Among 167 SNADETs over a period of 5 years, we recorded a 22.2% rate of clinically significant AE, and found a lesion size ≥ 30 mm to be the only statistically significant risk factor for AE. Noticeably, the risk of AE was not increased associated with patients’ or lesions’ characteristics, and currently recommended technique prophylactic measures, such as the closure of the resection bed with clips, had no influence on the risk of AE.
Retrospective studies suggested that delayed bleeding occurred in 4.4–17.4% of cases after EMR of duodenal adenomas 10–17, and that the risk increased with the size of the lesion and the presence of a protruding (Paris type 0-Is) lesion. In a prospective study including 110 lesions and 118 patients, delayed bleeding occurred in 18.6% of cases18. Aschmoneit-Messer et al., in a prospective study including 50 patients and 61 lesions, showed that prophylactic argon plasma coagulation (APC) of the resection bed lowered the risk of delayed bleeding after EMR of duodenal adenomas > 20 mm and/or in case of visible vessels ≥ 1 mm19. Lepilliez et al., in a retrospective study including 36 patients and 37 lesions, found that no delayed bleeding occurred in patients treated by prophylactic clipping or prophylactic argon plasma coagulation, or in patients treated for intraprocedural bleeding. In the meantime, delayed bleeding occurred in 21.7% of the rest of the patients16. Nonaka et al., in a retrospective study including 113 patients and 121 lesions, showed that delayed bleeding rate dropped from 32–7% in cases of prophylactic clipping (p < 0.004)17. Therefore, ESGE guidelines recommend prophylactic treatment of delayed bleeding by placing clips to close the mucosal defect or by non-contact hemostatic measures5. While the 15.6% delayed bleeding rate was in keeping with the literature data, we did not observe any statistically significant benefit of clipping the resection bed. This is likely to be explained by the large size of the resected lesions, with over 45% of lesions > 30 mm, precluding a complete closure of the resection bed with clips.
Immediate perforation, defined by a breach in the muscularis propria during endoscopic resection, occurs in 2.2-6% of the resections10–17. The management of immediate perforations consists in the closure of the perforation with clips, preferably after completing the resection. Perforation typically occur in pretreated or multibiopsied lesions with submucosal fibrosis, or insufficient submucosal injection. In our cohort, immediate perforation occurred in 2.4% of the resections.
Delayed perforations of the duodenal wall, caused by the thermal damage to the muscularis propria, possibly in conjunction with chemical aggression by bile acids, is the most feared AE after endoscopic resection. After EMR for duodenal adenomas, the reported rates range from 1.7 to 7.4%, and account for the 1% mortality associated with this procedure10–17. Our findings were in line with these numbers, with no mortality, and also illustrate the feasibility of endoscopic management of delayed perforations.
Based on retrospective studies, local recurrence rate ranges from 9 to 37%10,13−15. It appears to be maximal for piecemeal resections of lesions > 20 mm in size. We found an overall 55.6% recurrence rate and identified FAP syndrome, piecemeal resection, positive resection margins as risk factors. These high numbers can be explained by the high proportion of patients with FAP, and the large size of the lesions resected in our cohort.
The strengths of our study were the large number of resections, performed in consecutive and prospectively recorded patients at a single center, including large and giant lesions, with available follow-up data, allowing to assess the recurrence rates. Main limitations are the heterogeneity of the resection tools, reflecting the number of operators involved, and the retrospective analysis of the outcomes.
In conclusion, EMR for supracentimetric duodenal adenomas is associated with AE such as delayed bleeding or delayed perforation in 22.2% of the cases, particularly in lesions ≥ 30 mm. Preventive measures, such as the complete closure of the mucosal defect with clips is often technically impossible in large lesions, while prophylactic coagulation of the resection bed might increase the risk of delayed perforation. Novel preventive techniques, such as wound covering agents, or suturing of the duodenal mucosa, could help in limiting the high rate of adverse events following duodenal endoscopic mucosal resection.