Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
61
result(s) for
"Dobashi, Akira"
Sort by:
Multi-loop traction device facilitates gastric endoscopic submucosal dissection: ex vivo pilot study and an inaugural clinical experience
by
Futakuchi, Toshiki
,
Kamba, Shunsuke
,
Sumiyama, Kazuki
in
Animals
,
Biopsy
,
Bowel and bladder training
2022
Background
Endoscopic submucosal dissection (ESD) is technically difficult and requires considerable training. The authors have developed a multi-loop traction device (MLTD), a new traction device that offers easy attachment and detachment. We aimed to evaluate the utility of MLTD in ESD.
Methods
This ex vivo pilot study was a prospective, block-randomized, comparative study of a porcine stomach model. Twenty-four lesions were assigned to a group that undertook ESD using the MLTD (M-ESD group) and a group that undertook conventional ESD (C-ESD group) to compare the speed of submucosal dissection. In addition, the data of consecutive 10 patients with eleven gastric lesions was collected using electronic medical records to clarify the inaugural clinical outcomes of gastric ESD using MLTD.
Results
The median (interquartile range) speed of submucosal dissection in the M-ESD and C-ESD groups were 141.5 (60.9–177.6) mm2/min and 35.5 (20.8–52.3) mm2/min, respectively; submucosal dissection was significantly faster in the M-ESD group (p < 0.05). The rate of en bloc resection and R0 resection was 100% in both groups, and there were no perforation in either group. The MLTD attachment time was 2.5 ± 0.9 min and the MLTD extraction time was 1.0 ± 1.1 min. Clinical outcomes of MLTD in gastric ESD were almost the same as those of ex vivo pilot study.
Conclusions
MLTD increased the speed of submucosal dissection in ESD and was similarly effective when used by expert and trainee endoscopists without perforation. MLTD can potentially ensure a safer and faster ESD.
Journal Article
Endoscopic Submucosal Dissection Facilitating Techniques Among Non-experts: A Systematic Literature Review
2023
Background and AimsThe dissemination of endoscopic submucosal dissection (ESD) has been limited by its technical complexity and safety profile, particularly among non-experts. Various techniques and devices have facilitated the performance of ESD, but their yield and role in the path to learning ESD remain unclear.MethodsWe performed a systematic review by querying MEDLINE, EMBASE, Web of Science, and Japan Medical Abstracts Society specifically for comparative studies investigating the impact of assigned ESD techniques vs. conventional techniques among non-experts in ESD (< 50 ESD procedures). Procedural outcomes of efficacy, efficiency, and safety were assessed.ResultsWe identified 46 studies evaluating 54 cohorts in which a total 237 non-experts performed 2461 ESDs conventionally, and 1953 ESDs using an assigned ESD technique (knives, countertraction, miscellaneous techniques). The majority of studies were from East Asia (67%), single-center (96%), observational in design (61%), in an animal model (57%), and gastric location (63%). The most studied techniques were countertraction techniques (48% cohorts) and scissor knives (15% cohorts), both of which commonly enhanced efficiency of ESD, and less so efficacy or safety. Techniques found to be beneficial in experts were more likely to be beneficial in non-experts (70% concordance) than vice versa (47% concordance).ConclusionBased on the currently available literature, countertraction techniques and scissor knives should be considered for early incorporation into ESD training by non-experts. Several aspects of ESD training remain understudied, including techniques in Western non-experts, educational resources, and several commonly cited techniques. These areas should guide future investigation to enhance the pathway to learning ESD.
Journal Article
Magnet-assist endoscopic augmentation of the lower esophageal sphincter for treatment of gastroesophageal reflux disease: cadaveric and survival studies in a porcine model (with video)
by
Rajan, Elizabeth
,
Miller, Charles A
,
Dobashi Akira
in
Endoscopy
,
Esophagus
,
Gastroesophageal reflux
2021
BackgroundAugmentation of the lower esophageal sphincter (LES) is the primary goal of both surgical and endoscopic therapies for gastroesophageal reflux disease (GERD). The feasibility, efficacy, safety, and reversibility of a newly developed endotherapy for GERD using intraluminal magnets referred to as a magnet closure device (MCD) were evaluated.MethodsThis study involved nine cadaveric and six survival pigs. The MCD consisted of a ring neodymium magnet attached to a 2–0 polypropylene suture and suture anchor. The MCD was deployed onto the esophageal wall at the region of the LES using an endoscopic suturing device. Two to three MCDs were placed on opposing walls to induce closure of the esophageal lumen. LES pressures were measured using high-resolution manometry at the index procedure (baseline and immediately post-MCD placement) and at survival endoscopy. Endoscopic removal of the devices was performed followed by necropsy at week 2.ResultsMCDs were successfully deployed in all cadaveric (n = 22) and survival animals (n = 12). In cadavers, 20/22 (91%) sutures were full-thickness with no adjacent organ injury. In survival animals, mean LES pressure increased from 8.4 mmHg (baseline) to 32.4 mmHg immediately post-procedure (p < 0.01). No clinically significant adverse events occurred. Repeat endoscopy at two weeks showed intact MCDs in 4/6 (67%) animals with significant increase in median LES pressure (n = 4, 24.0 mmHg versus 7.4 mmHg [baseline], p < 0.05). Endoscopic removal of MCDs was successfully achieved.ConclusionsEndoscopic augmentation of the LES using a new MCD was feasible, safe and reversible with significantly increased LES pressures recorded. Future studies are needed to enhance durability. These preliminary results on a reversible technique are promising and may represent an attractive alternative to endoluminal GERD therapy.
