Underwater endoscopic mucosal resection of serrated adenomas

Endoscopic techniques for management of large colorectal polyps, strictures and leaks

The implementation of screening colonoscopy with polyp removal has significantly decreased mortality rates associated with colorectal cancer (CRC), although it remains a major cause of cancer-related deaths globally. CRC typically originates from adenomatous polyps, and increased removal of these growths has led to reduced CRC incidence and mortality. Endoscopic polypectomy techniques, including hot and cold snare polypectomy, play a pivotal role in this process. While both methods are effective for small polyps (<10 mm), recent evidence favors cold snare polypectomy due to its superior safety profile and comparable complete resection rates. Large polyps (>10 mm), particularly those with advanced features, pose increased cancer risks and often require meticulous assessment and advanced endoscopic techniques, including endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), for resection. This chapter also provides a practical overview of endoscopic techniques for managing colonic obstructions and pericolonic fluid collections, detailing their indications, advantages, disadvantages, and complications. The goal is to improve understanding and application in clinical practice. Additionally, we provide a summary of endoscopic closure techniques that have revolutionized the management of perforations and fistulas, offering safe and effective alternatives to surgery.

Cold EMR vs. Hot EMR for the removal of sessile serrated polyps larger than 10 mm: a systematic review and meta-analysis

BACKGROUND

Endoscopic mucosal resection (EMR) appears to be a promising technique for the removal of sessile serrated polyps (SSPs) ≥ 10 mm. To assess the effectiveness and safety of EMR for removing SSPs ≥ 10 mm, we conducted this systematic review and meta-analysis.

METHODS

We conducted a thorough search of Embase, PubMed, Cochrane, and Web of Science databases for relevant studies reporting on EMR of SSPs ≥ 10 mm, up until December 2023. Our primary endpoints of interest were rates of technical success, residual SSPs, and adverse events (AE).

RESULTS

Our search identified 426 articles, of which 14 studies with 2262 SSPs were included for analysis. The rates of technical success, AEs, and residual SSPs were 100%, 2.0%, and 3.1%, respectively. Subgroup analysis showed that the technical success rates were the same for polyps 10-19 and 20 mm, and en-bloc and piecemeal resection. Residual SSPs rates were similar in en-bloc and piecemeal resection, but much lower in cold EMR (1.0% vs. 4.2%, P = 0.034). AEs rates were reduced in cold EMR compared to hot EMR (0% vs. 2.9%, P = 0.168), in polyps 10-19 mm compared to 20 mm (0% vs. 4.1%, P = 0.255), and in piecemeal resection compared to en-bloc (0% vs. 0.7%, P = 0.169).

CONCLUSIONS

EMR is an effective and safe technique for removing SSPs ≥ 10 mm. The therapeutic effect of cold EMR is superior to that of hot EMR, with a lower incidence of adverse effects.

PROSPERO REGISTRATION NUMBER

CRD42023388959.

Endoscopic underwater detection and resection of anal squamous intraepithelial lesions in non-anesthetized patients - a feasibility study and comparison with standard surgical treatment

BACKGROUND

Anal squamous intraepithelial lesions (ASILs) correspond to premalignant changes preceding the development of anal squamous cell carcinoma.

OBJECTIVE

To describe a new endoscopic technique to detect and remove ASILs in non-anesthetized patients and compare it with standard surgical treatment.

METHODS

For endoscopic treatment, high resolution (HR) flexible endoscopes with a distal attachment were used. Underwater inspection of the anal canal was performed in near-focus mode with white light and narrow-band imaging. Detected lesions were resected with a diathermia snare after local injection of xylocaine/adrenaline. We did a retrospective comparison of all patients who underwent endoscopic or standard surgical treatment for ASILs at Ersta hospital in Stockholm between 2018 and 2020. Patient files were reviewed for number of lesions, treatments until macroscopic radicality, degree of dysplasia, bleeding, pain and other complications.

