Multicenter prospective randomized controlled clinical trial comparing the pocket-creation method with and without single-clip traction of colonic endoscopic submucosal dissection.

BACKGROUND: The pocket-creation method (PCM) was developed to overcome the technical difficulties of endoscopic submucosal dissection (ESD), although opening the pocket remains challenging. We developed a novel technique of PCM with single-clip traction (PCM-CT), which uses a reopenable clip as a traction device to maintain stability during the procedure. No prospective study has compared the efficacy of PCM-CT and PCM. This study aimed to investigate the effectiveness of PCM-CT vs. PCM in a randomized controlled trial. METHODS: This randomized controlled clinical trial was conducted at four Japanese institutions. Patients with superficial colorectal neoplastic lesions were included following Japanese guidelines for colorectal cancer. Seven moderately experienced endoscopists performed the ESD procedures using either PCM-CT or PCM. RESULTS: 100 patients were enrolled in the study. Compared with PCM, PCM-CT achieved significantly faster mean (SD) dissection speed (21.4 [10.8] vs. 27.0 [14.5] mm2/min [95%CI 0.5 to 10.7], P = 0.03), and reduced the mean procedure time (81.8 [57.9] vs. 64.8 [47.6] minutes [95%CI -38.2 to 4.3], P = 0.12) and pocket-opening time (37.8 [33.0] vs. 30.0 [28.9] minutes [95%CI -20.2 to 4.6], P = 0.22). En bloc and R0 resection rates were not significantly different between the two groups (100% vs. 100%, P >0.99; 100% vs. 96%, P = 0.50, respectively). No significant differences were observed in adverse events between the two groups. CONCLUSION: ESD facilitated by the novel PCM-CT method appeared to be significantly faster than PCM. Both methods achieved high R0 resection rates.

Endoscopic resection for gastric submucosal tumors: Japanese multicenter retrospective study.

OBJECTIVES: Limited information is available on the efficacy and safety of endoscopic resection (ER) of gastric submucosal tumors (SMTs) in Japanese endoscopic practice where ER for gastric tumors is extremely popular. METHODS: We conducted this study to elucidate the current scenario of ER for gastric SMTs in Japanese endoscopic practice. Patients (from 12 institutions) with gastric SMTs who underwent ER were enrolled from the first case until August 2020. RESULTS: We enrolled 117 patients with 118 lesions. The number of patients who underwent ER increased over the years. The mean endoscopic tumor size was 20 ± 7.2 (8-40) mm. The growth type was primarily intraluminal (90%). The mean resection and wound closure times were 58 ± 38 (range, 12-254) min and 31 ± 41 (range, 3-330) min, respectively. Complete ER was achieved for 117 (99%) lesions. Full-thickness resection rate was 44%; however, only 12 (10%) patients required abdominal paracentesis for decompression. Endoscopic treatments were completed in 115 (97%) lesions, while three lesions required conversions to laparoscopic surgery due to luminal collapse, uncontrolled bleeding, and difficulty in defect closure. Gastrointestinal stromal tumors were the most common pathology (74%). No recurrence was observed during the mean follow-up period of 4.3 ± 2.9 years. The 5-year overall survival rate was 98.9% (95% confidence interval 97.8-100%). CONCLUSION: Performance of ER for gastric SMTs is increasing in Japan. The technique seems feasible in Japanese endoscopic practice, warranting further validation in a prospective study.

Additional staining for lymphovascular invasion is associated with increased estimation of lymph node metastasis in patients with T1 colorectal cancer: Systematic review and meta-analysis.

