Deep learning in negative small-bowel capsule endoscopy improves small-bowel lesion detection and diagnostic yield.

OBJECTIVES: Although several studies have shown the usefulness of artificial intelligence to identify abnormalities in small-bowel capsule endoscopy (SBCE) images, few studies have proven its actual clinical usefulness. Thus, the aim of this study was to examine whether meaningful findings could be obtained when negative SBCE videos were reanalyzed with a deep convolutional neural network (CNN) model. METHODS: Clinical data of patients who received SBCE for suspected small-bowel bleeding at two academic hospitals between February 2018 and July 2020 were retrospectively collected. All SBCE videos read as negative were reanalyzed with the CNN algorithm developed in our previous study. Meaningful findings such as angioectasias and ulcers were finally decided after reviewing CNN-selected images by two gastroenterologists. RESULTS: Among 202 SBCE videos, 103 (51.0%) were read as negative by humans. Meaningful findings were detected in 63 (61.2%) of these 103 videos after reanalyzing them with the CNN model. There were 79 red spots or angioectasias in 40 videos and 66 erosions or ulcers in 35 videos. After reanalysis, the diagnosis was changed for 10 (10.3%) patients who had initially negative SBCE results. During a mean follow-up of 16.5 months, rebleeding occurred in 19 (18.4%) patients. The rebleeding rate was 23.6% (13/55) for patients with meaningful findings and 16.1% (5/31) for patients without meaningful findings (P = 0.411). CONCLUSION: Our CNN algorithm detected meaningful findings in negative SBCE videos that were missed by humans. The use of deep CNN for SBCE image reading is expected to compensate for human error.

Anchoring endoscopic mucosal resection versus conventional endoscopic mucosal resection for large nonpedunculated colorectal polyps: a randomized controlled trial.

BACKGROUND : Colorectal polyps > 10 mm in size are often incompletely resected. Anchoring-endoscopic mucosal resection (A-EMR) is the technique of making a small incision at the oral side of the polyp using a snare tip after submucosal injection to avoid slippage during ensnaring. This study was performed to evaluate whether A-EMR could increase the complete resection rate for large colorectal polyps compared with conventional endoscopic mucosal resection (C-EMR). METHODS : Polyps with sizes of 10-25 mm were randomly allocated to either the A-EMR or the C-EMR groups. RESULTS : 105 and 106 polyps were resected using A-EMR and C-EMR, respectively. In the intention-to-treat population, the complete resection rate was 89.5 % in the A-EMR group and 74.5 % in the C-EMR group (relative risk [RR] 1.20, 95 %CI 1.04 to 1.38; P = 0.01). The en bloc resection rates for the A-EMR and C-EMR groups were 92.4 % vs. 76.4 % (RR 1.21, 95 %CI 1.06 to 1.37; P = 0.005) and R0 resection rates were 77.1 % vs. 64.2 % (RR 1.18, 95 %CI 0.98 to 1.42; P = 0.07), respectively. The median (interquartile range [IQR]) total procedure time was 3.2 (2.6-4.1) minutes in the A-EMR group and 3.0 (2.2-4.6) minutes in the C-EMR group (median difference 0.2 minutes, 95 %CI -0.22 to 0.73; P = 0.25). There was one episode of delayed bleeding and one perforation in the C-EMR group. CONCLUSIONS : A-EMR was superior to C-EMR for the complete resection of large colorectal polyps. A-EMR can be considered one of the standard methods for the removal of colorectal polyps of 10 mm or more in size.

Effectiveness and safety of adalimumab in patients with intestinal Behçet's disease: a real-world prospective observational study in South Korea.

