Underwater Endoscopic Mucosal Resection Research Articles

Underwater Endoscopic Mucosal Resection Vs Conventional EMR for Superficial Nonampullary Duodenal Epithelial Tumors in the Western Setting

Background and aimsConventional endoscopic mucosal resection (C-EMR) is established as the primary treatment modality for superficial non-ampullary duodenal epithelial tumors (SNADETs) but recently underwater EMR (U-EMR) emerged as a potential alternative. The majority of previous studies focused on Asian populations and small lesions (≤20 mm). We aimed to compare the efficacy and outcomes of U-EMR versus C-EMR for SNADETs in a Western setting. MethodsThis was a retrospective multinational study from 10 European centers that performed both C-EMR and U-EMR between January 2013 and July 2023. The main outcomes were the technical success, procedure-related adverse events (AEs), and the residual/recurrent adenoma (RRA) rate, evaluated on a per-lesion basis. We assessed the association between the type of EMR and the occurrence of AEs or RRA using mixed-effects logistic regression models (propensity scores). Sensitivity analyses were performed for lesions ≤ or >20 mm. ResultsA total of 290 SNADETs submitted to endoscopic resection during the study period met the inclusion criteria and were analyzed (C-EMR n=201, 69.3%; U-EMR n=89, 30.7%). Overall technical success rate was 95.5% and comparable between groups. In logistic regression models, compared with U-EMR, C-EMR was associated with a significantly higher frequency of overall delayed AEs (OR 4.95; 95%CI=2.87-8.53), post-procedural bleeding (OR=7.92; 95%CI=3.95-15.89) and RRA (OR=3.66; 95%CI=2.49-5.37). Sensitivity analyses confirmed these results when solely considering either small (≤20 mm) or large (>20 mm) lesions. ConclusionCompared with C-EMR, U-EMR was associated with a lower rate of overall AEs and RRA, regardless of lesion size. Our results confirm the possible role of U-EMR as an effective and safe technique in the management of SNADETs.

Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024.

1: ESGE recommends cold snare polypectomy (CSP), to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of diminutive polyps (≤ 5 mm).Strong recommendation, high quality of evidence. 2: ESGE recommends against the use of cold biopsy forceps excision because of its high rate of incomplete resection.Strong recommendation, moderate quality of evidence. 3: ESGE recommends CSP, to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of small polyps (6-9 mm).Strong recommendation, high quality of evidence. 4: ESGE recommends hot snare polypectomy for the removal of nonpedunculated adenomatous polyps of 10-19 mm in size.Strong recommendation, high quality of evidence. 5: ESGE recommends conventional (diathermy-based) endoscopic mucosal resection (EMR) for large (≥ 20 mm) nonpedunculated adenomatous polyps (LNPCPs).Strong recommendation, high quality of evidence. 6: ESGE suggests that underwater EMR can be considered an alternative to conventional hot EMR for the treatment of adenomatous LNPCPs.Weak recommendation, moderate quality of evidence. 7: Endoscopic submucosal dissection (ESD) may also be suggested as an alternative for removal of LNPCPs of ≥ 20 mm in selected cases and in high-volume centers.Weak recommendation, low quality evidence. 8: ESGE recommends that, after piecemeal EMR of LNPCPs by hot snare, the resection margins should be treated by thermal ablation using snare-tip soft coagulation to prevent adenoma recurrence.Strong recommendation, high quality of evidence. 9: ESGE recommends (piecemeal) cold snare polypectomy or cold EMR for SSLs of all sizes without suspected dysplasia.Strong recommendation, moderate quality of evidence. 10: ESGE recommends prophylactic endoscopic clip closure of the mucosal defect after EMR of LNPCPs in the right colon to reduce to reduce the risk of delayed bleeding.Strong recommendation, high quality of evidence. 11: ESGE recommends that en bloc resection techniques, such as en bloc EMR, ESD, endoscopic intermuscular dissection, endoscopic full-thickness resection, or surgery should be the techniques of choice in cases with suspected superficial invasive carcinoma, which otherwise cannot be removed en bloc by standard polypectomy or EMR.Strong recommendation, moderate quality of evidence.