OBJECTIVES: Lymphovascular invasion (LVI) is a critical risk factor for lymph node metastasis (LNM), which requires additional surgery after endoscopic resection of T1 colorectal cancer (CRC). However, the impact of additional staining on estimating LNM is unclear. This systematic review aimed to evaluate the impact of additional staining on determining LNM in T1 CRC. METHODS: We searched five electronic databases. Outcomes were diagnostic odds ratio (DOR), assessed using hierarchical summary receiver operating characteristic curves, and interobserver agreement among pathologists for positive LVI, assessed using Kappa coefficients (κ). We performed a subgroup analysis of studies that simultaneously included a multivariable analysis for other risk factors (deep submucosal invasion, poor differentiation, and tumor budding). RESULTS: Among the 64 studies (18,097 patients) identified, hematoxylin-eosin (HE) and additional staining for LVI had pooled sensitivities of 0.45 (95% confidence interval [CI] 0.32-0.58) and 0.68 (95% CI 0.44-0.86), specificities of 0.88 (95% CI 0.78-0.94) and 0.76 (95% CI 0.62-0.86), and DORs of 6.26 (95% CI 3.73-10.53) and 6.47 (95% CI 3.40-12.32) for determining LNM, respectively. In multivariable analysis, the DOR of additional staining for LNM (DOR 5.95; 95% CI 2.87-12.33) was higher than that of HE staining (DOR 1.89; 95% CI 1.13-3.16) (P = 0.01). Pooled κ values were 0.37 (95% CI 0.22-0.52) and 0.62 (95% CI 0.04-0.99) for HE and additional staining for LVI, respectively. CONCLUSION: Additional staining for LVI may increase the DOR for LNM and interobserver agreement for positive LVI among pathologists.

Nonrecurrence Rate of Underwater EMR for ≤20-mm Nonampullary Duodenal Adenomas: A Multicenter Prospective Study (D-UEMR Study).

BACKGROUND AND AIMS: Endoscopic resection of nonampullary duodenal adenoma is often challenging, and its technique has not yet been standardized. To overcome the practical difficulty of conventional endoscopic mucosal resection, underwater endoscopic mucosal resection (UEMR) was recently developed; therefore, we investigated the effectiveness and safety of UEMR for nonampullary duodenal adenoma. METHODS: A multicenter, prospective cohort study was conducted at 21 institutions in Japan. We enrolled patients with no more than 2 nonampullary duodenal adenomas ≤20 mm in size, who were planned to undergo UEMR. After UEMR, follow-up endoscopies were scheduled at 2 and 12 months after the procedure, and biopsy specimens were taken from the post-UEMR scars. The primary endpoint was the proportion of patients with histologically proven nonrecurrence at follow-up endoscopy and biopsy. RESULTS: A total of 155 patients with 166 lesions underwent UEMR. One patient with a non-neoplastic lesion in the resected specimen and 10 patients with 10 lesions who were lost to follow-up were excluded. Finally, 144 patients with 155 lesions who received all follow-up endoscopies were analyzed for the primary endpoint. The proportion of patients with proven nonrecurrence was 97.2% (n = 140 of 144; 95% confidence interval, 92.8%-99.1%) which exceeded the predefined threshold value (92%). Two cases of delayed bleeding (1.2%) occurred and they were successfully managed by clips. All recurrences were successfully treated by additional endoscopic treatment. CONCLUSIONS: This multicenter, prospective cohort study demonstrated effectiveness and safety of UEMR for nonampullary duodenal adenomas ≤20 mm in size. (University Hospital Medical Network Clinical Trials Registry, Number: UMIN000030414).

Performance of perioperative antibiotics against post-endoscopic submucosal dissection coagulation syndrome: a multicenter randomized controlled trial.

BACKGROUND AND AIMS: This study aimed to evaluate the efficacy of perioperative antibiotics against post-endoscopic submucosal dissection (ESD) coagulation syndrome (PECS) in patients undergoing colorectal ESD. METHODS: A prospective, multicenter, randomized controlled, parallel, superiority trial was conducted at 21 Japanese tertiary institutions. Patients with superficial colorectal lesions ≥20 mm and those undergoing ESD management for a single lesion were eligible. Patients with perforation during and after ESD were withdrawn. Before the ESD procedure, participants were randomly assigned (1:1) to either undergo conventional treatment (nonantibiotic group) or investigational treatment (antibiotic group). In the antibiotic group, 3 g of ampicillin-sulbactam was administered just before, 8 hours after, and the morning after ESD. The primary endpoint was the incidence of PECS. The onset of PECS was defined as localized abdominal pain (both spontaneous pain and tenderness) and fever (≥37.6°C) or inflammatory response (leukocytosis [≥10,000 cells/µL] or elevated C-reactive protein level [≥.5 mg/dL]). RESULTS: From February 5, 2019 to September 7, 2020, 432 patients were enrolled and assigned to the antibiotic group (n = 216) or nonantibiotic group (n = 216). After withdrawal of 52 patients, 192 in the antibiotic group and 188 in the nonantibiotic group were analyzed. PECS occurred in 9 of 192 patients (4.7%) in the antibiotic group and 14 of 188 patients (7.5%) in the nonantibiotic group, with an odds ratio of .61 (95% confidence interval, .23-1.56; P = .29). CONCLUSIONS: Perioperative use of antibiotics was not effective in reducing the incidence of PECS in patients undergoing colorectal ESD. (Clinical trial registration number: UMIN000035178.).