BACKGROUND: Intestinal Behçet's disease (BD) is characterized by typical gastrointestinal ulcers in patients with BD followed by complications such as bleeding, perforation and fistula. Biologic agents are currently under active investigation to delay the disease course. Various data regarding infliximab are available, but there is relatively lack of data regarding adalimumab. METHODS: This was a multicenter, real-world prospective observational study to evaluate the effectiveness and safety of adalimumab in intestinal BD. The primary endpoint was disease activity at each follow up, including disease activity index for intestinal Behçet's disease (DAIBD), serum C-reactive protein (CRP) level, and endoscopic findings. The secondary endpoint was the incidence of adverse drug reactions (ADRs). RESULTS: A total of 58 patients were enrolled and 8 of them were excluded. Adverse events were reported in 72.0% of patients with 122 events. ADRs were reported in 24.0% with 28 events. For adverse events, arthralgia was most commonly reported (13.1%: 16/122) and only one experienced critical adverse event (0.82%, 1/122: death due to stroke). On multivariable regression analysis, a longer disease duration was significantly associated with decreased ADRs [Odds ratio 0.976 (0.953-0.999, 95% CI); p = 0.042]. Clinical response rates as assessed by DAIBD were 90.9% at Week 12 and 89.7% at Week 56, respectively. The mean serum CRP level at baseline was significantly decreased after 12 weeks (3.91 ± 4.93 to 1.26 ± 2.03 mg/dL; p = 0.0002). CONCLUSION: Adalimumab was found to be safe and effective in Korean patients with intestinal BD. A longer disease duration was significantly associated with decreased ADRs.

Association between regular physical activity and lower incidence of colorectal cancer in patients with diabetes mellitus: a nationwide cohort study.

AIM: The aim of this work was to investigate the association between changes in physical activity (PA) status and the development of colorectal cancer (CRC) in patients with diabetes. METHOD: This nationwide population study included 1 439 152 patients with diabetes who underwent a health screening provided by the Korean National Health Insurance Service between January 2009 and December 2012 and a follow-up screening after 2 years. Based on changes in PA status, participants were categorized into four groups: remained inactive, remained active, active-to-inactive and inactive-to-active. RESULTS: During the median follow-up period of 5.2 years, 38 244 new cases of CRC were diagnosed. Compared with the remained inactive group, among the three other groups, the remained active group had the lowest risk of CRC [adjusted hazard ratio (aHR) 0.93; 95% CI 0.90-0.96], followed by the inactive-to-active group (aHR 0.97; 95% CI 0.94-1.00) and active-to-inactive group (aHR 0.99; 95% CI 0.96-1.02), after adjusting for confounding variables (p = 0.0007). This reduction in cancer incidence in the remained active group was observed for both rectal cancer (aHR 0.87, 95% CI 0.79-0.95) and colon cancer (aHR 0.93, 95% CI 0.90-0.97), irrespective of sex. In terms of the intensity and amount of PA, moderate intensity PA was the most effective, and a positive correlation was found between the amount of PA and the reduction in CRC incidence. CONCLUSION: Regular PA was independently associated with a decreased risk of CRC in patients with diabetes. The intensity and amount of physical activity both play a role in reducing the risk.

Rescue technique for self-expandable metallic stent placement using ultrathin endoscope after failure of the conventional method in patients with malignant colon obstruction: a multicenter retrospective study.

BACKGROUND AND AIMS: Self-expandable metallic stents (SEMS) can be used to treat malignant colorectal obstruction (MCO). Guidewire insertion to the proximal site of MCO is the most important step for SEMS placement. However, some patients cannot undergo guidewire insertion because of total obstruction or location at anatomically challenging areas. We report a guidewire insertion technique using an ultrathin endoscope (UTE) in patients with MCO in whom conventional SEMS insertion failed. METHODS: This study was a retrospective cohort study conducted at three academic centers in Korea. The medical records of 956 consecutive patients who underwent SEMS placement during 2012-2021 were analyzed. After failing guidewire insertion using a colonoscope, a UTE was inserted. Guidewire insertion was done through the working channel of the UTE. Following guidewire insertion, the endoscope was removed from the patient. While removing the endoscope, the guidewire was advanced to be located at the originally inserted site. Then, the colonoscope was inserted over the guidewire, and SEMS was replaced. RESULTS: Conventional SEMS insertion failed in 75 patients. Of these, guidewire insertion using a UTE was tried in 59 patients. The rate of technical success was 91.5% (54/59). Considering all patients, the overall technical success rate of SEMS placement was 97.8% (935/956). This technique increased the technical success rate by 5.6% among the total cohort. CONCLUSIONS: The UTE facilitated guidewire insertion and enhanced the overall success rate for SEMS placement. In addition, this technique can be used as a rescue method when guidewire insertion fails using a colonoscope.

Performance of Balloon-Assisted Enteroscopy for Non-ERCP Indications in Patients with Surgically Altered Gastrointestinal Anatomy.

