A novel artificial intelligence-based endoscopic ultrasonography diagnostic system for diagnosing the invasion depth of early gastric cancer.

BACKGROUND: We developed an artificial intelligence (AI)-based endoscopic ultrasonography (EUS) system for diagnosing the invasion depth of early gastric cancer (EGC), and we evaluated the performance of this system. METHODS: A total of 8280 EUS images from 559 EGC cases were collected from 11 institutions. Within this dataset, 3451 images (285 cases) from one institution were used as a development dataset. The AI model consisted of segmentation and classification steps, followed by the CycleGAN method to bridge differences in EUS images captured by different equipment. AI model performance was evaluated using an internal validation dataset collected from the same institution as the development dataset (1726 images, 135 cases). External validation was conducted using images collected from the other 10 institutions (3103 images, 139 cases). RESULTS: The area under the curve (AUC) of the AI model in the internal validation dataset was 0.870 (95% CI: 0.796-0.944). Regarding diagnostic performance, the accuracy/sensitivity/specificity values of the AI model, experts (n = 6), and nonexperts (n = 8) were 82.2/63.4/90.4%, 81.9/66.3/88.7%, and 68.3/60.9/71.5%, respectively. The AUC of the AI model in the external validation dataset was 0.815 (95% CI: 0.743-0.886). The accuracy/sensitivity/specificity values of the AI model (74.1/73.1/75.0%) and the real-time diagnoses of experts (75.5/79.1/72.2%) in the external validation dataset were comparable. CONCLUSIONS: Our AI model demonstrated a diagnostic performance equivalent to that of experts.

Utility and advantage of the unroofing technique for gastrointestinal subepithelial tumors: A multicenter retrospective cohort study.

Background and aim: Various techniques for direct biopsy from gastrointestinal subepithelial tumors (SETs) have been reported, although no standard method has been established. A common feature of these techniques is the removal of overlaying mucosa to enable direct biopsies from the SETs. These methods have been synthesized under the collective term "unroofing technique". We conducted a multicenter retrospective study to assess its efficacy and identify potential complications. Methods: This study was conducted in 10 hospitals and involved all eligible patients who underwent unroofing techniques to obtain biopsies for gastrointestinal SETs between April 2015 and March 2021. The primary endpoint was the diagnostic accuracy of the unroofing technique, and the secondary endpoints were the incidence of adverse events and the factors contributing to the accurate diagnosis. Results: The study included 61 patients with 61 gastrointestinal SETs. The median tumor size was 20 mm, and the median procedure time was 38 min, with 82% successful tumor exposure. The rate of pathological diagnosis was 72.1%. In 44 patients with a pathological diagnosis, two showed discrepancies with the postresection pathological diagnosis. No factors, including facility experience, organ, tumor size, or tumor exposure, significantly affected the diagnostic accuracy. There was one case of delayed bleeding and two cases of perforation. Conclusion: The diagnostic yield of the unroofing technique was acceptable. The unroofing technique was beneficial regardless of institutional experience, organ, tumor size, or actual tumor exposure.

A Case of Lamina Lucida-Type Linear IgA Disease Complicated by Colon Polyposis and Rectal Adenocarcinoma.

Linear IgA disease (LAD) is a rare autoimmune bullous disease characterized by IgA deposition in the basement membrane zone (BMZ). A 66-year-old male was treated for myelodysplastic syndrome at our hospital for 5 years, during which his condition remained stable. He visited our department because of erythema with itching, which appeared 1 year ago and gradually exacerbated with the development of blisters and erosions. During the first visit, multiple erythemas with erosions and crusts on their periphery were observed on the trunk and lower limbs. Histopathological examination revealed subepidermal blisters with inflammatory cell infiltration, mainly constituting of neutrophils, eosinophils, and lymphocytes. Direct and indirect immunofluorescence showed linear IgA deposits in the BMZ and IgA anti-BMZ antibodies, respectively, while immunoblotting using a concentrated culture supernatant of HaCaT cells detected IgA antibodies reactive to 120-kDa LAD-1. Accordingly, the patient was diagnosed with lamina lucida-type LAD. Subsequent colonoscopy revealed multiple colorectal polyps and rectal adenocarcinoma (Tis, N0, and M0). Multigene panel test showed an ATM variant of unknown significance but did not detect any pathogenic variants associated with intestinal polyposis syndrome. The skin lesions quickly resolved with oral diaphenylsulfone 50 mg/day and resection of the colorectal polyps and adenocarcinoma. To our knowledge, this is the first reported case of LAD associated with multiple colorectal polyps and rectal adenocarcinoma. Additionally, we also analyzed reported cases of LAD associated with malignancy from the literature.

