We sincerely appreciate the letter from Bowen et al. regarding our article on underwater cap-suction pseudopolyp formation for endoscopic mucosal resection (CAP-UEMR) of appendiceal lesions. Their letter greatly contributes to a discussion that merits further investigation.

In our study [1], we treated 11 benign appendiceal lesions, six of which had deep orifice extension. We observed one case of delayed bleeding (in a patient on antiplatelets), but no intraprocedural bleeding, perforations, or appendicitis in this group. A nonlifting lesion involving the appendix did exhibit a minor recurrence, which we managed endoscopically.

We share the concerns of Bowen et al. regarding two specific issues: the risk of incomplete resection when the distal margin is indistinct before resection and the potential for long-term complications related to appendiceal outflow obstruction. To address the risk of incomplete resection, we routinely take biopsies from the macroscopically normal mucosa at the defect border in the orifice after completing the resection. Alternatively, the use of a cholangioscope to assess the defect or, as suggested by Bowen et al., prior appendicoscopy to guide management (e.g. endoscopic transcecal appendectomy) holds promise [2] [3]. To mitigate complications related to outflow obstruction, we systematically apply “remodeling” clips to the defect, typically using two to four clips placed in opposite directions to maintain the openness of the orifice during the healing process. This approach warrants further investigation.

In our (unpublished) updated long-term follow-up of the 11 appendiceal lesions treated during the study (median 20 months, range 13–36 months), we have not observed any long-term complications or the need for surgery. We did note another minor recurrence that was managed endoscopically.

The optimal approach for benign lesions with deep extension into the appendiceal orifice requires further research of the long-term outcomes, including the definition of follow-up protocols, and comparative cost-effectiveness studies. Meanwhile, endoscopy remains an alternative to surgery in selected cases.

Article published online:
30 January 2024

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