BACKGROUND AND AIMS: Surgically altered gastrointestinal (GI) tract anatomy hinders deep enteroscopy. While enteroscopy-assisted endoscopic retrograde cholangiopancreatography (ERCP) in patients with altered GI anatomy has been heavily investigated, the role of non-ERCP balloon-assisted enteroscopy (BAE) has yet to be fully elucidated.Please check and confirm the author names and initials are correct. Also, kindly confirm the details in the metadata are correct.I have checked all you asked and have no correction.  Thank you. METHODS: A multicenter retrospective study of non-ERCP BAEs in patients with surgically altered GI tract anatomy at two tertiary academic hospitals was performed from January 2006 to December 2020. Altered GI tract anatomy was defined by surgical reconstruction affecting the length, angle, or overall trajectory of the endoscope during the intended approach. The main outcome measurements included technical success rate, diagnostic and therapeutic yields, and complication rate.Please check the edit made in the title of the article and correct if necessary.No more correction. Thank you. RESULTS: A total of 68 patients with surgically altered GI tract anatomy underwent 56 antegrade and 24 retrograde non-ERCP BAE procedures. The technical success rate was 86.2% in both, including 83.9% via antegrade approach and 91.7% via retrograde approach. Antegrade approach in Roux-en-Y anatomy was associated with the lowest success rate of 77.8%, whereas retrograde approach in patients with colon resection resulted in the highest rate of 100%. The diagnostic and therapeutic yields of non-ERCP BAE were 79.4% and 82.9%, respectively. The diagnostic yields varied according to the procedural indications. The major complication was luminal perforation in one case (1.3%). CONCLUSIONS: Non-ERCP BAE is effective and safe via both antegrade and retrograde approaches with a high technical success rate and diagnostic and therapeutic yields in patients with surgically altered GI tract anatomy.

Long-term outcomes after endoscopic versus surgical resection of T1 colorectal carcinoma.

BACKGROUND: The long-term outcomes of patients with T1 colorectal cancer (CRC) who undergo endoscopic and/or surgical treatment are not well understood. Invasive CRC confined to the colonic submucosa (T1 CRC) is challenging in terms of clinical decision-making. We compared the long-term outcomes of T1 CRC by treatment method. METHODS: We examined 370 patients with pathological T1 CRC treated between 2000 and 2015 at Seoul St. Mary's Hospital. In total, 93 patients underwent endoscopic resection (ER) only, 82 underwent additional surgery after ER, and 175 underwent surgical resection only. Patients who did not meet the curative criteria were defined as "high-risk." High-risk patients were classified into three groups according to the treatment modalities: ER only (Group A: 35 patients), additional surgery after ER (Group B: 72 patients), and surgical resection only (Group C: 133 patients). The recurrence-free and overall survival (OS) rates, and factors associated with recurrence and mortality, were analyzed. Factors associated with lymph node metastasis (LNM) were subjected to multivariate analysis. RESULTS: Of the 370 patients, 7 experienced recurrence and 7 died. All recurrences occurred in the high-risk group and two deaths were in the low-risk group. In high-risk groups, there was no significant group difference in recurrence-free survival (P = 0.511) or OS (P =0.657). Poor histology (P =0.042) was associated with recurrence, and vascular invasion (P =0.044) with mortality. LNMs were observed in 30 of 277 patients who underwent surgery either initially or secondarily. Lymphatic invasion was significantly associated with the incidence of LNM (P < 0.001). CONCLUSIONS: ER prior to surgery did not affect the prognosis of high-risk T1 CRC patients, and did not worsen the clinical outcomes of patients who required additional surgery. Lymphatic invasion was the most important predictor of LNM.

Long-term prognosis of curative endoscopic submucosal dissection for early colorectal cancer according to submucosal invasion: a multicenter cohort study.

