Safety and efficacy of tip‐in endoscopic mucosal resection for large sessile colorectal polyps: A single‐center experience in Taiwan

Endoscopic mucosal resection (EMR) is an established technique for treating large colonic polyps. However, en bloc resection of large sessile lesions using conventional EMR is technically challenging and can generally be performed only in a piecemeal manner, resulting in low radical resection rates and high recurrence rates. Endoscopic submucosal dissection (ESD), a more difficult and time-consuming technique, is an alternative procedure with high en bloc resection rates and low recurrence rates. Therefore, we present a novel technique: tip-in EMR. We evaluated the feasibility and safety of tip-in EMR for the en bloc resection of large sessile colorectal polyps or laterally spreading tumors (LSTs). In this retrospective observational study, we included patients who underwent tip-in EMR for the removal of large colonic polyps (>10 mm) at Shuang Ho Hospital over a 2-year period (September 2015 to September 2017). Clinical variables, including age, gender, polyp size and morphology, procedure time, complications, and pathology, were analyzed. A total of 46 polyps were removed from 42 adult patients through tip-in EMR. The patients' mean +/- SD age was 61.0 +/- 12.0 years. The polyps were located in the right-side colon, transverse colon, left-side colon, and rectum in 39.1%, 17.4%, 37.0%, and 6.5% of the patients, respectively. The mean polyp size was 20.4 +/- 5.6 mm (range = 10-35 mm). LSTs were the predominant polyp type (n = 37, 81.5%). Among all LSTs (n = 37), 12 lesions were of granular type, and 25 lesions were nongranular. All polyps were removed en bloc using tip-in EMR. The mean procedure time was 14.9 +/- 8.8 min. Immediate bleeding occurred in only one patient (2.2%). No patient developed perforation or delayed bleeding. Regarding histopathological findings, 9 polyps (19.6%) were sessile serrated adenomas, 16 (34.8%) were tubular adenomas, 12 (26.1%) were tubulovillous adenomas, and 1 (2.2%) was a villous adenoma. High-grade dysplasia was observed in four polyps (8.7%), and one lesion was an in situ carcinoma. Surveillance colonoscopy was performed in 20 patients (47.6%) over a mean follow-up period of 12.7 +/- 5.3 months. Among these patients, only one patient exhibited local recurrence. Tip-in EMR is a novel alternative technique for polyp resection that is proven to be relatively safe and efficient for the en bloc removal of large sessile colonic polyps.