Occupational radiation exposure to the lens of the eyes and its protection during endoscopic retrograde cholangiopancreatography.

This study aimed to examine occupational radiation exposure to the lens of the eyes during endoscopic retrograde cholangiopancreatography (ERCP). In this multicenter, prospective, observational cohort study, we collected data regarding occupational radiation exposure to the lens of the eyes during ERCP. We measured radiation exposure of patients and examined its correlation with occupational exposure. In dosimetrically-measured ERCPs (n = 631), the median air kerma at the patient entrance reference point, air kerma-area product, and fluoroscopy time were 49.6 mGy, 13.5 Gycm2, and 10.9 min, respectively. The median estimated annual radiation dose to the lens of the eyes was 3.7, 2.2, and 2.4 mSv for operators, assistants, and nurses, respectively. Glass badge over lead aprons and eye dosimeter results were similar in operators but differed in assistants and nurses. A strong correlation was shown between eye dosimeter measurements and patients' radiation exposure. The shielding rates of the lead glasses were 44.6%, 66.3%, and 51.7% for operators, assistants, and nurses, respectively. This study revealed the actual occupational exposure dose for the lens of the eyes during ERCP and the efficacy of lead glass. Values of radiation exposure to patients can help estimate exposure to the lens of the eyes of medical staff.

Diagnostic value of endoscopic ultrasonography for the depth of gastric cancer suspected of submucosal invasion: a multicenter prospective study.

BACKGROUND: Although the combination of conventional endoscopy (CE) and endoscopic ultrasonography (EUS) is useful for predicting the depth of early gastric cancer (EGC), the diagnostic value of EUS for submucosal (SM) invasive cancer has not been fully investigated. METHODS: We conducted a multicenter prospective study from May 2017 to January 2021 to evaluate the validity of a diagnostic strategy combining CE and EUS and to clarify the additional value of EUS for EGC suspected of SM invasion. In each case, the diagnosis was first made using CE, followed by EUS, and finally confirmed using a combination algorithm. RESULTS: A total of 180 patients with EGC were enrolled from 10 institutions, of which 175 were analyzed. The histopathological depths were M, SM1, SM2, and ≥ MP in 72, 16, 64, and 23 lesions, respectively. Treatment included 92 endoscopic submucosal dissection cases and 83 surgical cases. The overall diagnostic accuracy classified by M-SM1 or SM2-MP was 58.3% for CE, 75.7% for EUS, and 78.9% for the combination of CE and EUS; the latter two were significantly higher than that of CE alone (P < 0.001). The CE, EUS, and combination accuracy rates in 108 differentiated-type lesions were 51.9%, 77.4%, and 79.6%, respectively; the latter two were significantly higher than CE alone (P < 0.001). A significant additive effect of EUS was observed in CE-SM2 low-confidence lesions but not in CE-M-SM1 lesions or in CE-SM2 high-confidence lesions. Among the nine CE findings, irregular surface, submucosal tumor-like elevation, and non-extension signs were significant independent markers of pSM2-MP. Poorly delineated EUS lesions were misdiagnosed. CONCLUSIONS: EUS provides additional value for differentiated-type and CE-SM2 low-confidence EGCs in diagnosing invasion depth. CLINICAL REGISTRATION NUMBER: UMIN000025862.

