Endoscopic full-thickness resection of polyps involving the appendiceal orifice: a multicenter international experience

Abstract

Background and Aims: Endoscopic resection of lesions involving the appendiceal orifice (AO) remains a challenge. We aim to report the outcomes of full-thickness resection device (FTRD) for the resection of appendiceal lesions and identify factors associated with the occurrence of appendicitis. Methods: This is a retrospective study at 18 tertiary-care centers (12 U.S., Canada 1, 5 Europe) between 11/2016 and 8/2020. Consecutive patients who underwent resection of AO lesions using the FTRD were included. The primary outcome was the rate of R0 margin resection in neoplastic lesions, defined as negative lateral and deep margins on post-resection histologic evaluation. Secondary outcomes included the rates of; technical success (en bloc resection), clinical success (technical success without need for further surgical interventions), post-resection appendicitis, and polyp recurrence. Results: A total of 66 patients (mean age 64 yr., 29 F) underwent resection of colonic lesions (mean size 14.5 (6.2) mm) involving the AO, with 40 (61%) deep extending into the appendiceal lumen. Technical success was achieved in 59/66 (89%) cases, out of which, 56 were found to be neoplastic lesions on post-resection pathology. Clinical success was achieved in 53/66 (80%). R0 resection was achieved in 52/56 (93%) cases. Out of the 58 patients of whom EFTR was completed and had no prior history of appendectomy, appendicitis was reported in 10 (17%) cases, with 6 (60%) requiring surgical appendectomies. Follow-up colonoscopy was completed in 41 cases with evidence of recurrence in 5 (12.2%). Conclusions: FTRD is a promising non-surgical alternative for resecting appendiceal lesions but appendicitis occurs in 1 out of 6 cases.

Feature-Based Attentional Weighting and Re-weighting in the Absence of Visual Awareness

“…This was indicated by significant RT differences between stay and switch trials in the weighted model. Switch costs due to changing features within a single feature dimension may be relatively small compared to cross-dimensional switch costs (see Müller et al, 1995), which could explain why there was no switch effect in the averaged model in any level of awareness. Thus, the putatively smaller effect of within-dimensional switches may require a strong prior feature weighting to emerge.…”

“…For consciously perceived visual stimuli, such history-driven attention weighting effects have been observed in singleton search tasks. For instance, repeated presentation of the same target-defining dimension leads to response time benefits and associated activation changes in dimension-specific visual processing areas (Pollmann et al, 2006) that were interpreted as evidence for an attentional weighting of the target-defining dimension (Müller et al, 1995;Liesefeld et al, 2018). In contrast, when the target-defining dimension changes, e.g., when the target was defined by a singleton color in recent trials and then is defined by a singleton motion direction, response time costs are observed, as would be expected when attention needs to be reweighted to the new target-defining dimension.…”

Evolving management of colorectal polyps

“…However, a nontrivial fraction of patients, 17% (95% confidence interval 9.4%-29%), did have post-EFTR appendicitis of which 60% required surgical appendectomies. 44 Therefore, this should primarily be considered in the setting of a multidisciplinary discussion of options, with transparency of this risk during the informed consent process. We would also argue that EFTR is not necessary for an appendiceal orifice polyp where all margins of the polyp are visible and accessible by other means of resection, such as hot or cold EMR.…”

Endoscopic transcecal appendectomy: a new endotherapy for appendiceal orifice lesions

“…In recent years, endoscopic full-thickness resection (EFTR) using a specially designed EFTR device (FTRD; Ovesco Endoscopy, Tübingen, Germany) has been introduced to dissect lesions involving the appendiceal orifice 6 7 8 . Although it is a single-step and non-exposure procedure, the EFTR still cannot ensure complete resection of lesions with deep invasion into the appendiceal lumen, and may lead to a higher incidence of postoperative appendicitis 6 7 8 . Surgery may be needed for some of these patients owing to postoperative perforation or intrabdominal abscess 6 7 8 .…”