BACKGROUND: Endoscopic submucosal dissection (ESD) can provide a high en bloc resection rate and has been widely applied as curative treatment for early colorectal cancer (ECC). However, surgical treatment is occasionally required, and reports on the long-term prognosis of ESD are insufficient. This study aimed to investigate the long-term outcomes of ECC removal by ESD, including local recurrence and metastasis. METHODS: This multicenter study was conducted retrospectively on 450 consecutive patients with ECC who were treated with ESD between November 2003 and December 2013. Clinical, pathological, and endoscopic data were collected to determine tumor depth, resection margin, lymphovascular invasion, and recurrence. RESULTS: The median follow-up period was 53.8 (12-138 months). The en bloc resection rate was 85.3% (384) and in intramucosal cancer being 84.1% and in superficial submucosal invasion (SM1) cancer being 89.8% (p = 0.158). The curative resection rate was 76.0% (n = 342), and there was no statistical difference between the two groups (77.3% vs. 71.4%, p = 0.231). The overall recurrence free survival rate (RFS) was 98.7% (444/450). In patients with curative resection, there was no statistically significant difference in RFS according to invasion depth (intramucosal: 99.3% vs. SM1: 97.1%, p = 0.248). CONCLUSIONS: Patients with curatively resected ECC treated with ESD showed favorable long-term outcomes. Curatively resected SM1 cancer has a RFS similar to that of intramucosal cancer.

Comparison of precutting endoscopic mucosal resection and endoscopic submucosal dissection for large (20-30 mm) flat colorectal lesions.

BACKGROUND AND AIM: The complete and safe removal of large (≥ 20 mm) colorectal lesions is an area of concern. Endoscopic submucosal dissection (ESD) effectively removes these lesions compared with endoscopic mucosal resection (EMR). However, ESD requires advanced techniques, longer procedure time, and high cost. Precutting EMR (EMR-P) is a modified EMR method that overcomes the limitations of EMR. This study aimed to compare the efficacy and safety of EMR-P and ESD in large (20-30 mm) flat colorectal lesions. METHODS: This was a retrospective analysis of cases in which 20- to 30-mm flat colorectal lesions were resected at Seoul St. Mary's Hospital from January 2014 to December 2019. Propensity score matching was performed to control for possible confounders. RESULTS: Two hundred and ninety-nine patients were included in this study. After matching, 90 patients were assigned to each group. There were no significant difference in complete resection rates (92.2% vs 92.2%, P = 1.000), en bloc resection rates (95.6% vs 97.8%, P = 0.682), and mean size of lesions (22.9 ± 3.1 mm vs 23.0 ± 3.1 mm, P = 0.867) between EMR-P and ESD. Procedure time was significantly shorter with EMR-P (11.0 ± 6.5 min vs 37.0 ± 19.3 min, P < 0.001). The adverse events rate was not significantly different between both groups. No local recurrence occurred in both groups. CONCLUSIONS: Precutting EMR was not significantly different to ESD in terms of complete resection rate and en bloc resection rate for 20- to 30-mm flat colorectal lesions without fibrosis. Furthermore, EMR-P has shorter procedure time than ESD. EMR-P could be considered one of standard treatments for large flat colorectal lesions.

Circumferential submucosal incision prior to endoscopic mucosal resection versus conventional endoscopic mucosal resection for colorectal lesions with endoscopic features of sessile serrated lesions.

BACKGROUND AND AIMS: Sessile serrated lesions (SSLs) are more prone to incomplete resection than conventional adenomas. This study evaluated whether circumferential submucosal incision prior to endoscopic mucosal resection (CSI-EMR) can increase the rate of complete and en bloc resections of colorectal lesions with endoscopic features of SSL. METHODS: Retrospective analyses and propensity score matching were performed for the resection of colorectal lesions ≥ 10 mm with endoscopic features of SSL. RESULTS: After 1:1 ratio matching, 127 lesions in the CSI-EMR group and 127 in the EMR group were selected for analysis. The median size of the lesions was 15 mm (IQR 12-16) in both groups. There was no significant difference in either the complete resection rate or en bloc resection rate between CSI-EMR and EMR groups (96.9% vs. 92.9%, P = 0.155; 92.1% vs. 89.0%, P = 0.391). By contrast, the R0 resection rate was significantly higher in the CSI-EMR group than in the EMR group (89.8% vs. 59.8%, P < 0.001). The median procedure time was significantly longer in the CSI-EMR group than in the EMR group (6.28 min vs. 2.55 min, P < 0.001), whereas there was no significant difference between the two groups in the incidence of adverse events or recurrence rate. Multivariate analysis showed that CSI-EMR was the only factor significantly associated with R0 resection (P < 0.001). CONCLUSIONS: For colorectal lesions with endoscopic features of SSL, CSI-EMR does not increase the complete or en bloc resection rate, but does increase the R0 resection rate. The procedure time is longer for CSI-EMR than EMR. The association of CSI-EMR with R0 resection and non-recurrence should be further evaluated.