Clinical and Histopathological Features of the Differentiated Type of Early Gastric Cancer with an Unclear Lateral Demarcation.

INTRODUCTION: Magnifying endoscopy with narrow-band imaging (M-NBI) is useful for determining lateral demarcation of early gastric cancers; however, this is sometimes difficult. Features related to an unclear lateral demarcation remain unknown. We evaluated the clinical and histopathological features of early gastric cancers with unclear lateral demarcation on M-NBI. METHODS: This single-center, retrospective, cohort study analyzed early gastric cancer treated by endoscopic submucosal dissection between January 2013 and August 2015. We evaluated the clinicopathological and immunohistochemical features using anti-p53, anti-Ki-67, anti-MUC5AC, anti-MUC6, anti-MUC2, and anti-CD10 antibody staining. We compared the lateral demarcation between the demarcation clear (DC) and the demarcation unclear (DU) lesions by using M-NBI. RESULTS: A total of 224 differentiated adenocarcinomas (DU group: 18 lesions; DC group: 206 lesions) were analyzed. A history of successful Helicobacter pylori eradication was significantly more frequent in the DU group (p = 0.001). We examined the tissues of 72 lesions (DU group: 18 lesions, DC group: 54 lesions [randomly selected]) immunohistochemically. The nonneoplastic superficial epithelium was observed more frequently in the DU group as compared to in the DC group (p = 0.006). Additionally, compared to the DC group, the DU group showed a significantly higher expression of the gastric phenotype markers (p = 0.023) and had lower p53 scores (p < 0.001) and Ki-67 labeling indexes (p = 0.029). Multivariate analysis revealed the nonneoplastic superficial epithelium and a low p53 score as the significant independent variables associated with an unclear lateral demarcation on M-NBI. CONCLUSIONS: The nonneoplastic superficial epithelium and a low p53 score were associated with difficulties in determining the lateral demarcation in early gastric cancers on M-NBI.

Geriatric nutritional risk index as a prognostic indicator in elderly patients with early colorectal cancer undergoing endoscopic submucosal dissection.

OBJECTIVES: Data on the long-term outcomes of endoscopic submucosal dissection (ESD) performed in elderly patients with early colorectal cancer (CRC) are limited. We analyzed the prognosis of elderly CRC patients, not only from the viewpoint of treatment curability but also from the patients' baseline physical condition assessed by several indexes. METHODS: A retrospective analysis of 729 patients aged ≥75 years who underwent ESD for Tis/T1 CRC in 16 institutions was conducted. The patients were classified into three groups based on curability: curative ESD (Group A, n = 582), non-curative ESD with additional surgery (Group B, n = 60), and non-curative ESD without additional surgery (Group C, n = 87). Overall survival (OS) was compared among the groups, and factors associated with reduced OS were investigated. RESULTS: The median follow-up periods in Groups A, B, and C were 41, 49, and 46 months, respectively (P = 0.62), during which 92 patients died. Two patients (0.3%) in Group A, none (0%) in Group B, and three (3.4%) in Group C died of CRC. Three-year OS rates in Groups A, B, and C were 93.9%, 96.1%, and 90.1%, respectively, without a significant difference (P = 0.07). Multivariate analysis indicated low (<96.3) geriatric nutritional risk index (GNRI) as the sole independent predictor for reduced OS (hazard ratio 3.37; 95% confidence interval 2.18-5.22; P < 0.0001). CONCLUSIONS: Low GNRI, but not the curability attained by ESD, was independently associated with reduced OS in patients with early CRC aged ≥75 years.

Effect of anticoagulants on the risk of delayed bleeding after colorectal endoscopic submucosal dissection.

