Characteristics and prognosis of sporadic neoplasias detected in patients with ulcerative colitis.

INTRODUCTION: Patients with ulcerative colitis (UC) develop not only UC-associated neoplasias but also sporadic neoplasias (SNs). However, few studies have described the characteristics of SNs in patients with UC. Therefore, this study aimed to evaluate the clinical features and prognosis of SNs in patients with UC. METHODS: A total of 141 SNs in 59 patients with UC, detected by surveillance colonoscopy at Hiroshima University Hospital between January 1999 and December 2021, were included. SNs were diagnosed based on their location, endoscopic features, and histopathological findings along with immunohistochemical staining for Ki67 and p53. RESULTS: Of the SNs, 91.5% were diagnosed as adenoma and 8.5% were diagnosed as carcinoma (Tis carcinoma, 3.5%; T1 carcinoma, 5.0%). Most lesions (61.0%) were located in the right colon, 31.2% were located in the left colon, and 7.8% were located in the rectum. When classified based on site of lesion, 70.9% of SNs occurred outside and 29.1% within the affected area. Of all SNs included, 95.7% were endoscopically resected and 4.3% were surgically resected. Among the 59 patients included, synchronous SNs occurred in 23.7% and metachronous multiple SNs occurred in 40.7% during surveillance. The 5-year cumulative incidence of metachronous multiple SNs was higher in patients with synchronous multiple SNs (54.2%) than in those without synchronous multiple SNs (46.4%). CONCLUSION: Patients with UC with synchronous multiple SNs are at a higher risk of developing metachronous multiple SNs and may require closer follow-up by total colonoscopy than patients without synchronous SNs.

Usefulness and Educational Benefit of a Virtual Scale Endoscope in Measuring Colorectal Polyp Size.

INTRODUCTION: The virtual scale endoscope (VSE) is a newly introduced endoscope that helps endoscopists in measuring colorectal polyp size (CPS) during colonoscopy by displaying a virtual scale. This study aimed to determine the usefulness of the VSE for CPS measurement and the educational benefit of using VSE images to improve CPS estimation accuracy. METHODS: This study included 42 colorectal polyps in 26 patients treated at Hiroshima University Hospital. In study 1, CPS measured using a VSE before endoscopic mucosal resection was compared with CPS measured on resected specimens, and the agreement between the two measurement methods was evaluated via Bland-Altman analysis. In study 2, 14 endoscopists (5 beginners, 5 intermediates, and 4 experts) took a pre-test to determine the size of 42 polyps. After the pre-test, a lecture on CPS measurement using VSE images was given. One month later, the endoscopists took a post-test to compare CPS accuracy before and after the lecture. RESULTS: In study 1, Bland-Altman analysis revealed no fixed or proportional errors. The mean bias ±95% limits of agreement (±1.96 standard deviations) of the measurement error was -0.05 ± 0.21 mm, indicating that the agreement between two measurement methods was sufficient. In study 2, the accuracy of CPS measurement was significantly higher among beginners (59.5% vs. 26.7%, p < 0.01) and intermediates (65.2% vs. 44.3%, p < 0.05) in the post-test than in the pre-test. CONCLUSION: The VSE accurately measures CPS before resection, and its images are useful teaching tools for beginner and intermediate endoscopists.

Comparison of clinical utility of deep learning-based systems for small-bowel capsule endoscopy reading.

BACKGROUND AND AIM: Convolutional neural network (CNN) systems that automatically detect abnormalities from small-bowel capsule endoscopy (SBCE) images are still experimental, and no studies have directly compared the clinical usefulness of different systems. We compared endoscopist readings using an existing and a novel CNN system in a real-world SBCE setting. METHODS: Thirty-six complete SBCE videos, including 43 abnormal lesions (18 mucosal breaks, 8 angioectasia, and 17 protruding lesions), were retrospectively prepared. Three reading processes were compared: (A) endoscopist readings without CNN screening, (B) endoscopist readings after an existing CNN screening, and (C) endoscopist readings after a novel CNN screening. RESULTS: The mean number of small-bowel images was 14 747 per patient. Among these images, existing and novel CNN systems automatically captured 24.3% and 9.4% of the images, respectively. In this process, both systems extracted all 43 abnormal lesions. Next, we focused on the clinical usefulness. The detection rates of abnormalities by trainee endoscopists were not significantly different across the three processes: A, 77%; B, 67%; and C, 79%. The mean reading time of the trainees was the shortest during process C (10.1 min per patient), followed by processes B (23.1 min per patient) and A (33.6 min per patient). The mean psychological stress score while reading videos (scale, 1-5) was the lowest in process C (1.8) but was not significantly different between processes B (2.8) and A (3.2). CONCLUSIONS: Our novel CNN system significantly reduced endoscopist reading time and psychological stress while maintaining the detectability of abnormalities. CNN performance directly affects clinical utility and should be carefully assessed.

Hybrid endoscopic submucosal dissection as a salvage option for difficult colorectal conventional endoscopic submucosal dissection.