Present situation of minimally invasive surgical treatment for early gastric cancer.

Minimally invasive surgery is a kind of surgical operation, which is performed by using professional surgical instruments and equipment to inactivate, resect, repair or reconstruct the pathological changes, deformities and wounds in human body through micro-trauma or micro-approach, in order to achieve the goal of treatment, its surgical effect is equivalent to the traditional open surgery, while avoiding the morbidity of conventional surgical wounds. In addition, it also has the advantages of less trauma, less blood loss during operation, less psychological burden and quick recovery on patients, and these minimally invasive techniques provide unique value for the examination and treatment of gastric cancer patients. Surgical minimally invasive surgical techniques have developed rapidly and offer numerous options for the treatment of early gastric cancer (EGC): endoscopic mucosal resection (EMR), underwater EMR (UEMR), endoscopic submucosal dissection (ESD), endoscopic full-thickness resection (EFTR), endoscopic submucosal excavation (ESE), submucosal tunnel endoscopic resection), laparoscopic and endoscopic cooperative surgery (LECS); Among them, EMR, EFTR and LECS technologies have a wide range of applications and different modifications have been derived from their respective surgical operations, such as band-assisted EMR (BA-EMR), conventional EMR (CEMR), over-the-scope clip-assisted EFTR, no-touch EFTR, the inverted LECS, closed LECS, and so on. These new and improved minimally invasive surgeries are more precise, specific and effective in treating different types of EGC.

Underwater EMR in the reconstructed gastric conduit after esophagectomy

Video 1Three cases of underwater EMR for small gastric neoplasms in the reconstructed gastric conduit after esophagectomy.

Underwater versus conventional endoscopic mucosal resection for ≥10 mm sessile or flat colorectal polyps: A systematic review and meta-analysis.

Underwater endoscopic mucosal resection (UEMR) has been an emerging substitute for conventional EMR (CEMR). This systematic review and meta-analysis aimed at comparing the efficiency and safety of the two techniques for removing ≥10 mm sessile or flat colorectal polyps. PubMed, Cochrane Library and Embase databases were searched up to February 2023 to identify eligible studies that compared the outcomes of UEMR and CEMR. This meta-analysis was conducted on the en bloc resection rate, R0 resection rate, complete resection rate, procedure time, adverse events rate and recurrence rate. Nine studies involving 1,727 colorectal polyps were included: 881 were removed by UEMR, and 846 were removed by CEMR. UEMR was associated with a significant increase in en bloc resection rate [Odds ratio(OR) 1.69, 95% confidence interval(CI) 1.36-2.10, p<0.00001, I2 = 33%], R0 resection rate(OR 1.52, 95%CI 1.14-2.03, p = 0.004, I2 = 31%) and complete resection rate(OR 1.67, 95%CI 1.06-2.62, p = 0.03, I2 = 0%) as well as a significant reduction in procedure time(MD ‒4.27, 95%CI ‒7.41 to ‒1.13, p = 0.008, I2 = 90%) and recurrence rate(OR 0.52, 95%CI 0.33-0.83, p = 0.006, I2 = 6%). Both techniques were comparable in adverse events rate. UEMR can be a safe and efficient substitute for CEMR in removing ≥10 mm sessile or flat colorectal polyps. More studies verifying the advantages of UEMR over CEMR are needed to promote its application.

Feasibility and Efficacy of Gastric Underwater Endoscopic Mucosal Resection.