Convolutional neural network-based object detection model to identify gastrointestinal stromal tumors in endoscopic ultrasound images.

BACKGROUND AND AIM: We aimed to develop a convolutional neural network (CNN)-based object detection model for the discrimination of gastric subepithelial tumors, such as gastrointestinal stromal tumors (GISTs), and leiomyomas, in endoscopic ultrasound (EUS) images. METHODS: We used 376 images from 114 patients with histologically confirmed gastric GIST or leiomyoma to train the EUS-CNN. We constructed the EUS-CNN using an EfficientNet CNN model for feature extraction and a weighted bi-directional feature pyramid network for object detection. We assessed the performance of our EUS-CNN by calculating its accuracy, sensitivity, specificity, and area under receiver operating characteristic curve (AUC) using a validation set of 170 images from 54 patients. Four EUS experts and 15 EUS trainees were asked to judge the same validation dataset, and the diagnostic yields were compared between the EUS-CNN and human assessments. RESULTS: In the per-image analysis, the sensitivity, specificity, accuracy, and AUC of our EUS-CNN were 95.6%, 82.1%, 91.2%, and 0.9234, respectively. In the per-patient analysis, the sensitivity, specificity, accuracy, and AUC for our object detection model were 100.0%, 85.7%, 96.3%, and 0.9929, respectively. The EUS-CNN outperformed human assessment in terms of accuracy, sensitivity, and negative predictive value. CONCLUSIONS: We developed the EUS-CNN system, which demonstrated high diagnostic ability for gastric GIST prediction. This EUS-CNN system can be helpful not only for less-experienced endoscopists but also for experienced ones. Additional EUS image accumulation and prospective studies are required alongside validation in a large multicenter trial.

Hot snare polypectomy versus endoscopic mucosal resection for small colorectal polyps: a randomized controlled trial.

BACKGROUND AND AIMS: This study was performed to compare endoscopic mucosal resection (EMR) with hot snare polypectomy (HSP) in terms of the complete resection rate and the incidence of adverse events for resecting small (5-10 mm) colorectal polyps. METHODS: Small colorectal polyps (5-10 mm) with neoplastic features were randomly allocated to either the HSP or EMR group. A submucosal injection was performed prior to hot snaring in the EMR group only. Complete resection was defined as the absence of neoplastic tissue from two additional biopsies of the polypectomy site. R0 resection was defined as the absence of neoplastic tissue at the margin of the resected specimen. RESULTS: A total of 362 colon polyps from 272 patients were included, and 167 polyps in the HSP group and 155 polyps in the EMR group were analyzed. Between the polypectomy techniques, there was no significant difference in the complete resection rates, which were 96.4% (161/167) in the HSP group and 95.5% (148/155) in the EMR group (P = 0.67). The R0 resection rate in the HSP and EMR groups was significantly different, with 49.7% (83/167) and 74.8% (116/155), respectively (P < 0.001). There was no significant difference in the incidence of adverse events between the two groups. CONCLUSIONS: The complete resection rates for small (5-10 mm) polyps were not different between HSP and EMR. TRIAL REGISTRY: ClincialTrials.gov number NCT02239536.

Improved classification and localization approach to small bowel capsule endoscopy using convolutional neural network.

BACKGROUND: Although great advances in artificial intelligence for interpreting small bowel capsule endoscopy (SBCE) images have been made in recent years, its practical use is still limited. The aim of this study was to develop a more practical convolutional neural network (CNN) algorithm for the automatic detection of various small bowel lesions. METHODS: A total of 7556 images were collected for the training dataset from 526 SBCE videos. Abnormal images were classified into two categories: hemorrhagic lesions (red spot/angioectasia/active bleeding) and ulcerative lesions (erosion/ulcer/stricture). A CNN algorithm based on VGGNet was trained in two different ways: the combined model (hemorrhagic and ulcerative lesions trained separately) and the binary model (all abnormal images trained without discrimination). The detected lesions were visualized using a gradient class activation map (Grad-CAM). The two models were validated using 5,760 independent images taken at two other academic hospitals. RESULTS: Both the combined and binary models acquired high accuracy for lesion detection, and the difference between the two models was not significant (96.83% vs 96.62%, P = 0.122). However, the combined model showed higher sensitivity (97.61% vs 95.07%, P < 0.001) and higher accuracy for individual lesions from the hemorrhagic and ulcerative categories than the binary model. The combined model also revealed more accurate localization of the culprit area on images evaluated by the Grad-CAM. CONCLUSIONS: Diagnostic sensitivity and classification of small bowel lesions using a convolutional neural network are improved by the independent training for hemorrhagic and ulcerative lesions. Grad-CAM is highly effective in localizing the lesions.