Journal Article
Blood group O is a risk factor for delayed post-polypectomy bleeding
by
Ohya, Tomohiko R
,
Dobashi Akira
,
Koizumi Akio
in
Blood groups
,
Colorectal cancer
,
Confidence intervals
2021
BackgroundBlood group O of ABO blood group system is considered as a risk factor for various bleeding events, but the relationship with endoscopic treatment-associated bleeding has yet to be investigated. This study aimed to evaluate whether blood group O is associated with delayed bleeding after colorectal endoscopic resection.MethodsThis was a retrospective observational study based on medical records at four university hospitals in Japan. We reviewed the records for consecutive patients who underwent colorectal endoscopic resection from January 2014 through December 2017. The primary outcome was the incidence of delayed bleeding, defined as hematochezia or melena, requiring endoscopy, transfusion, or any hemostatic intervention up to 28 days after endoscopic resection. Multivariate logistic regression analysis was performed to adjust the impact of blood group O on the delayed bleeding.ResultsAmong 10,253 consecutive patients who underwent colorectal endoscopic resection during the study period, 8625 patients met the criteria. In total, delayed bleeding occurred in 255 patients (2.96%). The O group had significantly more bleeding events compared with the non-O group (A, B, and AB) (relative risk, 1.62 [95% confidence interval, 1.24–2.10]; P < 0.001). In multivariate logistic regression analysis, blood group O remained an independent risk factor for the bleeding (adjusted odds ratio, 1.60 [95% confidence interval, 1.18–2.17]; P = 0.002).ConclusionsBlood group O was associated with an increased risk of delayed bleeding in patients undergoing colorectal endoscopic resection. Preoperative screening for ABO blood group could improve risk assessments.
Journal Article
Clinicopathological characteristics of duodenal epithelial neoplasms: Focus on tumors with a gastric mucin phenotype (pyloric gland-type tumors)
by
Hirooka, Shinichi
,
Mitsuishi, Takehiro
,
Saruta, Masayuki
in
Adenocarcinoma, Mucinous - metabolism
,
Adenocarcinoma, Mucinous - pathology
,
Adenoma - metabolism
2017
Epithelial tumors less commonly occur in the duodenum than in the stomach or large intestine. The clinicopathological characteristics of duodenal epithelial tumors remain a matter of debate. We therefore studied resected specimens to investigate the clinicopathological characteristics of duodenal epithelial tumors.
Among duodenal epithelial tumors resected endoscopically or surgically in our hospital, we studied the clinicopathological characteristics of 110 adenomas or intramucosal carcinomas. The grade of atypia of all tumors was classified into 3 groups according to the World Health Organization (WHO) 2010 classification. The tumors were immunohistochemically evaluated to determine the frequency of differentiation toward fundic glands.
As for patient characteristics, there were 76 men (75.2%) and 25 women (24.8%), with a median age of 65 years (range, 34 to 84). The tumors most commonly arose in the first to second part of the duodenum. Many lesions were flat, and the median tumor diameter was 8.0 mm. The lesions were classified into 2 types according to mucin phenotype: intestinal-type tumors (98 lesions, 89.1%) and gastric-type tumors (12 lesions, 10.9%). Intestinal-type tumors were subdivided into 2 groups: tubular-type tumors (91 lesions, 82.7%) and tubulovillous-type tumors (7 lesions, 6.4%). Gastric-type tumors were classified into 2 types: foveolar type (3 lesions, 2.7%) and pyloric gland-type (PG) tumors (9 lesions, 8.2%). The grade of atypia was significantly higher in gastric-type tumors (p<0.01). PG tumors were gastric-type tumors characterized by pyloric glands and findings suggesting differentiation toward fundic glands.
About 10% of the duodenal tumors had a gastric-type mucin phenotype. Gastric-type tumors showed high-grade atypia. In particular, PG tumors showed similarities to PG tumors of the stomach, such as differentiation toward fundic glands.