Computer-aided diagnosis of serrated colorectal lesions using non-magnified white-light endoscopic images.

PURPOSE: Computer-aided diagnosis systems for polyp characterization are commercially available but cannot recognize subtypes of sessile lesions. This study aimed to develop a computer-aided diagnosis system to characterize polyps using non-magnified white-light endoscopic images. METHODS: A total of 2249 non-magnified white-light images from 1030 lesions including 534 tubular adenomas, 225 sessile serrated adenoma/polyps, and 271 hyperplastic polyps in the proximal colon were consecutively extracted from an image library and divided into training and testing datasets (4:1), based on the date of colonoscopy. Using ResNet-50 networks, we developed a classifier (1) to differentiate adenomas from serrated lesions, and another classifier (2) to differentiate sessile serrated adenoma/polyps from hyperplastic polyps. Diagnostic performance was assessed using the testing dataset. The computer-aided diagnosis system generated a probability score for each image, and a probability score for each lesion was calculated as the weighted mean with a log10-transformation. Two experts (E1, E2) read the identical testing dataset with a probability score. RESULTS: The area under the curve of classifier (1) for adenomas was equivalent to E1 and superior to E2 (classifier 86%, E1 86%, E2 69%; classifier vs. E2, p < 0.001). In contrast, the area under the curve of classifier (2) for sessile serrated adenoma/polyps was inferior to both experts (classifier 55%, E1 68%, E2 79%; classifier vs. E2, p < 0.001). CONCLUSION: The classifier (1) developed using white-light images alone compares favorably with experts in differentiating adenomas from serrated lesions. However, the classifier (2) to identify sessile serrated adenoma/polyps is inferior to experts.

Depth of the cutting plane with underwater and conventional endoscopic mucosal resection: Post-hoc analysis of a randomized study.

BACKGROUND AND AIM: A multicenter randomized controlled trial reported a better R0 resection rate for intermediate-sized (10-20 mm) colorectal polyps with underwater endoscopic mucosal resection (UEMR) than conventional endoscopic mucosal resection (CEMR). To clarify whether UEMR removes enough submucosal tissue in the removal of unpredictable invasive cancers, we investigated the cutting plane depth with UEMR versus CEMR. METHODS: This was a post-hoc analysis of a randomized controlled trial in which 210 intermediate-sized colorectal polyps were removed in five Japanese hospitals. One pathologist and two gastroenterologists independently reviewed all resected specimens and measured the cutting plane depth. The cutting plane depth was evaluated as (i) maximum depth of submucosal layer and (ii) mean depth of submucosal layer, calculated using a virtual pathology system. RESULTS: We identified 168 appropriate specimens for the evaluation of the cutting plane depth, resected by UEMR (n = 88) and CEMR (n = 80). The median resection depth was not significantly different between UEMR and CEMR specimens, regardless of the measurement method ([i] 1317 vs 1290 µm, P = 0.52; [ii] 619 vs 545 µm, P = 0.32). All specimens in the UEMR and CEMR groups contained substantial submucosa and no muscularis propria. CONCLUSIONS: The cutting plane depth with UEMR was comparable with that with CEMR. UEMR can be a viable alternative method that adequately resects the submucosal layer for the histopathological assessment of unpredictable submucosal invasive cancers.