Gastric cancer, a leading cause of cancer-related deaths globally, necessitates effective and early detection and treatment strategies. Endoscopic resection techniques, particularly endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), have evolved significantly, enhancing the treatment of gastric neoplasms. Underwater endoscopic mucosal resection (UEMR) is a widely used technique for the resection of duodenal and colorectal neoplasms. However, the feasibility and efficacy of UEMR in the stomach are not well established. This retrospective observational study, conducted at a tertiary medical center, evaluated the efficacy and safety of UEMR in 81 patients with gastric neoplasms. Thus, it indicates that UEMR is a highly effective and safe technique for managing small to medium-sized gastric neoplasms, achieving 100% en bloc and 93.8% R0 resection rates with a low incidence of complications. Moreover, the procedure time was found to be significantly shorter for UEMR compared to ESD, thus highlighting its efficiency. While UEMR demonstrates high safety and efficacy, it is not suitable for all patients, with some requiring conversion to ESD as a treatment option. Despite the promising results, broader validation through extensive and randomized trials is recommended to establish UEMR as a standard approach in gastric cancer management.

A145 UNDERWATER EMR FOR LARGE FLAT DYSPLASTIC COLORECTAL LESIONS IN PATIENTS WITH CHRONIC ULCERATIVE COLITIS

Abstract Background Patients with chronic ulcerative colitis are at increased risk of colorectal cancer, in part due to increased prevalence of dysplastic lesions. To reduce CRC risk, endoscopic resection is preferable to surgery if feasible. However, large flat lesions can be challenging to remove endoscopically. We report our experience with underwater EMR for large, flat ulcerative colitis-associated dysplastic lesions. Aims To evaluate the safety and efficacy of UEMR for treatment of flat/sessile colorectal lesions with dysplasia, without overt signs of invasive cancer. To analyze rates of complications and outcomes for patients undergoing UEMR and compare to alternative methods of treatment for similar lesions. Methods We reviewed our IBD patient database from 2021 to 2023 for ulcerative colitis patients referred for large (≥ 20 mm diameter) flat/sessile colorectal lesions without overt signs of invasive cancer, who subsequently underwent underwater EMR. The procedure was performed by an endoscopist with extensive experience in UEMR for large colorectal lesions. Results Eleven de novo lesions in 8 patients (4 female; age 58 ± 14) were successfully treated with single-session UEMR. Mean lesion size was 42 ± 22 mm (range 20 to 80 mm); all morphologically flat (Paris IIa or IIb). Three cases were resected en bloc; the remainder piecemeal. Pathology showed tubulovillous adenoma, N=4 (36%); tubular adenoma, N=5 (45%); traditional serrated adenoma, N=1 (9%); sessile serrated lesion, N=1, (9%); high-grade dysplasia, N=1 (9%). There were no cases of invasive cancer. Endoscopic follow-up available for 5 patients over 10.4 ± 2 months showed benign diminutive recurrent/residual lesions in 2 cases, both amenable to UEMR. There were no procedural complications. Conclusions In this series of large, flat dysplastic CUC-associated lesions, UEMR was safe and effective, obviating surgery and endoscopic submucosal dissection. Funding Agencies None

A146 UNDERWATER EMR WITHOUT SUBMUCOSAL INJECTION FOR COLONIC ANGIODYSPLASIA

Abstract Background Angiodysplasia is a common source of overt or occult colonic bleeding. Lesions are amenable to endoscopic thermal treatment such as APC, which requires a dedicated device and carries a small risk of perforation. Underwater EMR without submucosal injection (UEMR) is safe and effective for colorectal polyps, and requires no special equipment. Aims This study explores the use of UEMR to treat colonic angiodysplasia. We endeavoured to assess the effectiveness of treatment with UEMR in patients with this unique condition and further quantify the safety and adequacy of the obtained sample to achieve diagnosis. Further analyses were undertaken to determine the cost-burden of this method compared to comparable methods of treatment. Methods Retrospective review of clinical database for patients who underwent UEMR for colonic angiodysplasia between 2021 and 2023. Indications for treatment were iron deficiency anemia (N=4), Hematochezia (N=2), and melena (N=1). Lesions were excised en bloc using standard UEMR technique without submucosal injection and soft-coagulation electrosurgical settings. Results Six patients (5 females, mean age 76 ± 10) underwent colonoscopy with UEMR for treatment of angiodysplasia. One patient with extensive lesions required two endoscopic sessions; the others were treated during a single procedure. The median number of lesions was two; range, 1 to 13). A total of 24 lesions (size 7 ± 2 mm) were treated with UEMR. All lesions were located in the proximal colon (cecum, 14; ascending colon, 10). Histology of excised specimens confirmed a diagnosis of angiodysplasia. There were no procedural complications. Overt bleeding and anemia resolved in all patients. Conclusions In this series of patients, UEMR without submucosal injection was simple, safe and effective for treatment of proximal colon angiodysplasia. Advantages of this approach over conventional therapy with APC include reduced equipment needs, lower cost and histologic diagnosis. Further study comparing UEMR to conventional thermal modalities is warranted. Funding Agencies None