Background and study aims In patients receiving antithrombotic therapy, the risks of delayed bleeding after endoscopic procedures for gastrointestinal neoplasms become a major problem. Few reports have shown the effects of delayed bleeding in patients taking anticoagulants after colorectal endoscopic submucosal dissection (ESD). This study aimed to evaluate the delayed bleeding events after colorectal ESD in patients receiving anticoagulant therapy. Patients and methods We retrospectively analyzed 87 patients taking anticoagulants who underwent colorectal ESD from April 2012 to December 2017 at 13 Japanese institutions participating in the Osaka Gut Forum. Among these patients, warfarin users were managed with heparin bridge therapy (HBT), continued use of warfarin, a temporary switch to direct oral anticoagulation (DOAC), or withdrawal of warfarin, and DOAC users were managed with DOAC discontinuation with or without HBT. We investigated the occurrence rate of delayed bleeding and compared the rates between warfarin and DOAC users. Results The delayed bleeding rate was 17.2 % among all patients. The delayed bleeding rate was higher in DOAC users than in warfarin users (23.3 % vs. 11.4 %, P  = 0.14), although no statistically significant difference was observed. In DOAC users, the delayed bleeding rates for dabigatran, rivaroxaban, apixaban, and edoxaban users appeared similar (30 %, 18.2 %, 22.2 %, and 25 %, respectively). The onset of delayed bleeding in both warfarin and DOAC users was late, averaging 6.9 and 9.4 days, respectively. Conclusions Among patients taking anticoagulants, the risk of delayed bleeding after colorectal ESD was relatively high and the onset of delayed bleeding was late.

Exosomal microRNAs derived from colon cancer cells promote tumor progression by suppressing fibroblast TP53 expression.

The tumor microenvironment offers favorable conditions for tumor progression, and activated fibroblasts, known as cancer-associated fibroblasts, play a pivotal role. TP53-deficient cancer cells are known to induce strong fibroblast activation. We aimed to elucidate the oncogenic role of exosomes derived from TP53-deficient colon cancer cells in fibroblast proliferation and tumor growth. Cancer cell-derived exosomes (CDEs) were isolated from the conditioned media of cancer cells using a sequential ultracentrifugation method. The effects of exosomes on tumor growth were evaluated using human cell lines (TP53-WT colon cancer, HCT116; TP53-mutant colon cancer, HT29; and fibroblasts, CCD-18Co and WI-38) and an immune-deficient nude mouse xenograft model. HCT116 (HCT116sh p53 ) cells deficient in TP53 accelerated cocultured fibroblast proliferation compared to TP53-WT HCT116 (HCT116sh control ) cells in vitro. Exosomes from HCT116sh p53 cells suppressed TP53 expression of fibroblasts and promoted their proliferation. Xenografts of HCT116sh p53 cells grew significantly faster than those of HCT116sh control cells in the presence of co-injected fibroblasts, but this difference was diminished by CDE inhibition. Microarray analysis identified upregulation of several microRNAs (miR-1249-5p, miR-6737-5p, and miR-6819-5p) in TP53-deficient CDEs, which were functionally proven to suppress TP53 expression in fibroblasts. Exosomes derived from TP53-mutant HT29 cells also suppressed TP53 expression in fibroblasts and accelerated their growth. The proliferative effect of HT29 on cocultured fibroblasts was diminished by inhibition of these miRNAs in fibroblasts. Our results suggest that CDEs play a pivotal role in tumor progression by fibroblast modification. Cancer cell-derived exosomes might, therefore, represent a novel therapeutic target in colon cancer.

The heart's exposure to radiation increases the risk of cardiac toxicity after chemoradiotherapy for superficial esophageal cancer: a retrospective cohort study.

