An Analysis of Delayed Bleeding in Cases of Colorectal Endoscopic Submucosal Dissection Due to Types of Direct Oral Anticoagulants in Japan.

BACKGROUND & AIMS: Reported rates of delayed bleeding (DB) after endoscopic resection using direct oral anticoagulants (DOACs) are high and heterogeneous. This large-scale multicenter study analyzed cases of DB after colorectal endoscopic submucosal dissection related to various types of DOACs in Japan (the ABCD-J study) with those associated with warfarin. METHODS: We retrospectively reviewed 1019 lesions in patients treated with DOACs and 459 lesions in patients treated with warfarin among 34,455 endoscopic submucosal dissection cases from 47 Japanese institutions between 2012 and 2021. The DB rate (DBR) with each DOAC was compared with that with warfarin. Risk factors for DB in patients treated with DOACs or warfarin were also investigated. RESULTS: The mean tumor sizes in the DOAC and warfarin groups were 29.6 ± 14.0 and 30.3 ± 16.4 mm, respectively. In the DOAC group, the DBR with dabigatran (18.26%) was significantly higher than that with apixaban (10.08%, P = .029), edoxaban (7.73%, P = .001), and rivaroxaban (7.21%, P < .001). Only rivaroxaban showed a significantly lower DBR than warfarin (11.76%, P = .033). In the multivariate analysis, heparin bridging therapy (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.27-3.73, P = .005), rectal location (2.01, 1.28-3.16, P = .002), and procedure time ≥55 minutes (2.43, 1.49-3.95, P < .001) were significant risk factors for DB in the DOAC group. The DB risk in the DOAC group (OR, (95% CI)) was 2.13 (1.30-3.50) and 4.53 (2.52-8.15) for 1 and 2 significant risk factors, respectively. CONCLUSIONS: Dabigatran was associated with a higher DBR than other DOACs, and only rivaroxaban was associated with a significantly lower DBR than warfarin.

Comparison of the efficacy and tolerability of elobixibat plus sodium picosulfate with magnesium citrate and split-dose 2-L polyethylene glycol with ascorbic acid for bowel preparation before outpatient colonoscopy: a study protocol for the multicentre, randomised, controlled E-PLUS trial.

BACKGROUND: Sodium picosulfate (SP)/magnesium citrate (MC) and polyethylene glycol (PEG) plus ascorbic acid are recommended by Western guidelines as laxative solutions for bowel preparation. Clinically, SP/MC has a slower post-dose defaecation response than PEG and is perceived as less cleansing; therefore, it is not currently used for major bowel cancer screening preparation. The standard formulation for bowel preparation is PEG; however, a large dose is required, and it has a distinctive flavour that is considered unpleasant. SP/MC requires a small dose and ensures fluid intake because it is administered in another beverage. Therefore, clinical trials have shown that SP/MC is superior to PEG in terms of acceptability. We aim to compare the novel bowel cleansing method (test group) comprising SP/MC with elobixibat hydrate and the standard bowel cleansing method comprising PEG plus ascorbic acid (standard group) for patients preparing for outpatient colonoscopy. METHODS: This phase III, multicentre, single-blind, noninferiority, randomised, controlled, trial has not yet been completed. Patients aged 40-69 years will be included as participants. Patients with a history of abdominal or pelvic surgery, constipation, inflammatory bowel disease, or severe organ dysfunction will be excluded. The target number of research participants is 540 (standard group, 270 cases; test group, 270 cases). The primary endpoint is the degree of bowel cleansing (Boston Bowel Preparation Scale [BBPS] score ≥ 6). The secondary endpoints are patient acceptability, adverse events, polyp/adenoma detection rate, number of polyps/adenomas detected, degree of bowel cleansing according to the BBPS (BBPS score ≥ 8), degree of bowel cleansing according to the Aronchik scale, and bowel cleansing time. DISCUSSION: This trial aims to develop a "patient-first" colon cleansing regimen without the risk of inadequate bowel preparation by using both elobixibat hydrate and SP/MC. TRIAL REGISTRATION: Japan Registry of Clinical Trials (jRCT; no. s041210067; 9 September 2021; https://jrct.niph.go.jp/ ), protocol version 1.5 (May 1, 2023).

Outcomes of repeated endoscopic submucosal dissection for superficial Esophageal squamous cell carcinoma on endoscopic resection scar.