Resectability of Small Duodenal Tumors: A Randomized Controlled Trial Comparing Underwater Endoscopic Mucosal Resection and Cold Snare Polypectomy.

Underwater endoscopic mucosal resection (UEMR) and cold snare polypectomy (CSP) are novel endoscopic procedures for superficial nonampullary duodenal epithelial tumors (SNADET). However, consensus on how to use both procedures appropriately has not been established. In this study, we evaluated treatment outcomes of both procedures, including resectability. In this single-center randomized controlled study conducted between January 2020 and June 2022, patients with SNADET ≤12 mm were randomly allocated to UEMR and CSP groups. The primary end point was sufficient vertical R0 resection (SVR0), which was defined as R0 resection including a sufficient submucosal layer. We compared treatment outcomes including SVR0 rate between groups. The SVR0 rate was significantly higher in the UEMR group than in the CSP group (65.6% vs 41.5%, P = 0.01). By contrast, the R0 resection rate was not significantly different between study groups (70.3% vs 61.5%, P = 0.29). The submucosal layer thickness was significantly greater in the UEMR group than in the CSP group (median 546 [range, 309-833] μm vs 69 [0-295] μm, P < 0.01). CSP had a shorter total procedure time (median 12 [range, 8-16] min vs 1 [1-3] min, P < 0.01) and fewer total bleeding events (9.4% vs 1.5%, P = 0.06). UEMR has superior vertical resectability compared with CSP, but CSP has a shorter procedure time and fewer bleeding events. Although CSP is preferable for most small SNADET, UEMR should be selected for lesions that cannot be definitively diagnosed as mucosal low-grade neoplasias.

Outcomes of cold snare EMR of nonampullary duodenal adenomas ≥1 cm: a multicenter study

Endoscopic mucosal resection (EMR) with use of electrocautery (conventional EMR) has historically been used to remove large duodenal adenomas; however, use of electrocautery can predispose to adverse events including delayed bleeding and perforation. Cold snare EMR (cs-EMR) has been shown to besafe and effective for removal of colon polyps, but data regarding its use in the duodenum are limited. Theaim of this study was to evaluate the efficacy and safety of cs-EMR for nonampullary duodenal adenomas≥1 cm. This was a multicenter retrospective study of patients with nonampullary duodenal adenomas≥1 cm who underwent cs-EMR from October 2014 to May 2023. Patients who received any form of thermal therapy were excluded. Primary outcomes were technical success and rate of recurrent adenoma. Secondary outcomes were adverse events and predictors of recurrence. A total of 125 patients underwent resection of 127 nonampullary duodenal adenomas with cs-EMR. Follow-up data were available in 89 cases (70.1%). The recurrent adenoma rate was 31.5% (n= 28). Adverse events occurred in 3.9% (n= 5), with 4 cases of immediate bleeding (3.1%) and 1 case of delayed bleeding (.8%). There were no cases of perforation. The presence of high-grade dysplasia was found to be an independent predictor of recurrence (odds ratio, 10.9 [95% confidence interval, 1.1-102.1]; P= .036). This retrospective multicenter study demonstrates that cs-EMR for nonampullary duodenal adenomas is safe and technically feasible with an acceptable recurrence rate. Future prospective studies are needed to directly compare outcomes of cs-EMR with conventional and underwater EMR.

Underwater endoscopic mucosal resection for a residual gastric lesion after unsuccessful endoscopic submucosal dissection in a patient with familial adenomatous polyposis.