BACKGROUND: Chemoradiotherapy effectively treats superficial esophageal cancer and is optimal to preserve organs. However, late toxicity, particularly in cardiac diseases, obstructs clinical outcomes. We revealed the risk factors for cardiac event development post-chemoradiotherapy. METHODS: Data from 80 patients who were diagnosed with submucosal invasive esophageal cancer without metastasis (confirmed using multiple modalities) and who underwent chemoradiotherapy between 2006 and 2014 were analyzed. Patients were 11% (9/80) female, and the median age and follow-up were 66.5 y and 73 mo, respectively. We calculated the individual radiation dose to the heart and analyzed relationships between the cardiac event occurrence rate and each clinical factor. RESULTS: The 5-y overall and recurrence-free survival rates were 74.6 and 62.4%, respectively. Among the total number of deaths, 34.6% was caused by esophageal cancer. During the follow-up, 13 patients developed severe cardiac events (ischemic heart diseases, n = 7; pericardial effusion, n = 3, atrial fibrillation, n = 1; and sudden death, n = 2). The significant risk factor for cardiac events post-chemoradiotherapy was the level of the heart's exposure to radiation, with higher exposure associated with greater occurrence. History of smoking, obesity, comorbidity, and history of cardiac disease were unrelated to cardiac event occurrence post-chemoradiotherapy. CONCLUSIONS: Chemoradiotherapy is a favorable intervention for superficial esophageal cancer. Reducing the radiation dose to the heart likely contributes to preventing cardiac toxicity post-chemoradiotherapy.

"Underwater" endoscopic submucosal dissection: a novel method for resection in saline with a bipolar needle knife for colorectal epithelial neoplasia.

BACKGROUND: Despite improvements in therapeutic strategy and instrumentation in colorectal endoscopic submucosal dissection (ESD), adverse events sometimes occur. Further advancements in available techniques are required to improve procedural success rates and safety. We developed a novel method for ESD in saline, referred to as "underwater" ESD (UESD). UESD involves using a bipolar needle knife and aims to enable complete resection while minimizing thermal damage to the muscle layer. In this study, we evaluated the safety and efficacy of this new technique. METHODS: This was a retrospective study using data from two referral centers and included 40 lesions diagnosed as colorectal epithelial neoplasia (> 20 mm in diameter or with severe fibrosis) and treated with UESD between December 2015 and March 2017. The main outcome measures were technical success rate, incidence of adverse events, and feasibility of histologic evaluation of the resected specimens. RESULTS: All 40 lesions, including those with submucosal fibrosis, underwent successful en bloc resection using the UESD technique. No procedural adverse events including perforation, delayed bleeding, and electrocoagulation syndrome were observed, and all patients had an uneventful clinical course associated with UESD. In all cases, UESD provided a resected specimen adequate for histological evaluation, without unwarranted burn effect to the tissues. CONCLUSIONS: Our UESD technique was safe and effective for complete resection of colorectal epithelial neoplasia.

Adenoma of colorectal laterally spreading tumor nongranular type with biological phenotypic features similar to cancer.

BACKGROUND AND AIM: Colorectal laterally spreading tumors (LSTs) are morphologically subdivided into granular (LST-G) and nongranular (LST-NG) categories. We aimed to elucidate the differences in oncogenic characteristics between the two types. METHODS: Laterally spreading tumors resected by endoscopic submucosal dissection and surgery from March 2009 to May 2017 were examined for p53 positivity, Ki-67 labeling index (LI), microvessel density, degree of fibrosis, intensities of inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT), and expression of acid mucins. We compared these factors between adenomas, noninvasive cancers, and invasive cancers, both LST-G and LST-NG. RESULTS: Ninety-three LST-G (53 adenomas [LST-GA] and 40 cancers [LST-GC]) and 55 LST-NG (24 adenomas [LST-NGA] and 31 cancers [LST-NGC]) were evaluated. Although p53 positivity was lower in LST-GA than in LST-NGA (P < 0.001), there was no difference between LST-GC and LST-NGC. Ki-67 LI was higher in LST-NGA than in LST-GA (P < 0.001) and higher in LST-NGC than in LST-GC of noninvasive cancers (P < 0.001). Microvessel density and degree of fibrosis were higher in LST-NGA than in LST-GA (P < 0.001), and intensities of iNOS and NT were also higher in LST-NGA than in LST-GA (P < 0.001). Expression of acid mucins was lower in LST-NGA than in LST-GA (P < 0.001). Although there were significant differences in p53 positivity, Ki-67 LI, microvessel density, degree of fibrosis, intensities of iNOS and NT, and expression of acid mucins between LST-GA and LST-NGA, these factors were only slightly different between LST-GC and LST-NGC of invasive cancers. CONCLUSIONS: Unlike LST-GA, LST-NGA possessed phenotypic features similar to cancer.