A risk-scoring model for the prediction of delayed bleeding after colorectal endoscopic submucosal dissection.

BACKGROUND AND AIMS: Delayed bleeding is an important adverse event after colorectal endoscopic submucosal dissection (ESD). We aimed to investigate the incidence and risk factors of delayed bleeding after colorectal ESD and to develop a risk-scoring model for predicting delayed bleeding. METHODS: This retrospective study was performed at 5 centers. The derivation and validation cohorts comprised 1189 patients from 1 center and 415 patients from the other 4 centers. We investigated the incidence and risk factors of delayed bleeding. Then, we developed a risk-scoring model for predicting delayed bleeding by using the data of the derivation cohort. We validated the scoring system in the validation cohort. RESULTS: Delayed bleeding occurred in 34 patients (2.9%) in the derivation cohort. In multivariate analysis, the risk factors of delayed bleeding were tumor location in the rectosigmoid colon (odds ratio [OR], 6.49; 95% confidence interval [CI], 1.96-21.42; P = .002), large tumor (≥30 mm) (OR, 2.10; 95% CI, 1.01-4.40; P = .048), and use of antiplatelet agents except for aspirin alone (OR, 4.04; 95% CI, 1.44-11.30; P = .008). These 3 factors were incorporated into a risk-scoring model for prediction of delayed bleeding. As the score based on this system increased, the incidence of delayed bleeding increased in the validation cohort. CONCLUSION: The risk-scoring model incorporating tumor location, tumor size, and use of antiplatelet agents can quantitatively predict the risk of delayed bleeding after colorectal ESD.

The effect of photo-documentation of the ampulla on neoplasm detection rate during esophagogastroduodenoscopy.

BACKGROUND: A few studies have investigated quality indicators of esophagogastroduodenoscopy (EGD) for identifying upper gastrointestinal (GI) malignancy. The current study aimed to evaluate whether the rate of ampulla photo-documentation could be associated with the detection of upper GI neoplasms. METHODS: We used data from 111 962 asymptomatic patients who underwent EGD performed by 14 endoscopists at a health promotion center. The rate of ampulla photo-documentation was calculated by reviewing EGD photos archived during each endoscopist's first year of working at the center. The detection of neoplasms during a 7-year period was investigated. We examined the association between the rate of ampulla photo-documentation and the rate of neoplasm detection. RESULTS: The mean rate of ampulla photo-documentation was 49.0 % (range 13.7 % - 78.1 %) during endoscopists' first year of working at the center. Endoscopists' rates of ampulla photo-documentation significantly correlated with the detection of total neoplasms (R2 = 0.57, P = 0.03) and small neoplasms (R2 = 0.58, P = 0.03). There was a significant difference in the detection rates of upper GI neoplasms between high (n = 7) and low (n = 7) ampulla observers (odds ratio [OR] 1.31, 95 % confidence interval [CI] 1.03 - 1.68; P = 0.03). The ampulla photo-documentation rate of each endoscopist significantly correlated with the examination time for a normal EGD (R2 = 0.55; P = 0.04). In multivariate analysis, high ampulla photo-documentation rate was a predictor of neoplasm detection (OR 1.33, 95 %CI 1.03 - 1.70). CONCLUSIONS: The ampulla photo-documentation rate was significantly associated with the detection rate for both total and small upper GI neoplasms. Ampulla photo-documentation should be considered as a quality indicator of EGD.

Comparison Between an Oral Sulfate Solution and a 2 L of Polyethylene Glycol/Ascorbic Acid as a Split Dose Bowel Preparation for Colonoscopy.