BACKGROUND: Endoscopic submucosal dissection (ESD) can be performed for superficial esophageal cancer. However, performing ESD for superficial esophageal cancer on a previous endoscopic resection scar may be difficult. METHODS: We compared the outcomes between ESD for superficial esophageal cancers on previous endoscopic resection scar (group A) and that for naïve lesions (group B). The study included outcomes of ESD, cumulative incidence of local failure, and predictors of the occurrence of local failure in ESD patients with squamous cell carcinoma (SCC). The outcome variables evaluated were en bloc resection rates, procedure times, adverse events, and overall survival rates. RESULTS: Overall, 220 lesions were extracted (groups A and B: 23 and 197 lesions, respectively). In groups A and B, the complete resection rates were 60.9 and 92.9% (P < 0.001), and the mean procedure times were 79 and 68 min (P = 0.15), respectively. The perforation rates in groups A and B were 4.3 and 1% (P = 0.28). The 1-year cumulative local failure rates were 22 and 1% (P < 0.001), respectively. In the multivariate Cox proportional hazards analysis, superficial esophageal SCC on a previous endoscopic resection scar was a strong predictor of local failure (hazard ratio = 21.95 [3.99-120.80], P < 0.001). The 3-year overall survival rates in groups A and B were 95 and 93% (P = 0.99), respectively. CONCLUSIONS: Repeated ESD on scar is an option for treating superficial esophageal SCC with an acceptable rate of adverse events. Because of the low complete resection rate and high local failure compared with conventional ESD, strict endoscopic follow-up is required after repeated esophageal ESD.

Investigation of vertical margin involvement in endoscopic resection for T1 colorectal cancer.

OBJECTIVES: The resection of vertical margin-negative submucosally invasive colorectal cancer (CRC) relies on the pathological risk assessment of lymph node metastasis. However, no large-scale study has clarified the endoscopic resection (ER) outcome for submucosally invasive CRC, focusing on the vertical margin status. This retrospective study aimed to examine vertical margin involvement in ER for submucosally invasive CRC and explore the treatment consequences associated with vertical margin status. METHODS: We analyzed 395 submucosally invasive CRC cases in 389 patients who underwent ER at our hospital between 2008 and 2020. The presence of residual tumors and simultaneous lymph node metastasis in patients who underwent additional surgery was assessed and compared between the vertical incomplete ER and the vertical margin-negative groups. RESULTS: Among the patients, 270 were men, with a median age of 69 years. The vertical incomplete ER rate was 21.5%, with positive vertical margins and unclear vertical margins identified in 12.2% and 9.3% of the cases, respectively. Among 154 patients who underwent additional surgery after ER, the vertical incomplete ER group had a significantly higher residual tumor rate than the vertical margin-negative group (P = 0.001). The vertical incomplete ER group had a significantly higher lymph node metastasis rate than the vertical margin-negative group (P = 0.029). CONCLUSION: This study clarified the substantial risk of vertical incomplete ER in submucosally invasive CRC and revealed the high risk of residual tumor and lymph node metastasis in vertical incomplete ER for submucosal CRC.

Proportions and characteristics of interval cancer in annual fecal immunochemical test screening and postcolonoscopy colorectal cancer: Results from a Japanese multicenter prospective study using questionnaires, the C-DETECT study.

OBJECTIVES: There are several types of colorectal cancer (CRC) according to the detection methods and intervals, including interval CRC (iCRC) and postcolonoscopy CRC (PCCRC). We aimed to examine their proportions and characteristics. METHODS: We conducted a multicenter prospective study using questionnaires in Japan ("C-DETECT study"), in which differences in CRC characteristics according to detection methods and intervals were examined from consecutive adult patients. Because the annual fecal immunochemical test (FIT) was used in population-based screening, the annual FIT-iCRC was assessed. RESULTS: In total, 1241 CRC patients (1064 with invasive CRC) were included. Annual FIT-iCRC (a), 3-year PCCRC (b), and CRC detected within 1 year after a positive FIT with noncompliance to colonoscopy (c) accounted for 4.5%, 7.0%, and 3.9% of all CRCs, respectively, and for 3.9%, 5.4%, and 4.3% of invasive CRCs, respectively. The comparison among these (a, b, c) and other CRCs (d) demonstrated differences in the proportions of ≥T2 invasion ([a] 58.9%, [b] 44.8%, [c] 87.5%, [d] 73.0%), metastasis ([a] 33.9%, [b] 21.8%, [c] 54.2%, [d] 43.9%), right-sided CRC ([a] 42.9%, [b] 40.2%, [c] 18.8%, [d] 28.6%), and female sex ([a] 53.6%, [b] 49.4%, [c] 27.1%, [d] 41.6%). In metastatic CRC, (a) and (b) showed a higher proportions of BRAF mutations ([a] [b] 12.0%, [c] [d] 3.1%). CONCLUSIONS: Annual FIT-iCRC and 3-year PCCRC existed in nonnegligible proportions. They were characterized by higher proportions of right-sided tumors, female sex, and BRAF mutations. These findings suggest that annual FIT-iCRC and 3-year PCCRC may have biological features different from those of other CRCs.

