The First Prospective Randomized Trial Comparing Cold and Hot Loop Resection for Removal of Medium-sized Benign Colon Tumors in Moscow, Russia.

Widespread introduction of high-resolution videocolonoscopy into clinical practice has led to an increase in the detection of epithelial lesions of the colon, a significant portion of which are small (<10 mm) and miniature (≤5 mm) lesions. According to the literature, 15.6-27% of colon lesions 6-9 mm in size and 4.4-10% of those ≤5 mm are high-risk lesions, i.e. they contain villous structures, foci of severe dysplasia or cancer. One of the methods for removing such lesions is the technique of cold loop polypectomy (CLP), i.e. mechanical removal of the polyp with a loop without the use of electric current. This method is common for colon lesions 4-9 mm in size. (For smaller lesions, a technically simple and effective method of removing them using biopsy forceps is most often used) Jung YS, Park JH, Kim HJ et al. Complete biopsy resection of diminutive polyps. Endoscopy 2013; 45: 1024-9). A number of studies have demonstrated the advantages of the CP technique over standard removal methods. "Cold" polypectomy reduces the incidence of complications associated with thermal effects on the mucous membrane and underlying tissues (Bo-In Lee. Polypectomy of Small Polyps: Technical Updates. IDEN 2016, 280-281). Not only the number of perforations and manifestations of postcoagulation syndrome is reduced (D. von Renteln1, H. Pohl. Polyp Resection - Controversial Practices and Unanswered Questions. Clin Transl Gastroenterol. 2017 Mar; 8(3): e76. doi: 10.1038/ctg.2017.6), but also delayed bleeding: 0% with cold snare removal versus 0.5-14% after classical removal using electric current (Horiuchi A, Nakayama Y et al. Removal of small colorectal polyps in anticoagulated patients: a prospective randomized comparison of cold snare and conventional polypectomy. Gastrointest Endosc. 2014 Mar;79(3):417-23. doi: 10.1016/j.gie.2013.08.040; T. Kawamura1, Y.Takeuchi A comparison of the resection rate for cold and hot snare polypectomy for 4-9 mm colorectal polyps: a multicentre randomised controlled trial (CRESCENT study) Gut Online First, published on September 28, 2017 as 10.1136/gutjnl-2017-314215) ! It is also important that the removal of polyps with a cold snare takes less time than with a hot one, averaging 18 min. versus 25 min. (Ichise Y1, Horiuchi A, Nakayama Y, Tanaka N. Prospective randomized comparison of cold snare polypectomy and conventional polypectomy for small colorectal polyps. Digestion. 2011;84(1):78-81. doi: 10.1159/000323959. However, there are currently clearly not enough large multicenter prospective randomized studies devoted to the comparison of the efficacy and safety of "standard" and cold polypectomy.

The opinion of specialists is also ambiguous regarding the instrumentation that should be used for endoscopic removal of small formations. Some endoscopists believe that the type of polypectomy snare used does not affect the efficacy, completeness and safety of removal of small formations, while others, on the contrary, pay special attention to the use of specially designed small-diameter snare loops, believing that only they are capable of ensuring the removal of formations in a single block in the vast majority of cases. (Horiuchi A, Hosoi K, Kajiyama M, et al. Prospective, randomized comparison of 2 methods of cold snare polypectomy for small colorectalpolyps. Gastrointest Endosc 2015;82:686-92.) The question of the need to inject fluid into the submucosal layer under the removed formation also requires a reasoned answer, given that many researchers skip this stage of the intervention and / or consider it unnecessary Toshiki Yamamoto, Sho Suzuki, Chika Kusano, Kyoko Yakabe, Maho Iwamoto, Hisatomo Ikehara, Takuji Gotoda, Mitsuhiko Moriyama. Histological outcomes between hot and cold snare polypectomy for small colorectal polyps. Saudi J Gastroenterol. 2017 Jul-Aug; 23(4): 246-252. doi: 10.4103/sjg.SJG_598_16