Underwater Endoscopic Mucosal Resection Research Articles

Underwater endoscopic mucosal resection of colon hemangiomas compatible with the blue rubber bleb nevus syndrome, following endoscopic ultrasonography.

Underwater endoscopic mucosal resection of colon hemangiomas compatible with the blue rubber bleb nevus syndrome, following endoscopic ultrasonography.

Recurrence rates after endoscopic resection of large colorectal polyps: A systematic review and meta-analysis.

BACKGROUNDComplete polyp resection is the main goal of endoscopic removal of large colonic polyps. Resection techniques have evolved in recent years and endoscopic submucosal dissection (ESD), endoscopic mucosal resection (EMR) with margin ablation, cold snare polypectomy (CSP), cold EMR, and underwater EMR have been introduced. Yet, efficacy of these techniques with regard to local recurrence rates (LRRs) vs traditional hot snare polypectomy and standard EMR remains unclear. AIMTo analyze LRR of large colonic polyps in a systematic review and meta-analysis.METHODSMEDLINE, EMBASE, EBM Reviews, and CINAHL were searched for prospective studies reporting LRR or incomplete resection rate (IRR) after colonic polypectomy of polyps ≥ 10 mm, published between January 2011 and July 2021. Primary outcome was LRR for polyps ≥ 10 mm. RESULTSSix thousand nine hundred and twenty-eight publications were identified, of which 34 prospective studies were included. LRR for polyps ≥ 10 mm at up to 12 mo’ follow-up was 11.0% (95%CI, 7.1%-14.8%; 15 studies; 4904 polyps). ESD (1.7%; 95%CI, 0%-3.4%; 3 studies, 221 polyps) and endoscopic mucosal resection with margin ablation (3.3%; 95%CI, 2.2%-4.5%; 2 studies, 947 polyps) significantly reduced LRR vs standard EMR without (15.2%; 95%CI, 12.5%-18.0%; 4 studies, 650 polyps) or with unsystematic margin ablation (16.5%; 95%CI, 15.2%-17.8%; 6 studies, 3031 polyps). CONCLUSIONLRR is significantly lower after ESD or EMR with routine margin ablation; thus, these techniques should be considered standard for endoscopic removal of large colorectal polyps. Other techniques, such as CSP, cold EMR, and underwater EMR require further evaluation in prospective studies before their routine implementation in clinical practice can be recommended.

Resection depth and layer of underwater versus conventional endoscopic mucosal resection of intermediate-sized colorectal polyps: A pilot study.

Background and study aims Curability of colorectal tumors is associated with resection depth and layer in endoscopic resection. Underwater endoscopic mucosal resection (UEMR) has not undergone sufficient histopathological evaluation. We conducted a pilot study to compare the effectiveness, including resection depth and layer, of UEMR and conventional endoscopic mucosal resection (CEMR). Patients and methods This study was a single-center, retrospective study. Patients with colorectal lesions were treated by UEMR or CEMR between January 2018 and March 2020. Eligible patients were selected from included patients in a 1:1 ratio using propensity score matching. We compared the resection depth and layer and treatment results between the UEMR and CEMR groups. Results We evaluated 55 patients undergoing UEMR and 291 patients undergoing CEMR. Using propensity score matching, we analyzed 54 lesions in each group. The proportion of specimens containing submucosal tissue was 100 % in both groups. The median thickness of the submucosal tissue was significantly greater in the CEMR group than in the UEMR group [1235 µm (95 % confidence interval [CI], 1020–1530 µm) vs. 950 µm (95 % CI, 830–1090 µm), respectively]. However, vertical margins were negative in all lesions in both groups. Conclusions Our findings suggest that the median thickness of submucosal tissue in the UEMR group was about 1,000 μm. Even though the resection depth achieved with UEMR was more superficial than that achieved with CEMR, UEMR may be a treatment option, especially for colorectal lesions ≤ 20 mm in diameter without suspicious findings of submucosal deeply invasive cancer.

Underwater endoscopic mucosal resection for gastric neoplasms

Underwater endoscopic mucosal resection for gastric neoplasms

Clip-line-assisted underwater endoscopic mucosal resection for duodenal adenoma.