Detection of colorectal adenomas with texture and color enhancement imaging: Multicenter observational study.

OBJECTIVES: We aimed to evaluate the efficacy of texture and color enhancement imaging (TXI), which allows the acquisition of brighter images with enhanced color and surface structure in colorectal polyp detection compared to white light imaging. METHODS: Patients who underwent colonoscopy with repeated ascending colon observation using TXI and white light imaging between August 2020 and January 2021 were identified in three institutions. The outcomes included the mean number of adenomas detected per procedure (MAP), adenoma detection rate (ADR), and ascending colonic adenoma miss rate (Ac-AMR). Logistic regression was used to determine the effects of the variables on the outcomes. RESULTS: We included 1043 lesions from 470 patients in the analysis. The MAP, ADR, flat polyp detection rate, and Ac-AMR in TXI and white light imaging were 1.5% (95% confidence interval 1.3-1.6%) vs. 1.0% (0.9-1.1%), 58.2% (51.7-64.6%) vs. 46.8% (40.2-53.4%), 66.2% (59.8-72.2%) vs. 49.8% (43.2-56.4%), and 17.9% (12.1-25.2%) vs. 28.2% (20.0-37.6%), respectively. TXI, age, withdrawal time, and endoscopy type were identified as significant factors affecting the MAP and the ADR using multivariate regression analysis. CONCLUSIONS: Our study indicates that TXI improve the detection of colorectal neoplastic lesions. However, prospective randomized trials are required to confirm these findings.

Prospective study on the risk of transmission due to droplets and aerosols during an endoscopic procedure and the usefulness of extraoral suction devices.

OBJECTIVES: Endoscopy poses a high risk of severe acute respiratory syndrome coronavirus 2 infection for medical personnel due to the dispersal of aerosols from the patient. We investigated the location and size of droplets generated during esophagogastroduodenoscopy (EGD) and endoscopic submucosal dissection (ESD), the contamination of the surrounding area before and after the procedures, and the effectiveness of using an extraoral suction device (Free arm arteo; TOKYO GIKEN, Inc., Tokyo, Japan). METHODS: Patients who consented to the study and underwent EGD or ESD between December 8, 2020, and April 15, 2021, at the National Cancer Center East Hospital were included. Adenosine triphosphate (ATP) hygiene monitoring tests and a particle counter were used for measurements. RESULTS: Assessments were performed on 22 EGD and 15 ESD cases. ATP hygiene monitoring tests showed significant elevations at three sites near the patient, and two sites 1.5 m away, for EGD, and at four sites near the patient and 1.5 m away for ESD. In both ESD and EGD, extraoral suction devices reduced the extent of the contamination. Particles <5 µm in size were generated during endoscopic procedures and dispersed from both the forceps hole and the patient's mouth. The extraoral suction device did not reduce the number of particles generated. CONCLUSIONS: During endoscopic procedures, cleaning the surrounding environment is important in addition to standard precautions the endoscopist and caregivers take. The use of extraoral suction devices can also potentially reduce contamination of the surrounding environment.

Short-term outcomes of endoscopic resection for colorectal neuroendocrine tumors: Japanese multicenter prospective C-NET STUDY.