Journal Article
Visibility evaluation of colorectal lesion using texture and color enhancement imaging with video
2022
Objective To evaluate the visibility of colorectal lesions using a novel image processing algorithm, texture and color enhancement imaging (TXI), that allows the acquisition of brighter images with enhanced color and surface structure. Methods During August–September 2019, patients referred for endoscopic treatment were prospectively recruited. Electronic data acquired while observing colorectal lesions using white light imaging (WLI) were obtained and recorded: WLI, TXI mode1 (with color enhancement), and TXI mode2 (without color enhancement) videos were constructed. The lesions were also recorded using narrow‐band imaging (NBI) from the same perspective as WLI. Four video clips (WLI, TXI mode1, TXI mode2, and NBI) were made per lesion. Thereafter, video files for evaluations were prepared by randomly arranging all video clips. Finally, visualization scores were evaluated by four endoscopists, and the WLI, TXI mode1, TXI mode2, and NBI results were compared. Results Overall, 22 patients with 68 lesions were recruited; the video file for evaluation subsequently comprised 272 randomly arranged video clips. Mean visualization scores using WLI, TXI mode1, TXI mode2, and NBI were 70.0 (±20.1), 80.5 (±18.6), 75.6 (±18.1), and 69.0 (±20.6), respectively. Mean visualization scores for flat lesions using WLI, TXI mode1, TXI mode2, and NBI were 64.1 (±21.2), 76.5 (±20.18), 71.8 (±19.4), and 64.2 (±22.0), respectively. Visualization scores using TXI mode1 were significantly better than those using WLI, TXI mode2, or NBI. Conclusions TXI enables improved visualization of colorectal lesions, even flat lesions, than WLI and NBI. TXI may allow better detection of colorectal lesions, although further prospective studies are required.
Journal Article
Detection of multiple signet ring cell carcinomas using texture and color enhancement imaging led to a diagnosis of hereditary diffuse gastric cancer
2025
Hereditary diffuse gastric cancer (HDGC) is an autosomal dominant cancer caused by CDH1 mutation. HDGC causes multiple signet ring cell carcinomas (SRCCs) throughout the stomach. Few reports exist on the endoscopic findings during screening endoscopy, leading to the diagnosis of HDGC in its early stages. Recently, a new image‐enhancement endoscopy technique, texture and color enhancement imaging (TXI), has been developed to improve the visibility of early gastric cancer. To the best of our knowledge, the use of TXI leading to HDGC diagnosis has not been reported. In this report, TXI contributed to the diagnosis of HDGC, and the patient was treated with total gastrectomy. A 27‐year‐old woman with a family history of gastric cancer underwent esophagogastroduodenoscopy, which revealed two pale lesions in the lower body of the stomach. Histological examination of the biopsy specimen revealed SRCC and the patient was referred to our hospital for treatment. Multiple lesions were found in the lower body using TXI, and a targeted biopsy confirmed other SRCCs. We suspected her disease to be HDGC, and the patient underwent a total gastrectomy. Histopathology showed multiple SRCCs (>60), but no lymph node metastases. Genetic testing revealed CDH1 mutations. The final pathological stage of the tumor was pT1a(m) N0M0 Stage I. TXI may be helpful in detecting multiple SRCCs in patients with HDGC. Endoscopists should be aware of HDGC, and careful investigation of the entire stomach is required for patients with diffuse‐type gastric cancer before treatment.
Journal Article
Texture and color enhancement imaging improves the visibility of gastric neoplasms: clinical trial with image catalogue assessment using conventional and newly developed endoscopes
2023
Background
Texture and color enhancement imaging (TXI) enhances the changes in endoscopic features caused by gastric neoplasms, such as redness/whiteness and elevation/depression. This study aimed to demonstrate the effectiveness of TXI in improving the visibility of gastric neoplasms compared with white light imaging (WLI) using conventional (CE) and newly developed endoscopes (NE).
Methods
We recruited patients who were histologically diagnosed with gastric neoplasms; endoscopy was performed, and gastric neoplasms photographed using three imaging modalities, including WLI, TXI mode 1 (TXI-1) and TXI mode 2 (TXI-2). Two different endoscopes (CE and NE) were used for the same patients. Six endoscopists provided the visibility scale scores ranging from 1 (poor) to 4 (excellent) for gastric neoplasms. The primary outcome was the visibility scale scores based on each modality and endoscope. The secondary outcome was the identification of factors including
H. pylori
infection, atrophy, location, size, morphology, histological diagnosis and intestinal metaplasia that affect the differences in visibility scale scores between TXI-1/TXI-2 and WLI.