BACKGROUND/AIMS: This study aimed to compare the efficacy and tolerability of an oral sulfate solution (OSS) versus 2 L of polyethylene glycol/ascorbic acid (2L-PEG/Asc) for bowel cleansing before colonoscopy. METHODS: A prospective, single-center, single-blinded, noninferiority, randomized, controlled trial was performed. The primary outcome was the rate of successful bowel cleansing, evaluated using the Boston Bowel Preparation Scale (BBPS). Secondary outcomes were examination time, polyp, and adenoma detection rate (PDR and ADR), tolerability, and safety. Ease of use, palatability, intention to reuse, and satisfaction were evaluated using a questionnaire. RESULTS: A total of 187 participants were randomized to receive either OSS (n=93) or 2L-PEG/Asc (n=94). Successful bowel cleansing was achieved in 86.0% (80/93) of the OSS group, which was noninferior to the 2L-PEG/Asc group (88.3%, 83/94), with a difference of -2.3% by ITT analysis [95% confidence interval (CI) -12.0 to +7.4]. The withdrawal time of the OSS group was significantly shorter than that of the 2L-PEG/Asc group (11.8±5.2 vs. 14.3±8.5; P=0.016). Ease of use, palatability, intention to reuse, and satisfaction were similar between the 2 groups. Adverse events were also similar between the 2 groups. Mucosal erythema (4.3%) and aphthous lesions (2.1%) were found only in the 2L-PEG/Asc group. CONCLUSIONS: OSS was as effective as 2L-PEG/Asc for successful bowel cleansing and had acceptable tolerability. OSS is a promising and safe low-volume preparation alternative for colonoscopy. (Clinical trial registration number: NCT02761213.).

Risk factors for peritonitis in patients on continuous ambulatory peritoneal dialysis who undergo colonoscopy: a retrospective multicentre study.

BACKGROUND: Colonoscopy is associated with a risk of peritonitis in patients on peritoneal dialysis. However, no study has yet described the risk factors in play. METHODS: This was a retrospective multicentre study. The medical records of patients on continuous ambulatory peritoneal dialysis (CAPD) who underwent colonoscopy from January 2003 to December 2012 were analysed. We recorded demographic characteristics, colonoscopic factors, use of prophylactic antibiotics, and development of peritonitis. Colonoscopy-related peritonitis was defined as peritonitis developing within 1 week after colonoscopy. Demographic and clinical characteristics were compared between patients who did and those who did not develop peritonitis. RESULTS: During the study period, 236 patients on CAPD underwent colonoscopy, of whom 9 (3.8%) developed peritonitis. The rates of polypectomy/endoscopic mucosal resection were significantly higher in the peritonitis group than in the no peritonitis group (66.7 vs. 23.4%, p = 0.009). Prophylactic antibiotics were prescribed before colonoscopy in 65 patients; none developed peritonitis. No patient who developed peritonitis received prophylactic antibiotics (p = 0.067). CONCLUSIONS: Advanced procedures including polypectomy or endoscopic mucosal resection increase colonoscopy-related peritonitis in patients on CAPD. Randomized controlled trials to investigate whether prophylactic antibiotics are needed to prevent peritonitis in all CAPD patients are warranted.

An Operable, Portable, and Disposable Ultrathin Endoscope for Evaluation of the Upper Gastrointestinal Tract.

BACKGROUND AND AIMS: A prototype of a disposable endoscope (DE) with easy viewing of the esophagus has been developed. The aim of this study was to develop a new version of DE with improved functionality and to assess the feasibility of DE as a screening tool for upper gastrointestinal diseases compared with conventional endoscopes. METHODS: Diagnostic accuracy and maneuverability of DE were evaluated by comparing endoscopy using DE with conventional endoscopy. Different examiners performed DE endoscopy and conventional endoscopy in a randomized order, blinded to the results. Examiners were asked to respond to a questionnaire about ease of handling and observation using DE in preformed result sheets. Tolerability of DE was also evaluated. Non-sedated participants were asked to respond to a questionnaire about the convenience and satisfaction with DE endoscopy on a nine-point Likert scale. RESULTS: The overall ease of insertion and handling of DE was excellent. The new device enabled observation and evaluation of the entire esophagus with a good agreement between DE endoscopy and conventional endoscopy in terms of endoscopic diagnosis (Kappa value; hiatal hernia; 0.910, reflux esophagitis; 0.949, Barrett's esophagus, 1.000). Participants suggested that they were more comfortable with DE endoscopy than with conventional endoscopy with a lower symptom score (p = 0.030). CONCLUSION: The new DE enabled easy observation of the entire esophagus owing to its improved maneuverability, and its diagnostic ability of esophageal diseases was comparable to that of conventional endoscopes. Non-sedated esophagoscopy with this disposable device potentially has widespread applications in outpatient clinics and areas without endoscopic facilities.