OBJECTIVES: The incidence of colorectal neuroendocrine tumors (NETs) has increased with colorectal cancer screening programs and increased colonoscopies. The management of colorectal NETs has recently shifted from radical surgery to endoscopic resection. We aimed to evaluate the short-term outcomes of various methods of endoscopic resection for colorectal NETs. METHODS: Among those registered in the C-NET STUDY, patients with colorectal NETs who underwent endoscopic treatment as the initial therapy were included. Short-term outcomes, such as the en bloc resection rate and R0 resection (en bloc resection with tumor-free margin) rate, were analyzed based on treatment modalities. RESULTS: A total of 472 patients with 477 colorectal NETs received endoscopic treatment. Of these, 418 patients with 421 lesions who met the eligibility criteria were included in the analysis. The median age of the patients was 55 years, and 56.9% of them were men. The lower rectum was the most commonly affected site (88.6%), and lesions <10 mm accounted for 87% of the cases. Endoscopic submucosal resection with a ligation device (ESMR-L, 56.5%) was the most common method, followed by endoscopic submucosal dissection (ESD, 31.4%) and endoscopic mucosal resection using a cap (EMR-C, 8.5%). R0 resection rates <10 mm were 95.5%, 94.8%, and 94.3% for ESMR-L, ESD, and EMR-C, respectively. All 16 (3.8%) patients who developed treatment-related complications could be treated conservatively. Overall, 23 (5.5%) patients had incomplete resection without independent clinicopathological risk factors. CONCLUSION: ESMR-L, ESD, and EMR-C were equally effective and safe for colorectal NETs with a diameter <10 mm.

Usefulness of endoscopic ultrasound in predicting treatment efficacy of salvage endoscopic therapy for local failure after chemoradiotherapy for esophageal squamous cell carcinoma.

BACKGROUND: Salvage endoscopic therapy, including endoscopic resection (ER) and photodynamic therapy (PDT), is effective for esophageal squamous cell carcinoma (ESCC) in local failure after chemoradiotherapy (CRT). Resection with pathologically vertical margin-negative (VM0) for ER and local complete response (L-CR) for PDT are important surrogate prognostic markers for each therapy's efficacy. We aimed to evaluate the usefulness of endoscopic ultrasound (EUS) in predicting the efficacy of salvage endoscopic therapy in local failure after CRT for ESCC. METHODS: We included patients who underwent EUS followed by ER or PDT for local failure after CRT or radiotherapy for ESCC from 2006 to 2020. We evaluated EUS findings associated with VM0 resection for ER and L-CR for PDT, which included the status of the outermost part of the submucosal layer, tumor thickness, and tumor invasion length into the muscularis propria (MP) layer. RESULTS: Thirty and 47 patients were enrolled into the ER and PDT groups, respectively. The VM0 resection rate in the ER group was 87% (26/30). The EUS findings associated with VM0 resection were tumor thickness < 2.3 mm (p = 0.01) and preserved hyperechoic line of the outermost part of the submucosa layer (p < 0.01). The L-CR rate in the PDT group was 69% (32/47). The EUS findings associated with L-CR were tumor thickness < 5.0 mm (p < 0.01) and tumor invasion length into the MP layer < 1.6 mm (p = 0.03). CONCLUSIONS: EUS can be useful in predicting the efficacy of salvage endoscopic treatment for local failure after CRT for ESCC.

The safety and feasibility of endoscopic submucosal dissection using a flexible three-dimensional endoscope for early gastric cancer and superficial esophageal cancer: A prospective observational study.

BACKGROUND AND AIM: Endoscopic submucosal dissection (ESD) is performed as one of standard treatments for patients with early gastric cancer (EGC) and superficial esophageal squamous cancer (SESCC). A prototype of a flexible endoscope with a 3-D system has been recently developed. This study aimed to investigate the safety and feasibility of ESD using a 3-D flexible endoscope (3-D ESD) for EGC and SESCC. METHODS: This single-center, prospective, observational study enrolled patients who underwent planned 3-D ESD. The clinical outcomes, including the incidence of adverse events and treatment results, were analyzed. Visibility and manipulation during 3-D ESD were evaluated using a visual analog scale (VAS). We also evaluated the effect of the 3-D system on the endoscopist using VAS and the critical flicker fusion frequency (CFFF). RESULTS: We analyzed 47 EGC and 20 SESCC cases. There are no bleeding cases that required transfusion and perforation during 3-D ESD in both EGC and SESCC patients. However, the incidence of delayed bleeding and delayed perforation was 1.5% (one case) each. The mean VAS scores for recognizing the submucosal layer during the submucosal dissection, visual perception of blood vessel, and depth perception were 72.7 ± 22.2, 74.7 ± 21.8, and 78.2 ± 19.9, respectively. In contrast, the mean VAS score for manipulation was 25.4 ± 19.7. Among endoscopists, there was no significant difference in the VAS of eyestrain and headache before and after ESD, and there was no significant difference in the CFFF. CONCLUSION: The safety and feasibility of 3-D ESD for EGC and SESCC are acceptable in both patients and endoscopists.