RESULTS

Endoscopic (n = 37) and surgical (n = 43) treatment displayed comparable number of lesions per patient (p = .37). The number of procedures until macroscopic radicality was higher for endoscopy than surgery (p = .04). However, in endoscopic follow up of 12 of the surgically treated patients, residual ASIL was found in 10 cases. Post-procedural bleeding requiring healthcare occurred in two endoscopy patients and one surgically treated patient.

CONCLUSIONS

Underwater resection using a HR flexible endoscope in non-anesthetized is a new, feasible and well tolerated method for ASILs treatment. Its efficacy and risk of complications seem comparable to standard surgical treatment while avoiding general anesthesia. However, minor lesions might be overlooked at surgery.

Underwater versus conventional endoscopic mucosal resection for colorectal lesions: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND & AIMS

Conventional endoscopic mucosal resection (CEMR) is the established method for the resection of non-pedunculated colorectal lesions (NPCRL) ≥ 10 mm. In the last decade, underwater endoscopic mucosal resection (UEMR) has been introduced as a potential alternative. The aim of this systematic review with meta-analysis is to compare the recurrence and safety of UEMR and CEMR by analyzing only randomized controlled trials (RCTs).

METHODS

We systematically searched PubMed, Cochrane Library and EMBASE until April 2023. Studies met the following inclusion criteria: (1) RCTs, (2) comparing UEMR with CEMR, (3) NPCRL ≥ 10 mm, and (4) reporting the outcomes of interest. Primary outcomes were recurrence and safety. Secondary outcomes were en bloc, R0, complete resection, clipping and adverse events per type.

RESULTS

Five RCTs were included. UEMR was associated with a lower recurrence rate (OR: 0.56; 95% CI: 0.32-0.97). Thus, the RR of recurrence was 1.7 times higher in the CEMR group (95% CI, 1.04-2.77). There was no significant difference in the pooled safety analysis. UEMR showed better en bloc resection rates (OR: 1.54; 95% CI: 1.15-2.07), but subgroup analysis showed comparable rates in lesions ≥ 20 mm. R0 resection was higher in UEMR (OR: 1.72; 95% CI: 1.23-2.41). Other outcomes were not different between the 2 groups.

CONCLUSIONS

UEMR is as safe as CEMR, with a higher overall R0 rate and a higher en bloc resection rate for lesions < 20 mm, leading to a lower overall recurrence rate. The results of this meta-analysis support the widespread use of UEMR.

Underwater endoscopic mucosal resection for colorectal lesions: Can it be an “Underwater” revolution?

Underwater endoscopic mucosal resection (UEMR) is a newly developed technique for the removal of colorectal, duodenal, esophageal, gastric, ampullary, and small intestinal lesions. We performed a PubMed literature search for articles reporting UEMR outcomes for colorectal polyps. Four randomized controlled trials, nine non‐randomized prospective trials, 16 retrospective studies, and 27 case reports were selected for assessment of the efficacy and safety of UEMR. We summarized the therapeutic outcomes of UEMR in each category according to the lesion characteristics [small size (<10 mm), intermediate size (10–19 mm), large size (≥20 mm), recurrent lesion, and rectal neuroendocrine tumor], and calculated the incidence of adverse events among the included articles. As the treatment outcomes for small polyps appeared similar between UEMR and conventional endoscopic mucosal resection (CEMR), UEMR can be a standard procedure for small colorectal polyps suspicious for high‐grade dysplasia to avoid incomplete removal of occult invasive cancer by cold snare polypectomy. As UEMR showed satisfactory outcomes for intermediate‐size lesions and recurrent lesions after endoscopic resection, UEMR can be a standard procedure for these lesions. Regarding large lesions and rectal neuroendocrine tumors, comparisons of UEMR with current standard methods for them were lacking, and further investigations are warranted. Adverse events appeared comparable or less frequent for UEMR compared with CEMR but still existed. Therefore, careful implementation of this new technique in clinical practice is important for its widespread use.

