Reply to Dr. Bronswijk

We thank Dr. Bronswijk for his interest and discussion of our recent article [1]. Dr. Bronswijk hypothesized that endoscopic full-thickness resection (eFTR) for lesions with extensive involvement of the appendiceal orifice might be associated with a lower risk of secondary appendicitis compared with lesions with partial appendiceal orifice involvement owing to pre-existent appendiceal obstruction. Although we appreciate the sharing of these interesting thoughts, we did not find supporting evidence for this hypothesis. First, appendicitis caused by intraluminal obstruction due to a benign colorectal polyp is very rare. Second, to the best of our knowledge appendiceal polyps, unlike malignant tumors, are not a known cause of appendicitis [2].

In our previous series, 3/7 patients had 50 % appendiceal orifice involvement with secondary appendicitis occurring in one. Of the remaining four patients with ≥ 75 % appendiceal orifice involvement, three underwent a previous appendectomy [3]. Unfortunately, data on the degree of appendiceal orifice involvement is missing in most studies [1] [4]. Therefore, we cannot draw conclusions on the risk of secondary appendicitis in relation to appendiceal orifice involvement.

We agree that it would be valuable to predict which patients are at risk of developing secondary appendicitis, especially as the incidence of appendicitis in our study was significant (20 %) [1]. The question why some patients develop secondary appendicitis is probably as interesting as why the majority do NOT develop appendicitis, even though a vital part of the remaining appendix is closed by a clip. What happens to the remaining appendix after clip closure? Will we encounter mucoceles or will the appendiceal orifice recanalize? For answers that will establish the final position of eFTR for appendiceal lesions, we need more data and longer follow-up.

Johan Cruijff, the famous soccer player Dr. Bronswijk mentioned, also quoted: “The highest achievement in knowledge is to understand what you cannot understand.” We hope the future will shed a light on this interesting topic.

Publication History

Article published online:
22 April 2021

• References

• 1 Zwager LW, Bastiaansen BAJ, Bronzwaer MES. et al. Endoscopic full-thickness resection (eFTR) of colorectal lesions: results from the Dutch colorectal eFTR registry. Endoscopy 2020;
• 2 Amini A, Koury E, Vaezi Z. et al. “Obscure” appendiceal orifice polyps can be challenging to identify by colonoscopy. Case Rep Gastroenterol 2020; 14: 15-26
• 3 Bronzwaer MES, Bastiaansen BAJ, Koens L. et al. Endoscopic full-thickness resection of polyps involving the appendiceal orifice: a prospective observational case study. Endosc Int Open 2018; 6: E1112-E1119
• 4 Schmidbaur S, Wannhoff A, Walter B. et al. Risk of appendicitis after endoscopic full-thickness resection of lesions involving the appendiceal orifice: a retrospective analysis. Endoscopy 2020;