection. From February 2020 to March 2021, nine patients with IBD had confirmed COVID-19 across four hospitals in Korea. The median age at COVID-19 diagnosis was 42 years. Six patients were male, and seven patients had ulcerative colitis (UC). No patients required oxygen therapy, intensive care unit hospitalizations, or died. The most common symptom was fever, and gastrointestinal (GI) symptoms developed as diarrhea in five patients with UC. Oral steroids were used to combat UC aggravation in two patients. In this case series of nine IBD patients diagnosed with COVID-19 in Korea, the clinical presentation was predominately a mild respiratory tract infection. Most patients with UC developed new GI symptoms including diarrhea.

Clinical significance of granulomas in Crohn's disease: A systematic review and meta-analysis.

BACKGROUND AND AIM: Epithelioid granuloma is one hallmark used to histologically diagnose Crohn's disease (CD). However, the clinical significance of granulomas in CD is unclear. Therefore, we performed a meta-analysis to compare the clinical features with CD according to the presence of granulomas. METHODS: A literature search in PubMed, EMBASE, and Cochrane databases was performed on manuscripts published until October 2018. We included studies that met the following inclusion criteria: (i) patient: patients with CD; (ii) exposure: granulomas on the pathology; (iii) comparator: no granulomas; and (iv) outcomes: disease location, disease behavior, perianal disease, disease activity, use of biologics, and CD-associated hospitalization, surgery. RESULTS: Nineteen studies met our inclusion criteria. Granulomas in CD patients were associated with a higher proportion of ileocolonic disease (odds ratio [OR]: 1.49, 95% confidence interval [CI]: 1.21-1.83), a higher proportion of upper gastrointestinal disease (OR: 2.25, 95% CI: 1.28-3.95), a higher proportion of penetrating behavior (OR: 1.48, 95% CI: 1.09-2.01), a higher prevalence of perianal disease (OR: 2.15, 95% CI: 1.48-3.11), and a higher severity index at presentation (standardized mean difference: 0.20, 95% CI: 0.09-0.32). In addition, the use of biologics was significantly higher in CD patients with granulomas compared with without granulomas (OR: 1.66, 95% CI: 1.07-2.59). The presence of granulomas was significantly associated with CD-associated hospitalization (OR: 3.88, 95% CI: 1.44-10.49), but not with CD-associated surgery. CONCLUSIONS: Clinical features in CD patients were significantly different according to the presence of granulomas. It may indicate a more aggressive phenotype of CD.

Endoscopic mucosal resection using anchored snare Tip-in versus precut technique for small rectal neuroendocrine tumors.

BACKGROUND/AIMS: Small rectal neuroendocrine tumors (NETs) can be treated with modified endoscopic mucosal resection (EMR). However, an optimal EMR method remains to be established. We aimed to assess the non-inferiority of Tip-in EMR versus precut EMR (EMR-P) for treating rectal NETs. METHODS: This prospective, multicenter, randomized controlled trial enrolled patients with rectal NETs of < 10 mm in diameter. The patients were randomly assigned to EMR-P and Tip-in EMR groups in a 1:1 ratio. Primary outcome was margin-negative (R0) resection rate between the two methods, with a noninferiority margin of 10%. RESULTS: Seventy-five NETs in 73 patients, including 64 eligible lesions (32 lesions in each, EMR-P and Tip-in EMR groups), were evaluated. In a modified intention-to-treat analysis, R0 resection rates of the EMR-P and Tip-in EMR groups were 96.9% and 90.6%, respectively, which did not demonstrate non-inferiority (risk difference, -6.3 [95% confidence interval: -18.0 to 5.5]). Resection time in the EMR-P group was longer than that in the Tip-in EMR group (p < 0.001). One case of intraprocedural bleeding was reported in each group. CONCLUSION: We did not demonstrate the non-inferiority of Tip-in EMR compared to EMR-P for treating small rectal NETs. However, the R0 resection rates for both techniques were high enough for clinical application.