Salvage endoscopic resection for cT1N0M0 local recurrence after chemoradiotherapy for esophageal squamous cell carcinoma: endoscopic submucosal dissection versus endoscopic mucosal resection.

OBJECTIVES: Salvage endoscopic resection is recommended when the local recurrence at primary site after chemoradiotherapy for esophageal squamous cell carcinoma is localized and superficial. This retrospective study aimed to comparatively analyse the short-term outcomes and local control of salvage endoscopic submucosal dissection versus salvage endoscopic mucosal resection for local recurrence after chemoradiotherapy or radiotherapy. METHODS: A total of 96 patients who underwent initial salvage endoscopic resection for cT1N0M0 local recurrence after chemoradiotherapy or radiotherapy for esophageal squamous cell carcinoma between December 1998 and August 2019 patients were assigned to either the salvage endoscopic submucosal dissection (40 patients; 40 lesions) or salvage endoscopic mucosal resection (56 patients; 56 lesions) group. We evaluated the en bloc and R0 resection rates, severe adverse events and local failure rate after salvage endoscopic resection. Multivariate analysis was conducted to identify risk factors of local failure after salvage endoscopic resection. RESULTS: The en bloc resection rate was significantly higher in the salvage endoscopic submucosal dissection group than in the salvage endoscopic mucosal resection group (95% versus 63%; P < 0.001). There were no differences in R0 resection rate between the two groups (73% versus 52%, P = 0.057). One patient (3%) in the salvage endoscopic submucosal dissection group had perforation. The 3-year cumulative local failure rate of salvage endoscopic mucosal resection was significantly higher than that of salvage endoscopic submucosal dissection (27% versus 5%, P = 0.032). In multivariate analysis, salvage endoscopic mucosal resection (hazard ratio: 2.7, P = 0.044) was the only independent risk factor of local failure after salvage endoscopic resection. CONCLUSIONS: Salvage endoscopic submucosal dissection is the effective treatment for local recurrence based on the short-term outcomes and local efficacy.

The usefulness of a double-balloon endolumenal interventional platform for colorectal endoscopic submucosal dissection by non-expert endoscopists in a porcine model (with video).

BACKGROUND: Endoscopic submucosal dissection (ESD) is an optimal treatment for colorectal tumors; however, it is technically difficult, especially for non-experts. Therefore, a device that helps non-experts perform colorectal ESD would be beneficial. A double-balloon endolumenal interventional platform (DEIP) was recently developed to assist colorectal ESD through endoscope stabilization and traction. This study assessed the usefulness of colorectal ESD using the DEIP (DEIP-ESD) by endoscopists, including non-experts, in a living porcine model. METHODS: Two pigs were used to perform eight DEIP-ESD and eight conventional cap-assisted ESD (C-ESD) procedures. Three experts and five non-experts each resected one lesion using DEIP-ESD and one using C-ESD. We evaluated the treatment outcomes and performed stratified analyses between the experts and non-experts. RESULTS: Dissection speed was significantly faster in DEIP-ESD than in C-ESD (13.3 mm2/min vs 28.5 mm2/min, P = 0.002). However, the total procedure time did not differ significantly between DEIP-ESD and C-ESD. In the stratified analyses, the dissection speed of non-experts was significantly faster in DEIP-ESD than in C-ESD (10.9 mm2/min vs 25.1 mm2/min, P = 0.016), while that of experts increased in DEIP-ESD but to a lesser extent (19.1 mm2/min vs 28.8 mm2/min, P = 0.1). The total procedure time did not differ between DEIP-ESD and C-ESD for both experts and non-experts. The self-completion rate of non-experts also increased in DEIP-ESD. Moreover, the number of muscularis propria injuries induced by non-experts was fewer in DEIP-ESD than in C-ESD. CONCLUSIONS: DEIP could facilitate colorectal ESD by improving dissection efficiency without increasing adverse events, especially when performed by non-experts.

