Evaluation and long-term outcomes of the different modalities used in colonic endoscopic mucosal resection

Cold endoscopic mucosal resection versus cold snare polypectomy for colorectal lesions: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Cold resection of colorectal lesions is widely performed because of its safety and effectiveness; however, it remains uncertain whether adding submucosal injection could improve the efficacy and safety. We aimed to compare cold endoscopic mucosal resection (C-EMR) versus cold snare polypectomy (CSP) for colorectal lesions.

METHODS

We performed a systematic review of randomized controlled trials (RCTs) identified from PubMed, Cochrane Library, and Embase. The primary outcome was complete resection. Secondary outcomes were procedure time, en bloc resection, and adverse events (AEs). Prespecified subgroup analyses based on the size and morphology of the polyps were performed. The random-effects model was used to calculate the pooled risk ratio (RR) and mean difference, with corresponding 95%CIs, for dichotomous and continuous variables, respectively. Heterogeneity was assessed using the Cochran Q test and I 2 statistics.

RESULTS

7 RCTs were included, comprising 1556 patients, with 2287 polyps analyzed. C-EMR and CSP had similar risk ratios for complete resection (RR 1.02, 95%CI 0.98-1.07), en bloc resection (RR 1.08, 95%CI 0.82-1.41), and AEs (RR 0.74, 95%CI 0.41-1.32). C-EMR had a longer procedure time (mean difference 42.1 seconds, 95%CI 14.5-69.7 seconds). In stratified subgroup analyses, the risk was not statistically different between C-EMR and CSP for complete resection in polyps<10 mm or ≥10 mm, or for complete resection, en bloc resection, and AEs in the two groups among nonpedunculated polyps.

CONCLUSIONS

The findings of this meta-analysis suggest that C-EMR has similar efficacy and safety to CSP, but significantly increases the procedure time.

PROSPERO

CRD42023439605.

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).

Underwater versus conventional endoscopic mucosal resection for sessile colorectal polyps: an updated systematic review and meta-analysis

BACKGROUND

underwater endoscopic mucosal resection (uEMR) without submucosal injection for sessile colorectal polyps was introduced as a new replacement for conventional EMR (cEMR). However, the optimal resection strategy remains a topic of debate. Hence, this meta-analysis was performed to compare the efficacy and safety of uEMR and cEMR in patients with sessile colorectal polyps.

METHODS

a comprehensive search of the literature from 2000 till January 2022 was performed from Medline, CENTRAL and Embase for randomized controlled trials (RCTs) comparing cEMR vs uEMR for colorectal polyps. The evaluated outcomes included en bloc resection, R0 resection, procedure time, overall bleeding and recurrence. Pooled risk ratios (RR) with 95 % confidence interval were calculated using a random effect model.

RESULTS

six studies were included, out of which four were full-text articles and two were conference abstracts. En bloc resection (RR 1.26, 95 % CI: 1.00-1.60), R0 resection (RR 1.10, 95 % CI: 0.96-1.26), overall bleeding (RR 0.85, 95 % CI: 0.54-1.34) and recurrence rate (RR 0.75, 95 % CI: 0.45-1.27) were comparable between uEMR and cEMR. However, uEMR was associated with a shorter procedure time (mean difference [MD] -1.55 minutes, 95 % CI: -2.71 to -0.39). According to the subgroup analysis, uEMR led to a higher rate of en bloc resection (RR 1.41, 95 % CI: 1.07-1.86) and R0 resection (RR 1.19, 95 % CI: 1.01-1.41) for polyps ≥ 10 mm in size.

CONCLUSION

both uEMR and cEMR have a comparable safety and efficacy. For polyps larger than 10 mm, uEMR may have an advantage over cEMR and should be the topic for future studies.

Modified endoscopic mucosal resection techniques for treating precancerous colorectal lesions

Endoscopic mucosal resection (EMR) is a technique allowing efficacious and minimally invasive resection of precancerous lesions across the entire gastrointestinal tract. However, conventional EMR, involving injection of fluid into the submucosal space, is imperfect, given the high rate of recurrence of post-endoscopic resection adenoma, especially after piecemeal resection. In light of these observations, modifications of the technique have been proposed to overcome the weakness of conventional EMR. Some of them were designed to maximize the chance of en bloc resection—cap-assisted EMR, underwater EMR, tip-in EMR, precutting, assisted by ligation device—while others were designed to minimize the complications (cold EMR). In this review, we present their modes of action and summarize the evidence regarding their efficacy and safety.