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Tip-in underwater endoscopic mucosal resection for a residual lower rectal lesion extending to the dentate line

Tip-in underwater endoscopic mucosal resection for a residual lower rectal lesion extending to the dentate line

Salvage treatment for local recurrence after endoscopic resection for superficial nonampullary duodenal epithelial tumors

Background and AimsLocal recurrence is a significant concern in endoscopic resection of superficial nonampullary duodenal tumors (SNADTs). Our objective was to elucidate the clinical outcomes of salvage endoscopic treatment. MethodsThis retrospective study included consecutive patients who underwent endoscopic resection of SNADTs between January 2013 and December 2021. Four hundred thirty-three patients were observed, excluding those with familial adenomatous polyposis and those who did not undergo surveillance endoscopy. Local recurrence was defined as histologically proven adenoma or adenocarcinoma in contact with a prior endoscopic resection scar. The clinicopathological characteristics of patients with local recurrence and outcomes of salvage endoscopic treatment were evaluated. ResultsLocal recurrence occurred in 33 (8%) of the 433 patients after endoscopic resection for SNADT. Multivariate analysis identified older age (≥63 years), larger lesion size (≥13 mm), and piecemeal resection as significant independent predictors of local recurrence. Among the 33 patients with 33 recurrent lesions, 10 lesions (30%) disappeared after forceps biopsy. Three patients (9%) remained untreated. Sixteen lesions (48%) disappeared after one session of salvage endoscopic treatment, and four lesions (12%) disappeared after two sessions of treatment. Among these 24 treatment sessions, underwater endoscopic mucosal resection was performed in 19 sessions. The median post-procedural hospitalization period was four days (interquartile range, 3–4.25 days). Delayed bleeding occurred in three sessions. No recurrences have been detected in the 30 salvaged patients. The median recurrence-free survival time was 24.5 months (interquartile range, 14–48.75 months). ConclusionsLocal recurrence after endoscopic resection of SNADT can be managed endoscopically.

Conventional versus underwater endoscopic resection for superficial non-ampullary duodenal epithelial tumours.

Several endoscopic resection methods have been developed as less invasive treatments for superficial non-ampullary duodenal epithelial tumours. This study aimed to compare outcomes of conventional endoscopic mucosal resection and underwater endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumours, including resection depth and rate of the muscularis mucosa contained under the lesion. This single-centre retrospective cohort study conducted from January 2009 to December 2021 enrolled patients who underwent conventional endoscopic mucosal resection and underwater endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumours and investigated their clinicopathological outcomes using propensity score matching. Of the 285 superficial non-ampullary duodenal epithelial tumours, 98 conventional endoscopic mucosal resections and 187 underwater endoscopic mucosal resections were included. After propensity score matching, 64 conventional endoscopic mucosal resections and 64 underwater endoscopic mucosal resections were analysed. The R0 resection rate was significantly higher in underwater endoscopic mucosal resection cases than in conventional endoscopic mucosal resection cases (70.3% vs. 50.0%; P=0.030). In the multivariate analysis, a lesion diameter> 10mm (odds ratio 7.246; P=0.001), being in the 1st-50th treatment period (odds ratio 3.405; P=0.008), and undergoing conventional endoscopic mucosal resection (odds ratio 3.617; P=0.016) were associated with RX/R1 resection. Furthermore, in underwater endoscopic mucosal resection cases, the R0 rate was significantly higher for lesions diameter≤10mm than >10mm, and was significantly higher in the 51st-treatment period than in the 1st-50th period. Conventional endoscopic mucosal resection and underwater endoscopic mucosal resection cases showed no significant difference in resection depth and muscularis mucosa containing rate. Underwater endoscopic mucosal resection may be more acceptable than conventional endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumours ≤ 10mm. A steep early learning curve may be acquired for underwater endoscopic mucosal resection. Large multicentre prospective studies need to be conducted to confirm the effectiveness of underwater endoscopic mucosal resection.