Recently, underwater endoscopic mucosal resection (U-EMR) has become established for treating duodenal adenomas. However, it is difficult to completely resect a large duodenal adenoma with en bloc resection [1]. An appropriate U-EMR method is desirable because the resection margin on the oral side is sometimes positive [2]. We devised a method for en bloc resection of large duodenal adenomas, called clip-line-assisted underwater endoscopic mucosal resection (CLU-EMR).

Spasmodic contraction induced by high concentration iodine staining to facilitate underwater endoscopic mucosal resection of early esophageal cancer.

Spasmodic contraction induced by high concentration iodine staining to facilitate underwater endoscopic mucosal resection of early esophageal cancer.

Underwater endoscopic mucosal resection for the diagnosis of metastatic gastric cancer in the descending colon.

Underwater endoscopic mucosal resection for the diagnosis of metastatic gastric cancer in the descending colon.

Reopenable-clip band-assisted underwater endoscopic mucosal resection to obtain a large specimen.

Reopenable-clip band-assisted underwater endoscopic mucosal resection to obtain a large specimen.

Underwater endoscopic mucosal resection for a protruding lesion in the esophagus.

Underwater endoscopic mucosal resection for a protruding lesion in the esophagus.

Gel Immersion Endoscopic Mucosal Resection (EMR) for Superficial Nonampullary Duodenal Epithelial Tumors May Reduce Procedure Time Compared with Underwater EMR (with Video).

Materials and Methods This was a retrospective cohort study conducted in two municipal hospitals. We identified 24 patients with SNADETs of 3–18 mm in diameter who underwent UEMR or GIEMR. One lesion was excluded from the analysis because it was found to be in the stomach after surgery. The primary outcome was procedure time. Results GIEMR significantly reduced the procedure time compared with UEMR (5 min vs. 10 min, P = 0.016). There was no significant difference between the UEMR and GIEMR groups for en bloc resection rate (93% vs. 100%, P = 1.0) and R0 resection rate (57% vs. 80%, P = 0.39). No serious complications were observed in either group. Conclusions GIEMR of SNADET has the potential to reduce procedure time compared with UEMR and may be particularly effective in areas where immersion in water is difficult.

Underwater endoscopic mucosal resection for rectal neuroendocrine tumors (with videos): a single center retrospective study

BackgroundUnderwater endoscopic mucosal resection (UMER) is a new method of endoscopic resection to completely remove the lesion without submucosal injection. But few attempts have been carried out for rectal neuroendocrine tumors (rectal NETs).MethodsWe retrospectively investigated data on the tumor characteristics and outcomes of patients with ≤ 10 mm rectal NETs who underwent UEMR or endoscopic submucosal dissection (ESD) from January 2019 to June 2021 in our institute.ResultsThe endoscopic resection rate was 100% in both UEMR and ESD groups. The histological complete resection rate of the UEMR group (95.5%) was lower than that of the ESD group (96.4%) with no significant difference. The average operation time, hospitalization time and operation cost of UEMR group were less than those of ESD group (P < 0.05). The incidence of postoperative abdominal pain and abdominal distention in the UEMR group was lower than that in the ESD group (P < 0.05). There was no significant difference in the incidence of delayed bleeding and perforation between the two groups. There was no local recurrence or distant metastasis in the two groups during the follow-up period.ConclusionsBoth the UEMR and ESD can effectively treat ≤ 10 mm rectal NETs with invasion depth confined to the mucosa and submucosa. UEMR is superior to ESD in operation time, hospitalization time, operation cost, postoperative abdominal pain and abdominal distention.

Underwater Endoscopic Mucosal Resections of Non-ampullary Small Duodenal Tumors

Conventional endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have been reported to be effective therapeutic options in sporadic non-ampullary duodenal tumors, but the rate of perforation is higher than that of other gastrointestinal lesions. Underwater EMR (UW EMR) has been reported to be a safe alternative to conventional EMR and ESD for superficial non-ampullary duodenal adenomas. We reviewed the medical chart and endoscopic report of patients who underwent endoscopic resection between August 2018 and February 2020. A total of 12 duodenal tumors were resected by UW EMR. The mean specimen and lesion sizes were 6.7 mm (2~16 mm) and 5.3 mm (2~10 mm), respectively. Of the 12 lesions, nine (75.0%) were located in the 2nd portion, and three (25.0%) were in the bulb. The mean procedural time was 7.8 minutes (3.2~18.7 minutes). Histologic results showed 10 dysplasia (nine low-grade, one high-grade) and two neuroendocrine tumors. UW EMR showed favorable efficacy and safety within small dysplastic lesions compared to previous studies’ results. Furthermore, it might be considered a treatment option with caution in patients with the duodenal subepithelial tumor within the third layer.