Results
Fifty-two gastric neoplasms were analyzed. The mean visibility scale scores with the NE were 2.79 ± 1.07, 3.23 ± 0.96 and 3.14 ± 0.92 for WLI, TXI-1 and TXI-2, respectively. The mean visibility scales with the CE were 2.53 ± 1.10, 3.04 ± 1.05 and 2.96 ± 1.92 for WLI, TXI-1 and TXI-2, respectively. For both endoscopes, significant differences were observed in visibility scale scores between WLI and TXI-1 (
p
< 0.001) and between WLI and TXI-2 (
p
< 0.001). The visibility scale scores of NE were superior to those of CE in all modalities. In the secondary outcome, there was no factor affected the differences of visibility scale scores between TXI-1/TXI-2 and WLI.
Conclusions
This study demonstrated that TXI-1 and TXI-2 enhanced the visibility scale scores of gastric neoplasms compared with that of WLI. Moreover, newly developed endoscope has the potential to improve visibility compared to conventional endoscope.
Trial Registration
This study was registered with the University Hospital Medical Information Network (UMIN000042429, 16/11/2020).
Journal Article
The competency of the novel through‐the‐scope suture device for gastric mucosal defects: In vivo study in a porcine model (with video)
by
Futakuchi, Toshiki
,
Tominaga, Takanori
,
Ito, Mamoru
in
Catheters
,
Defects
,
endoscopic closure
2025
Objectives Endoscopic closures of mucosal defects following endoscopic resection can be challenging and time‐consuming. The novel through‐the‐scope suture device has demonstrated acceptable closure times, but its learning curve is still unknown. This study aims to evaluate the number of cases required to achieve competency in this device. Methods Two endoscopists participated; a novice with less than 400 experiences in upper gastrointestinal endoscopy and an expert with over 500 experiences in endoscopic submucosal dissection. Neither endoscopist had previous exposure to the device. In four porcine models, 24 gastric mucosal defects, each 2–4 cm in diameter, were created by endoscopic mucosal resection with ligation. Each endoscopist performed endoscopic closure for 12 mucosal defects with a single through‐the‐scope suture device per lesion. The primary endpoint was the number of cases needed to reach competency, defined as achieving a procedure time below the average closure time reported in the literature. Secondary endpoints included procedure time, complete closure success rates, and incidence of adverse events. Results The mean defect size was 2.9 (±0.2) cm. Competency was achieved after six cases in the expert and seven cases in the novice. The median closure time was 9.0 (interquartile range [IQR]: 6.0–11.0) min for the expert and 8.0 (IQR: 6.2–9.7) min for the novice (p = 0.862). Complete closure success rates were 75.0% (n = 9) for the expert and 83.3% (n = 10) for the novice. No adverse events were reported. Conclusions A small number of cases were required for both expert and novice endoscopists to reach competency in the novel through‐the‐scope suture device.
Journal Article
Image assessment of Barrett’s esophagus using the simplified narrow band imaging classification
by
Takahashi, Masakazu
,
Kato, Mototsugu
,
Kato, Masayuki
in
Abdominal Surgery
,
Adenocarcinoma - diagnostic imaging
,
Adenocarcinoma - pathology
2017
Background
A simplified narrow band imaging (NBI) classification has been proposed with the objective of integrating multiple classifications of NBI surface patterns in Barrett’s esophagus (BE). Little is known about the impact of the simplified NBI classification on the diagnosis of BE when using high-definition magnification endoscopy with NBI (HM-NBI). This study aimed to evaluate (a) the reproducibility of NBI surface patterns and predicted histology and (b) the diagnostic accuracy of interpreting HM-NBI images by using the simplified NBI classification.
Methods
Two hundred and forty-eight HM-NBI images from macroscopically normal areas in patients with BE were retrieved from endoscopy databases and randomized for review by four endoscopists (two experts, two non-experts). We evaluated inter- and intra-observer agreement of the interpretation of NBI surface patterns and the predicted histology (dysplasia vs. non-dysplasia), as calculated by using
κ
statistics, and diagnostic values of the prediction.
Results
The overall inter-observer agreements were substantial for mucosal pattern (
κ
= 0.73) and vascular pattern (
κ
= 0.71), and almost perfect for predicting dysplastic histology (
κ
= 0.80). The overall intra-observer agreements were almost perfect for mucosal (
κ
= 0.84) and vascular patterns (
κ
= 0.86), and predicting dysplastic histology (
κ
= 0.89). The mean accuracy in predicting dysplastic histology for all reviewers was 95 % (experts: 96.8 %, non-experts: 93.1 %).
Conclusions
The simplified NBI classification has the potential to provide high diagnostic reproducibility and accuracy when using HM-NBI.
Journal Article