Depth diagnosis of early colorectal cancer: Magnifying chromoendoscopy or image enhanced endoscopy with magnification?

Depth diagnosis is extremely crucial in making a treatment choice between endoscopic resection and surgery in the early stages of cancers. Among several imaging modalities, we use magnifying endoscopy to diagnose lesions by close observation of the findings at mucosal surface layer. In combination with topical staining, magnifying endoscopy enables us to assess the definite pit structure, which referred to as magnifying chromoendoscopy (MCE). The pit pattern classification by MCE was proposed and is now widely accepted as the standard diagnostic criteria for colorectal lesions. Meanwhile, image enhanced endoscopy (IEE) represented by narrow-band imaging was developed to improve the visibility of surface and vascular findings without dyeing. Recent collaborative work performed by endoscopic experts in Japan yielded the unified diagnostic criteria, the Japan NBI Expert Team (JNET) classification, based on the findings of IEE with magnification. In this review, focusing on MCE and IEE with magnification, we aimed to give an outline of the pit pattern classification and the JNET classification, and further discuss their accuracy rate of depth diagnosis of early colorectal lesions by performing a review of the related literature. Both modalities have a high accuracy rate of nearly 90% for depth diagnosis. IEE with magnification is an ideal modality because it helps observe lesions without dye spraying; however, lesions with JNET type 2B have an inadequate diagnostic ability, which should be complemented by MCE. We conclude that accurate diagnosis is possible by examining lesions using both modalities properly to overcome the limitations of each modality.

Estimating colorectal polyp size with a virtual scale endoscope and visual estimation during colonoscopy: Prospective, preliminary comparison of accuracy.

The virtual scale endoscope (VSE) is a new endoscope that helps estimate the size of neoplasms in the gastrointestinal tract. We compared the accuracy of polyp size estimation by VSE with that of visual estimation. A dual center prospective study was conducted in two Japanese academic endoscopy units. Ten endoscopists (five trainees and five experts) estimated the size of 20 simulated polyps in four colon phantoms during colonoscopy by two methods: conventional visual estimation and estimation by VSE. The primary endpoint was the relative accuracy in relation to true polyp size according to visual estimation and VSE estimation during colonoscopy. The secondary endpoint was the required time (the time needed to measure in each procedure). The mean values of the primary end-point were 62.5% for visual estimation and 84.0% for VSE estimation; hence the result differed significantly (95% confidence interval 18.3-24.7; P < 0.001). The mean of required times was significantly longer for estimation by VSE (6.4 min) than that by visual estimation (2.9 min; P < 0.001). The accuracy of colorectal polyp size estimation was superior with VSE than with visual estimation during colonoscopy. In the future, VSE should be evaluated in actual clinical settings, including the time required for size estimation.

Detecting colon polyps in endoscopic images using artificial intelligence constructed with automated collection of annotated images from an endoscopy reporting system.

BACKGROUND: Artificial intelligence (AI) has made considerable progress in image recognition, especially in the analysis of endoscopic images. The availability of large-scale annotated datasets has contributed to the recent progress in this field. Datasets of high-quality annotated endoscopic images are widely available, particularly in Japan. A system for collecting annotated data reported daily could aid in accumulating a significant number of high-quality annotated datasets. AIM: We assessed the validity of using daily annotated endoscopic images in a constructed reporting system for a prototype AI model for polyp detection. METHODS: We constructed an automated collection system for daily annotated datasets from an endoscopy reporting system. The key images were selected and annotated for each case only during daily practice, not to be performed retrospectively. We automatically extracted annotated endoscopic images of diminutive colon polyps that had been diagnosed (study period March-September 2018) using the keywords of diagnostic information, and additionally collect the normal colon images. The collected dataset was devised into training and validation to build and evaluate the AI system. The detection model was developed using a deep learning algorithm, RetinaNet. RESULTS: The automated system collected endoscopic images (47,391) from colonoscopies (745), and extracted key colon polyp images (1356) with localized annotations. The sensitivity, specificity, and accuracy of our AI model were 97.0%, 97.7%, and 97.3% (n = 300), respectively. CONCLUSION: The automated system enabled the development of a high-performance colon polyp detector using images in endoscopy reporting system without the efforts of retrospective annotation works.