Inverted nonampullary duodenal adenocarcinoma treated with underwater EMR

Inverted nonampullary duodenal adenocarcinoma treated with underwater EMR

Underwater Endoscopic Mucosal Resection Versus Conventional Endoscopic Mucosal Resection for Superficial Non-ampullary Duodenal Epithelial Tumors ≤20mm: A Systematic Review With Meta-analysis.

Underwater endoscopic mucosal resection (UEMR) is increasingly applied in the treatment of superficial non-ampullary duodenal epithelial tumors (SNADETs). This meta-analysis aimed to assess the efficacy and safety of UEMR for SNADETs ≤20mm in comparison with conventional endoscopic mucosal resection (CEMR). The following electronic databases were searched from 2012 until November 20, 2021: PubMed, Embase, Scopus, Web of Science databases, and Cochrane Library. The primary outcomes were the rates of en bloc resection and complete (R0) resection, and the secondary outcomes were procedure time, adverse events (delayed bleeding and delayed perforation), and recurrence rate. A total of 6 studies with 679 lesions (331 underwent UEMR and 348 CEMR) were included in this study. The pooled analysis showed that UMER achieves a similar en bloc resection rate (87.6 vs. 89.9%; odds ratio [OR], 1.29; 95% confidence interval [CI], 0.45 to 3.73; P =0.64; I2 =74%), a similar R0 resection rate (67.3 vs. 73.6%; OR, 1.11; 95% CI, 0.55 to 2.23; P =0.78; I2 =59%), a shorter procedure time (min) (mean difference [MD], -4.05, 95% CI: -6.40 to -1.71; P =0.0007; I2 =70%) compared with CEMR. There were no significant differences in the rates of delayed bleeding, delayed perforation, and recurrence (2.4 vs. 1.7%, 0 vs. 0.6%, 2.2 vs. 4.4%, respectively). This meta-analysis demonstrated that UEMR appears to be an effective and safe alternative to CEMR for SNADETs ≤20mm.

Underwater versus conventional endoscopic mucosal resection for colorectal lesions: An updated meta-analysis of randomized controlled trials.

Background and study aims Colorectal malignancy is a leading cause of death. Conventional endoscopic mucosal resection (CEMR) is a strategy used to resect precancerous lesions that involves injecting fluid beneath a polyp to create a gap for resection. Underwater endoscopic mucosal resection (UEMR) is a newer method that forgoes injection, instead filling the intestinal cavity with water to facilitate polyp resection. Our aim was to compare the safety and efficacy of these approaches by synthesizing the most contemporary evidence. Methods PubMed, Embase, and Cochrane libraries were searched from inception through November 11, 2022 for randomized controlled trials (RCTs) comparing UEMR and CEMR for resection of colorectal lesions. The primary outcome was the rate of en bloc resection and secondary outcomes included recurrence, procedure time, and adverse events (AEs). Results A total of 2539 studies were identified through our systematic literature search. After screening, seven RCTs with a total of 1581 polyps were included. UEMR was associated with significantly increased rates of en bloc resection (RR 1.18 [1.03, 1.35]; I 2 = 76.6%) versus conventional approaches. No significant differences were found in procedure time, recurrence, or AEs. Conclusions UEMR is a promising effective technique for removal of colorectal lesions. The most contemporary literature indicates that it improves en bloc resection rate without increasing procedure time, recurrence, or AEs (PROSPERO ID CRD42022374935).

Resection of large terminal ileum polyp: usefulness of underwater EMR

Video 1Underwater endoscopic mucosal resection for a large polyp at the terminal ileum.

Complete resection of a rectal post-endoscopic-resection residual tumor including four endoclips using underwater endoscopic mucosal resection.

Complete resection of a rectal post-endoscopic-resection residual tumor including four endoclips using underwater endoscopic mucosal resection.

How to make cost-effective polyp simulators for high-fidelity simulation-based training in postpolypectomy bleeding management and EMR

Video 1Demonstration of manufacturing instructions and features of the postpolypectomy bleeding and conventional and underwater EMR simulators.