Fecal Calprotectin in Patients with Crohn's Disease: A Study Based on the History of Bowel Resection and Location of Disease.

Fecal calprotectin (FC) is commonly used to assess Crohn's disease (CD) activity. However, standardized cut-off values accounting for bowel resection history and disease location are lacking. In this study, we analyzed data from patients with CD who underwent magnetic resonance enterography, ileocolonoscopy, and FC measurements from January 2017 to December 2018. In 267 cases from 254 patients, the FC levels in the 'operated' patients were higher when the disease was active compared with those who were in the remission group (178 vs. 54.7 µg/g; p < 0.001), and similar findings were obtained for the 'non-operated' patients (449.5 vs. 40.95 µg/g; p < 0.001). The FC levels differed significantly according to the location of inflammation, with lower levels in the small bowel compared to those in the colon. The FC cut-off levels of 70.8 µg/g and 142.0 µg/g were considered optimal for predicting active disease for operated and non-operated patients, respectively. The corresponding FC cut-off levels of 70.8 µg/g and 65.0 µg/g were observed for patients with disease only in the small bowel. In conclusion, different FC cut-off values would be applicable to patients with CD based on their bowel resection history and disease location. Tight control with a lower FC target may benefit those with a history of bowel resection or small-bowel-only disease.

Effectiveness of Switching to Subcutaneous Infliximab in Ulcerative Colitis Patients Experiencing Intravenous Infliximab Failure.

Background/Aims: Studies on elective switching to the subcutaneous (SC) formulation of infliximab revealed comparable efficacy and safety and higher infliximab level than those exhibited by intravenous (IV) infliximab. However, no studies have reported on the effectiveness of SC switching in ulcerative colitis (UC) patients who experienced IV infliximab failure during maintenance treatment. Methods: This retrospective study included UC patients who had been switched to SC infliximab because of IV infliximab failure, between January 2021 and January 2023. Group A was defined as having clinically and biochemically active UC (secondary loss of response), and group B consisted of patients with stable symptoms but biochemically active UC. Results: Twenty-three patients met the inclusion criteria: 15 in group A and eight in group B. The serum infliximab levels significantly increased after SC switching in both groups. The electively switched group also exhibited increased infliximab levels after SC switching. Patients in group A showed improved partial Mayo score with a significant decrease in fecal calprotectin and C-reactive protein after switching. In group B, the fecal calprotectin level significantly decreased without clinical relapse after switching. A high proportion of patients (≥80%) in both groups achieved clinical and/or biochemical responses at the last follow-up. During the follow-up period, only two patients in group A discontinued SC infliximab, and only one complained of severe injection site reaction. Conclusions: In UC patients who experience IV infliximab failure during maintenance treatment, switching to SC infliximab may be a promising option because of better efficacy and safety.

Continuing or stopping 5-aminosalicylates in patients with inflammatory bowel disease on anti-TNF therapy: A nationwide population-based study.

BACKGROUND: The impact of continuing or stopping 5-aminosalicylates (5-ASA) after commencing anti-tumour necrosis factor (anti-TNF) therapy in patients with inflammatory bowel disease (IBD) remains unclear. AIMS: To compare the outcomes of patients with IBD who stopped or continued 5-ASA after starting anti-TNF therapy. METHODS: We analysed data from the Korean National Health Insurance claims database between 2007 and 2020. We compared the clinical outcomes of patients who stopped or continued 5-ASA within 90 days of anti-TNF initiation. The primary outcome was any adverse clinical event defined as a composite of new corticosteroid use, IBD-related hospitalisation, or intestinal surgery. RESULTS: Among 7442 patients included for analysis (4479 [60.2%] with Crohn's disease [CD] and 2963 [39.8%] with ulcerative colitis [UC]), 1037 (13.9%) discontinued 5-ASA within 90 days of starting anti-TNF therapy. During a median 4.3-year follow-up, discontinuation of 5-ASA was not associated with an increased risk of adverse clinical events (adjusted hazard ratio 1.01, 95% confidence interval 0.93-1.10). The cumulative incidence of each adverse clinical event and the composite outcome were not significantly different between groups (all, p > 0.05). Additionally, separate analyses in CD and UC cohorts revealed no differences in adverse clinical outcomes between the 5-ASA continuation and discontinuation groups. Subgroup analyses by presumed risk factors for disease relapse showed no significant differences in the risk of adverse events between groups. CONCLUSIONS: In this nationwide population-based study, discontinuing 5-ASA after starting anti-TNF therapy was not associated with an increased risk of adverse events in patients with IBD.