Efficacy and safety of second photodynamic therapy for local failure after salvage photodynamic therapy for esophageal cancer.

OBJECTIVES: Photodynamic therapy (PDT) is an optional salvage treatment for local failure of esophageal squamous cell carcinoma (ESCC) after chemoradiotherapy; however, local failure after PDT sometimes occurs. In such cases, second PDT is sometimes attempted, but its outcomes remain unclear. This study aimed to evaluate the efficacy and safety of second PDT. METHODS: We enrolled patients who underwent PDT for local failure of ESCC after chemoradiotherapy. We retrospectively evaluated local-complete response (L-CR) rate and clinical outcomes of first and second PDT. The indications for PDT were lesions within the muscle layer, <3 cm in size, and <3/4 of the esophageal circumference; not suitable for salvage surgery; and absence of metastasis. Second PDT was avoided when lesions were apparently refractory to first PDT, e.g. persistence of submucosal tumor-like protruded component or rapid regrowth of tumor at the ulceration after first PDT. L-CR was defined as endoscopic disappearance of tumor and post-PDT ulcer and absence of cancer cells histologically. RESULTS: Among 82 patients who underwent first PDT, 27 underwent second PDT. The L-CR rates with first and second PDT were 63.0% and 40.7%, respectively. The 2-year overall survival rates after second PDT in patients with L-CR and local-nonCR were 79.5% and 40.5%, respectively. Five of 11 patients with L-CR survived without any recurrence. No grade ≥3 adverse events occurred. CONCLUSIONS: Second PDT demonstrated excellent safety and acceptable efficacy; therefore, it could be a useful treatment for local failure after first PDT.

Factors of technical difficulty in conventional and traction-assisted esophageal endoscopic submucosal dissection.

BACKGROUND: The traction assisted (TA) method has reduced the technical difficulty associated with esophageal endoscopic submucosal dissection (ESD). However, it is unclear which factors associated with difficulty have been improved by the TA-ESD method. We aimed to evaluate and compare difficulty factors between conventional and TA-ESD. METHODS: We retrospectively enrolled patients treated by ESD from Apr 2010 to Jun 2014 for the conventional ESD cohort and from Jan 2016 to Dec 2019 for the TA-ESD cohort. Difficult cases were defined as; (1) ≥ 120 min ESD procedure time, (2) intraoperative perforation, or (3) piecemeal resection. We explored and compared the factors associated with technical difficulty in each cohort. RESULTS: The conventional and TA-ESD cohorts included 285 (299 lesions) and 387 (421 lesions) patients, respectively. For difficult cases, the conventional and TA-ESD cohorts had 91 (30%) and 71 (17%) lesions, respectively. Multivariate logistic regression showed that ≥ 30 mm lesion length (odds ratio (OR) 6.85, 95% confidence interval (CI) 3.47-13.50), lower esophagus (OR 2.37, 95% Cl 1.34-4.21), > 1/2 circumference (OR 2.26, 95% CI 1.28-3.99), and left wall (OR 2.72, 95% CI 1.42-5.20) in the conventional ESD cohort, and ≥ 30 mm lesion length (21.30, 95% CI 4.75-95.30), lower esophagus (OR 3.05, 95% CI 1.52-6.13), and > 1/2 circumference (OR 6.40, 95% CI 3.06-13.40) in the TA-ESD cohort, were independently associated with technical difficulty. CONCLUSIONS: TA-ESD can reduce the difficulty in cases including lesions in the left wall; however, cases in the lower esophagus and large lesions were still difficult to simplify.

Radial incision and cutting for dilation before endoscopic submucosal dissection in patients with esophageal cancer on the distal side of severe benign esophageal strictures.