EVALUATION OF UNDERWATER ENDOSCOPIC MUCOSAL RESECTION FOR COLORECTAL POLYPS IN AN OUTPATIENT CLINIC IN BRAZIL

BACKGROUND

Since 2012, a new technique for resection of large polyps has been described, the underwater endoscopic mucosal resection (UEMR). Some advantages that emerge from it is the needless of injection in submucosal layer and a greater chance of complete capture of the polyp.

OBJECTIVE

There are few studies of UEMR in Brazil. The aim of this study is to evaluate the safety and efficacy of this technique in one Brazilian center.

METHODS

This case series was conducted from February to December of 2020. Colorectal polyps greater than 9 mm without features of deep submucosal invasion were resected using UEMR.

RESULTS

Twenty-four large polyps were resected with the UEMR approach from 24 patients. The mean size of the polys was 19 mm, ranging from 12 to 35 mm. All lesions were successful resected and 66% (16/24) were resected en bloc. In histologic analyses, most of them were adenomas (70.8%) and only one had deep submucosal invasion. There were no cases of acute complications, such perforation or acute bleeding.

CONCLUSION

The UEMR is a safe and feasible procedure. With the emerging data on the procedure, it seems to be a wonderful tool in preventing colorectal cancer and its applicability and scope should be encourage to surpass reference centers.

The efficacy and safety of underwater endoscopic mucosal resection for ≥10-mm colorectal polyps: systematic review and meta-analysis

BACKGROUND

Underwater endoscopic mucosal resection (UEMR) is a promising strategy for nonpedunculated colorectal polyp removal. However, the efficacy and safety of the technique for the treatment of ≥ 10-mm colorectal polyps remain unclear. We aimed to comprehensively assess the efficacy and safety of UEMR for polyps sized 10-19 mm and ≥ 20 mm.

METHODS

PubMed, EMBASE, and the Cochrane Library databases were searched for relevant articles from January 2012 to November 2019. Primary outcomes were the rates of adverse events and residual polyps. Secondary outcomes were the complete resection, en bloc resection, and R0 resection rates.

RESULTS

18 articles including 1142 polyps from 1093 patients met our inclusion criteria. The overall adverse event and residual polyp rates were slightly lower for UEMR when removing colorectal polyps of 10-19 mm vs. ≥ 20 mm (3.5 % vs. 4.3 % and 1.2 % vs. 2.6 %, respectively). The UEMR-related complete resection rate was slightly higher for colorectal polyps of 10-19 mm vs. ≥ 20 mm (97.9 % vs. 92.0 %). However, the en bloc and R0 resection rates were dramatically higher for UEMR removal of polyps of 10-19 mm vs. ≥ 20 mm (83.4 % vs. 36.1 % and 73.0 % vs. 40.0 %, respectively). In addition, univariate meta-regression revealed that polyp size was an independent predictor for complete resection rate (P = 0.03) and en bloc resection (P = 0.01).

CONCLUSIONS

UEMR was an effective and safe technique for the removal of ≥ 10-mm nonpedunculated colorectal polyps. However, UEMR exhibited low en bloc and R0 resection rates for the treatment of ≥ 20-mm polyps.

Underwater Endoscopic Mucosal Resection for 10 mm or Larger Nonpedunculated Colorectal Polyps: A Systematic Review and Meta-Analysis

Background/Aims

Recent studies have reported the favorable outcomes of underwater endoscopic mucosal resection (UEMR) for colorectal polyps. We performed a systematic review and meta-analysis evaluating the efficacy and safety of UEMR for nonpedunculated polyps ≥10 mm.

Methods

We performed a comprehensive search of multiple databases (through May 2020) to identify studies reporting the outcomes of UEMR for ≥10 mm nonpedunculated colorectal polyps. The assessed outcomes were recurrence rate on the first follow-up, en bloc resection, incomplete resection, and adverse events after UEMR.