Underwater endoscopic mucosal resection: the best solution for treating local recurrence of duodenal adenoma.

Underwater endoscopic mucosal resection: the best solution for treating local recurrence of duodenal adenoma.

Underwater endoscopic mucosal resection after endoscopic ultrasound examination for safe and reliable complete resection of a deeply invasive submucosal cecal cancer.

Underwater endoscopic mucosal resection after endoscopic ultrasound examination for safe and reliable complete resection of a deeply invasive submucosal cecal cancer.

Resection depth for small colorectal polyps comparing cold snare polypectomy, hot snare polypectomy and underwater endoscopic mucosal resection.

Background and study aims Small colorectal polyps are removed by various methods, including cold snare polypectomy (CSP), hot snare polypectomy (HSP), and underwater endoscopic mucosal resection (UEMR), but the indications for using these methods are unclear. We retrospectively assessed the efficacy of CSP, HSP, and UEMR for small polyps, focusing on the depth of the resected specimens. Patients and methods Outpatients with non-pedunculated small polyps (endoscopically diagnosed as 6 to 9 mm), resected by two endoscopists between July 2019 and September 2020, were enrolled. We histologically evaluated the specimens resected via CSP, HSP, and UEMR. The main outcome was the containment rate of the muscularis mucosa (MM) and submucosa (SM) tissues. Results Forty polyps resected via CSP (n = 14), HSP (n = 12), or UEMR (n = 14) were enrolled after excluding 13 polyps with resection depths that were difficult to determine. The rates of specimens containing MM and SM tissue differed significantly (57 % and 29 % for CSP, 92 % and 83 % for HSP, and 100 % and 100 % for UEMR, respectively ( P = 0.005 for MM and P < 0.001 for SM tissue). Multiple logistic regression analysis showed UEMR was an independent factor relating to the containment of SM tissue. The thickness of SM tissue by CSP, HSP, and UEMR were 52 μm, 623 μm, and 1119 μm, respectively ( P < 0.001). The thickness by CSP was significantly less than those by HSP and UEMR ( P < 0.001, Bonferroni correction). Conclusions UEMR could be the best method to contain SM tissue without injection. Further studies are needed to evaluate the indication of UEMR for small polyps.

Use of a self-made additional working channel for underwater endoscopic mucosal resection of a rectal neuroendocrine tumor.

Use of a self-made additional working channel for underwater endoscopic mucosal resection of a rectal neuroendocrine tumor.

Underwater Endoscopic Mucosal Resection of Small Rectal Neuroendocrine Tumors

Background and Study AimsThe resection strategy for rectal neuroendocrine tumors (NET) < 10 mm is not uniform. We compared the utility of underwater endoscopic mucosal resection (UEMR) to endoscopic submucosal resection with a ligation device (ESMR-L) to resect rectal NETs.Patients and MethodsPatients with rectal NET < 10 mm treated with UEMR or ESMR-L were included. Their medical records were retrospectively reviewed.ResultsThirty-two patients were divided into a UEMR group (n = 7) and an ESMR-L group (n = 25). Histopathological diagnosis of NET by biopsy was known before resection in 43% (3/7) in the UEMR group and 68% (17/25) in the ESMR-L group, (p = 0.379). UEMR was performed on an outpatient basis for all patients, and 92% of ESMR-L (23/25) were performed as inpatient procedures (p < 0.001). The procedure time was significantly shorter in the UEMR group than in the ESMR-L group [median (IQR), min, 6 (5–8) vs. 12 (9–14), p = 0.002]. En bloc resection and R0 resection rates were 100% in both groups. Pathological evaluations were predominantly NET G1 in both groups (UEMR: 7/7, 100% and ESMR-L: 23/25, 92%). Two patients in the ESMR-L group developed delayed bleeding, controlled by endoscopic hemostasis. Device costs were significantly higher in the ESMR-L group than the UEMR group by approximately US$180 [median (IQR), $90.45 (83.64–108.41) vs. $274.73 (265.86–292.45), P < 0.001].ConclusionUEMR results in similar resection quality with shorter procedure time and lower costs compared to ESMR-L. We recommend UEMR for the resection of rectal NET < 10 mm.