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 versus conventional endoscopic mucosal resection for colorectal lesions: a systematic review and meta-analysis

Background and study aims  Underwater endoscopic mucosal resection (UEMR) for colorectal polyps has been reported to have good outcomes in recent studies. We conducted a systematic review and meta-analysis comparing the effectiveness and safety of UEMR to conventional EMR (CEMR). Methods  A comprehensive search of multiple databases (through May 2020) was performed to identify studies that reported outcome of UEMR and CEMR for colorectal lesions. Outcomes assessed included incomplete resection, rate of recurrence, en bloc resection, adverse events (AEs) for UEMR and CEMR. Results  A total of 1,651 patients with 1,704 polyps were included from nine studies. There was a significantly lower rate of incomplete resection (odds ratio [OR]: 0.19 (95 % confidence interval (CI), 0.05-0.78, P  = 0.02) and polyp recurrence (OR: 0.41, 95 % CI, 0.24-0.72, P  = 0.002) after UEMR. Compared to CEMR, rates overall complications (relative risk [RR]: 0.66 (95 % CI, 0.48-0.90) ( P  = 0.008), and intra-procedural bleeding (RR: 0.59, 95 % CI, 0.41-0.84, P  = 0.004) were significantly lower with UEMR. The recurrence rate was also lower for large non-pedunculated polyps ≥ 10 mm (OR 0.24, 95 % CI, 0.10-0.57, P  = 0.001) and ≥ 20 mm (OR 0.14, 95 % CI, 0.02-0.72, P  = 0.01). The rates of en bloc resection, delayed bleeding, perforation and post-polypectomy syndrome were similar in both groups ( P  > 0.05). Conclusions  In this systematic review and meta-analysis, we found that UEMR is more effective and safer than CEMR with lower rates of recurrence and AEs. UEMR use should be encouraged over CEMR.

Novel technique for endoscopic en bloc resection (EMR+) - Evaluation in a porcine model

BACKGROUND

Endoscopic en bloc resection of larger polyps is relevant because risk of advanced neoplasia or malignancy correlates with tumor size. Recurrence rates after piecemeal endoscopic mucosal resection (EMR) are high and endoscopic submucosal dissection (ESD) is associated with higher complication rates in the western world.

AIM

To develop a modified endoscopic en bloc resection technique using an external additional working channel and novel agent for submucosal injection.

METHODS

EMR+ was considered as modified grasp and snare technique. For simultaneous use of a grasping and cutting device a novel additional working channel was used (AWC^®, Ovesco Endoscopy, Tübingen, Germany). AWC^® is installed on the outer surface of the endoscope, covered with a plastic sleeve and designed for single use. For submucosal injection a new agent consisting of poloxamers was used (LiftUp^®, Ovesco Endoscopy, Tübingen, Germany). The agent is liquid at room temperature and forms a stable and permanent gel cushion after injection. Safety of LiftUp^® has been shown in a pre-clinical study in domestic pigs. LiftUp^® is commercially not yet available but approval is expected in early 2019. EMR+ was first developed ex vivo (explanted pig stomach) and subsequently evaluated in vivo (stomach, porcine model, 3 domestic pigs). Main outcome measurements were: Procedure time, macroscopic en bloc resection and adverse events.

RESULTS

Concept of EMR+ was first developed ex vivo (explanted pig stomach). Ex vivo, 22 resections were performed after technique was established. Median procedure time (measured from begin of injection to extraction of resection specimen) was 7 min (range 5-11, SD 1.68) and median size of resection specimens was 30 mm × 26 mm × 11 mm ex vivo. Subsequently 13 resections were performed in vivo (stomach, porcine model, 3 domestic pigs). In vivo, median procedure time (measured from begin of injection to extraction of resection specimen) was 5 min (range 3-12, SD 2.72) and median size of resection specimens was 35 mm × 35 mm × 11 mm. In vivo, resection was macroscopic complete in 92.3%, major adverse events were not observed. In one case (7.7%) minor periprocedural bleeding was observed and managed by coagulation.

CONCLUSION

EMR+ appeared to be effective and safe and was easy and fast to perform in the porcine model. EMR+ needs to be further evaluated clinically in comparative trials.

Endoscopic resection techniques for colorectal neoplasia: Current developments

Endoscopic polypectomy and endoscopic mucosal resection (EMR) are the established treatment standards for colorectal polyps. Current research aims at the reduction of both complication and recurrence rates as well as on shortening procedure times. Cold snare resection is the emerging standard for the treatment of smaller (< 5mm) polyps and is possibly also suitable for the removal of non-cancerous polyps up to 9 mm. The method avoids thermal damage, has reduced procedure times and probably also a lower risk for delayed bleeding. On the other end of the treatment spectrum, endoscopic submucosal dissection (ESD) offers en bloc resection of larger flat or sessile lesions. The technique has obvious advantages in the treatment of high-grade dysplasia and early cancer. Due to its minimal recurrence rate, it may also be an alternative to fractionated EMR of larger flat or sessile lesions. However, ESD is technically demanding and burdened by longer procedure times and higher costs. It should therefore be restricted to lesions suspicious for high-grade dysplasia or early invasive cancer. The latest addition to endoscopic resection techniques is endoscopic full-thickness resection with specifically developed devices for flexible endoscopy. This method is very useful for the treatment of smaller difficult-to-resect lesions, e.g., recurrence with scar formation after previous endoscopic resections.