Comparison of Underwater vs Conventional Endoscopic Mucosal Resection of Intermediate-Size Colorectal Polyps.

BACKGROUND & AIMS: Endoscopic mucosal resection (EMR) with submucosal injection is an established method for removing colorectal polyps, although the en bloc resection rate decreases when polyp size exceeds 10 mm. Piecemeal resection increases local recurrence. Underwater EMR (UEMR) is an effective technique for removal of sessile colorectal polyps and we investigated whether it is superior to conventional EMR (CEMR). METHODS: We conducted a multicenter randomized controlled trial at 5 institutions in Japan. Patients with endoscopically diagnosed, intermediate-size (10-20 mm) sessile colorectal lesions were randomly assigned to undergo UEMR or CEMR. Only the most proximal lesion was registered. The UEMR procedure included immersion of the entire lumen in water and snare resection of the lesion without submucosal injection of normal saline. We analyzed outcomes of 108 colorectal lesions in the UEMR group and 102 lesions in the CEMR group. R0 resection was defined as en bloc resection with a histologically confirmed negative resection margin. The primary endpoint was the difference in the R0 resection rates between groups. RESULTS: The proportions of R0 resections were 69% (95% confidence interval [CI] 59%-77%) in the UEMR group vs 50% (95% CI 40%-60%) in the CEMR group (P = .011). The proportions of en bloc resections were 89% (95% CI 81%-94%) in the UEMR group vs 75% (95% CI 65%-83%) in the CEMR group (P = .007). There was no significant difference in median procedure time (165 vs 175 seconds) or proportions of patients with adverse events (2.8% in the UEMR group vs 2.0% in the CEMR group). CONCLUSIONS: In a multicenter randomized controlled trial, we found that UEMR significantly increased the proportions of R0 resections for 10- to 20-mm sessile colorectal lesions without increasing adverse events or procedure time. Use of this procedure should be encouraged. Trials registry number: UMIN000018989.

Prospective randomized trial comparing the pocket-creation method and conventional method of colorectal endoscopic submucosal dissection.

BACKGROUND AND AIMS: Colorectal endoscopic submucosal dissection (ESD) is recognized as a challenging procedure. Previously, we reported that a new ESD strategy using the pocket-creation method (PCM) is useful for colorectal ESD, but no prospective randomized study has evaluated the efficacy of the PCM. The aim of this study was to evaluate the efficacy and safety of PCM for colorectal ESD compared with the conventional method (CM). METHODS: This was a prospective randomized controlled trial at 3 institutions in Japan. Patients with superficial colorectal neoplastic lesions >20 mm predicted to be intramucosal were randomly assigned to undergo ESD using the PCM or CM. Primary outcome was the ESD completion rate defined as completion of colorectal ESD with an en bloc resection using the assigned ESD method without changing to other methods or assisted by other devices. RESULTS: We analyzed 59 patients with 59 colorectal tumors in the PCM group and 55 in the CM group. The ESD completion rate was significantly higher in the PCM group compared with the CM group (93% [55/59] vs 73% [40/55]; P  = .01). En bloc resection rates, R0 resection rates, procedure time, and dissection speed were not significantly different between the 2 groups. The incidence of adverse events was similar in the 2 groups. CONCLUSIONS: Use of the PCM allows the endoscopist to complete the procedure with the intended method more often than the CM with similar clinical outcomes. (Clinical trial registration number: UMIN 000024394.).

Endoscopic Balloon Dilation Followed By Intralesional Steroid Injection for Anastomotic Strictures After Esophagectomy: A Randomized Controlled Trial.