Endoscopic management of difficult laterally spreading tumors in colorectum.

Due to the advent of the screening programs for colorectal cancer and the era of quality assurance colonoscopy the number the polyps that can be considered difficult, including large (> 20 mm) laterally spreading tumors (LSTs), has increased in the last decade. All LSTs should be assessed carefully, looking for suspicious areas of submucosal invasion (SMI), such as nodules or depressed areas, describing the morphology according to the Paris classification, the pit pattern, and vascular pattern. The simplest, most appropriate and safest endoscopic treatment with curative intent should be selected. For LST-granular homogeneous type, piecemeal endoscopic mucosal resection should be the first option due to its biological low risk of SMI. LST-nongranular pseudodepressed type has an increased risk of SMI, and en bloc resection should be mandatory. Underwater endoscopic mucosal resection is useful in situations where submucosal injection alters the operative field, e.g., for the resection of scar lesions, with no lifting, adjacent tattoo, incomplete resection attempts, lesions into a colonic diverticulum, in ileocecal valve and lesions with intra-appendicular involvement. Endoscopic full thickness resection is very useful for the treatment of difficult to resect lesions of less than 20 up to 25 mm. Among the indications, we highlight the treatment of polyps with suspected malignancy because the acquired tissue allows an exact histologic risk stratification to assign patients individually to the best treatment and avoid surgery for low-risk lesions. Endoscopic submucosal dissection is the only endoscopic procedure that allows completes en bloc resection regardless of the size of the lesion. It should therefore be indicated in the treatment of lesions with risk of SMI.

A30 RECURRENCE RATES AFTER ENDOSCOPIC RESECTION OF LARGE COLORECTAL POLYPS: A SYSTEMATIC REVIEW AND META-ANALYSIS

BackgroundComplete polyp resection is the main goal of endoscopic removal of large colonic polyps. Resection techniques used for their removal have evolved in recent years and endoscopic submucosal dissection (ESD), endoscopic mucosal resection (EMR) with margin ablation, cold snare polypectomy (CSP), cold snare EMR and underwater EMR have been introduced. Yet, efficacy of these techniques with regard to local recurrence rates (LRR) compared to traditional hot snare polypectomy (HSP) and standard EMR remains unclear.AimsWe aimed to analyze LRR of large colonic polyps in a systematic review and meta-analysis.MethodsMEDLINE, EMBASE, EBM Reviews, and CINAHL databases were searched to identify prospective studies reporting LRR or incomplete resection rate (IRR) after colonic polypectomy of polyps >10 mm, published between January 2011 and July 2021. Primary outcome was LRR for polyps >10 mm.Results6928 publications were identified, of which 34 prospective studies were included into the analysis. LRR for polyps >10 mm at follow-up (FU) up to 12 months was 11.0% (95% CI 7.1–14.8; 15 studies; 6259 polyps). ESD (1.7%; 95% CI 0–3.4; 3 studies, 221 polyps) and EMR with margin ablation (3.3%; 95% CI 2.2–4.5; 2 studies, 947 polyps) significantly reduced LRR compared to standard EMR without (15.2%; 95% CI 12.5–18.0%; 4 studies, 650 polyps) or with unsystematic margin ablation (16.5%; 95% CI 15.2–17.8; 6 studies, 3183 polyps).ConclusionsLocal polyp recurrence after standard EMR of large colonic polyps is high. LRR is significantly lower after ESD or EMR with routine margin ablation, so that these techniques should be considered standard for endoscopic removal of large colorectal polyps. CSP, cold snare EMR and underwater EMR should only be used within clinical trials until more high-quality data regarding LRR becomes available. Funding AgenciesNone

Effective Endoscopic Delineation With Acetic Acid Spray and Narrow Band Imaging in Underwater Endoscopic Mucosal Resection for Sessile Serrated Lesion.

Effective Endoscopic Delineation With Acetic Acid Spray and Narrow Band Imaging in Underwater Endoscopic Mucosal Resection for Sessile Serrated Lesion.