Introduction
Endoscopic resection techniques, such as Endoscopic Mucosal Resection (EMR) and Endoscopic Submucosal Dissection (ESD), are used to remove precancerous and early-stage cancerous lesions in the gastrointestinal tract. While ESD is the gold standard due to its en-bloc and R0 resection capability, Underwater Endoscopic Mucosal Resection (UEMR) has emerged as an alternative. UEMR uses water buoyancy to aid lesion resection, potentially improving safety and reducing procedure time. However, its comparative effectiveness remains unclear.
Aims & Methods
The primary aim of this systematic review and meta-analysis is to compare the efficacy, safety, and procedural efficiency of Underwater Endoscopic Mucosal Resection (UEMR) versus Endoscopic Submucosal Dissection (ESD) in the treatment of gastrointestinal lesions.
A systematic search was conducted in PubMed, Embase, Google Scholar, Scopus, and Cochrane Library. Eligible studies compared UEMR and ESD in gastrointestinal lesions, providing data on en-bloc resection, R0 resections, adverse events, and procedure time. Randomized controlled trials (RCTs), cohort studies, and comparative studies were included.
Two reviewers independently extracted data, resolving discrepancies by discussion. Study quality was assessed using the Cochrane Risk of Bias Tool. Random-effects models were used for pooled analyses, calculating odds ratios (OR) and mean differences with 95% confidence intervals (CI). Heterogeneity was evaluated via the I² statistic.
Results
The analysis included four studies (three RCTs and one cohort study), with a total of 651 patients. Regarding efficacy, UEMR showed significantly lower en-bloc resection rates compared to ESD (OR = 0.01, 95% CI [0.01–0.06], Z = 6.85, p < 0.00001), suggesting a reduced ability to achieve complete lesion removal in a single piece. Similarly, R0 resection rates were also lower in the UEMR group (OR = 0.16, 95% CI [0.09–0.22], Z = 9.09, p < 0.0001), although with high heterogeneity (I² = 83%), possibly reflecting variations in patient selection, operator expertise, and technical differences among studies. In terms of safety, no significant difference was observed in adverse event rates between UEMR and ESD (OR = 0.48, 95% CI [0.10–2.34], Z = 0.90, p = 0.37), indicating comparable safety profiles. However, UEMR demonstrated an advantage in procedural time, being 5.89 times faster than ESD (p < 0.0001). This suggests that while UEMR may offer time efficiency, it comes at the cost of lower en-bloc and R0 resection rates, raising questions about its suitability for lesions requiring complete and margin-free excision. Further studies are needed to clarify the impact of these differences on long-term patient outcomes and to determine the optimal indications for UEMR in clinical practice.
Adverse Events
|
|
|---|
| Total | - | 248 | - | 401 | 100% | 0.14 [0.09, 0.22] |
| Study | UEMR Adverse Events | UEMR Total Pacients | ESD Adverse Events
| ESD Total Pacients
| Weight | Odds Ratio M-H, Fixed, 95% CI |
| Inoue et. al | 45 | 125 | 263 | 306 | 87,6% | 0.09 [0.06,0.15] |
| Kim et al. | 71 | 76 | 5 | 5 | 0,7% | 1.18 [0.06, 24.27] |
| Okimoto K. | 4 | 11 | 11 | 11 | 6,4% | 0.03 [0.00, 0.56] |
| Park et al. | 31 | 36 | 68 | 79 | 5,3% | 1.00 [0.32, 3.13] |
Conclusion
UEMR offers a quicker alternative to ESD but lacks its high resection quality, making ESD preferable for lesions requiring en-bloc or R0 resection. Gastroenterologists must weigh UEMR’s speed against ESD’s superior efficacy. Standardizing UEMR techniques may improve its resection quality and expand its role in clinical practice. Future research should optimize UEMR and address variability in resection outcomes.
References
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