Safety of Biologics and Small Molecules for Inflammatory Bowel Diseases in Organ Transplant Recipients.

PURPOSE: This study aimed to evaluate the safety of biologics and small molecules for the treatment of inflammatory bowel diseases (IBD) in patients receiving antirejection therapies after organ transplants. MATERIALS AND METHODS: We reviewed the medical records of patients with IBD who received organ transplants at the Asan Medical Center between January 1989 and December 2021. We compared the parameters of patients receiving biologics or small molecules to those of patients without those therapies. RESULTS: This study included a total of 53 patients (ulcerative colitis, 41; Crohn's disease, 6; and gastrointestinal Behçet's disease, 6). Among them, 15 patients were receiving biologics or small molecules and 38 were not. During a mean follow-up of 119 months, the proportion of patients experiencing severe infections was significantly higher in those treated with biologics or small molecules than in those not treated. However, other safety outcomes (e.g., malignancies, adverse events, including organizing pneumonia or hepatic failure, and death) were not different between the two groups. Kaplan-Meier curve analysis revealed no significant difference in the safety outcome rate related to the use of biologics or small molecules. During follow-up, eight patients underwent bowel resections for IBD. The rate of bowel resection was not different between the two groups. CONCLUSION: The use of biologics or small molecules for patients with IBD who received organ transplants did not show a significant difference in safety outcomes. However, the possibility of severe infections must be considered.

Clinical characteristics and long-term disease course in patients with Crohn's disease as diagnosed by video capsule endoscopy: a multicenter retrospective matched case-control study.

Background/Aims: Video capsule endoscopy is rarely used to diagnose Crohn's disease in patients with negative ileocolonoscopy or cross-sectional image findings. We evaluated clinical characteristics and long-term outcomes of these rare cases. Methods: This multicenter study included patients with Crohn's disease from 3 tertiary hospitals from January 2007 to October 2022. Patients with normal findings on ileocolonoscopy and computed tomography (CT)/magnetic resonance (MR) enterography but had ulcerations at the small bowel detected by video capsule endoscopy were included. The controls were patients with abnormal findings on endoscopy or CT/MR enterography. Controls were case-matched in a ratio of 3:1 for sex, calendar year of diagnosis, and age at diagnosis. Results: Among 3,752 patients, 24 (0.6%) were diagnosed with Crohn's disease using video capsule endoscopy findings. The disease location (P< 0.001) and behavior at diagnosis (P= 0.013) of the cases significantly differed from that of controls. The perianal fistula modifier (25.0% vs. 33.3%, P= 0.446) did not differ significantly between the 2 groups. Initial disease activity and C-reactive protein and fecal calprotectin levels were significantly lower in cases versus controls. The median Lewis score was 838 (interquartile range, 393-1,803). Over 10 years of follow-up, the cases showed significantly lower cumulative risk of complicated behavior, biologics use, Crohn's disease-related hospitalization, and surgeries (log-rank test P< 0.05). Conclusions: Patients with Crohn's disease whose lesions were observed only by video capsule endoscopy were rare, and exhibit different clinical characteristics and a more favorable long-term disease course compared to those who were conventionally diagnosed.