Results

A total of 1276 polyps from 16 articles were included in our study. The recurrence rate was 7.3% (95% confidence interval [CI], 4.3–12) and 5.9% (95% CI, 3.6–9.4) for nonpedunculated polyps ≥10 and ≥20 mm, respectively. For nonpedunculated polyps ≥10 mm, the en bloc resection, R0 resection, and incomplete resection rates were 57.7% (95% CI, 42.4–71.6), 58.9% (95% CI, 42.4–73.6), and 1.5% (95% CI, 0.8–2.6), respectively. The rates of pooled adverse events, intraprocedural bleeding, and delayed bleeding were 7.0%, 5.4%, and 2.9%, respectively. The rate of perforation and postpolypectomy syndrome was 0.8%.

Conclusions

Our systematic review and meta-analysis demonstrates that UEMR for nonpedunculated colorectal polyps ≥10 mm is safe and effective with a low rate of recurrence.

Underwater endoscopic mucosal resection of adenomas and colorectal serrated lesions: a prospective clinical study

Background

Underwater endoscopic mucosal resection (UEMR) without submucosal injection has been described as an alternative technique to the endoscopic resection of adenomas and colorectal serrated lesions. We aimed to assess the feasibility, safety, and efficacy of UEMR in a Brazilian setting.

Methods

This was a prospective observational study of consecutive patients who underwent UEMR between January and July 2019, in a single tertiary care center. Inclusion criteria were lesions without endoscopic stigmata of deep submucosal invasion in patients referred for endoscopic resection of colorectal adenomas, and serrated lesions detected in a previous colonoscopy. The following features were assessed: complete resection rate, en bloc resection rate, resection time, adverse events, and resection infeasibility.

Results

A total of 36 patients underwent UEMR for 51 colorectal lesions. The mean/median lesion size was 16.24/13 mm and the mean/median resection time was 16.97/9.19 min. Histopathology revealed the following: tubular adenoma (43.1%), tubulovillous adenoma (13.7%), serrated lesions (41.2%), and intramucosal adenocarcinoma (2%). Complete resection was achieved in 86.3% of cases; 52.9% of the lesions were removed en bloc, while 47.1% were resected in a piecemeal fashion. UEMR was feasible in 96.1% of cases and failed on 2 occasions, requiring conversion to standard endoscopic mucosal resection. Minor intraoperative bleeding occurred in 5 patients (9.8%) and only 1 presented with delayed bleeding (2%), all controlled endoscopically.

Conclusion

UEMR for removal of adenomas and colorectal serrated lesions was demonstrated to be feasible, safe and effective.

Effectiveness of underwater endoscopic mucosal resection versus conventional endoscopic mucosal resection for 10 to 20 mm colorectal polyps: A protocol of systematic review and meta-analysis

BACKGROUND

Endoscopic mucosal resection (EMR) is a standard method commonly for removing 10 to 20 mm colorectal polyps. While the incidence of residual or recurrent after conventional EMR is remarkably high. Underwater endoscopic mucosal resection (UEMR) as an alternative technique to conventional EMR for removing colorectal polyps has high adenoma detection and complete resection rates, improves patient comfort, decreases sedation needs, eliminates the risks associated with submucosal injection, and reduces snare and diathermy-induced mucosal injury. We will conduct a comprehensive systematic review and meta-analysis to compare the effectiveness of these two therapies in the management of 10 to 20 mm colorectal polyps.

METHODS

PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, China Science and Technology Journal Database and Chinese Biomedical Literature Database will be searched from inception of databases to November 2020 without language limitation. Two reviewers will independently conduct article selection, data collection, and assessment of risk of bias. Any disagreement will be resolved by discussion with the third reviewer. Review Manager Software 5.3 will be used for meta-analysis. The Cochrane risk of bias tool will be used to assess the risk of bias.

RESULTS

This study will provide a systematic synthesis of current published data to compare the effectiveness of UEMR and conventional EMR for 10 to 20 mm colorectal polyps.

CONCLUSIONS

This systematic review and meta-analysis will provide clinical evidence as to whether UEMR is more effective and safer than conventional EMR for 10 to 20 mm colorectal polyps.

STUDY REGISTRATION NUMBER

INPLASY2020100006.

