Successful further endoscopic mucosal resection with an over-the-scope clip with circumferential mucosal incision for a residual rectal neuroendocrine tumor

Endoscopic mucosal resection with an over-the-scope clip for colorectal tumors (with video)

Background

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection may result in complications or may be unsuitable for tumors that are difficult to treat endoscopically. We investigated the usefulness of a newly developed endoscopic resection technique-EMR with an over-the-scope clip (EMR-O)-for difficult-to-treat lesions.

Method

We retrospectively examined patients who underwent EMR-O for colorectal tumors between September 2017 and January 2024. Patient and lesion characteristics, technical success rates, en bloc resection rates, R0 resection rates, procedure time, histopathology, and the clinical course were evaluated.

Results

EMR-O was performed for 18 patients. Indications for EMR-O included residual or recurrent lesions (seven patients; 38.9%), diverticulum lesions (five patients; 27.8%), appendiceal orifice lesions (three patients; 16.7%), T1 cancers (two patients; 11.1%), and subepithelial tumors (one patient; 5.5%). The median lesion size was 11 mm. The rates of technical success, en bloc resection, and R0 resection were 100%, 86.7%, and 86.7%. The median procedure time was 10 min. The only adverse event was diverticulitis (one patient; 5.5%). Intraoperative and delayed perforation and bleeding were not observed. The pathological resection depths were full-thickness for three patients (16.7%), muscularis resection for four patients (22.2%), and deep submucosal resection for 11 patients (61.1%).

Conclusion

Although EMR-O is limited by the target lesion size, it shortens the procedure time, prevents perforation, and avoids the need for surgery. EMR-O may be a minimally invasive treatment option for small lesions that are difficult to treat endoscopically.

Endoscopic resection using an over-the-scope clip for duodenal neuroendocrine tumors

Background and study aims  Endoscopic resection of duodenal neuroendocrine tumors (DNETs) remains controversial, and its indications are still unclear. This study aimed to evaluate short-term outcomes of a newly developed endoscopic muscularis resection (EMR) method that utilizes an over-the-scope clip (OTSC), termed EMRO, for treating DNETs. Patients and methods  In total, 13 consecutive patients with 14 small (≤ 10 mm) DNETs who underwent EMRO from September 2017 to March 2020 were retrospectively enrolled. EMRO was performed by a single experienced endoscopist. Patients' characteristics and treatment outcomes were assessed. Results  The En bloc and R0 resection rates were 100 % (14/14) and 92.9 % (13/14), respectively. The median pathological resected specimen size was 10 mm, with a median pathological resected tumor size of 6 mm. During the EMRO procedure, there was no occurrence of misplacement of the OTSC to the target lesion. With respect to the pathological resection depth, nine cases (64.3 %) and five cases (35.7 %) were categorized as deep submucosal resection and muscularis resection, respectively, whereas no case was categorized as full-thickness resection. There were no intraoperative or delayed perforations. However, delayed bleeding occurred in two cases. At a median follow-up of 12 months (range 7-36) after EMRO, there was no incidence of local recurrence. At the first follow-up endoscopy performed at 6 months after EMRO, the OTSC was retained in place in two of 14 DNETs (14.3 %). Conclusions  EMRO can be performed safely, by an experienced endoscopist, for small (≤ 10 mm) DNETs.