Underwater Endoscopic Mucosal Resection without Submucosal Injection Facilitates En bloc Resection of Colon Adenomas Extending into a Diverticulum

Underwater endoscopic mucosal resection for colorectal lesions: Can it be an “Underwater” revolution?

Underwater endoscopic mucosal resection (UEMR) is a newly developed technique for the removal of colorectal, duodenal, esophageal, gastric, ampullary, and small intestinal lesions. We performed a PubMed literature search for articles reporting UEMR outcomes for colorectal polyps. Four randomized controlled trials, nine non‐randomized prospective trials, 16 retrospective studies, and 27 case reports were selected for assessment of the efficacy and safety of UEMR. We summarized the therapeutic outcomes of UEMR in each category according to the lesion characteristics [small size (<10 mm), intermediate size (10–19 mm), large size (≥20 mm), recurrent lesion, and rectal neuroendocrine tumor], and calculated the incidence of adverse events among the included articles. As the treatment outcomes for small polyps appeared similar between UEMR and conventional endoscopic mucosal resection (CEMR), UEMR can be a standard procedure for small colorectal polyps suspicious for high‐grade dysplasia to avoid incomplete removal of occult invasive cancer by cold snare polypectomy. As UEMR showed satisfactory outcomes for intermediate‐size lesions and recurrent lesions after endoscopic resection, UEMR can be a standard procedure for these lesions. Regarding large lesions and rectal neuroendocrine tumors, comparisons of UEMR with current standard methods for them were lacking, and further investigations are warranted. Adverse events appeared comparable or less frequent for UEMR compared with CEMR but still existed. Therefore, careful implementation of this new technique in clinical practice is important for its widespread use.

Digital compression for hemostasis in acute hemorrhagic rectal ulcer: a report of 4 cases and review of the literature

Acute hemorrhagic rectal ulcer is a relatively rare cause of lower gastrointestinal bleeding. It most commonly occurs in bedridden elderly patients with multiple comorbidities. While the diagnosis can be confirmed on colonoscopy, achieving hemostasis may be difficult due to the poor visual field resulting from severe bleeding and stool remaining in the rectum, the stiffness of ulcers which may preclude effective clipping, the poor tolerability of patients for the procedure, and high risk of recurrence. Here, we present 4 cases of acute hemorrhagic rectal ulcer, where hemostasis could not be achieved through traditional methods. In each case, the assistant introduced his finger into the rectal lumen and digitally compressed the bleeding vessel under endoscopic guidance. Once hemostasis was achieved, the responsible vessel could be visualized and traditional hemostatic measures were taken. No recurrence was observed in any of the cases during follow-up. This simple maneuver can be applied safely and effectively even by assistants attempting the maneuver for the first time. The technique was effective with the endoscope in retroflexed position and could be combined with gel immersion endoscopy to first identify the location of hemorrhage. We also review the existing literature on acute hemorrhagic rectal ulcers.