Feasibility and safety of modified underwater endoscopic mucosal resection for colorectal polyps

BACKGROUND

Conventional endoscopic mucosal resection (EMR) with submucosal injection has been widely performed to remove colorectal polyps, although it often makes sessile lesions flattened and enlarged, resulting in the failure of lesion snaring. Air deflation and water immersion during underwater EMR (UEMR) sometimes interfere with the exposure of colorectal polyps. Modified UEMR may facilitate the resection of colorectal polyps due to integrating the advantages of EMR and UEMR.

AIM

To investigate the feasibility and safety of the modified UEMR in the treatment of colorectal polyps.

METHODS

Fifty-nine patients with 76 colorectal polyps treated by modified UEMR were enrolled in the study from July 2015 to June 2019, and compared with 43 patients with 65 colorectal polyps treated by UEMR during the same period. All lesions were classified as Paris Is or IIa, and the size of the polyp ranged from 1 cm to 3 cm in diameter. Endoscopic procedure was as follows: Once observed, the polyp was completely immersed by warm water infusion. The polyp was placed in the 6 o'clock direction. Following submucosal injection with normal saline plus methylene blue, an appropriate snare was used for en bloc resection. The mucosal defect was closed with clips. The excised specimen was sent for pathological evaluation after crystal violet staining.

RESULTS

All the 76 lesions in the study group were successfully resected by modified UEMR. Among them, 64 polyps less than 2 cm in size received en bloc resection. In 12 polyps ranging 2-3 cm in size, 5 received en bloc resection and 7 received piecemeal UEMR. The overall en bloc resection rate was 91%; the rate for those polyps < 2 cm was 100%, and the rate for polyps ranging from 2 cm to 3 cm was 42%. All the 65 lesions in the control group were successfully treated by conventional UEMR. Of 58 lesions less than 2 cm in size, 49 underwent en bloc resection and the other 9 underwent additional argon plasma coagulation (APC) due to residual lesion. Of 7 lesions ranging from 2 cm to 3 cm in size, 2 underwent en bloc resection, 1 undewent additional APC due to residual lesion, and the other 5 underwent piecemeal UEMR or were converted to modified endoscopic submucosal dissection. The overall en bloc resection rate in the control group was 76%; the rate for the lesions < 2 cm was 84%, and that for lesions 2-3 cm was 14%. During operation, minor bleeding occurred in 9 patients of the study group and 13 patients of the control group. There were no complications such as delayed bleeding and perforation in either group. During the follow-up period, local recurrence was found in 2 patients of the study group, and 9 patients of the control group.

CONCLUSION

Compared with conventional UEMR, modified UEMR can provide more excellent exposure for polyps, and achieve higher en bloc resection rate by discontinuous suction during tightening of the snare, resulting in a high complete resection rate and low recurrence rate.

UNDERWATER ENDOSCOPIC MUCOSAL RESECTION FOR NON-PEDUNCULATED COLORECTAL LESIONS. A PROSPECTIVE SINGLE-ARM STUDY

BACKGROUND

Underwater endoscopic mucosal resection (UEMR) has emerged as a revolutionary method allowing resection of colorectal lesions without submucosal injection. Brazilian literature about this technique is sparse.

OBJECTIVE

The aim of this study was evaluate the efficacy and safety of UEMR technique for removing non-pedunculated colorectal lesions in two Brazilian tertiary centers.

METHODS

This prospective study was conducted between June 2016 and May 2017. Naïve and non-pedunculated lesions without signs of submucosal invasion were resected using UEMR technique.

RESULTS

A total of 55 patients with 65 lesions were included. All lesions, except one, were successfully and completely removed by UEMR (success rate 98.5%). During UEMR, two cases of bleeding were observed (3.0%). One patient had abdominal pain on the day after resection without pneumoperitoneum. There was no perforation or delayed bleeding.

CONCLUSION

This study supports the existing data indicating acceptable rates of technical success, and low incidence of adverse events with UEMR. The results of this Brazilian study were consistent with previous abroad studies.