BACKGROUND: When total submucosal dissection is difficult to achieve during conventional colorectal endoscopic submucosal dissection (C-ESD), the lesion can be resected by final snaring through salvage hybrid ESD (SH-ESD). This study aimed to examine the outcomes of SH-ESD and identify its indications that could achieve en bloc resection. METHODS: We recruited 1039 consecutive patients with colorectal lesions that underwent ESD at Hiroshima University Hospital between January 2015 and December 2020. C-ESD was attempted thoroughly in 924 lesions (C-ESD group, including 9 lesions in which ESD was discontinued), and SH-ESD was performed owing to some difficulties in 115 lesions (SH-ESD group). Risk factors for incomplete resection by SH-ESD and ESD discontinuation were evaluated using multivariate analysis. The outcomes were compared between cases with remaining undissected submucosa of < 20 mm in diameter in the SH-ESD and C-ESD groups, using propensity score matching. RESULTS: Multivariate analysis revealed that a procedure time > 80 min and remaining undissected submucosa ≥ 20 mm in diameter were significant risk factors for incomplete resection after SH-ESD and ESD discontinuation. By propensity score matching analysis, procedure time was significantly shorter in the SH-ESD group with remaining undissected submucosa < 20 mm in diameter than in the C-ESD group (71 min vs. 90 min, p = 0.0053), although no significant difference was found in the en bloc resection rate (94% vs. 87%, p = 0.0914). CONCLUSION: SH-ESD can be an alternative surgical method when conventional ESD is difficult to continue in cases in which the remaining undissected submucosa is < 20 mm in diameter.

Novel endoscopic ultrasonography classification for assured vertical resection margin (≥500 µm) in colorectal endoscopic submucosal dissection.

BACKGROUND AND AIM: The risk of local recurrence might be low in pT1 colorectal carcinoma with a tumor vertical margin (VM) ≥500 µm. We investigated the relationship between endoscopic ultrasonography (EUS) findings and VM in cases with colorectal endoscopic submucosal dissection (ESD) categorized as Type 2B according to the Japan NBI Expert Team (JNET) classification. METHODS: We analyzed 179 JNET Type 2B colorectal tumors resected by ESD at Hiroshima University Hospital from January 2010 to May 2021. The distance from the tumor invasive front to the muscle layer on EUS was defined as the tumor-free distance (EUS-TFD) and classified as Type I (EUS-TFD ≥1 mm) and II (<1 mm). We investigated the relationship between EUS-TFD and VM and analyzed the predictive factors for VM ≥500 µm. RESULTS: EUS-TFD Type I was diagnosed in 133 (74.3%) lesions: VM ≥500 µm (114, 85.7%); VM <500 µm (19, 14.3%); and VM positive (VM1) (0, 0%). Type II was diagnosed in 46 (25.7%) lesions: VM ≥500 µm (14, 30.5%); VM <500 µm (22, 47.8%); and VM1 (10, 21.7%). In the EUS-TFD Type I cases, 84.5% and 87.8% were protruded and superficial types; whereas for Type II cases, these were 38.9% and 25%, respectively. EUS-TFD classification (Type I), scope operability (good), submucosal invasion depth (<2000 µm), histology at the deepest invasive portion (favorable), and degree of fibrosis (F0/F1) were significant predictors of VM ≥500 µm. CONCLUSIONS: In JNET Type 2B lesions, EUS-TFD classification is a novel diagnostic indicator to predict VM ≥500 µm in ESD preoperatively.

Risk of Bleeding after Colorectal Endoscopic Resection in Patients with Continued Warfarin Use Compared to Heparin Replacement: A Propensity Score Matching Analysis.

The Japan Gastroenterological Endoscopy Society (JGES) guidelines recommend continued warfarin treatment during gastroenterological endoscopic procedures with a high risk of bleeding as an alternative to heparin replacement in patients on warfarin therapy. However, there is insufficient evidence to support the use of warfarin in colorectal endoscopic resection (ER). The present study is aimed at verifying the risk of bleeding after ER for colorectal neoplasia (CRN) in patients with continued warfarin use. This was a single-center retrospective cohort study using clinical records. We assessed 126 consecutive patients with 159 CRNs who underwent ER (endoscopic mucosal resection, 146 cases; endoscopic submucosal dissection, 13 cases) at Hiroshima University Hospital between January 2014 and December 2019. Patients were divided into two groups: the heparin replacement group (79 patients with 79 CRNs) and the continued warfarin group (47 patients with 80 CRNs). One-to-one propensity score matching was performed to compare the bleeding rate after ER between the groups. The rate of bleeding after ER was significantly higher in the heparin replacement group than in the continued warfarin group for both before (10.1% vs. 1.3%, respectively; P = 0.0178) and after (11.9% vs. 0%, respectively; P = 0.0211) propensity score matching. None of the patients experienced thromboembolic events during the perioperative period. The risk of bleeding after colorectal ER was significantly lower in patients with continued warfarin use than in those with heparin replacement. Our data supports the recommendations of the latest JGES guidelines for patients receiving warfarin therapy.