Gelatin-chlorin e6 conjugate for in vivo photodynamic therapy.

BACKGROUND: Improving the water solubility of hydrophobic photosensitizer and increasing its accumulation in tumor tissue are essential for in vivo photodynamic therapy (PDT). Considering commercialization or clinical application in future, it will be promising to achieve these purposes by developing new agents with simple and non-toxic structure. RESULTS: We conjugated multiple chlorin e6 (Ce6) molecules to gelatin polymer, synthesizing two types of gelatin-Ce6 conjugates with different amounts of Ce6: gelatin-Ce6-2 and gelatin-Ce6-8. The resulting conjugates remained soluble in aqueous solutions for a longer time than hydrophobic Ce6. The conjugates could generate singlet oxygen and kill tumor cells upon laser irradiation. After intravenous injection into SCC-7 tumor-bearing mice, gelatin-Ce6-2 showed prolonged blood circulation and highly increased accumulation in tumor tissue as observed in real-time imaging in vivo. After laser irradiation, gelatin-Ce6-2 suppressed tumor growth completely and enabled improved PDT compared to free Ce6 and gelatin-Ce6-8. CONCLUSIONS: This work demonstrates that a simple structure based on photosensitizer and gelatin can highly improve water solubility and stability. Superior tumor tissue accumulation and increased therapeutic efficacy of gelatin-Ce6 during in vivo PDT showed its high potential for clinical application.

Longer Observation Time Increases Proportion of Neoplasms Detected by Esophagogastroduodenoscopy.

BACKGROUND & AIMS: Esophagogastroduodenoscopy (EGD) is commonly used to detect upper gastrointestinal (GI) neoplasms. However, there is little evidence that longer examination time increases rate of detection of upper GI neoplasia. We investigated the association between length of time spent performing a normal screening EGD and rate of neoplasm detection. METHODS: We performed a retrospective analysis of data from 111,962 subjects who underwent EGD as part of a comprehensive health-screening program from January 2009 to December 2015 in Korea. Endoscopy findings were extracted from reports prepared by 14 board-certified endoscopists. Endoscopists were classified as fast or slow based on their mean examination time for a normal EGD without biopsy during their first year of the study. All endoscopists used the same endoscopy unit. We obtained findings from histologic analyses of GI biopsies from patient records; positive findings were defined as the detection of neoplasms (esophageal, gastric, or duodenal lesions). We examined the association between examination time and proportions of neoplasms detected. The primary outcome measure was the rate of neoplasm detection for each endoscopist (total number of neoplastic lesions detected divided by the number of subjects screened) and as the proportion of subjects with at least 1 neoplastic lesion. RESULTS: The mean examination time was 2 minutes 53 seconds. Using 3 minutes as a cutoff, we classified 8 endoscopists as fast (mean duration, 2:38 ± 0:21 minutes) and 6 endoscopists as slow (mean duration, 3:25 ± 0:19 minutes). Each endoscopist's mean examination time correlated with their rate of neoplasm detection (R2 = 0.54; P = .046). Fast endoscopists identified neoplasms in the upper GI tract in 0.20% of patients, whereas slow endoscopists identified these in 0.28% of patients (P = .0054). The frequency of endoscopic biopsy varied among endoscopists (range, 6.9%-27.8%) and correlated with rate of neoplasm detection (R2 = 0.76; P = .0015). On multivariable analysis, slow endoscopists were more likely to detect gastric adenomas or carcinomas than fast endoscopists (odds ratio, 1.52; 95% CI, 1.17-1.97). CONCLUSIONS: In a retrospective analysis of data from more than 100,000 subjects who underwent EGD in a screening program, we found slow endoscopists detected a higher proportion of neoplasms than fast endoscopists. Examination time is therefore a useful indicator of quality for EGD.