Efficacy and safety of underwater endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumors: a systematic review and meta-analysis

Endoscopic Resection Techniques for Duodenal and Ampullary Adenomas

Background and Aims

Duodenal polyps have a reported incidence of 0.3% to 4.6%. Sporadic, nonampullary duodenal adenomas (SNDAs) comprise less than 10% of all duodenal polyps, and ampullary adenomas are even less common. Nonetheless, the incidence continues to rise because of widespread endoscopy use. Duodenal polyps with villous features or those that are larger than 10 mm may raise concern for malignancy and require removal. We demonstrate endoscopic resection of SNDAs and ampullary adenomas using some of our preferred techniques.

Methods

The duodenum has several components that can make EMR of duodenal polyps technically challenging. Not only does the duodenum have a thin muscle layer, but it is also highly mobile and vascular, which may explain higher rates of perforation and bleeding of duodenal EMR reported in the literature compared with colon EMR. A standard adult gastroscope with a distal cap is commonly used for duodenal EMRs. Based on the location, however, side-viewing duodenoscopes or pediatric colonoscopes may be used. To prepare for EMR, a submucosal injection is performed for an adequate lift. The polyp is then resected via stiff monofilament snares and subsequently closed with hemostatic clips if feasible. The ampullectomy technique differs slightly from duodenal EMRs and carries the additional risk of pancreatitis. Submucosal injection in the ampulla may not lift well; thus, its utility is debatable. Biliary sphincterotomy should be performed, and based on endoscopist preference, the pancreatic duct (PD) guidewire can be left during resection to maintain access. After resection, a PD stent is placed to minimize pancreatitis risk.

Results

The video shows the aforementioned duodenal EMR techniques. Two clips of ampullectomy are also shown in the video.

Conclusions

A few common techniques used to perform duodenal EMR and ampullectomy are highlighted in the video. It is important to understand and manage adverse events associated with these procedures and to have established surveillance plans.

Efficacy and safety of underwater endoscopic mucosal resection for ≤20 mm superficial non-ampullary duodenal epithelial tumors: Systematic review and meta-analysis

Background and aims

Superficial non-ampullary duodenal epithelial tumors (SNADETs) as a rare disease have gradually increased in recent years. Underwater endoscopic mucosal resection (UEMR) has emerged as a newly available option for the endoscopic resection of SNADETs. This study aimed to evaluate the efficacy and safety of UEMR for ≤20 mm SNADETs.

Methods

A literature search was performed across multiple databases, including PubMed, Embase, Scopus, and Clinical trials for studies containing tumors ≤20 mm published from January 1, 2012, to August 8, 2022. Outcomes examined were the pooled rates of en bloc resection, R0 resection, adverse events, and recurrence. Subgroup analyses of the resection rate were conducted stratified by sample size and polyp size.

Results

A total of 10 studies with UEMR performed in a total of 648 tumors were included for analysis. The pooled rate of en bloc resection and R0 resection was 88.2% (95% confidence interval (CI): 82.1-93.2) and 69.1% (95% CI: 62.2-76.1), respectively. The results showed pooled rate of intraoperative bleeding rate was 2.9% (95% CI: 0-9.0), delayed bleeding rate was 0.9% (95% CI: 0.1-2), recurrence rate was 1.5% (95% CI: 0-4.9). In the subgroup analysis, R0 and en-bloc resection rates were significantly higher in <10 mm than 10-20 mm SNADETs subgroups (R0 resection rate 83.1 vs. 48.6%; en bloc resection rate 100.0 vs. 84.0%, P < 0.05).

Conclusion

Underwater endoscopic mucosal resection was an effective and safe technique for the optional treatment for ≤20 mm SNADETs, especially of <10 mm.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022340578.

Underwater Versus Conventional Endoscopic Mucosal Resection for Superficial Non-ampullary Duodenal Epithelial Tumors: A Systematic Review and Meta-Analysis

BACKGROUND/AIMS

Duodenal underwater endoscopic mucosal resection (UEMR) has been suggested as a feasible treatment option for superficial non-ampullary duodenal epithelial tumors (SNADETs). However, its efficacy and safety have not been fully established yet. Thus, the objective of this systematic review and meta-analysis was to determine the efficacy and safety of UEMR as compared with conventional endoscopic mucosal resection (CEMR) in the treatment of SNADETs.

METHODS

We conducted a comprehensive literature search in PubMed, EMBASE, the Cochrane Library. Studies comparing CEMR and UEMR for the resection of SNADET were included. Outcomes included en-bloc and complete resection rates, adverse events, and procedure time.

RESULTS

A total of six studies with 2454 lesions were included in the quantitative synthesis. En-bloc and complete resection rates were not significantly different between UEMR and CEMR (OR for en-bloc resection: 0.997 [95% CI 0.439-2.266]; OR for complete resection: 0.960 [95% CI 0.628-1.468]). There was no significant risk difference for perforation (risk difference: - 0.002; 95% CI - 0.009 to 0.005) or delayed bleeding (risk difference: - 0.001; 95% CI - 0.014 to 0.011). Procedure time was significantly shorter in the UEMR (standardized mean difference: - 1.294; 95% CI - 2.461 to - 0.127). The risk of recurrence was not significantly different between UEMR and CEMR (risk difference: 0.001; 95% CI - 0.041 to 0.044).

CONCLUSION

Although our results did not show any superiority of UEMR over CEMR in the treatment of SNADETs, UEMR showed equivalent efficacy and safety as compared with CEMR and was associated with a shorter procedure time.

Endoscopic Treatment for Superficial Nonampullary Duodenal Tumors

Superficial nonampullary duodenal epithelial tumors are considered rare but have been increasingly recognized in recent years. Accordingly, the importance of endoscopic treatment for the lesions are also increasing. An endoscopic resection can be considered for duodenal adenoma and mucosal cancer. The choice of resection method should be made based on the size of the lesion, endoscopic findings, pathologic diagnosis, and risk of procedure-related complication. For small adenomas <10 mm in size, endoscopic mucosal resection (EMR), cold snare polypectomy, and underwater EMR can be considered. An en bloc or piecemeal resection using EMR or underwater EMR can be selected for 10-20 mm sized adenomas. For lesions ≥20 mm in size or suspicious for mucosal cancer, an endoscopic submucosal dissection followed by closure of the mucosal defect conducted by an experienced endoscopist is appropriate.