OBJECTIVE: Endoscopic balloon dilation (EBD) is a standard treatment for anastomotic strictures after esophagectomy, and requires multiple dilations. We conducted a randomized controlled trial to assess the efficacy of adding a steroid injection to EBD to reduce restricture. METHODS: Patients were randomized to receive EBD combined with either triamcinolone or placebo injection. The primary endpoint was the number of dilations required to resolve the stricture. The secondary endpoints were restricture-free survival and adverse events. Patients with a dysphagia symptom score of ≥2 after esophagectomy with an endoscopy-confirmed anastomotic stricture were included. A total of 50 mg of triamcinolone acetonide (50 mg/5 mL) or an identical volume of normal saline solution as a placebo was injected per site using a 25-gauge needle immediately after EBD. Both the patient and treating physician were blinded to the treatment given. RESULTS: During the 4-year study period, 65 patients were randomized to either the steroid group (n = 33) or placebo group (n = 32). The median number of EBDs required to resolve strictures was 2.0 (interquartile range, 1.0-2.5) in the steroid group and 4.0 (interquartile range, 2.0-6.8) in the placebo group (p < 0.001). After 6 months of follow-up, 39% of patients who had received steroid injections remained recurrence free compared with 16% of those who had received saline injections (p = 0.002). No adverse events occurred during follow-up. CONCLUSIONS: Steroid injection shows promising results for the prevention of stricture recurrence in patients who underwent EBD for anastomotic strictures.

Balloon-assisted endoscopy facilitates endoscopic submucosal dissection of difficult superficial proximal colon tumors.

BACKGROUND: Colorectal endoscopic submucosal dissection (ESD) can be technically difficult in some situations, such as paradoxical movement of the proximal colon. The double-balloon endoscope provides stable endoscopic maneuvering, even in the small intestine. The aim of this study was to assess the outcomes of balloon-assisted endoscopic submucosal dissection (BAESD) of colonoscopically difficult superficial proximal colon tumors. METHODS: We retrospectively reviewed the records of patients who underwent BAESD of superficial proximal colon tumors where colonoscopic difficulties were encountered, from January 2011 to September 2016. Difficulties were defined as a previous incomplete colonoscopy using a conventional colonoscope or unstable endoscopic maneuverability around the tumor with a conventional colonoscope. A propensity score model was used as a secondary analysis to compare outcomes of the BAESD group with those of a non-BAESD group.  RESULTS: BAESD was performed on 63 tumors in 63 patients. En bloc resection was achieved for 62 tumors (98 %) and an R0 resection was achieved for 55 tumors (87 %). Propensity score matching analysis created 59 matched pairs from the BAESD and non-BAESD groups. There were no statistically significant differences between the two groups in en bloc resection (100 % vs. 100 %; P > 0.99), R0 resection (90 % vs. 93 %; P = 0.74), perforation (0 % vs. 2 %; P > 0.99) or postoperative bleeding (3 % vs. 0 %; P = 0.50). CONCLUSION: Balloon-assisted endoscopy achieved safe and reliable ESD of colonoscopically difficult superficial proximal colon tumors.

Line-assisted complete closure for a large mucosal defect after colorectal endoscopic submucosal dissection decreased post-electrocoagulation syndrome.

BACKGROUND AND AIM: The incidence of post-endoscopic submucosal dissection (ESD) coagulation syndrome (PECS) can be decreased by closing mucosal defects. However, large mucosal defects after colorectal ESD cannot be closed endoscopically. We established line-assisted complete clip closure (LACC), a novel technique for large mucosal defects after colorectal ESD. We evaluated the prophylactic efficacy of LACC for preventing PECS. METHODS: Sixty-one consecutive patients on whom LACC after colorectal ESD was attempted from January 2016 to August 2016 were analyzed. After exclusion of patients with incomplete LACC and adverse events during ESD, 57 patients comprised the LACC group. In contrast, 495 patients who did not undergo closure of a mucosal defect comprised the control group. Propensity score matching was used to adjust for patients' backgrounds. Treatment outcomes were evaluated between the groups. RESULTS: Median resected specimen size in the LACC-attempted group was 35 mm (range, 20-72 mm), and LACC success rate was 95% (58/61). Median procedure time of LACC was 14 min. In the LACC group, incidence of PECS was only 2%, and no delayed bleeding or perforation occurred. Propensity score matching created 51 matched pairs. Adjusted comparisons between the LACC and control groups showed a lower incidence of PECS (0% vs 12%, respectively; P = 0.03) and shorter hospitalization (5 vs 6 days, respectively; P < 0.001) in the LACC group. CONCLUSION: This study suggests that LACC can effectively reduce the incidence of PECS, although further large-scale studies are warranted.

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.