We investigated the efficacy and safety of radial incision and cutting as a novel dilation method for strictures just before endoscopic submucosal dissection in patients with metachronous esophageal cancer localized on the distal side of strictures and determined the optimal dilation method. Consecutive patients who underwent endoscopic submucosal dissection for superficial esophageal squamous cell carcinomas localized on the distal side of severe strictures were investigated retrospectively and assigned to a radial incision and cutting (19 patients; 23 lesions) or an endoscopic balloon dilation (20 patients; 20 lesions) group. We evaluated the passage success rates of cap-wearing endoscopes with diameters ≥8.9 mm, the procedural success, en bloc resection, complete resection, major adverse event rates, and total procedure times. Compared to the endoscopic balloon dilation group, the passage success rate of a conventional endoscope with a transparent cap (87% vs. 50%) and procedural success rate (96% vs. 63%) were significantly higher in the radial incision and cutting group. The mean procedure time of 'dilation and ESD' was significantly shorter in the radial incision and cutting group than in the endoscopic balloon dilation group. Neither group experienced any serious adverse events. Radial incision and cutting followed by endoscopic submucosal dissection was effective and safe in patients with superficial esophageal squamous cell carcinomas localized on the distal side of severe benign esophageal strictures. Endoscopic submucosal dissection using a cap-wearing endoscope was possible with radial incision and cutting, and the procedure time was shorter than that for endoscopic balloon dilation.

Relationship between the microvascular patterns observed by magnifying endoscopy with narrow-band imaging and the depth of invasion in superficial pharyngeal squamous cell carcinoma.

BACKGROUND: Prediction of the invasive depth is the objective of endoscopic observation for digestive cancer. In superficial esophageal cancer, a close relationship between microvascular patterns observed by magnifying endoscopy with narrow-band imaging (M-NBI) and pathological depth of invasion is well known. The ability of M-NBI to predict the invasion depth in superficial pharyngeal squamous cell carcinoma (SPSCC) has been seldom evaluated. This study aimed to clarify the relationship between the microvasculature patterns and pathological depth in SPSCC. METHODS: SPSCC lesions evaluated with M-NBI followed by endoscopic resection were analyzed between April 2010 and March 2017. Endoscopic images were classified as microvasculature tumor types B1, B2, and B3 according to the Japan Esophageal Society classification. The pathological depth of invasion was described as either squamous cell carcinoma in situ (Tis) or invasive subepithelial cancer, and the tumor thickness of all lesions was examined. Data were analyzed using the unpaired t, χ2, or Mann-Whitney U test. RESULTS: Type B1 and type B2/B3 (35/3) microvessels were found in 180 lesions (82%) and 39 (18%), respectively. Of the flat lesions, 115 (83%) were classified as Tis and 23 (17%) as subepithelial cancer. Positive and negative predictive values of the B1 vessels were 77% and 82%, respectively. Additional analysis showed that the positive predictive value of the B1 vessels for the flat-type lesions was 87%; the negative predictive value for the elevated lesions was 93%. CONCLUSIONS: Microvascular patterns observed by M-NBI are an important factor in predicting the pathological depth of invasion.

Clinical features and risk factors of gastric cancer detected by esophagogastroduodenoscopy in esophageal cancer patients.

BACKGROUND: Gastric cancer is the most frequent primary cancer-associated with esophageal cancer and is most commonly detected by endoscopic surveillance. However, the clinical features of synchronous or metachronous gastric cancer that could be detected by esophagogastroduodenoscopy in esophageal cancer patients are unknown. METHODS: We reviewed the clinical records of all esophageal cancer patients (n = 1379) registered in the cancer registration database who underwent initial treatment between April 2010 and October 2015. We retrospectively analyzed the proportions of synchronous and metachronous gastric cancer cases, the cumulative incidence rate of metachronous gastric cancer in total and by esophageal cancer treatments (endoscopic resection, esophagectomy, and chemoradiotherapy), and the clinical features of esophageal cancer patients with synchronous or metachronous gastric cancer. RESULTS: Overall, 67 (5.3% of 1275) esophageal cancer patients with synchronous gastric cancer and 40 (5.1% of 791) esophageal cancer patients with metachronous gastric cancer were analyzed. The 5-year cumulative incidence rate of metachronous gastric cancer was 5.6% in total, 7.8% after endoscopic resection, 4.7% after esophagectomy, and 4.1% after chemoradiotherapy for esophageal cancer. From the results of multivariate analysis, the risk factors for synchronous gastric cancer were male (odds ratio 13.3) and moderate/severe atrophic gastritis (odds ratio 17.9), and the risk factor of metachronous gastric cancer was moderate/severe atrophic gastritis (hazard ratio 27.6) in patients with esophageal cancer. CONCLUSIONS: The incidence rates of synchronous and metachronous gastric cancer with esophageal cancer were both over 5%. Careful endoscopic observation is required for moderate and severe atrophic gastritis at detecting concomitant gastric cancer in esophageal cancer patients.