Early gastric cancer with lymphoid stroma presenting as a subepithelial lesion diagnosed by endoscopic submucosal dissection.

A 53-year-old man underwent an esophagogastroduodenoscopy that showed a 20-mm subepithelial lesion in the middle gastric body. Endoscopic ultrasound revealed a hypoechoic mass located in the submucosa. Biopsy specimens revealed a benign gastric mucosa with severe lymphocytic infiltration in the submucosa. Malignant lymphoma or gastric cancer with lymphoid stroma was suspected. We performed endoscopic submucosal dissection for definitive diagnosis. Histological examination showed undifferentiated adenocarcinoma, which showed positive Epstein-Barr virus-encoded RNA in situ hybridization results, invading the submucosa mixed with dense lymphocytic infiltration. Thus, Epstein-Barr virus-positive gastric cancer with lymphoid stroma was diagnosed. Gastric cancer with lymphoid stroma is a rare subtype of gastric cancer, which is associated with Epstein-Barr virus infection; it sometimes appears as a subepithelial lesion, which makes it difficult to diagnose using standard biopsy. Endoscopic submucosal dissection was useful in obtaining a sufficient tissue for full histological assessment, including immunostaining.

Risk of perforation in balloon dilation associated with steroid injection for preventing esophageal stricture after endoscopic submucosal dissection.

BACKGROUND AND STUDY AIMS: Endoscopic local steroid injection (LSI) has been used to prevent esophageal strictures after endoscopic submucosal dissection (ESD) for superficial esophageal neoplasms (SENs). This study aimed to evaluate the safety and efficacy of LSI therapy. PATIENTS AND METHODS: From May 2007 to September 2014, at four institutions, 40 consecutive patients with SENs were treated with ESD that left a mucosal defect of more than three-quarters of the esophageal circumference. Two patients who underwent esophagectomy after ESD were excluded, and 38 patients were analyzed. The incidence of post-ESD strictures and adverse events associated with LSI were retrospectively investigated. RESULTS: Prophylactic LSI was administered in 28 patients (LSI group), and not administered in 10 patients (Non-prevention group). Post-ESD stricture rates were significantly lower in the LSI group (43 %) than in the Non-prevention group (90 %) ( P  = 0.012). Endoscopic balloon dilation (EBD) was conducted in 11 patients (39 %) in the LSI group and in 7 (70 %) in the Non-prevention group. In the LSI group, perforation caused by EBD occurred in five patients, while in the Non-prevention group, it occurred in only one patient who had received subsequent LSI before the perforation. Four patients with perforation successfully recovered after conservative therapy, but the other two patients required surgical treatment. A review of follow-up examinations with endoscopic ultrasonography and narrow-band imaging showed impaired ulcer-healing process after LSI. CONCLUSION: LSI is useful for preventing post-ESD strictures, but it appears to increase the risk of perforation in cases of EBD.

Cardiac metastasis from colon cancer effectively treated with 5-fluorouracil, leucovorin, and oxaliplatin (modified FOLFOX6) plus panitumumab: a case report.

