Publications by authors named "Yasutsugu Shimohara"

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.

View Article and Find Full Text PDF

Objectives: A single-balloon overtube (SBO) can improve poor scope operability during colonic endoscopic submucosal dissection (ESD). We aimed to evaluate the clinical usefulness of SBO for ESD in the proximal colon and the predictive factors for cases in which SBO is useful.

Methods: A total of 88 tumors located in the proximal colon resected by balloon-assisted ESD (BA-ESD) using SBO and 461 tumors resected by conventional ESD (C-ESD) between June 2015 and November 2020 were considered.

View Article and Find Full Text PDF

Objectives: There are some endoscopic resection (ER) methods for neuroendocrine tumors (NETs), however, which method is most useful remains unclear. This study aimed to compare the outcomes of different ER techniques, such as conventional endoscopic mucosal resection (cEMR), endoscopic submucosal dissection (ESD), and endoscopic submucosal resection with a ligation device (ESMR-L) for rectal NETs.

Methods: We retrospectively analyzed 96 consecutive patients with 102 rectal NETs of less than 10 mm in diameter who underwent ER between January 2001 and December 2019 at Hiroshima University Hospital.

View Article and Find Full Text PDF

Background: Serrated polyposis syndrome (SPS), a type of colorectal polyposis characterized by multiple serrated polyps, is associated with a high risk of colorectal carcinoma (CRC). This study aimed to clarify the clinicopathological characteristics of SPS in Japan.

Methods: We investigated the clinicopathological characteristics of patients with SPS from the "Multicenter Study on Clinicopathological Characteristics of SPS (UMIN 000032138)" by the Colorectal Serrated Polyposis Syndrome (SPS) Study Group.

View Article and Find Full Text PDF

Background: Vertical tumor margin-negative T1 colorectal carcinoma (CRC) is an absolute curative condition following complete endoscopic resection (ER). However, the influence on prognosis in relation to vertical tumor margin is unclear. Therefore, we evaluated the influence of the distance from vertical tumor margin to resected specimen edge (vertical margin distance) of ER for T1b (submucosal invasion depth > 1000 μm) CRC on the prognosis of patients undergoing additional surgery after ER.

View Article and Find Full Text PDF

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.

View Article and Find Full Text PDF
Article Synopsis
  • A computer-aided diagnosis (CADx) system was developed to help identify colorectal lesions using two classification methods: the NICE and JNET systems.
  • The CADx systems were trained on NBI (narrow band imaging) images, achieving high accuracy rates of around 97% for the NICE classification and varied but generally strong performance for the JNET classification.
  • The results suggest that these CADx systems can assist non-expert endoscopists in accurately diagnosing colorectal lesions, thereby improving diagnostic consistency and education.
View Article and Find Full Text PDF

Background: In Japan, endoscopic submucosal dissection (ESD) is standardized for large colorectal tumors. However, its validity in the elderly population is unclear. We aimed to evaluate the safety and efficacy of ESD for colorectal tumors in elderly patients aged over 80 years.

View Article and Find Full Text PDF

Background: An educational and training program is required for generalization of Japan NBI Expert Team (JNET) classification. However, there is no detailed report on the learning curve of the diagnostic accuracy of endoscopists using JNET classification. We examined the effect of an educational lecture on beginners and less experienced endoscopists for improving their diagnostic accuracy of colorectal lesions by JNET classification.

View Article and Find Full Text PDF
Article Synopsis
  • Some colorectal cancers (CRCs) can be missed during colonoscopies, prompting a study to explore the characteristics of these post-colonoscopy CRCs (PCCRCs).
  • Researchers analyzed data from 1,619 patients, narrowing down to 32 patients with 34 PCCRCs, focusing on their pathological features and genomic alterations.
  • The findings revealed that many PCCRCs are invasive cancers, particularly in the proximal colon, with notable genetic mutations and deficiencies in mismatch repair proteins associated with poorer prognoses.
View Article and Find Full Text PDF