BACKGROUND: Cardiac metastasis from colorectal cancer is rare. There is little evidence supporting the effectiveness of chemotherapy, and standard therapy for metastatic cardiac tumors has not been established. CASE PRESENTATION: A 76-year-old woman presented with a right ventricle tumor that was detected incidentally on screening cardiac ultrasonography. The initial computed tomography (CT) scan showed the cardiac tumor, which was approximately 40 mm in size, and multiple pulmonary nodules. Serum levels of tumor markers CEA and CA19-9 were elevated aberrantly. The suspected primary tumor, a well-differentiated adenocarcinoma of the transverse colon with wild-type KRAS was found by colonoscopy, and treatment with 5-fluorouracil, leucovorin, and oxaliplatin (modified FOLFOX6) plus panitumumab was initiated. After 4 courses of the therapy, a CT scan showed that the cardiac tumor size had markedly decreased and the pulmonary nodules had diminished. The serum levels of CEA and CA19-9 were also markedly decreased. After 12 courses of chemotherapy during 10 months of treatment, the patient continued to show a partial response, and she remained asymptomatic with continuation of the treatment through 15 courses. CONCLUSION: To the best of our knowledge, this is the first report of the efficacy of combination therapy using cytotoxic and molecular targeted agents against cardiac metastasis from colon cancer.

Incomplete resection rate of cold snare polypectomy: a prospective single-arm observational study.

Background and study aims Cold snare polypectomy (CSP) is considered to be safe for the removal of subcentimeter colorectal polyps. This study aimed to determine the rate of incomplete CSP resection for subcentimeter neoplastic polyps at our center. Patients and methods Patients with small or diminutive adenomas (diameter 1 - 9 mm) were recruited to undergo CSP until no polyp was visible. After CSP, a 1 - 3 mm margin around the resection site was removed using endoscopic mucosal resection. The polyps and resection site marginal specimens were microscopically evaluated. Incomplete resection was defined as the presence of neoplastic tissue in the marginal specimen. We also calculated the frequency at which the polyp lateral margins could be assessed for completeness of resection. Results A total of 307 subcentimeter neoplastic polyps were removed from 120 patients. The incomplete resection rate was 3.9 % (95 % confidence interval [CI] 1.7 % - 6.1 %); incomplete resection was not associated with polyp size, location, morphology, or operator experience. The polyp lateral margins could not be assessed adequately for 206 polyps (67.1 %). Interobserver agreement between incomplete resection and lateral polyp margins that were inadequate for assessment was poor (κ = 0.029, 95 %CI 0 - 0.04). Female sex was an independent risk factor for incomplete resection (odds ratio 4.41, 95 %CI 1.26 - 15.48; P  = 0.02). Conclusions At our center, CSP resection was associated with a moderate rate of incomplete resection, which was not associated with polyp characteristics. However, adequate evaluation of resection may not be routinely possible using the lateral margin from subcentimeter polyps that were removed using CSP.Trial registered at University Hospital Medical Information Network (UMIN 000010879).

Scissor-type knife significantly improves self-completion rate of colorectal endoscopic submucosal dissection: Single-center prospective randomized trial.

BACKGROUND AND AIM: Colorectal endoscopic submucosal dissection (C-ESD) is recognized as a difficult procedure. Recently, scissors-type knives were launched to reduce the difficulty of C-ESD. The aim of this study was to evaluate the efficacy and safety of the combined use of a scissors-type knife and a needle-type knife with a water-jet function (WJ needle-knife) for C-ESD compared with using the WJ needle-knife alone. METHODS: This was a prospective randomized controlled trial in a referral center. Eighty-five patients with superficial colorectal neoplasms were enrolled and randomly assigned to undergo C-ESD using a WJ needle-knife alone (Flush group) or a scissor-type knife-supported WJ needle-knife (SB Jr group). Procedures were conducted by two supervised residents. Primary endpoint was self-completion rate by the residents. RESULTS: Self-completion rate was 67% in the SB Jr group, which was significantly higher than that in the Flush group (39%, P = 0.01). Even after exclusion of four patients in the SB Jr group in whom C-ESD was completed using the WJ needle-knife alone, the self-completion rate was significantly higher (63% vs 39%; P = 0.03). Median procedure time among the self-completion cases did not differ significantly between the two groups (59 vs 51 min; P = 0.14). No fatal adverse events were observed in either group. CONCLUSIONS: In this single-center phase II trial, scissor-type knife significantly improved residents' self-completion rate for C-ESD, with no increase in procedure time or adverse events. A multicenter trial would be warranted to confirm the validity of the present study.